Category Archives: Medical Students

Approach to Inguinal and Femoral Hernias in the Emergency Department

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Medical Student Pearl

Julia Short

Med 2

DMNB Class of 2025

Reviewed by Dr D Lewis

Copy Edited by Dr. J Vonkeman

PDF Download: EMSJ Approach to Inguinal and Femoral Hernias in the ED by JShort

Case

A 52-year-old male patient presents in the ER with a lump in their right groin. The lump protrudes when they cough and when laying on their left side, although it re-enters the abdomen on its own. You wonder if it could be a femoral or an inguinal hernia, and how to go about differentiating between the two.

Introduction

A hernia is defined as an organ, or part of an organ, that protrudes through the body wall in which it is normally contained. The etiology of a hernia can be due to congenital anatomical malformations or from acquired weakening of the body wall tissues. There are various subtypes of abdominal hernias, while groin hernias consist of inguinal and femoral hernias. Throughout their lifetime, males have a 27 to 43% chance of developing a groin hernia, while females have a 3 to 6% lifetime prevalence1. Although it is much more likely that a groin hernia is inguinal in nature (they account for 96% of groin hernias), it is clinically useful to identify and distinguish between the types of groin hernias. Additionally, there are important clinical features that must not be overlooked when characterizing a groin hernia.

Distinguishing inguinal from femoral hernias

An important landmark in determining the hernia origin is the inguinal ligament. Inguinal hernias protrude superior to the inguinal ligament, while femoral hernias present inferior to the inguinal ligament (Figure 1). This is because femoral hernias protrude from the femoral ring, located medial to the femoral vein. As a result, in males, femoral hernias will never course into the scrotum. Femoral hernias also present more lateral than inguinal hernias and may be difficult to differentiate from lymph nodes. Although they account for only 3% of all groin hernias, 40% of femoral hernias present as urgent due to bowel strangulation or incarceration1. Females are more likely to develop femoral hernias, while males are more likely to develop inguinal hernias.

Figure 1. Groin anatomy © 2023 UpToDate7

Distinguishing between direct and indirect inguinal hernias

Direct inguinal hernias originate medially, near the pubic tubercle and external inguinal ring. They protrude through Hesselbach’s triangle as a result of weakness in the floor of the inguinal canal. On exam, a bulge near the external (superficial) inguinal ring is suggestive of a direct inguinal hernia. In contrast, indirect inguinal hernias protrude near the midpoint of the inguinal ligament, at the internal (deep) inguinal ring (Figure 2). In males and females respectively, the internal inguinal ring is where the spermatic cord and round ligament exit the abdomen. A bulge in this area therefore suggests an indirect inguinal hernia. This type of hernia is the most common in all ages and sexes, accounting for approximately two thirds of all inguinal hernias2. In males, the indirect hernia often courses into the scrotum, which can be palpated if the patient strains or coughs. In contrast, it is rare for a direct hernia to course into the scrotum.

Figure 2. Anatomical comparison of direct and indirect inguinal hernias © 2020 Dr. Vaibhav Kapoor8

Clinical Approach

General considerations for investigating groin hernias include assessing the symptoms at presentation as well as any “red flag” physical findings. Patients commonly complain of dull or heavy types of discomfort when straining, which resolves when straining stops. Most groin hernias occur on the right side. Common physical findings include a bulge in the groin, which can indicate the type of hernia based on location relative to the inguinal ligament (Figure 3). However, in female or obese patients, the layers of abdominal wall may make the hernia more difficult to locate. In these cases, ultrasound or other imaging is needed to detect hernias. Clinicians should also determine if the hernia is reducible, or if the herniated bowel can be returned to the abdominal cavity when moderate pressure is applied externally.

Figure 3. Locations of femoral and inguinal hernias on examination © 2023 UpToDate7

 

Physical examination has a 76 to 92% sensitivity and 96% specificity for diagnosing groin hernias, although imaging may also be required1,2. Nausea, vomiting, fever, moderate-to-severe abdominal pain, localized tenderness, or bloating may indicate more sinister pathology such as bowel incarceration (when the hernia contents cannot return to the abdominal cavity), strangulation (when the blood supply to the involved bowel section is compromised) or necrosis.

Figure 5. CT images of A) femoral hernia (courtesy of Chris O’Donnell9 and B) inguinal hernia (courtesy of Erik Ranschaert10)

Management

Uncomplicated or asymptomatic hernias in males can be monitored through watchful waiting. Surgical repair is a definitive treatment for inguinal hernias and should be considered for symptomatic or complex hernias. If repair is needed for an uncomplicated inguinal hernia, a laparoscopic repair is recommended. Watchful waiting is not recommended for femoral hernias – these patients should have a laparoscopic repair (when anatomically feasible).

Manual reduction of the hernia can be performed by following the GPS Taxis technique. Taxis is a non-invasive technique for manual reduction of incarcerated tissues in a hernia to the original compartment5. “GPS” is an acronym to remind clinicians to be gentle, be prepared, and be safe when performing taxis5. Conscious sedation with intravenous diazepam and morphine is recommended for the procedure. Consider having an anesthetist present for the procedure if the patient is frail. Provide appropriate early resuscitation by monitoring vital signs, administering oxygen therapy and establishing IV access. Place the patient in Trendelenburg position. Begin the GPS Taxis technique by palpating the fascial defect around the base of the hernia and gently manipulating hernia contents back into the abdominal cavity. Use gentle manipulation pressure over 5-10 minutes until a gurgling sound is heard (indicating successful reduction of bowel).

 

Taxis guided by ultrasound may increase success rates for reduction.

https://sjrhem.ca/taxis-reduction-of-inguinal-hernia/

Figure 4. Colourized clip demonstrating PoCUS assisted Taxis reduction of an inguinal hernia11

 

It should be noted that the major contraindication to performing GPS Taxis is bowel strangulation within the hernia. A rare but serious complication of manual reduction is reduction en masse, when a loop of bowel remains incarcerated at the neck of the hernia after manual reduction6. This can lead to early strangulation, intestinal necrosis, sepsis, organ failure and death. Femoral hernias and indirect inguinal hernias are at higher risk of reduction en masse from manual reduction attempts.

References:

  1. UpToDate – Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults
  2. Hammoud M, Gerken J. Inguinal hernia. StatPearls. 2022 Aug 15.
  3. UpToDate – Overview of treatment for inguinal and femoral hernia in adults
  4. Bates’ Guide to Physical Examination and History Taking, 12th ed. (pdf). Chapter 13: Male Genitalia and Hernias
  5. Pawlak M, East B, de Beaux AC. Algorithm for management of an incarcerated inguinal hernia in the emergency settings with manual reduction. Taxis, the technique and its safety. Hernia, 25, 1253-1258. 2021 May 25.
  6. Yatawatta A. Reduction en masse of inguinal hernia: a review of a rare and potentially fatal complication following reduction of inguinal hernia. BMJ Case Rep. 2017 Aug 7.
  7. UpToDate – Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults
  8. Kapoor, V. Difference between and inguinal and umbilical hernia. 2020. Retrieved from: https://www.drvaibhavkapoor.com/difference-between-inguinal-and-umbilical-hernia.html
  9. Patel, MS. Femoral hernia. Radiopaedia. 2022 Dec 28. Retrieved from: https://radiopaedia.org/articles/femoral-hernia
  10. Fahrenhorst-Jones, T. Inguinal hernia. Radiopaedia. 2022 Apr 12. Retrieved from: https://radiopaedia.org/articles/inguinal-hernia
  11. PoCUS assisted Taxis reduction of an inguinal hernia. Video obtained courtesy of Dr. David Lewis.

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Nursemaid’s Elbow

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Nursemaid’s Elbow

Medical Student Pearl

 

Erika Maxwell

@ErikaMaxwell

Memorial University Class of 2023

Reviewed by: Dr. David Lewis

Case

A 10-month-old female is brought into the Emergency Department by her mother with a left arm injury. The infant had a fall from standing and the mother reached out to grab her and caught her left forearm. After the incident, the patient’s mother noticed that the infant was no longer using the arm. The child has no medical history and is not taking any medications. She is vitally stable.

On exam, the child’s left arm is limp and extended at her side. She is using her right arm and hand exclusively, including to grasp for items on the left side of her body (pseudoparalysis). There is no deformity, erythema, edema, or ecchymosis. The arm and hand are neurovascularly intact (strong brachial pulse, pink and warm).

Differential Diagnosis

  • Nursemaid’s elbow/pulled elbow/radial head subluxation
  • Elbow fracture
  • Wrist fracture or soft tissue injury
  • Shoulder dislocation

Background

A pulled elbow occurs most frequently in young children with the median age for presentation being 2 years [1]. The reason for this is debated in the literature with some sources saying that the annular ligament is weaker in children [2] and others saying that the radial head is smaller [1], both resulting in a less stable joint.

The most common mechanism of injury is axial traction (i.e. pulling on the arm or hand), but falls or rough play may also be responsible [2].

Anatomical Context

The annular ligament holds the radial head in place next to the ulna. When axial traction is applied by pulling the forearm or hand, the radial head may move underneath the annular ligament and trap it in the radiohumeral joint, against the capitellum [1].

Figure 1: The arm on the left displays a normal elbow, whereas on the right the radius is subluxated and trapping the annular ligament against the capitellum [3].

Signs and Symptoms [3]

  • Pain at elbow
  • Pseudoparalysis of injured arm
  • Extension or light flexion of injured arm, often pronated

Diagnosis and Management

A full examination of the upper limb is required. Leave obviously swollen or deformed areas until the end. Palpate the clavicle, humerus, forearm and gently move the joints (shoulder, wrist, and lastly elbow). Pulled elbows rarely result in joint swelling. If this is present an alternative diagnosis should be considered (e.g., supracondylar fracture).

If a pulled elbow is the only likely diagnosis, then it may be reasonable to proceed to a subluxated radial head reduction manoeuvre. However, when the history is not clear (e.g., unwitnessed mechanism involving siblings or a fall), then it is much safer to perform further diagnostic tests prior to manipulation. These include radiograph of the elbow to rule out fracture or elbow ultrasound to rule out joint effusion [4].

Reduction Technique

 This is done by supporting the elbow with one hand and using your other hand to move the patient’s arm through the recommended maneuvers. There are 2 different maneuvers to try, and they may be used alone or in combination [1-3,5].

  • Supinate the child’s forearm with your hand and flex the elbow

 

Figure 2: Demonstration of the supination/flexion maneuver [5]

  • Hyperpronate the child’s forearm

Figure 3: Demonstration of the hyperpronation maneuver [5]

Some research has indicated that the hyperpronation maneuver may be more effective and less painful for the patient [2,6], so it may be worth attempting this maneuver first.

If the maneuvers are successful, you may hear a click from the radial head as it moves back into place. The child may briefly cry as the subluxation is reduced. Movement recovery can take anywhere from a few minutes to several hours, but usually occurs within 30 minutes. The greater the delay from injury to presentation and subsequent reduction, the longer it will take for post reduction return to normal movement [2].

If a click is heard or felt during the manoeuvre it can usually be assumed that reduction has occurred. Ideally, it is recommended that the child remain under observation until normal movement returns. However, if delayed, it is reasonable to discharge the child with advice to return.

In any case where an x-ray or ultrasound has not been performed and the child does not rapidly start using their arm post manoeuvre, then imaging is required prior to any further manipulation.

Prognosis

Although a pulled elbow does not result in a permanent injury, it is important to inform the family that their child will be vulnerable to recurrent pulled elbows in the affected arm. Up to 27% of patients with a pulled elbow may experience a recurrence [7-8].

Case continued:

Based on the patient’s history and physical exam, she was diagnosed with a pulled elbow. Using the supination and flexion maneuver followed by the hyperpronation maneuver, an audible click was elicited from the patient’s elbow. Shortly thereafter, she began using the arm again as if no injury had occurred and was discharged home.

Key points:

 

  1. A pulled elbow is a common upper limb injury in young children presenting to the Emergency Department
  2. Careful assessment may preclude the need for diagnostic imaging however if in any doubt further investigation should be performed prior to manipulation. Many physicians will never forget the time they used a pulled elbow reduction technique in a child with an unexpected supracondylar fracture
  3. HYPERPRONATE and/or SUPINATE & FLEX!
  4. Recurrence is common

References

  1. Aylor, M., Anderson, J., Vanderford, P., Halsey, M., Lai, S., & Braner, D. A. (2014). Reduction of pulled elbow. New England Journal of Medicine, 371(21), e32.
  2. Wolfram, W., Boss, D., & Panetta, M. (2018, December 18). Nursemaid Elbow. Medscape. Retrieved September 6, 2022, from https://emedicine.medscape.com/article/803026-overview#a5
  3. Boston Children’s Hospital. (2021). Nursemaid’s elbow. Retrieved September 6, 2022, from https://www.childrenshospital.org/conditions/nursemaids-elbow
  4. Varga, M., Papp, S., Kassai, T., Bodzay, T., Gáti, N., & Pintér, S. (2021). Two- plane point of care ultrasonography helps in the differential diagnosis of pulled elbow. Injury, 52(1), S21-24.
  5. Kilgore, K., & Henry, K. (2021). Nursemaid’s elbow. Society for Academic Emergency Medicine – Clerkship Directors in Emergency Medicine. Retrieved September 6, 2022, from https://www.saem.org/about-saem/academies-interest-groups-affiliates2/cdem/for-students/online-education/peds-em-curriculum/nursemaid%27s-elbow
  6. Lewis, D., Argall, J., & Mackway-Jones, K. (2003). Reduction of pulled elbows. Emergency Medicine Journal, 20, 61-62.
  7. Schunk, J. F. (1990). Radial head subluxation: epidemiology and treatment of 87 episodes. Annals of emergency medicine, 19(9), 1019-1023.
  8. Teach, S. J., & Schutzman, S. A. (1996). Prospective study of recurrent radial head subluxation. Archives of pediatrics & adolescent medicine, 150(2), 164-166.
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Management of Supraventricular Tachycardia (SVT) in Pregnancy

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Management of Supraventricular Tachycardia (SVT) in Pregnancy

Medical Student Clinical Pearl

 

Tyson Fitzherbert, DMNB Class of 2024

Reviewed by Dr. Luke Taylor and Dr. David Lewis

 

Case:

A 30-year-old pregnant (32 weeks) female presents to the emergency department with palpitations and chest discomfort. On ECG they are diagnosed with supraventricular tachycardia, a narrow complex arrythmia – how would you proceed?

 

Introduction:

Pregnant women have a higher incidence of cardiac arrhythmias. The exact mechanism of increased arrhythmia burden during pregnancy is unclear, but has been attributed to hemodynamic, hormonal, and autonomic changes related to pregnancy. A common arrhythmia in pregnancy is supraventricular tachycardia (SVT). SVT is a dysrhythmia originating at or above the atrioventricular (AV) node and is defined by a narrow complex (QRS < 120 milliseconds) at a rate > 100 beats per minute (bpm). The presentations of SVT in pregnancy are the same as the nonpregnant state and include symptoms of palpitations that may be associated with presyncope, syncope, dyspnea, and/or chest pain. Diagnosis is confirmed by electrocardiogram (ECG).

 

Figure 1: Rhythm strip demonstrating a regular, narrow-complex tachycardia, or supraventricular tachycardia (SVT).

In general, the approach to the treatment of arrhythmias in pregnancy is similar to that in the nonpregnant patient. However, due to the theoretical or known adverse effects of antiarrhythmic drugs on the fetus, antiarrhythmic drugs are often reserved for the treatment of arrhythmias associated with clinically significant symptoms or hemodynamic compromise. Below is a detailed description of the management of SVT in pregnancy.

 

Management:

Figure 2: Treatment algorithm for SVT in pregnancy.

 

General Considerations:

  • Non‐pharmacological treatment including vagal manoeuvres such as carotid massage and Valsalva manoeuvre are well tolerated and aid in management.
  • Intravenous adenosine can be used in all three trimesters, including labor.
  • Electrical cardioversion is an effective treatment method for hemodynamically unstable or drug-refractory patients, which has proven to be safe in all three trimesters, including labor. There are some examples of this leading to pre-term labor in the third trimester.
  • AV nodal blocking agents and anti-arrhythmic agents may be considered for cardioversion; see table below for effects in pregnancy and breast feeding.

 

 

Case Continued:

A modified Valsalva manoeuvre is performed with resolution to sinus rhythm after 2 attempts. The patient is discharged with OBGYN follow-up.

https://sjrhem.ca/modified-valsalva-maneuver-in-the-treatment-of-svt-revert-trial/

 

Further Reading

References:

  1. Patti L, Ashurst JV. Supraventricular Tachycardia. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www-ncbi-nlm-nih-gov.ezproxy.library.dal.ca/books/NBK441972/
  2. UpToDate – https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy#H11407709
  3. Ibetoh CN, Stratulat E, Liu F, Wuni GY, Bahuva R, Shafiq MA, Gattas BS, Gordon DK. Supraventricular Tachycardia in Pregnancy: Gestational and Labor Differences in Treatment. Cureus. 2021 Oct 4;13(10):e18479. doi: 10.7759/cureus.18479. PMID: 34659918; PMCID: PMC8494174. https://www-ncbi-nlm-nih-gov.ezproxy.library.dal.ca/pmc/articles/PMC8494174/
  4. Ramlakhan KP, Kauling RM, Schenkelaars N, et al, Supraventricular arrhythmia in pregnancy, Heart 2022;108:1674-1681. https://heart.bmj.com/content/early/2022/01/26/heartjnl-2021-320451#T2
  5. Goyal A, Hill J, Singhal M. Pharmacological Cardioversion. [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www-ncbi-nlm-nih-gov.ezproxy.library.dal.ca/books/NBK470536/
  6. Vaibhav R. Vaidya, Nandini S. Mehra, Alan M. Sugrue, Samuel J. Asirvatham, Chapter 60 – Supraventricular tachycardia in pregnancy, Sex and Cardiac Electrophysiology. https://www-sciencedirect-com.ezproxy.library.dal.ca/science/article/pii/B9780128177280000607

 

 

 

 

 

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Drop it like it’s Hot – Tetracaine eye drops following corneal abrasion?

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Drop it like it’s Hot- A case presentation and critical appraisal on the use of tetracaine eye drops following corneal abrasion: A Medical Student Pearl

Claudia Cullinan

DMNB, Med 3

Reviewed by Dr. Kavish Chandra

Case:

It’s a sunny July afternoon and you are just starting your shift in the ED when a 25-year-old male presents with sudden onset of severe right eye pain. You bring him into the exam room, and he explains he ran into a tree branch. He is reluctant to open his eye due to the pain and his eye is watering uncontrollably. He also keeps his sunglasses on while you talk because his eye is now extremely sensitive to the bright ED lights.

The patient is visibly in a lot of distress, so you do a quick penlight exam and attempt to assess visual acuity to confirm there is no evidence of penetrating trauma.

At this point you suspect a corneal abrasion, so you move onto a slit lamp and fluorescein examination and add a tetracaine 0.5% (topical anesthetic) to the affected eye. The patient appears more comfortable within seconds. You are able to complete the exam with the patient sitting comfortably in the exam chair. There is no evidence of Seidel sign (streaming fluorescein caused by leaking aqueous humor) and no visible foreign body in the eye. You can visualise a linear yellow lesion along the lateral cornea when viewed with fluorescein under cobalt blue light and you are confident this is a simple corneal abrasion.

Figure 1. Corneal abrasion viewed with cobalt blue light after fluorescein staining. Accessed from DFOptometrists.com

You explain to the patient that he has a corneal abrasion, prescribe him erythromycin 0.5% ophthalmic ointment to be inserted into the affected eye QID for 5 days and encourage him to avoid rubbing his eyes. He can also take PRN ibuprofen if needed. He asks “That one eye drop made my eye feel so much better, can I have a bottle of that to bring home?”

You know he is talking about Tetracaine, and you remember learning about the controversy of using topical anesthetics for the outpatient treatment of corneal abrasions….what do you tell him?

Critical Appraisal : Short-term topical tetracaine is highly efficacious for the treatment of pain caused by corneal abrasions: a double-blind, randomized clinical trial. (2020)

Background:

Corneal abrasions are among the most common ophthalmic presentations to the emergency department (ED). They occur when the corneal epithermal becomes disrupted, such as when tiny foreign bodies land in your eye or when your new puppy accidentally scratches the surface of your eye.  Although corneal abrasions typically heal rapidly with minimal risk of complication, they are often VERY painful and can be extremely debilitating. There has been controversy on whether patients should be discharged home with topical anesthetics for short term management of corneal abrasions because of previously described safety concerns regarding toxicity. However, recent literature is beginning to surface suggesting there may be a role for short term topical analgesia following simple corneal abrasion, with appropriate follow up.

Figure 2. Anatomy of the cornea. Accessed form AAFP.org

Clinical Question:

How effective is the home use of topical tetracaine every 30 minutes PRN pain for 24 hours following corneal abrasion?

Reference

Shipman, S., Painter, K., Keuchel, M., & Bogie, C. (2021). Short-Term Topical Tetracaine Is Highly Efficacious for the Treatment of Pain Caused by Corneal Abrasions: A Double-Blind, Randomized Clinical Trial. Annals of Emergency Medicine, 77(3), 338–344.       https://doi.org/10.1016/j.annemergmed.2020.08.036

Study Overview:

Population: Patients 18-80 years old presenting to an urban ED in Oklahoma City with suspected acute corneal abrasion.

Intervention: 2mL bottle of Tetracaine 0.5% one drop applied q30 minutes PRN pain for a maximum of 24 hours + antibiotic ophthalmic solution (polymyxin B sulfate/ trimethoprim sulfate) 2 drops to affected eye q4h.

Control: 4 separate 0.5mL ampules of artificial tears (Systane) one drop applied q30 minutes PRN pain for a maximum of 24 hours + antibiotic ophthalmic solution (polymyxin B sulfate/ trimethoprim sulfate) 2 drops to affected eye q4h.

Outcome: Pain rating at 24-48h follow up.

Methods:

  • Prospective, double blind, randomised control trial of topical tetracaine vs control (artificial tears) in the ED following diagnosis of corneal abrasion in the ED.
  • Took place in an urban Oklahoma ED from 2015 to 2017.
  • One hundred and eleven patients were included and were randomly assigned to the treatment or control group.
  • The patients in both groups had similar baseline characteristics and baseline numeric rating scale (NRS) pain scores (0-10, 10 being the most pain).

Inclusion criteria:

Patients 18 to 80 years old, presenting to the ED with suspected acute corneal abrasion, and gave written informed consent.

Exclusion criteria:

Contact lens wearers, previous corneal surgery or transplant in the affected eye, presented more than 36 hours after their injury, had a grossly contaminated foreign body, had coexisting ocular infection, currently pregnant, retained foreign body, penetrating eye injury, receiving immunosuppression, allergy to study medication, unable to attend follow-up, unable to fluently read and speak English or Spanish, and any injury requiring urgent ophthalmologic evaluation.

Results:

Main outcomes at the 24-48hr follow up appointment:

  • The overall numeric rating scale (NRS) pain score was significantly lower in the tetracaine group compared to the control group (1 versus 8, P<0.001).
  • The number of patients found to have a small residual corneal abrasion on their follow up slit-lamp examination was similar between groups (18% in the tetracaine group and 11% in the control group).
  • There were only two complications in the tetracaine group (versus 6 in the control group), with similar rates of worsening corneal abrasions in both groups. All patients had normal healing after 10 days. No serious adverse outcomes were encountered.

Table 1. Patient baseline demographics and 24-48hr follow up data points.

Group Tetracaine (n=59) Control (n=59)
Age, y 35 (28-43) 38 (27-47)
Male patients, No. (%) 36 (61) 34 (58)
Baseline pain rating 7 (6-7.5) 7 (6-8)
24-48hr pain rating 1 (1-2) 8 (7-8)
No. of hydrocodone tablets recorded 1 7
Adverse Events, No (%) 2 (3.6) 6 (11)

Limitations and suggestions for future studies:

  • Although this was a double-blind study, there are two things that could have made patients aware of their treatment group. First, the control was packaged in 4 ampules and the treatment was packaged in a single bottle. Second, Tetracaine burns when administered to the eye and Systane (control) does not.
  • The study was slightly underpowered for the primary outcome of efficacy and certainly not powered to determine safety for rare adverse events associated with topical anesthetics. That being said, there are more patients in this trial demonstrating short term safety than previous care reports and series demonstrating tetracaine harm.
  • There was an extensive exclusion criterion, including patients who wear contacts (which are a common cause of corneal abrasions). By broadening the inclusion criteria, the results could be applied to a greater number of patients.
  • Patients were required to return for follow up at which time they were required to return their “study drops” so the drops cannot be abused. It would be more feasible to limit the amount of eye drops in the bottle so the patient does not have to return to the ED for bottle disposal.

Our conclusions:

Short term topical tetracaine is an efficacious analgesic for acute corneal abrasions, is associated with less hydrocodone use compared to control, and appears to be safe.

 

Case

Back to our original question…what do we tell our patient?

Provide him with a limited number of tetracaine drops and administer one drop in affected eye q30 minutes PRN pain for a maximum of 24 hours. Advise him to return to ED if his symptoms persist beyond 48 hours or get worse.

References

McGee, H. T., & Fraunfelder, F. (2007). Toxicities of topical ophthalmic anesthetics. Expert Opinion    on Drug Safety, 6(6), 637–640. https://doi.org/10.1517/14740338.6.6.637

Shipman, S., Painter, K., Keuchel, M., & Bogie, C. (2021). Short-Term Topical Tetracaine Is Highly        Efficacious for the Treatment of Pain Caused by Corneal Abrasions: A Double-Blind, Randomized             Clinical Trial. Annals of Emergency Medicine, 77(3), 338–344.       https://doi.org/10.1016/j.annemergmed.2020.08.036

Wipperman, J. L., & Dorsch, J. N. (2013). Evaluation and management of corneal abrasions.    American Family Physician, 87(2), 114–120.

Yu, C. W., Kirubarajan, A., Yau, M., Armstrong, D., & Johnson, D. E. (2021). Topical pain control for     corneal abrasions: A systematic review and meta-analysis. Academic Emergency Medicine, 28(8), 890–908. https://doi.org/10.1111/acem.14222

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A Case of Herpes Simplex Virus Keratitis in The Emergency Department

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A Case of Herpes Simplex Virus Keratitis in The Emergency Department – A Medical Student Clinical Pearl

Patrick Gallagher, MED III

MUN Class of 2022

Reviewed by Dr. Robin Clouston

Copyedited by Dr. Mandy Peach

Case

A 53-year-old female presents to the emergency department with a two-day history of left-eye pain, which she describes as “something being stuck in her eye.” The patient endorses left eye tearing, pruritis, and photophobia. She notes that her eye has been “blurry” since she awoke this morning. The patient denies any infectious symptoms at present but states that a cold sore erupted on her upper lip seven days ago. She does not use contact lenses.

Past medical history: T2DM and hypothyroidism.

Past surgical history: None.

Medications: Metformin 500 mg OD and Synthroid 125 mcg OD.

Physical exam:

Upon inspection, the patient has conjunctival injection and tearing in the left eye. Mild periorbital edema and erythema is noted. The patient’s pupils are equal and reactive to light, and visual acuity is 20/20 in the left eye and 20/40 on the left eye. Extraocular eye movements and visual fields are normal. The patient has decreased corneal sensation.

On slit lamp examination using fluorescein-based dye, a small branching dendritic ulcer was seen (Figure 1).

Figure 1: Dendritic ulcer noted on slit-lamp exam with fluorescein-based dye.

 

What is the differential diagnosis of dendrites?

• Herpes simplex keratitis
• Acanthamoeba keratitis
• Other keratitis caused by Varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein–Barr virus (EBV), or adenovirus.
• Dendritiform keratopathy
• Ramous epithelial changes
• Limbal stem cell deficiency
• Drug induced corneal changes (epinephrine, antivirals, beta-blockers) 1,2

Herpes simplex virus keratitis :

Herpes simplex is a DNA virus that can cause a wide variety of infections, most commonly involving the mouth, genitalia, and eyes3. While HSV-1 and HSV-2 can involve the eye, HSV-1 is the most common cause of keratitis1. Herpes simplex keratitis (HSK) is characterized by recurrent infections of the corneal epithelium and stroma2. HSK can be classified as primary or recurrent and further divided into three subtypes: epithelial, stromal, and endothelial3. Epithelial keratitis is the most commons subtype of ocular herpes (50% to 80%)2.

Herpes simplex virus (HSV) infections are the leading cause of infectious corneal blindness in developed countries3. It is estimated that 1.5 million people worldwide experience HSV keratitis every year2.

Pathophysiology:

Primary HSV eye infections occur when the virus enters mucous membranes by direct contact. This initial infection is usually subclinical, but it can cause unilateral blepharitis, follicular conjunctivitis, and occasional epithelial keratitis (Figure 2)4. The initial infection is typically asymptomatic, and it occurs in children less than five years old5.

Figure 2: Pictorial representation of blepharitis (inflammation of the eyelid), keratitis (inflammation of cornea), conjunctivitis (inflammation of conjunctiva), and ocular anatomy. Diagram retrieved from 7

After the initial infection, the virus can remain latent in the ophthalmic division of the trigeminal ganglion for the lifetime of the host. HSV reactivation in the latently infected ganglia can lead to corneal scarring, thinning, stromal opacity, and neovascularization5. The cumulative effect of numerous infections results in vision loss and eventually blindness if left untreated.

History and physical:

Diagnosis of HSK is primarily diagnosed by clinical presentation on slit lamp exam using fluorescein and either rose bengal or lissamine green3. However, it is crucial to complete a thorough history and physical exam to narrow the differential diagnosis (Table 1).

Table 1: Key points on history and physical

Figure 3: Slit-lamp corneal findings for patient’s diagnosed with HSV epithelial keratitis. A: Classic dendritic lesion with terminal bulbs. B: More advanced dendritic lesion presenting as geographic ulcer. Figure modified from 6.

Investigations:

The diagnosis of HSVK is based off of clinical findings and does not require additional investigations; however, for atypical lesions, polymerase chain reaction has been used to confirm HSVK. Enzyme-linked immunosorbent assay and viral cultures are also effective in the diagnosis of the HSVK subgroups3.

Treatment/management of HSVK in the emergency department:

In the emergency department, typical findings on the slit lamp exam is diagnostic for epithelial HSVK.

Care providers should initiate treatment immediately to reduce the risk of complications; however, the patient must be referred to ophthalmology within the next few days for follow-up.

Topical and oral antiviral treatments effectively treat epithelial HSVK, although no topical ophthalmic antivirals are currently available in Canada7. It is crucial to adjust the dose of oral antivirals according to the patient’s renal function. See Table 2 for available oral antiviral treatments. For symptomatic management, artificial tears or eye lubricants can ease eye discomfort and over-the-counter analgesics can help relieve pain7.

Table 2: Oral antiviral treatment for epithelial HSVK in adults. Modified from 7

Back to the case:

Given our patient’s classic symptoms of epithelial HSVK (conjunctival injection, tearing, vision changes, foreign body sensation, photophobia, hx of HSV infection) and finding of dendritic ulcers on slit lamp examination, we treated this case as epithelial HSVK until proven otherwise. Therefore, we prescribed the patient valacyclovir 1000mg PO TID and arranged an urgent ophthalmology consult for the following day.

References:

  1. Roozbahani, M., & Hammersmith, K. M. (2018). Management of herpes simplex virus epithelial keratitis. Current opinion in ophthalmology, 29(4): 360-364.

  2. Wilhelmus, K. R. (2015). Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis. Cochrane Database of Systematic Reviews, 1.

  3. Azher, T. N., Yin, X. T., Tajfirouz, D., Huang, A. J., & Stuart, P. M. (2017). Herpes simplex keratitis: challenges in diagnosis and clinical management. Clinical Ophthalmology, 11:185–191.

  4. Sibley, D., & Larkin, D. F. (2020). Update on Herpes simplex keratitis management. Eye, 34: 2219–2226.

  5. Toma, H. S., Murina, A.T., Areaux, R.G., Neumann, D.M., & Bhattacharjee, P.S. (2008). Ocular HSV-1 Latency, Reactivation and Recurrent Disease. Seminars in Ophthalmology, 23(4), 249–273.
  6. Leon, S., & Pizzimenti, J. (2017). Be a Hero to Your HSVK Patients. Review of Optometry-Leadership in clinical care. Retrieved from https://www.reviewofoptometry.com/article/ro0717-be-a-hero-to-your-hsvk-patients2
  7. Institut national d’excellence en santé et en services sociaux. (2018). Herpes Simplex Eye Disease. INESSS Guides. Retrieved from https://www.inesss.qc.ca/fileadmin/doc/INESSS/Outils/GUO/Herpes/Guide_HerpesSimplex_web_EN_VF.pdf

 

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Lateral Canthotomy

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Lateral  Canthotomy – A Medical Student Clinical Pearl

Scott Clarke

Med III, Class of 2022

Dalhousie Medical School New Brunswick (DMNB)

Reviewed by Dr. Fraser MacKay

Copyedited by Dr. Mandy Peach

 

Case:

You are a clinical clerk working your first shift in a busy emergency department when you hear overhead those heart stopping, adrenaline pumping words: “Trauma team activation, room 24”. You arrive to find an unconscious 45 year old male. Report from the paramedics tells you there was a workplace accident whereby a tree had fallen and struck the patient in the face. The team works swiftly and efficiently to secure an airway and stabilize his vitals. From the team leader, your role is to perform a brief neurological exam.

Despite heavy sedation and swelling in the face, you are able to identify significant proptosis of his left eye. His right pupil is reactive to light but you notice his left responds significantly less and there is a positive relative afferent pupillary defect (RAPD). You relay your findings to the team lead and suggest an urgent CT scan of the head.

 

Before departing for CT your attending asks you – what diagnosis are you concerned for? What clinical findings support this diagnosis?

Orbital Compartment Syndrome1

Vision threatening condition where intraocular pressure (IOP) exceeds 40 mmHg.

Clues on exam:

  • Impaired extraocular movements (from a retrobulbar hematoma)
  • Decreased visual acuity
  • RAPD
  • Blown Pupil

Your attending agrees there is concern for orbital compartment syndrome and ophthalmology should be urgently paged – do you wait for CT to confirm retrobulbar hematoma?

No – You quickly grab a tono-pen and measure the intraocular pressure to be 50mmHg. In order to save this patient’s vision, a lateral canthotomy is immediately performed in an attempt to temporarily release pressure before definitive hematoma evacuation can occur.

Procedural Overview:

Equipment:

  1. Tono-pen
  2. Hemostat
  3. Local anesthesia
  4. Curved iris scissors (or scalpel)

Anatomy review:

The globe of the eye is held firmly in place by the strong tarsal plates and the medial and lateral canthal ligaments (Figure 2). By dividing the lateral canthus (inferior limb or both inferior and superior limbs), the globe has room to expand which can greatly reduce pressure3.

Figure 2: Anatomy of the components holding the globe of the eye4.

Procedure5:

  1. Clean the lateral portion of the eye using chlorhexidine or a similar solution.
  2. Inject 2-3cc of 1% lidocaine with 1:100,000 epinephrine into the site of the lateral canthus primarily for hemostasis
  3. Insert the hemostat into the lateral portion of the eye and crush the lateral canthus. Hold this for 30-45 seconds. This will devascularize the tissue resulting in further reduction in bleeding.
  4. Using the curved iris scissors (or scalpel), cut the lateral canthus to the rim of the globe, ~1-2cm at a slight downward angle.
  5. The inferior limb of the lateral canthal ligament will be able to be palpated and resembles a guitar string. This should be divided as well.
  6. If significant intraocular pressure remains, divide the superior limb of the lateral canthal ligament as well.
  7. Reassess ocular pressure.

 

Once the procedure is completed you wait 5 minutes and reassess the intraocular pressure. You notice that it has gone from 50mmHg to 38mmHg. The patient is sent for CT head which confirms a retrobulbar hematoma.

You follow up with the patient during his hospital stay and discover his vision eventually returns to his normal pre-injury.

 

Keys to remember6:

Indications include trauma patients with:
– Proptosis
– Impaired ocular movements
– Elevated Intraocular pressure, usually >40mmHg
– Decreased visual acuity
– RAPD

Ideally performed within 60-120 min of features of ischemia to the optic nerve1.

Absolute contraindication:
– Globe rupture

Medical treatment can also be initiated with the goal to help decrease intraocular pressure 1:

  • mannitol
  • acetazolamide
  • pilocarpine
  • timolol

See below for video of a lateral canthotomy on an actual patient (viewer discretion advised):

References

  1. Helman, A. Swaminathan, A. Austin, E. Strayer, R. Long, B, McLaren, J. Brindley, P. EM Quick Hits 24 – Lateral Canthotomy, Cannabis Poisoning, Hyperthermia, Malignant Otitis Externa, BBB in Occlusion MI, Prone CPR. Emergency Medicine Cases. December, 2020. https://emergencymedicinecases.com/em-quick-hits-december-2020/. Accessed [May 5, 2021].
  2. Retrobulbar Hematoma from Warfarin Toxicity and the Limitations of Bedside Ocular Sonography – The Western Journal of Emergency Medicine. https://westjem.com/videos/retrobulbar-hematoma-from-warfarin-toxicity-and-the-limitations-of-bedside-ocular-sonography.html. Accessed March 29, 2021.
  3. Amer E, El-Rahman Abbas A. Ocular Compartment Syndrome and Lateral Canthotomy Procedure. J Emerg Med. 2019;56(3):294-297. doi:10.1016/j.jemermed.2018.12.019
  4. Chan D, Sokoya M, Ducic Y. Repair of the Malpositioned Lower Lid. 2017. doi:10.1055/s-0037-1608711
  5. How to do Lateral Canthotomy – Eye Disorders – Merck Manuals Professional Edition. https://www.merckmanuals.com/en-ca/professional/eye-disorders/how-to-do-eye-procedures/how-to-do-lateral-canthotomy. Accessed March 29, 2021.
  6. Lateral Canthotomy – YouTube. https://www.youtube.com/watch?v=Qs5Smx-cxbo. Accessed March 29, 2021.
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An interesting derm case in the ED: Mycosis Fungoides

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Mycosis Fungoides: A Medical Student Clinical Pearl

 

Nicholas Relja, B.Sc.(Hon), M.Sc.
Dalhousie Medicine New Brunswick
M.D. Candidate, Class of 2022

All case histories are illustrative and not based on any individual

Reviewed by Dr. Devon Webster

Copyedited by Dr. Mandy Peach

Case

A 55-year-old male presented to the ED after concerned family brought him in due to ongoing generalized weakness lasting approximately one month. On inspection he had erythematous, scaly, ulcerative lesions covering his entire body with only facial sparing. He mentioned burning-like pain originating from his ulcerative lesions. He had been previously diagnosed with T-cell lymphoma 30 years ago and had gone through multiple rounds of chemo and radiation therapy since that time.

Picture from: Denis D, Beneton N, Laribi K, Maillard H (2019). Management of mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL): focus on chlormethine gel. Cancer Management and Research. Vol 11: 2241-2251

Differential for itchy, erythematous rash:

Condition
Atopic dermatitis
Contact dermatitis
Drug eruptions
Erythrodermic psoriasis
Psoriasis
Sezary syndrome
Various lymphomas

 

When reviewing the patient’s past medical history you see they were previously diagnosed with Mycosis Fungoides – a rare cutaneous form of T-cell lymphoma.

Epidemiology

Mycosis fungoides has an incidence of approximately 6 cases per million per year in the United States. It is more common in adults over 50 years of age, with a male to female ratio of 2:1. The disease is also more common amongst the Black population than in Caucasians or Asians.8,9

Etiology

The exact cause of mycosis fungoides is not known; however, there a variety of mechanisms that have been postulated:2

• Genetic and epigenetic abnormalities.3,4
• Environmental and occupational exposure to noxious substances and chemicals.5
• Human T-lymphotropic virus Type 1 – a suspected infection-type etiology.6
• Cytokines such as IL-2 and IL-4 due to their increased presence in patients with mycosis fungoides and Sezary syndrome.7

 

There are three stages of mycosis fungoides and therefore clinical presentation will vary depending on the stage of disease:

Patch stage: Erythematous, or brownish scaly patch, which may show some atrophy. It is possible to have one or multiple lesions develop in areas such as the gluteal region or on the proximal thighs. The likeness of this stage has been compared to “small-plaque” or “large plaque” parapsoriasis; however, the plaques are actually not plaques but patches instead.10

Plaque stage: This is the second stage – lesions will be larger, more numerous and will show infiltration. The lesions appear annular, are raised and have well-defined edges as well as asymmetry in terms of their distribution. Face and scalp involvement can also be seen starting at this stage.11

Tumor stage: The final stage – erythematous-purplish papules or nodules of larger diameter.12

There are other clinical variants of mycosis fungoides, but they are not as common, and some are quite rare.

Sezary syndrome:
In advanced form of the mycosis fungoides, Sezary syndrome may be present. This syndrome involves erythroderma with pruritus, lymphadenopathy and atypical circulating lymphocytes (referred to as Sezary or Lutzner cells).13

Evaluation in the ED

A detailed history and physical exam including checking for lymphadenopathy (most commonly cervical nodes) and organomegaly14,15 in addition to documenting the rash characteristics.

Labs: CBC, liver function tests, LDH

Radiological tests: depends on extent of lymphadenopathy and organomegaly. Can do a CXR in the ED for lung involvement, but otherwise advanced imaging can be decided upon by specialist consultant and may include CT, US, PET or MRI.

Biopsy: lymph nodes and rash – by consultants

Treatment and Management – refer to your friendly neighborhood dermatologist.

Early stage:

Treatment options include topical therapies such as corticosteroids and other agents, UV therapy, local radiation and systemic immunosuppressants 15,16,17.

Advanced Stage:

Treatment for the advanced stages of mycosis fungoides are directed at disease control and symptom relief. Localized radiation, targeted immunotherapy or chemotherapy. 15, 18

Prognosis

The prognosis of mycosis fungoides is variable but in general as the stage gets more advanced and with patients over the age of 60, the prognosis becomes poorer. Other poor prognostic factors include increased LDH, tumor distribution and organ involvement.2

Case Conclusion

The patient seen in hospital by the dermatologist on call and was deemed to be in the plaque stage. He was admitted due to the advancing course and and inability to manage his symptoms from home. Further care will involve palliation and a focus on quality of life.

 

References:

  1. Olisova, O. Y. et al. [Current possibilities of the differential diagnosis of plaque parapsoriasis and the early stages of mycosis fungoides]. Arkh. Patol. 81, 9–17 (2019).
  2. Lim, H. L. J. et al. Epidemiology and prognostic factors for mycosis fungoides and Sézary syndrome in a multi-ethnic Asian cohort: a 12-year review. J. Eur. Acad. Dermatol. Venereol. JEADV 33, 1513–1521 (2019).
  3. Bergallo, M. et al. DNA from Human Polyomaviruses, MWPyV, HPyV6, HPyV7, HPyV9 and HPyV12 in Cutaneous T-cell Lymphomas. Anticancer Res. 38, 4111–4114 (2018).
  4. Väisänen, E. et al. Cutavirus DNA in Malignant and Nonmalignant Skin of Cutaneous T-Cell Lymphoma and Organ Transplant Patients but Not of Healthy Adults. Clin. Infect. Dis. Off. Publ. Infect. Dis. Soc. Am. 68, 1904–1910 (2019).
  5. Slodownik, D., Moshe, S., Sprecher, E. & Goldberg, I. Occupational mycosis fungoides – a case series. Int. J. Dermatol. 56, 733–737 (2017).
  6. Blaizot, R., Ouattara, E., Fauconneau, A., Beylot-Barry, M. & Pham-Ledard, A. Infectious events and associated risk factors in mycosis fungoides/Sézary syndrome: a retrospective cohort study. Br. J. Dermatol. 179, 1322–1328 (2018).
  7. Fujii, K. New Therapies and Immunological Findings in Cutaneous T-Cell Lymphoma. Front. Oncol. 8, 198 (2018).
  8. Amorim, G. M., Niemeyer-Corbellini, J. P., Quintella, D. C., Cuzzi, T. & Ramos-E-Silva, M. Clinical and epidemiological profile of patients with early stage mycosis fungoides. An. Bras. Dermatol. 93, 546–552 (2018).
  9. Amorim, G. M., Niemeyer-Corbellini, J. P., Quintella, D. C., Cuzzi, T. & Ramos-E-Silva, M. Hypopigmented mycosis fungoides: a 20-case retrospective series. Int. J. Dermatol. 57, 306–312 (2018).
  10. Pimpinelli, N. et al. Defining early mycosis fungoides. J. Am. Acad. Dermatol. 53, 1053–1063 (2005).
  11. Burg, G., Dummer, R., Nestle, F. O., Doebbeling, U. & Haeffner, A. Cutaneous lymphomas consist of a spectrum of nosologically different entities including mycosis fungoides and small plaque parapsoriasis. Arch. Dermatol. 132, 567–572 (1996).
  12. Keehn, C. A., Belongie, I. P., Shistik, G., Fenske, N. A. & Glass, L. F. The diagnosis, staging, and treatment options for mycosis fungoides. Cancer Control J. Moffitt Cancer Cent. 14, 102–111 (2007).
  13. Lopez, A. T., Bates, S. & Geskin, L. Current Status of HDAC Inhibitors in Cutaneous T-cell Lymphoma. Am. J. Clin. Dermatol. 19, 805–819 (2018).
  14. Prince, H. M. & Querfeld, C. Integrating novel systemic therapies for the treatment of mycosis fungoides and Sézary syndrome. Best Pract. Res. Clin. Haematol. 31, 322–335 (2018).
  15. Wain, T., Venning, V. L., Consuegra, G., Fernandez-Peñas, P. & Wells, J. Management of cutaneous T-cell lymphomas: Established and emergent therapies. Australas. J. Dermatol. 60, 200–208 (2019).
  16. Dairi, M., Dadban, A., Arnault, J.-P., Lok, C. & Chaby, G. Localized mycosis fungoides treated with laser-assisted photodynamic therapy: a case series. Clin. Exp. Dermatol. 44, 930–932 (2019).
  17. Photiou, L., van der Weyden, C., McCormack, C. & Miles Prince, H. Systemic Treatment Options for Advanced-Stage Mycosis Fungoides and Sézary Syndrome. Curr. Oncol. Rep. 20, 32 (2018).
  18. Alpdogan, O., Kartan, S., Johnson, W., Sokol, K. & Porcu, P. Systemic therapy of cutaneous T-cell lymphoma (CTCL). Chin. Clin. Oncol. 8, 10 (2019).

 

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Well, that’s a pain – in the lower back: A case of back pain in the ED

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Lower Back Pain: Medical Student Clinical Pearl

Grace Dao, CC4

MD Candidate

Class of 2021

Case Presentation

Mr. Payne Bach is a 54 yo male who presents to the emergency department via EMS with lower back pain.
He reports that he hurt his back this afternoon when he was picking up a heavy, antique chair. Immediately, he felt something “give out” in his back and reports a sharp 10/10 central lower back pain that radiates unilaterally to the left side. It did not radiate down his legs. He was unable to ambulate due to the pain and called EMS.

He received 975 mg Acetaminophen in the ambulance which did not alleviate his pain. Mr. Bach reports that before picking up the chair he was feeling well. He denies any history of back pain or activities of back overuse. He denies any history of trauma or injury to his back recently or in the past. In the emergency department he reports his pain remains at 10/10 and cannot sit up or move in bed due to the pain.

He denies any change in sensation or pain to his legs. He denies any change in sensation to his perineum or any bowel incontinence. He has not urinated since the incident. Incidentally when reviewing a past medical history he reports an unintentional weight loss of 15 lbs in the last 2 months. He denies any history of a prior cancer diagnosis. On review of systems he denies history of cough, fevers, night sweats, hematochezia or gross hematuria. Mr. Bach has a 20 pack year smoking history.

Mr. Bach had difficulty with the physical exam due to pain. He appeared very distressed. All vital signs were within normal limits. An order for IV opiods was ordered and he was reassessed 30 minutes later.

Physical exam

Inspection: there were no obvious deformities of the back, no scarring or bruising or abrasions. Mr. Bach continued to look uncomfortable but was no longer in any acute distress.
Palpation: Mr. Bach was tender to palpation over L4-5. There was tenderness to palpation of the paraspinal muscles at the same level.
ROM: Mr. Bach was very hesitant to move, thus, it was difficult to assess his range of motion.
Neuro: Reflexes at the knee and ankle were normal. Babinski was negative. Normal sensation throughout all dermatomes. 5/5 strength on flexion/extension at the hip, knee and ankle.
Special tests: Straight leg raise and Lasegue’s test were negative.

Back Pain

Back pain is an extremely common condition. It is estimated that 70-85% of people will experience back pain at some point in their life1. A recent study out of an emergency department in Halifax, found that 3.17% of patients presented with to the emergency department with a complaint of lower back pain2. Back pain is within the top 5 reasons for primary care visits3. The differential diagnosis for lower back pain ranges from mechanical lower back pain to critical conditions that need to be recognized 4. Due to its prevalence and potentially sinister causes it is important to have an evidence-based approach to lower back pain.

 

To Image or Not to Image-That is the Question

Choosing Wisely Canada has put out recommendations for both Family and Emergency physicians with regards to low back pain. For family medicine the recommendation is “don’t do imaging for lower-back pain unless red flags are present” 5. It has been found that imagining those without red flags before 6 weeks does not improve outcomes.5

Similarly, for emergency medicine the recommendation is “don’t order lumbosacral (low back) spinal imaging in patients with non-traumatic low back pain who have no red flags/pathologic indicators.”6

Red flags 6:

Cauda Equina Syndrome
Severe worsening pain, especially at night
Significant trauma
Weight loss
History of Cancer
Fever
Night sweats
Steroid use
IV drug use
First episode of back pain in age > 50, especially concerning if age > 65
Widespread neurological signs (loss of sensation, loss of motor function, loss of reflexes in the legs)

 

It is also important to remember that not all red flags are created equal and to include clinical judgement in the decision making process.8 A systematic review examining the predictive value of commonly assessed red flags found that for fracture older age, prolonged steroid use, severe trauma, and contusion/abrasion increased the probability of fracture to 10-33%, and if multiple red flags are present fracture risk increases to 42-90%.

When considering red flags that increase risk of malignancy, previous history of malignancy increased risk 7-33%; while older age, unexplained weight loss, and failure to improve after one month all were found to have post-test probabilities of less than 3% when predicting malignancy risk8.

Back to our case

Mr. Bach has red flags for both fracture and malignancy:

Severe, worsening pain
Age > 50
Weight loss

XRs of the lumbar spine were ordered and indicated several compression fractures, with one area suspicious for a metastatic lesion. Follow CT spine was ordered and confirmed metastatic disease. Mr. Bach was admitted to hospital for pain control, physiotherapy and a malignancy work up.

 

References
1. Andersson, G. B. (1999). Epidemiological features of chronic low-back pain. Lancet 354(9178):581-585. doi:10.1016/S0140-6736(99)01312-4
2. Edwards, J., Hayden, J., Asbridge, M., & Magee, K. (2018). The prevalence of low back pain in the emergency department: A descriptive study set in the Charles V. Keating Emergency and Trauma Centre, Halifax, Nova Scotia, Canada. BMC Musculoskeletal Disorders, 19(1), 306. https://doi.org/10.1186/s12891-018-2237-x
3. Finley, C. R., Chan, D. S., Garrison, S., Korownyk, C., Kolber, M. R., Campbell, S., Eurich, D. T., Lindblad, A. J., Vandermeer, B., & Allan, G. M. (2018). What are the most common conditions in primary care? Systematic review. Canadian family physician Medecin de famille canadien, 64(11), 832–840.
4. Patel, A.T., & Ogle, A.A. (2000). Diagnosis and management of acute low back pain. Am Fam Physician 61(6):1779-1790.
5. College of Family Physicians of Canada. Choosing Wisely Canada. Thirteen Things Physicians and Patients should question. July, 2019. Retrieved from: https://choosingwiselycanada.org/family-medicine/
6. Canadian Association of Emergency Physicians. Choosing Wisely Canada. Ten things Physicians and Patients Should Question. July, 2019. Retreived from: https://choosingwiselycanada.org/emergency-medicine/
7. Toward Optimized Practice (TOP). (2011). Guideline for the evidence-informed primary care Management of Low Back Pain. Retrieved from: https://portal.cfpc.ca/resourcesdocs/uploadedFiles/Directories/Committees_List/Low_Back_Pain_Guidelines_Oct19.pdf
8. Downie, A., Williams, C. M., Henschke, N., Hancock, M. J., Ostelo, R. W. J. G., de Vet, H. C. W., Macaskill, P., Irwig, L., van Tulder, M. W., Koes, B. W., & Maher, C. G. (2013). Red flags to screen for malignancy and fracture in patients with low back pain: Systematic review. BMJ, 347.

Copyedited by Dr. Mandy Peach

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Detection of Foreign Bodies in Soft Tissue – A PoCUS-Guided Approach

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Medical Student Clinical Pearl

Sophia Miao, CC4

MD Candidate, Class of 2021

Dalhousie University

 

Reviewed & Edited by Dr David Lewis (@e_med_doc)

All case histories are illustrative and not based on any individual.

 

Case Report

A 33-year-old woman presents to the ED with pain and swelling over the third digit of her right hand.  One week prior to this, she had shattered a jar and a small glass splinter lodged into her finger.  This was promptly removed at home, and the puncture wound healed without intervention.

She presented to the emergency room 7 days later with new pain and swelling surrounding the initial puncture wound.  There is no significant past medical history and most recent Td booster was given 2 years ago.  On examination, there was some mild erythema, swelling, and tenderness on palpation of the lateral aspect of the middle phalanx of the right hand.  She is otherwise well.  You wonder about the possibility of a retained foreign body.

 

PoCUS-Guided Approach to the Detection of Foreign Bodies in Soft Tissue

Foreign bodies in soft tissue are a common complaint in the emergency department, with open wounds comprising 5.7 million (or 4.5% of total) visits to the ED in 2010.[1]  Foreign bodies were found in up to 15% of wounds.[2]  If retained, complications of these include allergic reaction, inflammation, delayed wound healing, damage to adjacent tissue structures, neurovascular damage, tetanus, and infectious complications including cellulitis, necrotizing fasciitis, synovitis, and abscess formation.[3],[4]  Proper detection, and subsequent removal, of retained foreign bodies is therefore essential to evaluate the wound and prevent associated complications.

Diagnosis of a retained FB requires a high index of suspicion.  Clinical suspicion should be raised when there is a compelling history and physical exam.  The latter may include signs of inflammation and/or infection, including warmth, swelling, erythema, tenderness, abscess formation, and discharging wound).[5],[6]

Conventional radiography is known to commonly miss radiolucent materials such as wood and plastic.  It has been shown that plain radiographs have only a 7.4% sensitivity in the detection of wood foreign bodies.5  Remarkably, even glass – a radiopaque material – has been demonstrated to have been missed in up to 35% of x-ray film studies.[7]  There is increasingly compelling evidence for the clinical usefulness and accuracy of bedside ultrasonography in the detection of soft-tissue foreign bodies.  It has been shown to have a specificity of 92% (95% CI = 88%-95%) and sensitivity ranging from 83.3% to 100%.[8],[9]

PoCUS Technique

Probe selection: the use of a high-frequency ultrasound probe is recommended.  This allows for greater axial resolution at the expense of less penetration, which is suitable for the detection of small foreign bodies, as they typically lodge in superficial tissues.[10]

If the wound is open, a transparent covering such as a Tegaderm or probe cover can be used to cover either the wound or probe before scanning.[11]

Medium: standard technique for assessment of soft-tissue structures by ultrasound involves the use of a standoff pad or gel mound.  However, this is not always possible due to the irregular curvature of extremities such as fingers and feet, which may result in poor contact between the probe and skin, decreased field of view, and patient discomfort.  A water-bath technique can circumvent this and has been shown to be superior in such cases.[12]

Method: the area of interest should be scanned in both longitudinal and transverse planes.  Foreign bodies are best detected when the transducer aligns with the longitudinal axis of the foreign body, and therefore revealing the span of the object.[13]  As foreign bodies tend to embed less than 2 cm below the surface of the skin, the depth of field should remain superficial in order to avoid false positives.

US Probe: Ultrasound Water Bath for Distal Extremity Evaluation

 

Findings

Ultrasonography and plain film findings of foreign bodies in soft tissue are summarized in the table below.

Table 1. Ultrasound and x-ray findings of foreign bodies.6,[14],[15],[16]

Material Ultrasound findings X-ray findings
Wood Hyperechoic; may become isoechoic with surrounding tissue as it denatures over time

Posterior acoustic shadowing

 Radiolucent, often undetectable
Glass Hyperechoic, bright

Posterior acoustic shadowing

± Posterior comet tail reverberation, diffuse beam scattering

 Radiopaque
Plastic Hyperechoic

Posterior acoustic shadowing

 Radiolucent, often undetectable
Metal Hyperechoic, bright

Posterior acoustic shadowing

± Posterior comet tail reverberation

 Radiopaque

 

Foreign bodies may also display a straight or regular contour.6

 

Image 1 – Wood splinter in volar aspect digit, mildly hyperechoic, surrounding hypoechoic halo, irregular acoustic shadowing

Image 2 – Plastic FB, within tendon sheath, volar aspect digit, brightly hyperechoic, long axis

Image 3 – Plastic FB, within tendon sheath, volar aspect digit, brightly hyperechoic, short axis

 

Image 4 – Glass FB – brightly echogenic, posterior reverberation, FB long axis

 

Image 5 – Metal FB – brightly echogenic, posterior reverberation, FB long axis

 

 

It is important to note that the acoustic shadowing may be complete or partial, as this is dependent on the angle of sonography and foreign body material.[17]  It is also possible to see a hypoechoic halo around the FB, which may be suggest edema, abscess formation, granulation tissue, or other inflammatory process.[18]  As the inflammatory reaction develops, the halo effect becomes more apparent; therefore the foreign body is therefore best visualized by PoCUS several days after the initial injury.6

PoCUS-Guided Foreign Body Removal

There are several options for removal of a foreign body with PoCUS:[19]

  1. Needle localization. Once the foreign body has been identified on PoCUS, a hollow injection needle can be inserted under ultrasound guidance and local anesthetic is delivered through this.  This can be done in either the transverse or longitudinal plane.  The ultrasound probe is then removed, and an incision is made along the needle.  Through the incision site, tweezers or forceps can be used to remove the foreign body.
  2. Real-time ultrasound-guided extraction. This technique is similar to the needle localization method. However, rather than removing the transducer following the needle insertion, the entire procedure is done under direct ultrasound visualization.  The probe is held in the longitudinal plane to visualize both the forceps and the foreign body during the extraction process.

 

There is a risk of obscuring the view of the foreign body on ultrasound with air as a result of the incision itself or through anesthetic delivery.  Saline may be used to irrigate and therefore mitigate the issue.19

The patient’s tetanus status should be verified and updated, if required.  Antibiotic therapy may also be provided, should the risk of infection justify it.

Limitations

There is the possibility of false positives.  Foreign bodies must be differentiated from other hyperechoic body structures, including ossified cartilage, sesamoid bones, scar tissue, gas bubbles, and intermuscular fascia.14  Visualization is therefore important in both longitudinal and transverse planes, as well as comparison with the opposite side.  Acoustic shadowing, hypoechoic halo, and posterior comet tails, if present, can also be indicative of a FB rather than organic body tissue.

Traumatic air injection as a result of penetrating injury can create a scatter artifact on ultrasound, which can be misinterpreted as an acoustic shadow associated with a foreign body.  To differentiate this from a true acoustic shadow, pressure may be applied through the transducer to displace the scatter artifact.6

As is commonplace with all emergency ultrasonography, limitations also include the technical skill of the operator.[20]  A foreign body may also be too small to be detectable by ultrasound.  It is therefore important to remember that a negative scan does not necessarily rule out the possibility of a retained foreign body, and the history and physical examination must be considered in conjunction with the ultrasound findings.

 

 

References

[1] National Center for Health Statistics. Emergency Department Visits. Available from: http://www.cdc.gov/nchs/fastats/emergency-department.htm.

[2] Steele MT, Tran LV, Watson WA, Muelleman RL. Retained glass foreign bodies in wounds: predictive value of wound characteristics, patient perception, and wound exploration. Am J Emerg Med. 1998 Nov;16(7):627-30. DOI: 10.1016/s0735-6757(98)90161-9. PMID: 9827733.

[3] Skinner EJ, Morrison CA. Wound Foreign Body Removal. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554447/.

[4] Ebrahimi A, Radmanesh M, Rabiei S, Kavoussi H. Surgical removal of neglected soft tissue foreign bodies by needle-guided technique. Iran J Otorhinolaryngol. 2013 Winter;25(70):29-36. PMID: 24303416; PMCID: PMC3846242.

[5] Levine MR, Gorman SM, Young CF, Courtney DM. Clinical characteristics and management of wound foreign bodies in the ED. Am J Emerg Med. 2008 Oct;26(8):918-22. DOI: 10.1016/j.ajem.2007.11.026. PMID: 18926353.

[6] Atkinson P, Bowra J, Harris T, Jarman B, Lewis D. Point of Care Ultrasound for Emergency Medicine and Resuscitation. Oxford, United Kingdom: Oxford University Press; 2019. DOI: 10.1093/med/9780198777540.001.0001.

[7] Kaiser, C. William MD; Slowick, Timothy MBA; Spurling, Kathleen Pfeifer RN, JD; Friedman, Sissie MA. Retained Foreign Bodies, The Journal of Trauma: Injury, Infection, and Critical Care: July 1997 – Volume 43 – Issue 1 – p 107-111.

[8] Davis J, Czerniski B, Au A, Adhikari S, Farrell I, Fields JM. Diagnostic Accuracy of Ultrasonography in Retained Soft Tissue Foreign Bodies: A Systematic Review and Meta-analysis. Acad Emerg Med. 2015 Jul;22(7):777-87. DOI: 10.1111/acem.12714. Epub 2015 Jun 25. PMID: 26111545.

[9] Atkinson P, Madan R, Kendall R, Fraser J, Lewis D. Detection of soft tissue foreign bodies by nurse practitioner-performed ultrasound. Crit Ultrasound J. 2014 Jan 29;6(1):2. DOI: 10.1186/2036-7902-6-2. PMID: 24476553; PMCID: PMC3922659.

[10] Dean AJ, Gronczewski CA, Costantino TG. Technique for emergency medicine bedside ultrasound identification of a radiolucent foreign body. The Journal of Emergency Medicine. 2003;24(3):303–8. DOI: 10.1016/S0736-4679(02)00765-5.

[11] Chen KC, Lin AC, Chong CF, Wang TL. An overview of point-of-care ultrasound for soft tissue and musculoskeletal applications in the emergency department. J Intensive Care. 2016 Aug 15;4:55. DOI: 10.1186/s40560-016-0173-0. PMID: 27529031; PMCID: PMC4983782.

[12] Krishnamurthy R, Yoo JH, Thapa M, Callahan MJ. Water-bath method for sonographic evaluation of superficial structures of the extremities in children. Pediatr Radiol. 2013 Mar;43 Suppl 1:S41-7. DOI: 10.1007/s00247-012-2592-y. Epub 2013 Mar 12. PMID: 23478918.

[13] Rooks VJ, Shiels WE 3rd, Murakami JW. Soft tissue foreign bodies: A training manual for sonographic diagnosis and guided removal. J Clin Ultrasound. 2020 Jul;48(6):330-336. DOI: 10.1002/jcu.22856. Epub 2020 May 8. PMID: 32385865.

[14] Mohammadi A, Ghasemi-Rad M, Khodabakhsh M. Non-opaque soft tissue foreign body: sonographic findings. BMC Med Imaging. 2011 Apr 10;11:9. DOI: 10.1186/1471-2342-11-9. PMID: 21477360; PMCID: PMC3079678.

[15] Lewis D, Jivraj A, Atkinson P, Jarman R. My patient is injured: identifying foreign bodies with ultrasound. Ultrasound. 2015 Aug;23(3):174-80. DOI: 10.1177/1742271X15579950. Epub 2015 Mar 26. PMID: 27433254; PMCID: PMC4760591.

[16] Campbell EA, Wilbert CD. Foreign Body Imaging. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470294/.

[17] Anderson MA, Newmeyer WL 3rd, Kilgore ES Jr. Diagnosis and treatment of retained foreign bodies in the hand. Am J Surg. 1982 Jul;144(1):63-7. DOI: 10.1016/0002-9610(82)90603-1. PMID: 7091533.

[18] Little CM, Parker MG, Callowich MC, Sartori JC. The ultrasonic detection of soft tissue foreign bodies. Invest Radiol. 1986 Mar;21(3):275-7. DOI: 10.1097/00004424-198603000-00014. PMID: 3514541.

[19] Paziana K, Fields JM, Rotte M, Au A, Ku B. Soft tissue foreign body removal technique using portable ultrasonography. Wilderness Environ Med. 2012 Dec;23(4):343-8. DOI: 10.1016/j.wem.2012.04.006. Epub 2012 Jul 25. PMID: 22835803.

[20] Pinto A, Pinto F, Faggian A, Rubini G, Caranci F, Macarini L, Genovese EA, Brunese L. Sources of error in emergency ultrasonography. Crit Ultrasound J. 2013 Jul 15;5 Suppl 1(Suppl 1):S1. DOI: 10.1186/2036-7902-5-S1-S1. Epub 2013 Jul 15. PMID: 23902656; PMCID: PMC3711733.

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Periorbital Inflammation – Red Eye – Red Flags

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Medical Student Clinical Pearl

Alysha Roberts

MD Candidate, Class of 2021

Dalhousie University

@aeroberts_21

Reviewed & Edited by Dr David Lewis (@e_med_doc)

All case histories are illustrative and not based on any individual.

Case

A 40 year old male presents to the emergency department with a red, swollen eye. Without a known trigger, he had a one day history of progressive pain, erythema, and edema surrounding his left eye. He denied any fever or chills or visual changes, or headache. A thorough review of systems was negative, except for a complaint of worsening pain with extraocular movement.

On exam, he was afebrile and his vital signs were within normal limits. His visual acuity was normal, and pupils were equal and reactive to light. Extraocular movements were intact but associated with worsening pain. The periorbital tissue was erythematous, edematous, and hot to touch. Examination is limited by the severity of the patient’s swelling. Figure 1 illustrates an example of a patient with severe, unilateral eyelid swelling and erythema.

You suspect periorbital cellulitis.

Figure 1. Unilateral eyelid edema. Retrieved from https://www.merckmanuals.com/professional/eye-disorders/orbital-diseases/preseptal-and-orbital-cellulitis

 

Periorbital Versus Orbital Cellulitis

Periorbital cellulitis, commonly referred to as pre-septal cellulitis, is an infection of the skin and soft tissue surrounding the orbit. Most commonly, it is the result of an infection spreading from the sinuses or from local trauma.1,2 It presents as a unilateral swelling of the eye-lid. Both periorbital and orbital cellulitis are most commonly caused by Staphylococcus Aureus and Streptococcus Pneumoniae. It is important to distinguish periorbital from orbital cellulitis, which is an infection of the orbit itself extending beyond the orbital septum. Orbital cellulitis is a sight-threatening emergency, and urgent imaging should be acquired in addition to consultation with ophthalmology or otolaryngology.3 Other complications of orbital cellulitis include orbital or subperiosteal abscess, and cavernous sinus thrombosis. Figure 2 illustrates the difference between periorbital (preseptal) and orbital cellulitis, as well as its complications.

Figure 2. Orbital anatomy and potential complications from orbital cellulitis. Retrieved from https://www.merckmanuals.com/professional/eye-disorders/orbital-diseases/preseptal-and-orbital-cellulitis

Any patient with unilateral eyelid edema should be evaluated for red flags of orbital cellulitis, given its potential seriousness. Red flag signs and symptoms include:3,4

  • Painful or restricted extraocular movements
  • Reduced visual acuity
  • Relevant afferent pupillary defect
  • Diplopia
  • Proptosis
  • Chemosis
  • Severe headache

 

Differential Diagnosis

Other considerations for the differential diagnosis in a unilateral, swollen red eye include:5

  • Periorbital ecchymosis due to blunt trauma
  • Contact dermatitis secondary to local irritant
  • Atopic dermatitis due to allergic sensitivity
  • Orbital tumors

 

Risk Factors

Risk factors for periorbital and orbital cellulitis include:6

  • Sinusitis
  • Dental infection
  • Insect bite
  • Trauma

 

Periorbital cellulitis is most commonly caused by an insect bite in children, and trauma in adults. Comparatively, orbital cellulitis is most often the result of trauma in children, and sinusitis in adults.

 

Diagnostic Investigations

Patients who are febrile or appear unwell should have early initiation of IV antibiotics following blood cultures. Though periorbital cellulitis is a clinical diagnosis, if there is suspicion for orbital cellulitis a CT scan of the orbits and sinuses is the gold standard. Positive findings include inflammation of extraocular muscles, anterior globe displacement, and fat stranding. Inflammation of the sinuses should not be used to differentiate periorbital from orbital cellulitis, as up to 41% of cases of periorbital cellulitis may have CT evidence of sinusitis. Figure 3 displays a labelled CT image with common findings in orbital cellulitis.7

 

Figure 3. Orbital CT image with labels. Retrieved from https://ctscanmachines.blogspot.com/2018/07/ct-scan-of-periorbital-cellulitis.html

In addition to CT imaging, there may be a role for point of care ultrasound (PoCUS) in the diagnosis and management of periorbital and orbital cellulitis. However, research is currently lacking on whether its use may avoid the need for further diagnostic imaging.8 Findings from pediatric emergency medicine suggest that orbital ultrasound may be preferred in evaluating young patients who are unable to cooperate with a thorough physical examination.9 One important application of orbital PoCUS is in the assessment of orbital abscesses. Subperiosteal abscesses may complicate more than 50% of cases of orbital cellulitis, and are not reliably detected by CT.10 Additionally, orbital ultrasound may be an appropriate alternative in settings where advanced imaging is not available, in order to guide early initiation of antibiotics.

Orbital Abscess from – The PoCUS Atlas

 

 

Treatment Best Practices  

Antibiotic choice should be guided by local susceptibility guidelines. An appropriate choice would cover S. aureus, S. pyogenes, and anaerobes.11,12 In this case, we initiated intravenous ceftriaxone and metronidazole while awaiting CT results.

The following therapeutic guidelines are from Bugs and Drugs – It is recommended that that guidelines for therapy are accessed directly from their website or from other reputable sources.

Periorbital Cellulitis

 

Orbital Cellulitis

From Bug and Drugs

 

Case Conclusion

Given this patient’s complaint of increased pain with extraocular movement, a CT orbit was performed. Fortunately, there were no signs of orbital cellulitis. The patient was treated with IV ceftriaxone and metronidazole and scheduled to return to the emergency department the next day for re-evaluation and consideration of step-down to oral antibiotics.

Summary

Orbital cellulitis is a serious condition that should be carefully distinguished from periorbital cellulitis. On history, clinicians should ensure they inquire about recent sinus or dental infections, trauma to the orbit, or possible insect bites. Physical exam should carefully assess for signs of orbital cellulitis, including proptosis, chemosis, and limited extraocular movements. Any positive red flag or clinical suspicion warrants a CT scan of the orbits and sinuses to exclude orbital cellulitis.

Further Reading

Great photo article in Canadian Family Physician

Management algorithm

Patient Information Leaflet

 

 

 

References

  1. Preseptal and Orbital Cellulitis – Eye Disorders – Merck Manuals Professional Edition. (n.d.).Retrieved January 12, 2021, from https://www.merckmanuals.com/professional/eye-disorders/orbital-diseases/preseptal-and-orbital-cellulitis
  2. Lightning Learning: Orbital Cellulitis — #EM3: East Midlands Emergency Medicine Educational Media. (n.d.). Retrieved January 12, 2021, from https://em3.org.uk/foamed/7/5/2019/lightning-learning-orbital-cellulitis
  3. Periorbital cellulitis — entsho.com. (n.d.). Retrieved January 12, 2021, from https://entsho.com/periorbital-cellulitis
  4. Distinguishing Periorbital from Orbital Cellulitis. (2003). American Family Physician, 67(6), 1349.
  5. Differential Diagnosis of the Swollen Red Eyelid – American Family Physician. (n.d.). Retrieved January 12, 2021, from https://www.aafp.org/afp/2015/0715/p106.html
  6. Risk factors of preseptal and orbital cellulitis – PubMed. (n.d.). Retrieved January 12, 2021, from https://pubmed.ncbi.nlm.nih.gov/19149979/
  7. Ct Scan Of Periorbital Cellulitis – ct scan machine. (n.d.). Retrieved January 12, 2021, from https://ctscanmachines.blogspot.com/2018/07/ct-scan-of-periorbital-cellulitis.html
  8. Kang, T. L., Seif, D., Chilstrom, M., & Mailhot, T. (2014). Ocular ultrasound identifies early orbital cellulitis. Western Journal of Emergency Medicine, 15(4), 394. https://doi.org/10.5811/westjem.2014.4.22007
  9. Seguin, J., Le, C.-K., Fischer, J. W., Tessaro, M. O., & Berant, R. (2019). Ocular Point-of-Care Ultrasound in the Pediatric Emergency Department. Pediatric Emergency Care, 35(3), E53–E58. https://doi.org/10.1097/PEC.0000000000001762
  10. Derr, C., & Shah, A. (2012). Bedside ultrasound in the diagnosis of orbital cellulitis and orbital abscess. Emergency Radiology, 19(3), 265–267. https://doi.org/10.1007/s10140-011-0993-0
  11. Orbital Cellulitis – StatPearls – NCBI Bookshelf. (n.d.). Retrieved January 12, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK507901/
  12. Periorbital Cellulitis – StatPearls – NCBI Bookshelf. (n.d.). Retrieved January 12, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK470408/
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