Category Archives: Resident

Evidence of Raised Intracranial Pressure on ECG

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Evidence of Raised Intracranial Pressure on ECG – A Resident Clinical Pearl

Robert Dunfield, PGY2 FMEM program,  Dalhousie University Saint John

Reviewed & Edited by Dr. Mandy Peach

Case

A 44 year old male presents to your trauma bay with progressive confusion and altered level of consciousness for the past three days. Collateral history reveals possible recent recreational methamphetamine use. No specific abnormal neurological features or findings on history and physical. A full workup is performed and investigations reveal a left frontal intracerebral hematoma with the following CT head (Figure 1) and ECG (Figure 2):

 

1. What clinical (history and physical) features suggest an elevated intracranial pressure? [4, 5]

On history, suspect an elevated intracranial pressure with:

• headaches
• vomiting
• altered mental status (ranging and alternating from drowsiness to coma)
• visual changes (blurred, diplopia, photophobia)
• history of malignancy, trauma

On examination, suspect an elevated intracranial pressure with:

• Cushing triad: hypertension, bradycardia and irregular respiration. This is a sign of impending brain herniation
• pupils unequal, unreactive
• disc edema
• optic atrophy
• bulging anterior fontanelle (in infants)
• evidence of trauma

 

2. What features on ECG are in keeping with an elevated intracranial pressure? [1, 2, 6]

Elevations in ICP or brain injuries are commonly associated with the following ECG changes:

• “Cerebral” T waves: widespread giant T wave inversion
• Flat T waves
• ST elevation/depression
• QTc prolongation
• Sinus bradycardia (if seen assess for other features of Cushing triad)
• Increased U wave amplitude
• Osborn (J) waves
• Other dysrhythmias: sinus tachycardia, junctional rhythms, premature ventricular contractions, atrial fibrillation, AV blocks

ECG changes are common with elevated ICP and intracranial hemorrhage. Approximately 56% of patients with intracranial hemorrhage have associated ECG changes.

Most importantly, recognize that these ECG changes can mimic acute coronary syndromes. This is potentially dangerous as a misdiagnosis of STEMI in a patient with an intracranial bleed could lead to unnecessary thrombolytics or PCI. For this reason, keep an elevated ICP in mind when identifying the above ECG changes.

 

3. What is a cerebral T wave? [1, 5]

Cerebral T waves are deep, symmetric, inverted T-waves seen on an ECG in patients with large intracranial bleeds. They are typically widespread

 

4. What other causes, other than elevated ICP, result in inverted T waves and should be kept on your differential? [2]

When analyzing an ECG it is important to recognize other causes of inverted T waves. The differential for inverted T waves includes:

• Myocardial ischemia and infarction
• Bundle branch block
• Ventricular hypertrophy
• Pulmonary embolism
• Hypertrophic cardiomyopathy

 

5. What is the pathophysiological cause for the ECG changes associated with an elevated ICP? [3, 4]

The full pathophysiology of ECG changes related to an elevated ICP is not fully understood.

ECG changes related to an elevation in ICP are thought to be related to neurogenic cardiac injury. This is mostly due to a surge of systemic catecholamines as a result of significant sympathetic activation from the central neuroendocrine axis and activation of the adrenal glands. Additionally, any injury to the hypothalamus or insula can cause dysfunction of the autonomic nervous system and a systemic inflammatory response.

Systemic catecholamine levels can be elevated for as long as 10 days. This prolonged exposure to catecholamines as well as the systemic inflammatory response can result in cardiac injury and dysfunction.

It is also possible for the heart to suffer from “neurogenic stunned myocardium syndrome” (NSM). This is reversible myocyte damage that results in ECG changes, in addition to other cardiac effects, due an excessive release of norepinephrine. The amount of cardiac damage caused by NSM correlates with the degree of brain injury. NSM can develop within four hours of brain injury. Other causes of NSM include pheochromocytoma, near drowning, and severe emotional experiences.

 

6. What are the most common intracranial findings associated with ECG changes related to an increased ICP? [1, 3]

The most common causes of ECG changes related to an elevation in ICP involve massive intracranial hemorrhage, including subarachnoid hemorrhage (49 to 100% of cases)3 and intraparenchymal hemorrhage (57% of cases)1.

Less commonly, ECG changes are associated with massive ischemic stroke causing cerebral edema, traumatic brain injury, or less commonly cerebral metastases.

 

7. How long do ECG changes last with brain injuries related to elevated ICP, and what are the clinical implications for a finding of prolonged ECG changes? [3]

Normally, as brain injuries and elevated ICP resolve, so will ECG changes. Most ECG changes will resolve within three days but have been reported to last up to eight weeks from the etiology of the elevated ICP.

Some reports have shown that prolonged ECG changes are associated with an increased risk for ischemic neurological deficit, poor outcome, and death following a subarachnoid hemorrhage. Specifically, persistent prolonged QTc is associated with poor clinical outcomes and death, whereas recovery of QTc is associated with good clinical outcomes.

 

SUMMARY & KEY POINTS:

• Be aware of Cushing triad on clinical assessment of patients with potential elevation in ICP (sinus bradycardia, hypertension, and abnormal respiratory pattern).

• There are multiple nonspecific ECG changes associated with an elevation in ICP, including: cerebral T waves, ST elevation/depression, sinus bradycardia, increased U wave amplitude, J waves, and other dysrhythmias.

• The exact pathophysiology for the cause of elevated ICP causing ECG changes is complicated and not fully understood. It is thought to mostly be due to excess catecholamine and norepinephrine exposure, along with a dysregulated inflammatory reaction.

• Subarachnoid hemorrhage and intraparenchymal hemorrhage are the most common causes of ECG changes associated with elevated ICP.

• Be aware that ECG changes related to elevated ICP can mimic acute coronary syndrome, so keep intracranial pathologies on your differential when the above ECG changes are found.

 

Of note, the patient described in the clinical scenario was admitted to neurosurgery and observed for nearly two weeks. He recovered without operative management.

 

REFERENCES:

  1. Cadogan M. Raised Intracranial Pressure. Life in the Fast Lane 2020; Last updated: Nov. 3, 2020, Accessed: December 28, 2020. Available from: https://litfl.com/raised-intracranial-pressure-ecg-library/

  2. Gregory T and Smith M. Cardiovascular complications of brain injury, Continuing Education in Anaesthesia Critical Care & Pain. 2012; 12:2, 67–71. Available from: https://doi.org/10.1093/bjaceaccp/mkr058

  3. Levis JT. ECG Diagnosis: Deep T Wave Inversions Associated with Intracranial Hemorrhage. Perm J. 2017; 21:16, 049. doi:10.7812/TPP/16-049

  4. Pinto VL, Tadi P, Adeyinka A. Increased Intracranial Pressure. [Updated 2020 Jul 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482119/

  5. Tannenbaum L. ECG Pointers: Intracranial Hemorrhage. emDocs.net: Electrocardiography. 2018; Last updated: November 14, 2018. Accessed: December 29, 2020. Available from: http://www.emdocs.net/ecg-pointers-intracranial-hemorrhage/

  6. Yogendranathan N, Herath HM, Pahalagamage SP, Kulatunga A. Electrocardiographic changes mimicking acute coronary syndrome in a large intracranial tumour: A diagnostic dilemma. BMC Cardiovasc Disord. 2017;17(1):91. Published 2017 Apr 4. doi:10.1186/s12872-017-0525-2

 

 

 

 

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“The Mother’s Kiss”

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A Tool in Nasal Foreign Body Removal in Pediatric Patients

Melanie Johnston, PGY2 iFMEM Dalhousie University Saint John

Reviewed by Dr. Mandy Peach

 

Introduction:

The highest incidence of nasal foreign bodies is in pediatric patients, ages 2-5.1 The removal of nasal foreign bodies in the emergency department can be challenging.

The most common objects removed are beads, nuts, chalk, eraser heads, pebbles, and other small objects.1,2 While most nasal foreign bodies are benign, some objects can cause severe damage and need to be urgently removed.

The diagnosis of nasal foreign may be obvious as the caregiver may have witnessed the event and present acutely. Others may have delayed presentations of weeks-months after the child develops symptoms of nasal irritation/infection from the retained foreign body. In general, organic foreign bodies (flowers, plants, bugs) tend to be more irritating to the nasal mucosa and cause symptoms much earlier.2

 

Details on history and physical exam findings that should raise suspicion of a potential nasal foreign body in a paediatric patient include:

  • Witnessed insertion of foreign body
  • Unilateral foul-smelling purulent discharge
  • Mucosal erosions/ulceration

  • Unilateral epistaxis

  • Headache focused on the same side as the foreign body
  • Nasal obstruction
  • Mouth breathing2

 

Nasal foreign bodies have the potential to dislodge posteriorly and aspirate.1 Consider aspirated FB if new wheeze/cough/shortness of breath in a child with suspected intranasal FB and be prepared for a precipitous change in the airway. 6 

 

Nasal foreign bodies are most commonly located on the floor of the nasal passage under the inferior turbinate, or superiorly  in front of the middle turbinate.2

Foreign bodies are most frequently located on the right side, due to the right handed dominance of most children.2

Figure 1. Anatomy of the nose.3

 

Examination:

Ensure good lighting to be able to visualize the canal. Place the patient in a sniffing position with caregiver assistance (they may have to firmly hold child for cooperation). Suction should be readily available for nasal discharge and to aid in visualization. Nasal speculum can be used to aid visualization of the canal. Visualization of the foreign body confirms the diagnosis.

 

Figure 2. Marble nasal foreign body in pediatric patient.4

 

ENT referral is warranted if:


– Foreign body suspected, but unable to visualize by anterior rhinoscopy
– Impacted foreign body with marked inflammation (eg button batteries)
– Penetrating foreign body
– Any foreign body that cannot be removed due to poor cooperation, bleeding, or limited instrumentation2

 

Foreign Body Removal Options:

There are a number of techniques for nasal foreign body removal in the Emergency Department: alligator forceps, suction, balloon catheters, cyanoacrylate glue.2 Depending on the patient, these methods can be technically challenging if the patient is uncooperative, and may require the use of procedural sedation. A less invasive alternative for children not willing to cooperate with manipulation in the nasal canal is the Mothers’ Kiss.

 

Mothers’ Kiss Technique:

This technique was first described in the 1960s by a general practitioner in New Jersey and uses positive pressure to mobilize the foreign body from the nasal passage.1 It is effective in approximately 60% of attempts5, and generally most effective for smooth/soft foreign bodies that totally occlude the anterior nasal cavity.2 Even when not successful, it may improve visibility of the foreign body. Theoretical risks include barotrauma to both the tympanic membranes or pneumothorax, but these complications have never been reported.5 The pressure used by the caregiver to attempt expulsion of the foreign body is equivalent to that of a sneeze, approximately 60mmHg.1 The main danger in removing a foreign body from the nose is the risk of aspiration.

Procedure:5
1) Instruct the caregiver to place their mouth over the childs’ open mouth, forming a firm seal (similar to mouth-to-mouth resuscitation).
2) Next, occlude the unaffected nostril with a finger
3) The caregiver should blow until they feel resistance (caused by the closure of the childs’ glottis), then they should deliver a short puff of air into the childs’ mouth
4) The puff of air travels through the nasopharynx, and if successful results in the expulsion of the foreign body
5) If unsuccessful, the procedure can be repeated a number of times

Figure 3: Caregiver performing “Mother’s Kiss”. Shows occlusion of unaffected nare,
with seal formed around childs’ mouth.

 

 

If the caregiver is unable to perform the procedure, the approach can be recreated with a bag-valve-mask as the positive pressure source, ensuring the mask covers only the childs’ mouth.

Figure 4: Positive Pressure Ventilation with Bag-Valve-Mask.6

 

 

For a visual review of these techniques, please refer to the following videos:

“Mother’s Kiss”

 Positive Pressure Ventilation

 

Bottom Line:

Nasal foreign bodies are a common occurrence in the paediatric population. Their removal in the Emergency Department can be challenging as the patient may be fearful and non-cooperative. While there are a number of methods for removal of nasal foreign bodies, the “Mothers’ Kiss” technique provides a relatively non-invasive alternative. It has been shown to be effective in removal of 60% of nasal foreign bodies, and is most effective if foreign bodies are smooth and located in the anterior nasal cavity. If the caregiver is unable to perform the procedure, the approach can be recreated with BVM as the positive pressure source. The risks of this technique are minimal, and even when unsuccessful, can assist in improving the visualization of the nasal foreign body.

 

References:

  1. Cook, S., Burton, M., & Glasziou, P. (2012). Efficacy and safety of the “mother’s kiss” technique: a systematic review of case reports and case series. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 184(17), E904–E912. https://doi.org/10.1503/cmaj.111864

  2. Isaacson, G., Ojo, A. (2020). Diagnosis and management of intranasal foreign bodies. Up to Date. Retrieved from https://www.uptodate.com/contents/diagnosis-and-management-of-intranasal-foreign-bodies.

  3. Le, P. (2020). Anatomy, Head and Neck, Nasal Concha. Retrieved from: https://www.statpearls.com/ArticleLibrary/viewarticle/32550

  4. Nose-Foreign Body Nose, Dr Vaishali Sangole. Retrieved Oct 31,2020 from: http://vaishalisangole.com/NOSE_Foreign.html

  5. Glasziou, P., Bennett, J. (2013). Mothers’ kiss for nasal foreign bodies. Australian Family Physician, 42(5): https://www.racgp.org.au/afp/2013/may/mothers-kiss/.

  6. Thoreckzo. (2017). Foreign Bodies in the Head and Neck. Pediatric Emergency Playbook. Retrieved from: https://pemplaybook.org/podcast/foreign-bodies-in-the-head-and-neck/

  7. Pretel, M. Removing object from child’s nose using the kiss technique. Youtube- retrieved from: https://www.youtube.com/watch?v=RR3SxICqdAY.

  8. Dudas, R. Nasal foreign body removal. Youtube- retrieved from: https://www.youtube.com/watch?v=PacvHiJFhNA.

 

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Fascia Iliaca Nerve Block

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Hip Broke? Hip Block. Use of the fascia iliaca nerve block for analgesia in hip fractures.

Resident Clinical Pearl (RCP) July 2020

Luke Edgar, BScH MD

PGY1 Family Medicine Integrated Emergency Medicine

Dalhousie Saint John

 

Reviewed by Dr. David Lewis

Background

Hip fractures are a common and painful injury diagnosed and treated in the emergency department, with elderly patients representing the majority of cases. Advanced age, comorbidities, and increased sensitivity to side effects from systemic analgesia all pose challenges to achieving adequate pain control.1,2 Additionally, NSAID use in the elderly is frequently contraindicated due renal, cardiac, and gastrointestinal comorbidities as well as drug interactions. In elderly patients, both undertreated pain and opioid analgesia can precipitate delirium.3

Regional nerve blocks for the indication of hip and femoral neck fractures have been shown to reduce pain and need for IV opiates.1 Contraindications include infection over the injection site, patient refusal, and allergy to local anesthetic. Additionally, patients at risk for compartment syndrome (such as those with a concomitant ipsilateral tibial plateau fracture) should be selected cautiously as they may not reliably have increased pain after block.4

There are three main techniques described for regional nerve blocks to provide analgesia for hip and femoral neck fractures.1

  • Fascia Iliaca Nerve Block: Insert a needle through the fascia lata and fascia iliaca, to infiltrate dilute local anesthetic into the fascial compartment which diffuses to block the femoral, lateral femoral cutaneous, and obturator nerves.
  • Femoral Nerve Block: At the level of the femoral triangle, infiltrate local anesthetic around the femoral nerve.
  • 3-in-1 Femoral Nerve Block: At the level of the femoral triangle, infiltrate local anesthetic around the femoral nerve while applying pressure distal to the injection site, encouraging local anesthetic to track superiorly to block the femoral, lateral femoral cutaneous, and obturator nerves.

Figure 1. Lower limb peripheral nerve sensory distribution.5 Circled in red are the nerves blocked using the fascia iliaca technique. Cutaneous distribution of the obturator nerve is not depicted but consists of a small area on the proximal medial thigh.

Technique

Table 1. Supplies and equipment for performing a fascia iliaca nerve block

Table 2. Steps to complete a fascia iliaca nerve block6

Table 3. One person technique  – Steps to complete a fascia iliaca nerve block

Figure 2. Video demonstrating the sonoanatomy of the right femoral triangle. From lateral to medial, femoral nerve, artery and vein (NAVel), labeled with yellow, red, and blue arrows, respectively.

Figure 3. Sonoanatomy of the right femoral triangle, transverse view for the fascia iliaca nerve block.

Figure 4. Sonoanatomy of the right femoral triangle demonstrating ultrasound-guided needle placement using an in-plane technique. Note two pops should be felt as the needle crossed the two fascial planes.

 

For a visual review of these steps and ultrasonographic landmarks, please see the following videos and webpage by EM Ottawa, 5 Minute Sono, and NYSORA:

EM Ottawa

5 Minute Sono

NYSORA

Ultrasound-Guided Fascia Iliaca Block

 

Complications

Serious complications of this procedure are rare, but present.

  • Local Anesthetic Systemic Toxicity (LAST) as a complication of inadvertent intravenous or intra arterial anesthetic injection.7
    1. Incidence is 8 – 30 in 100,0008
    2. Manifestations typically occur within 20 minutes of injection (although onset can be as late as >1 hr) and are primarily neurologic and cardiovascular in nature. Neurologic effects include perioral numbness, metallic taste, mental status change or anxiety, muscle twitches and visual changes, followed by loss of consciousness and seizure. Cardiovascular effects are hypertension and tachycardia followed by arrhythmias, bradycardia, hypotension and cardiac arrest.
    3. Treatment is with intravenous lipid emulsion therapy (Intralipid 20%) 1.5 mL/kg bolus followed by 0.25 mL/kg/min, Maximum total dose 12 mL/kg. Contact your poison control centre if you suspect LAST.
    4. Prior to performing a fascia iliaca block, confirm availability of intralipid within your department to be used in the event of this rare complication.
  • Femoral Nerve injury secondary to intrafascicular injection
    1. Incidence 2-30/100,0008
    2. Most symptoms of paresthesias, numbness, and weakness resolved after several months in the event of this complication8
  • Other complications include infection, nerve block failure, injury secondary to numbness/weakness of limb, and allergy to the local anesthetic.

 

Take Home Message

Femoral nerve blocks are recommended for hip and femoral fractures to reduce pain and opioid analgesia requirements. Given that poor pain control and opioid analgesia are risk factors for delirium in elderly patients, hip blocks may also reduce rates of delirium (further study required). A fascia iliaca block with 20 cc of 0.5% bupivacaine is a well described technique with very few contraindications. To reduce the risk of complications, these blocks should be completed using sterile technique under ultrasound guidance with the help of an assistant. Hip broke? Hip block.

 

 

References

  • Ritcey B, Pageau P, Woo M, Perry J. Regional Nerve Blocks For Hip and Femoral Neck Fractures in the Emergency Department: A Systematic Review. CJEM 2015;18(1):37-47.
  • Hwang U, Richardson LD, Sonuyi TO, Morrison RS. The effect of emergency department crowding on the management of pain in older adults with hip fractures. J Am Geriatr Soc. 2006;54(2):270-5.
  • Morrison RS, Magaziner J, Gilbert M, et al. Relationship between pain and opioid analgesics on the development of delirium following hip fracture. J Gerontol A Biol Sci Med Sci 2003;58(1):76-81.
  • Erak M, EM Ottawa Grand Rounds. Ah, that feels better! The Use of Nerve Blocks in the ED. 2016. https://emottawablog.com/2016/10/ah-that-feels-better-the-use-of-nerve-blocks-in-the-ed/. Accessed July 25, 2020.
  • Gray H. 1918. Nerve supply of the leg. Anatomy of the Human Body. Image retrieved from https://en.wikipedia.org/wiki/Nerve_supply_of_the_human_leg. Accessed July 24, 2020
  • Woo M. How to perform the Ultrasound Guided Femoral Nerve Block. EM Ottawa. 2018. https://youtu.be/_OugsPA4rxY Accessed July 25, 2020.
  • Warren L, Pak A. Local anesthetic systemic toxicity. UpToDate. 2019. uptodate.com/contents/local-anesthetic-systemic-toxicity. Accessed July 25, 2019.
  • Helman, A, Morgenstern, J, Spiegel, R, Lee, J. Regional Nerve Blocks for Hip Fractures. Emergency Medicine Cases. August, 2018. https://emergencymedicinecases.com/regional-nerve-blocks-hip-fractures/. Accessed July 25, 2020.
  • Haines L, Dickman E, Ayvazyan S, et al. Ultrasound-guided fascia iliaca compartment block for hip fractures in the emergency department. J of Ultrasound in Emergency Medicine 2012;43(4):692-697.

 

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Ear Foreign Body Removal

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Ear Foreign Body Removal

Resident Clinical Pearl (RCP) May 2020

Dr. Sultan Alrobaian (PEM Fellow and Dalhousie PoCUS Fellow, Saint John, NB, Canada)

Reviewed by Dr. David Lewis

Introduction

  • Most patients with ear Foreign Bodies (FB) are children, adults can also present with ear FB
  • The most common objects removed include beads, pebbles, tissue paper, small toys, popcorn kernels, and insects
  • Diagnosis is often delayed because the causative event is usually unobserved or the symptoms are nonspecific
  • Most of the patients with ear FBs were asymptomatic at presentation, other patients presented with otalgia, bleeding from the ear, otorrhea, tinnitus, hearing loss, a sense of ear fullness or symptoms of otitis media
  • Successful removal depends on several factors, including location of the foreign body, type of material and patient cooperation
  • Visualization of a foreign body on otoscopy confirms the diagnosis, the other ear and both nostrils should also be examined closely for additional foreign bodies.

Clinical Anatomy

© 2020 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Equipment

  • Multiple options exist for removal of external auditory canal foreign bodies
  • Which piece of equipment to use will be influenced by the type of FB, the shape of the FB, the location of the FB and the cooperativeness of the patient

Timing

  • The type of foreign body determines the timing for removal
  • Button batteries, live insects and penetrating foreign bodies warrant urgent removal

Indications for consultation or referral to a specialist

  • Button battery
  • Potentially penetrating foreign bodies
  • Foreign body with evidence of injury to the external ear canal (EAC), tympanic membrane, middle ear, vestibular symptoms or marked pain

Technique

1 – Irrigation

  • This technique is used for small inorganic objects or insects
  • Irrigation is often better tolerated than instrumentation and does not require direct visualization
  • Contraindicated in patients with tympanostomy tubes, perforated tympanic membranes or button battery because the potential for caustic injury.
  • An angiocatheter or section of tubing from a butterfly syringe
  • Using body temperature water, retract the pinna, and squirt water superiorly in the external auditory canal, behind the FB

© 2020 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

2 – Instrumentation under direct visualization

  • Instrumentation can be painful and frequently warrants procedural sedation in young children or other uncooperative patients
  • General anesthesia may be required to ensure safe removal
  • Restrain if needed for safety

  • Commonly used pieces of equipment are curettes, alligator forceps, and plain forceps. Other equipment options include using a right angle hook, balloon catheter, such as a Fogarty catheter

  • Used in conjunction with the operating head of an otoscope
  • The pinna should be retracted, and the FB visualized
  • When using forceps, the FB can be grasped and removed

  • Both curettes and right angle hooks should be gently maneuvered behind the FB and rotated so the end is behind the FB, which can then be pulled out

© 2020 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

3 – Suction

  • This should be performed with a soft suction tipped catheter that has a thumb controlled release valve
  • Insert the suction against the FB under direct visualization and then activate the suctions and remove the FB

© 2020 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

4 – Cyanoacrylate

  • Apply a small amount of cyanoacrylate or skin glue to the blunt end of a cotton-tipped applicator
  • Insert it against the FB under direct visualization and hold in place until the glue dries
  • Slowly and carefully withdraw

5 – Insect removal

  • The first step is to kill the insect with mineral oil followed by lidocaine
  • Once the insect is neutralized, it can be removed by any of the above methods

SUMMARY

  • Foreign bodies of EAC frequently occur in children six years of age and younger
  • Patients with foreign bodies of the EAC are frequently asymptomatic
  • Button batteries , penetrating foreign bodies or injury to the EAC should undergo urgent removal by an otolaryngologist.
  • With adequate illumination, proper equipment, and sufficient personnel, many EAC foreign bodies can be removed

REFERENCES

1.Lotterman S, Sohal M. Ear Foreign Body Removal. [Updated 2019 Jun 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459136/

2.https://www.uptodate.com

3.Heim S W, Maughan K L. Foreign bodies in the ear, nose, and throat. Am Fam Physician. 2007;76(08):1185–1189. [PubMed] [Google Scholar]

4.Awad AH, ElTaher M. ENT Foreign Bodies: An Experience. Int Arch Otorhinolaryngol. 2018;22(2):146–151. doi:10.1055/s-0037-1603922

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PoCUS in COVID

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Point of Care Ultrasound (PoCUS) during the Covid-19 pandemic – Is this point of care tool more efficacious than standard imaging?

Resident Clinical Pearl (RCP) May 2020

Dr. Colin Rouse– (PGY-3  CCFP Emergency Medicine) | Dalhousie University

and Dr. Sultan Alrobaian (Dalhousie PoCUS Fellow, Saint John, NB, Canada)

Reviewed by Dr. David Lewis

 

Case

A 70 year of woman present to the ED with a history of fever, cough and dyspnoea. After a full clinical assessment (with appropriate PPE), Lung PoCUS is performed.

Introduction

The Covid-19 Pandemic has created the largest international public health crisis in decades. It has fundamentally changed both societal norms and health care delivery worldwide. Changes have been implemented into resuscitation protocols including ACLS to prioritise appropriate donning of personal protective equipment (PPE) and consideration of resuscitation appropriateness prior to patient contact.1 Equipment has been removed from rooms to limit cross-contamination between patients. In this Pearl we will explore why PoCUS should not be discarded as an unnecessary tool and should be strongly considered in the assessment of a potential Covid Patient.

Disclaimer: Given the novel nature of CoVid-19 there is a lack of RCT data to support the use of PoCUS. These recommendations are based solely on expert opinion and case reports until superior evidence becomes available.

Potential Benefits of PoCUS

  • Lung PoCUS has increased sensitivity compared to conventional lung X-ray for known lung pathologies such as CHF4 and Pneumonia5 with similar specificities. Given that Pneumonia is the most common complication of Covid-19 it may help diagnose this complication in patients who have a normal CXR.
  • PoCUS can be performed by the assessing physician limiting the unnecessary exposure to other health care providers such and Radiologic Technologists and other staff in the diagnostic imaging department.
  • Lung PoCUS is low cost, repeatable and available in rural settings
  • Once pneumonia is diagnosed other potential complications can be sought including VTE and cardiovascular complications.

The assessment of the potential Covid-19 patient.

First one must consider the potential risk for coronavirus transmission at each patient encounter and ensure proper PPE2 for both oneself and the PoCUS device3.

Lung Ultrasound in the potential Covid-19 Patient

Technique

  • Appropriate level PPE
  • A low-frequency (3–5 MHz) curvilinear transducer
  • Set Focus to Pleural Line and turn off machine filters (e.g THI) to maximize artifacts
  • Scanning should be completed in a 12-zone assessment6
    • 2 anterior windows
    • 2 lateral windows
    • 2 posterior windows

Findings7

Mild Disease

  • Focal Patchy B-lines in early disease/mild infection (May have normal CXR at this point)
  • Areas of normal lung

 

Moderate/Severe Disease – Findings of bilateral Pneumonitis

  • B-lines begin to coalesce (waterfall sign)
  • Thickened and irregular pleura
  • Subpleural Hypoechoic consolidation      +/- air bronchograms

 

Other Covid-19 Pearls

  • Large/Moderate Pleural Effusion rarely seen in Covid-19 (consider another diagnosis) – Small peripleural effusions are common in COVID
  • The virus has a propensity for the base of the posterior lung windows and it imperative to include these views in your assessment.

Example COVID PoCUS Videos8

Confluent B Lines and small sub pleural consolidation

 

Patchy B lines and Irregular pleura

 

Irregular pleura

 

Air Bronchogram

CT & ultrasonographic features of COVID-19 pneumonia9

It has been noted that lung abnormalities may develop before clinical manifestations and nucleic acid detection with some experts recommending early Chest CT for screening suspected patients.10 Obviously there are challenges with this recommendation mainly regarding feasibility and infection control. A group of researchers in China compared Ultrasound and CT findings in 20 patients with COVID-19. Their findings are summarized in the table below:

Their conclusion was that ultrasound has a major utility for management of COVID-19 due to its safety, repeatability, absence of radiation, low cost and point of care use. CT can be reserved for patients with a clinical question not answered by PoCUS. CT is required to assess for pneumonia that does not extend to the pleura. Scatter artifact from aerated lung obscures visualization of deep lung pathology with PoCUS. When PoCUS is sufficient it can be used to assess disease severity at presentation, track disease evolution, monitor lung recruitment maneuvers and prone positioning and guide decisions related to weaning of mechanical ventilation.

Learning Points

  • Lung PoCUS is helpful in the initial assessment of the suspected or known COVID19 Patient
  • Lung PoCUS may reveal pathology not visible on CXR
  • Lung PoCUS can provide insight into COVID19 disease severity
  • Lung PoCUS is a useful tool to track disease progression in COVID19

Lung PoCUS in COVID Deep Dive

Deep Dive Lung PoCUS – COVID 19 Pandemic

 

 

References

  1. Edelson, D. P., Sasson, C., Chan, P. S., Atkins, D. L., Aziz, K., Becker, L. B., … & Escobedo, M. (2020). Interim Guidance for Basic and Advanced Life Support in Adults, Children, and Neonates With Suspected or Confirmed COVID-19: From the Emergency Cardiovascular Care Committee and Get With the Guidelines®-Resuscitation Adult and Pediatric Task Forces of the American Heart Association in Collaboration with the American Academy of Pediatrics, American Association for Respiratory Care, American College of Emergency Physicians, The Society of Critical Care Anesthesiologists, and American Society of …. Circulation.
  2. COVID-19 – Infection Protection and Control. http://sjrhem.ca/covid-19-infection-protection-and-control/
  3. Johri, A. M., Galen, B., Kirkpatrick, J. N., Lanspa, M., Mulvagh, S., & Thamman, R. (2020). ASE Statement on Point-of-Care Ultrasound (POCUS) During the 2019 Novel Coronavirus Pandemic. Journal of the American Society of Echocardiography.
  4. Maw, A. M., Hassanin, A., Ho, P. M., McInnes, M., Moss, A., Juarez-Colunga, E., Soni, N. J., Miglioranza, M. H., Platz, E., DeSanto, K., Sertich, A. P., Salame, G., & Daugherty, S. L. (2019). Diagnostic Accuracy of Point-of-Care Lung Ultrasonography and Chest Radiography in Adults With Symptoms Suggestive of Acute Decompensated Heart Failure: A Systematic Review and Meta-analysis. JAMA network open, 2(3), e190703. https://doi.org/10.1001/jamanetworkopen.2019.0703
  5. Balk, D. S., Lee, C., Schafer, J., Welwarth, J., Hardin, J., Novack, V., … & Hoffmann, B. (2018). Lung ultrasound compared to chest X‐ray for diagnosis of pediatric pneumonia: A meta‐analysis. Pediatric pulmonology, 53(8), 1130-1139.
  6. Wurster, C., Turner, J., Kim, D., Woo, M., Robichaud, L. CAEP. COVID-19 Town Hall April 15: Hot Topics in POCUS and COVID-19. https://caep.ca/covid-19-town-hall-april-15-hot-topics-in-pocus-and-covid-19/
  7. Riscinti, M. Macias, M., Scheel, T., Khalil, P., Toney, A., Thiessen, M., Kendell, J. Denver Health Ultrasound Card. http://www.thepocusatlas.com/covid19
  8. Images obtained from. Ultrasound in COVID-19. The PoCUS Atlas. http://www.thepocusatlas.com/covid19
  9. Peng, Q., Wang, X. & Zhang, L. Findings of lung ultrasonography of novel corona virus pneumonia during the 2019–2020 epidemic. Intensive Care Med (2020). https://doi.org/10.1007/s00134-020-05996-6
  10. National Health Commission of the people’s Republic of China. Diagnosis and treatment of novel coronavirus pneumonia (trial, the fifth version)[EB/OL]. (2020-02-05)[2020-02-06]. http://www.nhc.gov.cn/yzygj/s7653p/202002/3b09b894ac9b4204a79db5b8912d4440.shtml
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Superficial can also be Deep – Superficial Thrombophlebitis

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Superficial Thrombophlebitis – an approach to diagnosis and management

Resident Clinical Pearl (RCP) May 2020

Dr. Devon Webster – PGY2 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. David Lewis

 

Case

Claude Virchow is a 59-year-old gentleman who presents to your emergency department complaining of pain to his medial right leg. 2 days ago, he bumped his knee and since then, has developed a hard, rope-like, tender swelling along the inside of his knee. On exam, you see the following image and he winces as you palpate along the indurated cord.

Figure 1 Source

In the next bed over, is a 39-year-old man presents with similar induration along his antecubital fossa bilaterally. He has a history of IVDU and was seen a week prior for the same problem. He is back as the indurated areas seem to be extending and his pain is worsening despite abstinence from injection and adherence to conservative measures. There are no signs of infection.

What are your recommendations?

 

What is superficial thrombophlebitis?

  • Thrombus formation in a superficial vein with associated inflammation of the vessel wall.
  • Typically involves the lower extremities with greater saphenous vein involvement in 60-80% of cases
  • Less commonly, affects the superficial veins of the upper extremities, neck (external jugular) or causes ‘Mondor’s syndrome,’ a superficial thrombophlebitis of the anterior chest wall.

 

Why does it matter?

  • In patients with superficial venous thrombosis (ST) >5cm in length, approximately 20% have a concomitant DVT and 4% have a PE
  • Some patients with ST may be candidates for anticoagulation

 

Anatomy review:

  • Lower extremity:
    • Superficial venous system: primarily comprised of the greater and lesser saphenous veins (aka long and short saphenous veins)
    • Deep venous system: anterior tibial, peroneal and femoral veins.
    • The saphenofemoral junction (SFJ) forms the connection between the deep and superficial systems.
  • Upper extremity:
    • Superficial: digital, metacarpal, cephalic, basilic and median veins
    • Deep: radial, ulnar, brachial, axillary, subclavian veins

Figure 2 Source

 

Figure 3 Source

 

Risk Factors:

  • The same as VTE! E.g. malignancy, trauma, hormone therapy, etc.
  • Varicose veins account for up to 90% of cases of lower limb ST and risk factors for varicose veins (e.g. lack of physical activity, venous stasis) increase the risk of ST.
  • Risk factors suggesting concomitant DVT when ST is also present: age >60, male sex, bilateral ST, presence of systemic infection, absence of varicose veins.
  • Mondor’s: often associated with breast reconstruction

 

History & Physical:

  • The patient may describe a painful, erythematous, swollen, hard vein that is tender to touch.
  • Inquire about symptoms and looks for signs suggestive of DVT, PE or secondary infection.
  • Low grade fever may be present in uncomplicated ST but higher fevers and erythema extending beyond the borders of the vein suggest suppurative ST.
  • Ask about risk factors as per VTE though may be idiopathic.
  • Note that a D-Dimer is not a helpful tool for distinguishing ST from DVT

 

Which patients with superficial thrombophlebitis require ultrasonography?  

  • Lower limb:
    • US recommended for MOST patients
    • If clinical picture is not obvious
    • If suspected concomitant DVT
    • ST is above the knee, especially if above mid-thigh
    • ST is in the upper calf near perforating veins in the popliteal fossa
  • Upper limbs:
    • Patients with ST of veins approaching the deep venous system (basilic, cephalic veins) that do not respond to conservative measures or have progression of their symptoms should undergo duplex US to evaluate for clot extension.
  • Mondor’s (anterior chest): US rarely required

 

Key points on ultrasound report:

  • For lower extremities, assess proximity to the saphenofemoral junction (SFJ) and the length of the ST. Specifically determine if ST is >5cm in length or if <3cm proximity to the SFJ.
  • Rule out DVT
  • Rule out other causes of pain (e.g. popliteal cyst, muscle mass)

 

Treatment:

  • General measures:
    • Non-pharmacologic
      • Elevate extremity
      • Apply continuous, moist heat x72 hrs
      • Remove any offending solution or catheter
      • Encourage early mobility
    • Pharmacologic
      • Tylenol, NSAIDs
      • Topical NSAIDs
      • Do not give antibiotics unless signs of infection.
  • Upper extremity ST
    • Anticoagulation?
      • Limited data to guide management!
      • Some experts would suggest consideration of anticoagulation for patients with ST that are at risk for DVT (e.g. ST in veins in close proximity to deep veins).
      • May consider anticoagulation for pts with persistent symptoms despite conservative mgmt. (e.g. ongoing excessive pain and swelling) as anticoagulation is effective in alleviating symptoms, especially if ST precipitated by malignancy.
      • However, when considering treatment, important to note that PE from upper extremity ST is rare!

 

  • Mondor’s (chest well) ST
    • Self-limited. Conservative management.

 

  • Lower limb ST (see algorithm below):
    • ST within 3 cm of saphenofemoral junction: therapeutic dose of anticoagulation for 3 months
      • g.: rivaroxaban 15mg PO BID x3 weeks, followed by 20 mg OD, warfarin, full dose LMWH
    • ST >/5cm in length but >3 cm from saphenofemoral junction: prophylactic doses of anticoagulation
      • g.: rivaroxaban 10mg PO OD, dalteparin 5,000U SC q24hrs
    • ST <5cm, >3 cm from saphenofemoral junction but with severe symptoms or risk factors for extension: prophylactic doses of anticoagulant for up to 45 days
    • ST <5cm, >3cm from saphenofemoral junction, no severe symptoms or risk factors: conservative treatment

Figure 4 Approach to lower limb superficial thrombophlebitis. Source: Thrombosis Canada

 

 

Disposition & Prognosis:

  • Patients with extensive or recurrent ST should be referred to a specialist
  • Isolated lower limb uncomplicated ST not affecting the great or small saphenous veins and no risk factors for DVT: organize repeat clinical examination in 7-10 days to assess for resolution or progression. If symptoms or exam worsens, order ultrasound.
  • Resolution of ST may take up to 2-6 weeks.

 

Bottom Lines:

  • Superficial thrombophlebitis may be associated with DVT in up to 20% of cases and PE in up to 4%.
  • Ultrasound should be organized for most patients with lower limb ST and for some patients with upper extremity ST (progressive symptoms and concern for extension to deep venous system)
  • Patients with lower limb ST within 3 cm of the saphenofemoral junction should be treated with full dose anticoagulants. Those with ST >5 cm in length but farther from the SFJ, with severe symptoms or at high risk for clot extension should be treated with lower doses of anticoagulant.
  • Consider anticoagulants for patients with upper extremity ST with severe persistent symptoms not responding to conservative measures to alleviate their discomfort.
  • Patients with uncomplicated lower limb ST should have follow up organized within 7-10 days.

 

References:

  1. Chopra, V. Uptodate. Catheter-related upper extremity venous thrombosis [internet]. 2019 Nov 14. Available from: https://www.uptodate.com/contents/catheter-related-upper-extremity-venous-thrombosis?search=Catheter%20related%20upper%20extremity%20venous%20thrombosis&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
  2. Scovell, S. Uptodate. Phlebitis and thrombosis of the superficial lower extremity veins [internet]. 2019 Oct 3. Available from: https://www.uptodate.com/contents/phlebitis-and-thrombosis-of-the-superficial-lower-extremity-veins?search=Phlebitis%20and%20thrombosis%20of%20the%20superficial%20lower%20extremity%20veins&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
  3. Thrombosis Canada. Superficial Thrombophlebitis, Superficial Vein Thrombosis [internet]. 2019 Mar 25. Available from: https://thrombosiscanada.ca/clinicalguides/?search=superficial%20thrombophlebitis#
  4. Thrombosis Canada. Deep Vein Thrombosis (DVT): Treatment [internet]. 2016 May 19. Available from: http://thrombosiscanada.ca/wp-content/uploads/2016/05/3_Deep-Vein-Thrombosis-Treatment-2016May19-FINAL.pdf
  5. Mustonen, P. EBM Guidelines. Superficial venous thrombophlebitis [internet]. 2020 Mar 16. Available from: https://www.ebm-guidelines.com/ebmg/ltk.free?p_artikkeli=ebm00920
  6. Venes, D. Taber’s Medical Dictionary. Phlebitis [Internet]. Available from: https://www.tabers.com/tabersonline/view/Tabers-Dictionary/749144/all/phlebitis.
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An approach to removing hair tourniquets

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Getting out of a hairy situation – an approach to removing hair tourniquets 

Resident Clinical Pearl (RCP) May 2020

Renee Amiro – PGY3 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. Kavish Chandra

 

A two-month-old male presents with his mother to the emergency department with two tightly wound hairs around his fourth and fifth toes. He is visibly upset and crying excessively. His mother says that his toes looked like this when he woke up this morning. He is otherwise well and has had his two-month immunizations.

His toes look like this:

 

 

Hair tourniquet syndrome

Definition – a tightly wound hair, thread, rubber band that is wrapped around an appendage and causes impaired blood flow.

Why this is bad – the constriction causes edema which restricts venous blood flow causes more edema which then impedes arterial blood flow and that can cause ischemia and if left undetected could cause amputation.

Most common appendages involved – Toes, external genitalia, fingers

Most common presenting symptom – excessively crying young child or swollen appendage found by mom or dad.

 

Management

Goal is to remove the restricting band ASAP!

Remember to treat pain! Using emla gel on the digit prior to any manipulation and use other analgesics as you deem appropriate. Remember the use of sugar for pain management in babies.

In all management types- ensure you have gotten all of the hair and have released the constricted band completely.

  1. Try and unwind the hair!
  • Works best if caught early
  • You can use a cutting suture needle to try and get underneath the hair and release it.

 

  1. Depilatory Cream
  • Apply Nair to the affected toe and allow 2-8 minutes to see if the hair dissolves.
  • Should not be used on open wounds and can cause skin irritation.
  • Does not dissolve cotton, polyester or rayon threads.

 

  1. Dorsal Slit Procedure (for digits)
  • Do a slit on the dorsal surface along the long axis of the digit through the area of constriction down to the bone to ensure release of tourniquet.
  • Lateral aspect contains nerves and blood vessels and should be avoided. You may cut the tendon doing a dorsal slit along the long axis- but you won’t affect function of the digit.
  • Ensure that the patient has close follow up to ensure healing and complete resolution of the tourniquet.

 

The bottom line

  1. Think of this diagnosis and LOOK for it in a young child brought to the ED with “excessive crying”
  2. Ensure adequate pain management prior any invasive removal of the tourniquet.
  3. Move quickly down the list to the dorsal slit procedure (for digit) if deeply embedded hair with significant edema or tissue compromise.

 

Copyedited by Kavish Chandra

 

References

Lin, Michelle 2012. https://www.aliem.com/trick-of-trade-hair-tourniquet-release/

Fox, Sean 2015. https://pedemmorsels.com/hair-tourniquet/

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Modified Valsalva maneuver in the treatment of SVT – REVERT Trial

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Falling heels over head: you make my heart skip a beat

Resident Clinical Pearl (RCP) November 2019

 

Patricia Marks – PGY1 (FRCPC) Dalhousie University, Halifax, NS

Reviewed by Dr David Lewis

 

 

Introduction:

Supraventricular tachycardias (SVT) is a common presentation to the emergency room, and most patients will require treatment with adenosine or electrical cardioversion, as vagal maneuvers are less than 20% of the time in clinical practice. Adenosine and electrical cardioversion both require additional hospital resources, and adenosine is poorly tolerated by patients.

 

The REVERT trial published in 2015 in the Lancet by Appelboam et al. proposed a modified Valsalva maneuver in the treatment of SVT.  The study was a multicentre randomized control trial in England involving 433 patients with stable SVT. According to an intention to treat analysis, the authors found a 43% success rate of conversion to sinus rhythm with the modified Valsalva maneuver compared to 17% with standard Valsalva. No significant dangerous adverse effects occurred in this study.

 

Modified Valsalva: The How-To

  1. Patient identification:

    1. Is my patient eligible for Valsalva?
      • Stable SVT
      • Age > 18 years
      • Able to perform Valsalva
      • Able to lie flat and have legs lifted
    2. Contraindications:
      • Unstable or indication for immediate cardioversion
      • Atrial fibrillation, atrial flutter, sinus tachycardia
      • Recent MI
      • Aortic stenosis
      • Glaucoma
      • Retinopathy
      • Third trimester of pregnancy

  2. Materials

      • 10cc syringe
      • Manometer (optional)

  3. Performing the modified Valsalva maneuver

    1. Position the patient in a semi-recumbent position (45º)
    2. Instruct the patient to blow into the tip of a 10cc syringe for 15 seconds. The patient should be targeting a pressure reading on the manometer of 40mmHg, or blowing hard enough to move the plunger tip*
    3. Lower the patient flat and passively raise their legs to a 45º angle for 15 seconds
    4. Return the patient to a semi-recumbent position for an additional 45 seconds
    5. Assess the rhythm
    6. Repeat x1 if unsuccessful before moving on to adenosine or electrical cardioversion (provided the patient remains stable)

*The REVERT trial used a manometer to measure 40mmHg of pressure, however Smith and Boyle have demonstrated that 40mmHg of pressure is generated when a patient is instructed to blow into a 10cc syringe until the plunger moves

Image obtained from https://www.ecgmedicaltraining.com/wp-content/uploads/2016/06/REVERT-Trial-SVT.jpg on February 21, 2020.

 

Watch the REVERT authors perform the maneuver:

 

 

Benefits of this method:

  • Easy to instruct patients; can try at home
  • Higher success rate than standard Valsalva
  • Similar ED length of stay compared to standard Valsalva
  • Less patients require adenosine or cardioversion

Additional considerations

  • No formal studies exist for pediatric patients, however a recent case report by Rayburn and Wagers did demonstrate successful conversion to sinus rhythm with this maneuver

 

Bottom Line 

In adults with stable SVT, the modified Valsalva maneuver as published in the REVERT trial achieves a high rate of conversion to sinus rhythm with a NNT of 3.8 and without significant adverse effects. In patients without contraindications, the modified Valsalva maneuver is a low-cost and easy to teach strategy that should be trialled to convert patients in SVT prior to adenosine or electrical cardioversion.

 

 

References

  • Appelboam A, Reuben A, Mann C, Gagg J, Ewings P, Barton A, Lobban T, Dayer M, Vickery J, Benger J; REVERT trial collaborators. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. Lancet. 2015 Oct 31;386(10005):1747-53. doi: 10.1016/S0140-6736(15)61485-4.
  • Rayburn D, Wagers B. Modified Valsalva Maneuver for Pediatric Supraventricular Tachycardia. Pediatr Emerg Care. 2020 Jan;36(1):e8-e9. doi: 10.1097/PEC.0000000000002023
  • Smith G, Boyle MJ. The 10 mL syringe is useful in generating the recommended standard of 40 mmHg intrathoracic pressure for the Valsalva manoeuvre. Emerg Med  Australas. 2009 Dec;21(6):449-54. doi: 10.1111/j.1742-6723.2009.01228.x
  • Smith GD, Fry MM, Taylor D, Morgans A, Cantwell K. Effectiveness of the Valsalva Manoeuvre for reversion of supraventricular tachycardia. Cochrane Database of Systematic Reviews 2015, Issue 2. Art. No.: CD009502. DOI: 10.1002/14651858.CD009502.pub3
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PoCUS assisted lumbar puncture

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PoCUS assisted lumbar puncture

Resident Clinical Pearl (RCP) November 2019

Allyson Cornelis – PGY3 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. Kavish Chandra

 

Lumbar punctures (LPs) are an essential emergency physician skill. Indications including assessing for serious causes of headaches such as meningitis and subarachnoid hemorrhage.

Various limitations to successful lumbar puncture include a large body habitus, arthritic spines, and altered spinal anatomy. Furthermore, this leads to increased procedural risks (failed attempts, pain, hematoma formation, infection and traumatic tap leading to difficult CSF interpretation)

Traditional lumbar puncture

The traditional way to perform a LP is using surface landmarks. The superior iliac crests are identified and a line is drawn across the back to connect them. This helps in identifying L3/L4 space. This is deemed a safe place for LP as the spinal cord ends above this.

 

PoCUS guided lumbar puncture

Ultrasound has become a common tool used in the emergency department for assessment of patients and to assist in certain procedures. Lumbar puncture is one procedure where ultrasound has potential to increase success.1,2

 

The evidence

Meta-analysis of PoCUS guided LPs in the ED with adult and pediatric patients showed improved success rates (NNT 11) and fewer traumatic taps (NNT 6), less pain and less time to obtaining a CSF sample.4

Similar studies in neonates and infants showed reduced LP failure and traumatic taps in the PoCUS guided LP group.5

 

The procedure

The goal of the LP is to place a needle into the subarachnoid space where the CSF can be sampled. At the safe level, LP needle moves in-between the caudal equina.

Adapted from Tintinalli’s Emergency Medicine : A Comprehensive Study Guide, 8th ed.

 

Landmark based LP (briefly)

Place the patient in the lateral decubitus or seated position, allowing them to curve their spine and open the space between adjacent spinous processes

Identify the superior iliac spines and connect a line between the two iliac spines across the back (this should intersect the L4 spinous process).

LP can be safely performed in the L3/4 or L4/5 interspaces. During the procedure, the needle is directed towards the patient’s umbilicus.

 

PoCUS guided LP2,3,6

Identify the midline

  • Position patient either sitting with a curved lumbar spine or laying down in a lateral decubitus position with back perfectly perpendicular to the table and not angled at all. Using either a linear or curvilinear probe (curvilinear is recommended for obese patients), in the transverse plane start at the sacrum which will appear as a bright white line.
  • Move the transducer towards the patient’s head while maintaining a transverse orientation. A space will appear followed by a smaller bright curved line with posterior shadowing, this is the L5 spinous process.

  • Center the spinous process in your screen, and mark the location with a surgical marking pen.

  • Continue moving the transverse transducer cephalad, you will see the interspaces (lack of spinous process and the accompanying shadow and possibly evidence of the articular processes which appear as bat ears).
  • Connect each mark identifying the spinous processes—this marks the midline of the spine

 

Identify the interspaces

  • Turn the transducer into the saggital plane with the indicator towards the patient’s feet (to line up the patient’s head with the view on the screen).

  • Place transducer along the spinal line you marked, starting at the top, and identify the spinous processes and the interspaces.
  • Place the interspace in the center of the transducer and mark with a line. Move caudally, identifying the remaining interspaces.

  • Connect these lines to your spinal line. Where they intersect are the ideal locations for needle entry.

 

The bottom line

Ultrasound is a tool being utilized more often in clinical practice, including in the emergency department. Research shows that its use in obtaining lumbar punctures has potential benefits, including more success in obtaining a CSF sample and less traumatic taps, with minimal harms or downsides to use of the ultrasound.

 

Copyedited by Kavish Chandra

 

Resources:

  1. Ladde JG. 2011. Central nervous system procedures and devices. In: Tintinalli JE, Stapczynski JS, Cline DM, Ma OJ, Cydula RK, Meckler GD, editors. Tintinalli’s emergency medicine: Acomprehensive study guide. 7th ed. China: McGraw-Hill Companies, Inc. p 1178-1180.
  2. Millington SJ, Restrepo MS, Koenig S. 2018. Better with ultrasound: Lumbar puncture. Chest 2018. 154(5): 1223-1229.
  3. Ladde JG. 2020. Central nervous system procedures and devices. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH, editors. Tintinalli’s emergency medicine: A comprehensive study guide. 9th ed. New York, NY: McGraw-Hill: http://accessmedicine.mhmedical.com.ezproxy.library.dal.ca/content.aspx?bookid=2353&sectionid=221017819. Accessed November 17,2019.
  4. Gottlieb M, Holladay D, Peksa GD. 2018. Ultrasound-assisted lumbar punctures: A systematic review and meta-analysis. Acad Emerg Med. 2019 Jan. 26(1). 85-96.
  5. Olowoyeye A, Fadahunsi O, Okudo J, Opaneye O, Okwundu C. 2019. Ultrasound imaging versus palpation method for diagnostic lumbar puncture in neonates and infants: A systematic review and meta-analysis. BMJ Pediatrics Open. 2019 Mar. 3(1):e000412.
  6. Jarman B, Hoffman B, Al-Githami M, Hardin J, Skoromovsky E, Durham S, et al. Ultrasound and procedures. In: Atkinson P, Bowra J, Harris T, Jarman B, Lewis D, editors. Point of Care Ultrasound for Emergency Medicine and Resuscitation. 1st ed. United Kingdom: Oxford University press; 2019. p. 198-199.
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Color Flow Doppler to Assess Cardiac Valve Competence

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Color Flow Doppler to Assess Cardiac Valve Competence

Resident Clinical Pearl (RCP) April 2019

Dr. Scott Foley – CCFP-EM PGY3 Dalhousie University, Halifax NS

Reviewed by Dr. David Lewis

 

 

Background:

When colour Doppler is initiated, the machine uses the principals of the Doppler effect to determine the direction of movement of the tissues off which it is reflecting.

The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to a wave source. It was named after the Austrian physicist Christian Doppler who first described the phenomenon in 1842. The classic example is the change in pitch of a siren heard from an ambulance as it moves towards and away from an observer.

These principles are applied to POCUS in the form of colour Doppler where direction of flow is reflected by the colour (Red = moving towards the probe, Blue = moving away from the probe), and the velocity of the flow is reflected by the intensity of the colour (brighter colour = higher velocity).
*Note: the colour does not represent venous versus arterial flow.

 

The use of colour Doppler ultrasound can be useful in the emergency department to determine vascular flow in peripheral vessels as well as through the heart. It is one way to determine cardiac valve competency by focusing on flow through each valve.

 

Obtaining Views:

To optimize valve assessment, proper views of each valve must be obtained. It is best to have the direction of the ultrasound waves be parallel to the direction of flow. External landmarks for the views used are seen below:

  • Mitral Valve and Tricuspid Valve: The best view for each of these is the apical 4 chamber view. If unable to obtain this view, the mitral valve can be seen in parasternal long axis as well.
  • Aortic Valve: The best view is the apical 5 chamber or apical 3 chamber but are challenging to obtain. Instead, the parasternal long axis is frequently used.
  • Pulmonic Valve: Although not commonly assessed, the parasternal short axis can be used.
  • Visit 5minutesono.com for video instruction on obtaining views

Parasternal long axis: MV, AV

Parasternal short axis: PV, TV

Apical 4 chamber: TV, MV

 

Assessing Valvular Competency:

How to examine valvular competency:

  1. Get view and locate valve in question
  2. Visually examine valve: opening, closing, calcification
  3. Use colour Doppler:
    1. Place colour box over valve (as targeted as possible (resize select box) to not include other valves)
    2. Freeze image and scroll through images frame by frame
    3. Examine for pathologic colour jets in systole and diastole
  4. Estimating severity:
    1. Grade 1 – jet noticeable just at valve
    2. Grade 2 – jet extending out 1/3 of atrium/ventricle
    3. Grade 3 – jet extending out 2/3 of atrium/ventricle
    4. Grade 4 – jet filling entire atrium/ventricle

See video tutorial below for more

Mitral Regurgitation A4C

Tricuspid Regurgitation A4C

Aortic Stenosis PSLA

Bottom line:

Color flow Doppler on POCUS is a straightforward way to assess for valvular competency in the Emergency Department. A more detailed valvular assessment requires skill, knowledge and experience.

 

Useful Video Tutorials:

Mitral Regurgitation

 

Aortic Stenosis vs Sclerosis

Tricuspid Valve

References:

  1. https://www.radiologycafe.com/medical-students/radiology-basics/ultrasound-overview
  2. By Patrick J. Lynch and C. Carl Jaffe – http://www.yale.edu/imaging/echo_atlas/views/index.html, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=21448310
  3. 5minutesono.com
  4. ECCU ShoC 2018 powerpoint, Paul Atkinson, David Lewis
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Shining a light on acute vision loss: PoCUS for the retina

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Shining a light on acute vision loss: PoCUS for retinal pathology

Resident Clinical Pearl (RCP) August 2019

Dr. Devon Webster – PGY2 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. Kavish Chandra

 

It’s a quiet night in RAZ and you pick up your next chart- a 68 year old Ms. Iris Snellen has come in with new onset, painless, monocular vision loss. You pick up the ophthalmoscope to perform fundoscopy, and despite your best attempts, like many ED physicians before you, you see nothing helpful. So instead you pick up your investigative tool of choice, the ultrasound probe, and begin your ocular POCUS exam…

Anatomy and pathophysiology

The retina is composed of multiple layers of neurons that allow for the human eye to convert light energy (photons) into images within the occipital brain. The retina sits on top of the vascular choroid which provides blood flow.

Fundoscopy allows for visualization of the following structures:

  • Optic disc
  • The macula (central, high-resolution, color vision)
  • The fovea (sits centrally in the macula and provides sharp, central vision)
  • The retinal artery and vein

https://stanfordmedicine25.stanford.edu/the25/fundoscopic.html

 

PoCUS is adjunctive test to assess for vision-threatening and common conditions impacting the eye such as retinal detachment (RD), posterior vitreous detachment (VD) and vitreous hemorrhage (VH).

A normal eye should allow you to visualize the following structures:

https://www.nuemblog.com/ocular

In retinal detachment, the retina is separated from the choroid either through formation of a hole in the retina, peeling away from the choroid if attached to the vitreous humour or through edematous infiltration between the two layers. Separation results in rapid ischemia and death of photoreceptors with subsequent vision-loss.

Posterior vitreous detachment is common and occurs secondary liquification of the gel-like vitreous body.

Vitreous hemorrhage can occur secondary trauma, spontaneous retinal tears or vitreous detachment or any cause of retinal neovasculiarzation such as in diabetes.

 

Retinal detachment and the DDx

When assessing your pt, a retinal detachment should be at the top of your list of diagnoses to rule out given that prompt recognition and referral to ophthalmology may be a vision-saving intervention.

On history she may describe the following features of RD:

  • Floaters: may appear as spiderwebs, a large spot that comes and goes that may ‘look like a big fly’ or a showering of many small black dots.
  • Painless monocular vision loss: may present as a ‘curtain descending’ across her vision and/or visual field loss.
  • Flashes: may be easier to see at night or in a dark room (consider turning off the lights in the exam room)

Assess for risk factors for retinal detachment:

  • Myopia (near-sightedness): Major risk factor!
  • Cataract surgery
  • Family history of retinal detachment
  • Diabetes
  • Glaucoma
  • Old age
  • History of posterior vitreous detachment

Physical exam:

  • Assess for changes in visual acuity
  • Assess for loss of visual fields
  • Fundoscopy may reveal advanced detachments however, early detachments are often not visible with direct fundoscopy. Advanced detachments may reveal absence of a red reflex and a billowing retinal flap.
  • Ultrasound!

Your DDx may include:

  • Posterior vitreous detachment
  • Vitreous hemorrhage
  • Ocular migraine
  • CRAO/CRVO
  • Amaurosis fugax

(see below for distinguishing features of the DDx)

 

The PoCUS assessment

Most ED physicians feel more comfortable with their ultrasonography skills over their fundoscopy skills. PoCUS is a fast, portable and radiation-free approach to assessing patients for potential vision-threatening pathology such as retinal detachment. While ultrasonography should not replace ophthalmologic assessment and fundoscopy, it can be used as an additional tool to support your primary diagnosis.

Most recently, Lanham, et al., published a prospective diagnostic study involving 225 patients and 75 ED providers that found POCUS was 96.9% sensitive and 88.1% specific for the diagnosis of retinal detachment1. While studies have varied in whether sensitivity was better than specificity or vice versa, ultimately each study has shown that when trained, emergency providers are quite good at identifying RD by US2,3. In addition to RD, Lanham, et al further found ED providers did well at identifying vitreous hemorrhage (sens 81.9%, sp 82.3%) and vitreous detachment (sens 42.5%, sp 96%).

Get the PoCUS Scan:

  • Place a tegaderm over the eye to protect it from US gel which may be painful. You may consider using topical freezing drops to limit irritation.
  • Use the linear probe and scan through the eye until you are able to visualize the optic nerve, the hypoechoic structure at the back of the eye
  • Have the patient look side to side/up and down as this will accentuate movement of retinal or vitreous pathology.
    1. Retinal detachment: Bright echogenic line that appears to have separated from the posterior eye/choroid and remains tethered to the optic nerve.
    2. Posterior vitreous detachment: Bright echogenic line separated from posterior eye/choroid that is detached from the optic nerve.
    3. Posterior vitreous hemorrhage: Vitreous shows fluid collection with variable echogenicity and ‘washing machine’ appearance.

Jacobsen et al. (2016). WestJEM. 17(2)

 

Differential of painless visual loss

 

Resources:

  1. Lahham S, et al. Point-of-Care Ultrasonography in the Diagnosis of Retinal Detachment, Vitreous Hemorrhage, and Vitreous Detachment in the Emergency Department. JAMA Netw Open. Published online April 12, 20192(4):e192162. doi:10.1001/jamanetworkopen.2019.2162
  2. Kim, D., et al. Test Characteristics of Point-of-care Ultrasound for the Diagnosis of Retinal Detachment in the Emergency Department. Academic Emergency Medicine. 2019;26[1]:16; http://bit.ly/2TEFutH
  3. Vrablik ME, et al. The diagnostic accuracy of bedside ocular ultrasonography for the diagnosis of retinal detachment: a systematic review and meta‐analysis. Ann Emerg Med 2015; 65( 199–203): e1.
  4. Mason, J. (Host). (2019 Jan). C3-Vision Loss-Retinal Detachment [Audio podast]. Retrieved from EMRAP: https://www.emrap.org/episode/c3visionloss/c3visionloss1 .
  5. Arroyo, J. (Jan 2018). Retinal Detachment. Retrieved from Uptodate: https://www.uptodate.com/contents/retinal-detachment
  6. Givre, S., et al. (Feb 2019). Amaurosis fugax (transient monocular or binocular visual loss). Retrieved from Uptodate: https://www.uptodate.com/contents/amaurosis-fugax-transient-monocular-or-binocular-visual-loss?search=painless%20monocular%20vision%20loss&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
  7. Porfiris, G. (2015). ABCs of Emergency Medicine, 14th Edition, Chapter 23: Eye Emergencies.

 

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