A 66 year-old female presented to the Emergency Department with shortness of breath and back pain. She had a known dilated aortic root, which was being followed with repeat CT scans. Given the nature of her presenting complaint, a PoCUS was performed to assess her aorta.
Long Axis Parasternal View:
PoCUS for Cardiac imaging has been studied in the acute care setting; focusing on the assessment for pericardial effusion, chamber size, global cardiac function, and volume status, and cardiac arrest.1
In the setting of acute aortic dissection, further evaluation is often recommended depending on the practitioner’s skill level.2 There have been case reports where ultrasound has been used to assess both Type A and Type B aortic dissections.3–5
In order to assess the aortic root, have the patient in a supine position. Either the phased array or the curvilinear probe can be used depending on examiner’s preference. The probe should be positioned with the marker towards the patient’s right shoulder on the anterior chest to the left of the patient’s lower left sternal border. By tilting the transducer between the left shoulder and right hip, long axis views are obtained at different levels with the goal of identifying four main structures; the aorta, the left atrium, and the right and left ventricles. The parasternal long axis view of our patient is shown in Figure 1, where her aortic root measured 3.83cm.
Figure 1: Parasternal Long Axis View of Heart: Patient’s root diameter was found to be 3.83cm.
More generally, this view can be used to assess left ventricular contractility and the presence of pericardial effusion, which were not present in this patient. She went on to have a confirmatory CT scan where her aortic root was found to be unchanged from her last scan and was 3.8 cm in diameter as assessed by PoCUS.
In Summary:
Although not rigorously studied to assess aortic root dilatation at the bedside, we present a case where PoCUS was reliable in the assessment of the aortic root. There have been other cases of aortic dissection identified by ultrasound in the emergency department setting, however confirmatory studies (either CT scan or formal echocardiography) are still recommended.
References:
Labovitz AJ, Noble VE, Bierig M, et al. Focused cardiac ultrasound in the emergent setting: A consensus statement of the American society of Echocardiography and American College of Emergency Physicians. J Am Soc Echocardiogr. 2010;23(12):1225-1230. doi:10.1016/j.echo.2010.10.005.
Andrus P, Dean A. Focused cardiac ultrasound. Glob Heart. 2013;8(4):299-303. doi:10.1016/j.gheart.2013.12.003.
Perkins AM, Liteplo A, Noble VE. Ultrasound Diagnosis of Type A Aortic Dissection. J Emerg Med. 2010;38(4):490-493. doi:10.1016/j.jemermed.2008.05.013.
Bernett J, Strony R. Diagnosing acute aortic dissection with aneurysmal degeneration with point of care ultrasound. Am J Emerg Med. 2017;35(9):1384.e3-1384.e4. doi:10.1016/j.ajem.2017.05.052.
Kaban J, Raio C. Emergency department diagnosis of aortic dissection by bedside transabdominal ultrasound. Acad Emerg Med. 2009;16(8):809-810. doi:10.1111/j.1553-2712.2009.00448.x.
A 32 year old woman with a history of chronic abdominal pain has been sitting in RAZ, presenting with, predictably, lower abdominal pain. She has been investigated multiple times over, with comprehensive labs, ultrasounds, pelvic exams and a previous CT, all of which have been normal. She carries with her a myriad of diagnoses; chronic abdominal and pelvic pain, IBS, fibromyalgia, depression and anxiety.
On history she reports near constant, left lower quadrant pain over the past 4 months. It is worse when sitting up and lying on her left side. The pain is sharp and she is able to localize the pain with a single fingertip. On history, you elicit no red flags for an intra-abdominal source of her pain. You ask her to lay down on the examination bed and hold your finger over the area of maximal pain. You feel no mass or abdominal wall defects. You apply light pressure, which triggers the pain, and ask her to lift her legs up. She yelps in pain, noting significant worsening to the site after tensing her abdominal muscles.
While you think of your differential for abdominal wall pain, you are highly suspicious of anterior cutaneous nerve entrapment syndrome (ACNES)…
What is ACNES?
Anterior cutaneous nerve entrapment syndrome (ACNES) is one of the most frequent causes of chronic abdominal wall pain and often goes undiagnosed. It is caused by entrapment of the anterior cutaneous abdominal nerves as they pass through the fibrous abdominal fascia.
This common condition can be treated rapidly and effectively by local trigger point injection of lidocaine and long acting steroid in the emergency department.
Pathophysiology:
The cutaneous branches of the sensory nerves arising from T7-T12 must make two 90* turns, traversing through channels within the abdominal fascia at the linea semilunaris (lateral border of the rectus muscles) in order to innervate the cutaneous surface of the abdomen.
While the neurovascular bundle should be protected from impingement by fat, it is susceptible to entrapment due to the tight passageway through the fibrous channels and sharp angulation.
Risk factors:
There are multiple risk factors for entrapment, and subsequent pain: tight clothing or belts, intra or extra-abdominal pressure, scarring and obesity. Pregnant women and those taking OCPs may also be at higher risk.
4x more common in women, particularly those between ages 30-50 years of age.
Clinical features on history:
Patients may describe chronic abdominal pain with maximal tenderness over a small area of the abdomen, typically <2cm
Pain is typically at the lateral edge of the rectus abdominis muscles and has a predilection for the right side although, the pain may be anywhere over the abdomen and may be in multiple locations.
Pain tends to be sharp in nature, positional and aggravated by activities that tense the abdominal muscles. Pain is generally better supine and worse when sitting or lying on the side.
There should be no red flags associated with the history suggestive of a more nefarious source of pain (e.g. GI bleeding, change in bowel function).
Physical exam:
Use a Q-tip to apply pressure as you move along the abdomen and try to locate the area of maximal tenderness. In most ACNES patients, you will find an area of allodynia or hyperalgesia corresponding to the area of nerve entrapment.
Look for a positive Carnett’s sign:
Ask the patient to either lift the head and shoulders or alternatively, lift their legs off of the bed while lying flat while you apply pressure over the area of pain on the abdomen.
Tightening of the rectus muscles should protect intra-abdominal pathology and pain will be reduced. In the case of abdominal wall pathology, including ACNES, pain will remain the same or be increased.
Understanding extra vs intra-abdominal pain:
There are 2 types of pain receptors: A-delta and C fibers.
A-delta: These fibers mediate sharp, sudden pain and innervate skin and muscles. Patient’s can localize this pain with a fingertip and this corresponds well with extra-abdominal wall pain, such as in ACNES
C fibers: Mediate dull ‘visceral’ pain that is often difficult to localize and results in pain over larger areas of the abdomen. These fibers innervate the viscera and parietal peritoneum.
Approach and Differential Diagnosis for Abdominal Wall Pain:
Look for ‘red flags’ (e.g. GI bleeding, abnormal labs, malnourished appearance) and rule out intra-abdominal sources of pain.
Once this has been ruled out, consider your differential for extra-abdominal wall pain which may include the following…
Diagnosis:
ACNES can be diagnosed on the basis of 3 criteria:
1) Well localized abdominal pain
2) Positive Carnett’s sign
3) Response to trigger point injection of local anesthetic and steroid
Treatment
Trigger point injections:
Act as both a source of treatment and diagnosis.
Provides immediate relief of symptoms to 83-91% of patients.
Injections can be repeated q-monthly.
Works through immediate anesthetization of the nerve, steroidal thinning of surrounding connective tissue and hydrodissection.
If the pain returns after trigger point injections, after considering other diagnoses, patient’s can be referred for chemical neurolysis (alcohol injections) or in some instances, surgical neurectomy.
Conservative treatment may include activity modification (e.g. avoid stomach crunches) and physical therapy
Technique for trigger point injections:
Mark the site of maximal tenderness
Inject 1-3 mL of 1% lidocaine and 1 mL of a long acting steroid using a 1.5 inch 26 gauge needle. Insert the needle until the tender area is reached (pt will let you know)
Pain should resolve within 5 minutes.
US guidance may be useful for increasing the precision of the injection and can be used to visualize the passage of the nerve through the abdominal fascia.
Its early afternoon during your ortho call shift and you get a call from emerge staff saying that they have two patients coming with potentially significant injuries when a piece of equipment rolled over during transport. EMS has informed them that one has a broken ankle. When you arrive to the ED he tells you they are just getting the patient’s pain under control and ordering x-rays.
You head to the room to see the patient, a large burly 35 y/o with an obviously deformed R ankle. His exam is otherwise unremarkable at this time, he has good cap refill to the toes, sensation to the web space, dorsum/plantar and medial/lateral surfaces of the foot is intact and he is able to move his toes. On palpation his lower leg compartments are firm but not hard. An x-ray is done at bedside and shows a Weber Type B fracture of the fibula. His pain seems to be increasing as you speak with him and he has no significant past medical history. He tells you he was loading a piece of equipment when it got away from them and rolled over his leg pinning him momentarily, so he was hanging off a piece of equipment by the leg. Your exam is limited by pain and you ask the nurse if she can give the patient some more pain medication and you’ll return as soon as you see the other patient.
Clinical Pearl: Compartment Syndrome
Compartment Syndrome occurs when the pressure within a muscle compartment exceeds the pressure needed to adequately perfuse tissue. It is considered a true orthopedic emergency and delays in diagnosis and treatment can result in the loss of a patient’s life or limb
Anatomy/Pathophysiology
-Muscle compartments are bound by bone or fascia, two restrictive tissues that create a relatively fixed volume compartment with a very limited ability to compensate for any increase in fluid volume.
-When a traumatic or pathological process results in increased fluid within a muscle compartment the pressure within the compartment increases. This increase in pressure results in reduced arteriovenous pressure gradient (reduced arterial pressure and increased venous pressure) that impairs tissue perfusion within the compartment.
As the pressure rises within the compartment capillary flow declines resulting in an enhanced local blood vessel permeability which further increases compartment pressures. If pressures continue to rise tissue ischemia and necrosis will develop.
Time for tissue necrosis to occur will vary from patient to patient it can occur in as little as 3 hours and most literature suggests that a fasciotomy must be performed within 4 hours of the onset of ACS to prevent irreversible damage.2
Signs and Symptoms
Compartment syndrome is a true orthopedic emergency and early recognition of its clinical signs is critical in preventing irreversible tissue damage, rhabdomyolysis, and limb loss.
Pain out of proportion
Pain with passive stretch
Paresthesia
Pain at rest
Paresis
Severe pain out of proportion to the examination and pain with passive stretching are the first symptoms of ACS to occur. While the early signs are 97% specific for ACS they are only 19% sensitive in the absence of other findings.
The combination of pain with passive stretch, paresthesia, and pain with rest has been reported to be 93% sensitive and if paresis is present the sensitivity increases to 98%1. Unfortunately, paraesthesia and paresis are late findings of ACS and delaying the diagnosis until they are present can result in unacceptable delays in treatment. Once a motor nerve deficit has occurred patients will rarely recover function after fasciotomy.
Diagnosis 1
Normal compartment pressures are between 8 and 10mmHg in adults and 10-15mmHg in children.
30mmHg is diagnostic for compartment syndrome and should prompt an orthopedic referral when combined with clinical symptoms of compartment syndrome.
An alternative is to calculate a differential compartment pressure for an individual patient as factors such as hypertension, peripheral vascular disease and patient medication can cause a large variance in individuals compartment pressures.
Differential compartment pressure is calculated by the diastolic blood pressure minus the intra-compartmental pressure if this is under 20mHg then fasciotomy is indicated.
If the patient is alert and able to elevate the affected limb, serial examinations over a two-hour period may prevent unnecessary fasciotomies. This should be done in consultation with your orthopedic colleagues.
Measuring compartment pressures
Devise: dedicated compartment manometer (Stryker Intra-Compartmental Pressure Monitor) or by using IV tubing and an ART line transducer attached to a long needle.
Who is most at risk of developing compartment syndrome?
Fractures represent 70% of all cases5.
Fractures of the tibial diaphysis account for 40% of all cases in North America.
Open fractures of the tibia are still high risk for compartment syndrome because the opening is insufficient to relieve the compartment pressure associated with the fracture.6
Management of potential compartment syndrome in the ED
Supplemental oxygen if indicated
Remove all cast material, clothing or wraps around the limb
Elevate the limb to the level of the hear
Apply ice to the affected limb if the compartment syndrome is secondary to trauma.
Definitive treatment is a surgical fasciotomy.
Case Part 2
You return to see the patient and nursing staff tell you they are unable to get the patients pain under control despite significant amounts of narcotics.
The examination of the lower leg is repeated and the compartments of the leg feel the same however the patient is unable to move his toe. He reports significant pain on passive flexion and extension of the great toe. You call your staff to inform her of the change in the patient and that you are concerned about compartment syndrome and she requests compartment pressure measurements using the Stryker Kit. The senior resident performs the compartment pressure measurements with you and you record pressures of 14, 14 and 25mmHg.
In discussion with the staff you decide to leave the leg on a posterior slab unwrapped, at the level of the heart, and with ice applied 20 on 20 off and perform serial examinations. The serial examinations are unremarkable and the patients pain becomes manageable. The patient is brought to the OR approximately 5 hours later for ORIF of his distal fibula. Compartment pressures are repeated in the OR and were 12, 10, 32 mmHg. An ORIF is performed and you perform serially examinations on the patient q1h overnight. The patient is discharged the following day
Case Follow Up
The patient had significant leg pain on discharge and subsequently presented to the ED on POD#7 for significant leg swelling. Ultrasound was performed to rule out DVT and the patient was discharged for follow up in clinic. He did not go on to develop any further complications.
Bottom Line
Compartment syndrome is an important not to miss diagnosis. It should be considered in any hard to control limb pain, especially when associated with fracture.
References
1.Duckworth, A. D., & McQueen, M. M. (2017). The Diagnosis of Acute Compartment Syndrome: A Critical Analysis Review. JBJS Reviews, 5(12), e1. https://doi.org/10.2106/JBJS.RVW.17.00016
Long, B., Koyfman, A., & Rdms, M. G. (2019). Clinical Review. Journal of Emergency Medicine, (December 2018), 1–12. https://doi.org/10.1016/j.jemermed.2018.12.021
McQueen, M. M., & Court-Brown, C. M. (1996). Compartment monitoring in tibial fractures. The pressure threshold for decompression. The Journal of Bone and Joint Surgery. British Volume, 78(1), 99–104.
McQueen, M. M., Duckworth, A. D., Aitken, S. A., Sharma, R. A., & Court-Brown, C. M. (2015). Predictors of Compartment Syndrome After Tibial Fracture. Journal of Orthopaedic Trauma, 29(10), 451–455. https://doi.org/10.1097/BOT.0000000000000347
Stella, M., Santolini, E., Sanguineti, F., Felli, L., Vicenti, G., Bizzoca, D., & Santolini, F. (2019). Aetiology of trauma-related acute compartment syndrome of the leg : A systematic review. Injury, (2018). https://doi.org/10.1016/j.injury.2019.01.047
Strohm, P. C., & Su, N. P. (2004). Acute compartment syndrome of the limb, 1221–1227. https://doi.org/10.1016/j.injury.2004.04.009
A 53-year-old man comes in to the emergency department after having fallen at work and “hurt his shoulder”. Clinically, it is assessed as an anterior shoulder dislocation and he is sent to x-ray which confirms your diagnosis.
Traditionally, the way to reduce a dislocated shoulder involves procedural sedation and some pulling on the arm. While it may save the patient some pain, procedural sedation is not without its risks to the patient and has high staffing needs. Learning some less risky techniques for shoulder reduction can make it safer for your patient and less time intensive for you and your staff!
Anatomy
The shoulder is an inherently unstable joint. The glenoid is shallow and only a small portion of the humeral head is articulating with the glenoid in any position. The rotator cuff provides additional support to the shoulder joint.
Mechanism of Injury for an Anterior Shoulder Dislocation
Most commonly it is a blow to the abducted, externally rotated, and extended arm.
Less commonly a blow to the posterior humerus or fall on an outstretched arm.
Clinical Exam
The arm will be slightly abducted and externally rotated. It will be lost of the normal rounded appearance of the shoulder.
Examination of the axillary nerve and peripheral pulses are essential when examining a patient with an anterior shoulder dislocation before and after reduction.
Imaging
On AP radiograph the head of the humerus will appear medial to the glenoid. On a lateral radiograph it will appear anteriorly displaced. Take care with posterior dislocations as these can appear in joint on the AP, and may only be apparent on the lateral Y view.
Figure 2. radiograph of an anterior shoulder dislocation.2
Don’t forget you can use PoCUS to triage shoulder injuries too:
Based on your clinical examination and imaging, you have determined that this patient indeed has an anterior shoulder dislocation. You have decided to avoid procedural sedation if you can and attempt reduction with the Cunningham technique!
The Cunningham Technique
Step 1
Inform the patient of what you are going to attempt. Tell them that their cooperation is necessary for success. Try and relax the patient by getting them to do deep, slow breathing.
Step 2
Sit the patient up with the back straight and shoulder blades pulled back. You can use a bed or a chair, whatever is easiest and most comfortable for both you and the patient.
Step 3
Get the patient to support the arm and bring it in to the best position to facilitate reduction. That location is typically with the arm abducted and pointing down with the elbow flexed at 90 degrees with the forearm pointing horizontally and anteriorly.
Step 4
Sit opposite the patient and place your hand on their elbow in between their body and their arm. Rest their forearm and hand on your arm.
Step 5
Apply steady downward traction with the weight of your forearm. Keep the gentle weight on the arm through out. Should now be causing pain as this will cause the muscles to spasm.
Step 6
Massage the trapezius, deltoid, and biceps muscles in sequential order. Repeat this process over and over. Your thumb should be anterior with four fingers posterior as your massaging these muscles. Most times you will not get the traditional “clunk” sound so frequent reassessments are necessary to see if the shoulder has been relocated.
YouTube Video Link of Cunningham Technique
The Bottom Line
The Cunningham technique can be used as a safe, successful and less resource intensive procedure to relocate an anterior shoulder dislocation. Patient engagement and cooperation is essential in its success.
Similar Alternative to the Cunningham Technique (The Sool’s Method):
References
Cunningham N. A new drug free technique for reducing anterior shoulder dislocations. Emerg Med (Fremantle). 2003 Oct-Dec;15(5-6):521-4. PMID: 14992071.
Sherman, S. (2018, August). Shoulder dislocation. Retrieved March 01, 2019, from UTD
A 90 year-old male presented with worsening shortness of breath on exertion, crackles bilaterally at the bases on auscultation with known history of congestive heart failure. Bedside ultrasound was performed to assess for pleural effusion
Lung Views:
In order to perform ultrasound of the lungs, there are four views that are obtained (see Figure 1). Place the patient supine. The high frequency linear array transducer is often used, but either the phased array or curvilinear transducers can be used. The first views are taken at both right and left mid-clavicular lines of the anterior chest. With the marker of the transducer pointed toward the patient’s head, a minimum of 3-4 rib spaces should be identified. The next views are of the posterior-lateral chest. The patient can be supine or in the sitting position. It is these views where a pleural effusion can be identified.
Figure 1: Chest views with ultrasound. ‘A’ are anterior chest view positions and ‘B’ are posterolateral view positions
Pleural Effusion
Pleural effusion is assessed by ultrasound placing the transducer in the midaxillary line with the marker oriented toward the patient’s head. On the patient’s right side the diaphragm, the liver, and the vertebral line can be seen. On the left, the diaphragm, spleen, and vertebral line should be in view. In a patient without pleural effusion, one should not be able to visualize the lung as it is mostly air and scatters the sound produced by the transducer. However, in the presence of pleural effusion, the area above the diaphragm is filled with fluid and therefore will appear anechoic. In addition, the vertebral line will be present past the diaphragm as the fluid allows the sound waves to propagate and not scatter. This is known as the ‘spine sign’ (also known as the ‘V-line’). Finally, one is often able to see the atelectatic lung float and move with respirations in the fluid, this is known as the ‘sinusoid sign.’ These are the three criteria outlined by consensus statements in the identification of pleural effusions.1 Occasionally, the area above the diaphragm may look like spleen or liver, but this is known as ‘mirror image’ artifact and is normal.2 Figure 2 shows both the right and left views of our patient.
Ultrasound is more accurate than either chest x-ray or physical exam in the identification of small pleural effusions.3 For a chest x-ray to identify fluid there usually needs to be more than 200cc present.2 A meta-analysis found that ultrasound had a mean sensitivity of 93% (95%CI: 89-96%) and specificity of 96% (95%CI: 95-98%).4
Our patient went on to have a chest x-ray where he was found to have bilateral pleural effusions (see Figure 3).
Figure 3: Bilateral pleural effusions seen on chest radiography in our patient.
In Summary
Three criteria are used to identify pleural effusion on ultrasound; anechoic fluid above the diaphragm, the ability to visualize the spine above the diaphragm (‘spine sign’), and atelectatic lung moving with respirations (‘sinusoid sign’). Lung ultrasound for the detection of pleural effusion is more reliable to identify small effusions in comparison to both radiography and physical exam.
References:
Volpicelli G, Elbarbary M, Blaivas M, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577-591. doi:10.1007/s00134-012-2513-4.
Liu RB, Donroe JH, McNamara RL, Forman HP, Moore CL. The practice and implications of finding fluid during point-of-care ultrasonography: A review. JAMA Intern Med. 2017;177(12):1818-1825. doi:10.1001/jamainternmed.2017.5048.
Wong CL, Holroyd-leduc J, Straus SE. CLINICIAN ’ S CORNER Does This Patient Have a Pleural Effusion ? PATIENT SCENARIO. Jama. 2010;301(3):309-317. doi:10.1001/jama.2008.937.
Grimberg AI, Carlos Shigueoka DI, Nagib Atallah III Á, et al. Diagnostic accuracy of sonography for pleural effusion: systematic review Acurácia diagnóstica da ultrassonografia nos derrames pleurais: revisão sistemática
Can diagnostic ultrasound reliably rule out appendicitis?
Do mandibular fractures need to be admitted?
Can neuromuscular disorders alone result in symptoms of dyspnoea?
Can diagnostic ultrasound reliably rule out appendicitis?
Accuracy depends upon the skill and experience of the sonographer – when the appendix is visualized the accuracy of ultrasound is equivalent to CT – sensitivity and specificity of 91-98% and 86-92%
Inaccurate examinations were significantly associated with high body mass index (≥85th percentile, primarily false-negative results)
In this case, a patient with clinically suspected appendicitis, had an ultrasound that was reported normal i.e the appendix was visualized and appeared normal. A subsequent CT confirmed the diagnosis of appendicitis.
Take Home Point: All diagnostic tests have a false negative rate. If it looks like a sock, even if the test says it isn’t, it still might be.
Do mandibular fractures need to be admitted?
Must assess open vs closed – open needs ABx
Consider MOI/associated injuries
Bilateral #’s – airway obstruction
Posterior displacement of the tongue
Bleeding – tearing of the periosteum and muscles attached to the mandible – sublingual hematoma, swelling and life-threatening airway compromise
In this case the patient was admitted to Family Medicine after discussion with other relevant specialties.
Recommended Disposition Guidelines for Trauma Patients:
Take Home Point: Mandibular fractures are usually indicative of significant force. They are usually fractured in 2 places and therefore unstable. Disposition to appropriate specialist and level of care is recommended.
Can neuromuscular disorders alone result in symptoms of dyspnoea?
Consider all the common causes of dyspnoea first
“No single abnormality is diagnostic of respiratory muscle weakness; rather, diagnosis is based on a constellation of abnormalities. The use of single tests tends to overdiagnose respiratory muscle weakness, whereas use of combinations of tests increase diagnostic accuracy.”
Take Home Point: A differential diagnosis should always include the common conditions, but also consider the rarer conditions. Online tools are available to help with rare disease diagnosis – see this article
Are you concerned about ED Crowding? After a busy shift do you ever “..dream it’s over”? Do you work in a “Crowded House”?
Come to the Crowded House Track at CAEP19 on May 26th 1pm. International and Canadian experts present their experience and we discuss possible solutions.
Including Dr. Taj Hassan (President Royal College of Emergency Medicine UK), Dr. Alecs Chochinov (President CAEP), Dr. Judy Morris and Dr. David Lewis.
Join in the debate – “are redirection strategies better than accommodation strategies” – should we invest all our energy in redirection to alternative services or should we accept that we can’t stem the tide and bring all these services under one roof?
Register for CAEP19 – CAEP By The Ocean. https://caepconference.ca/registration/
SJRHEM is massively involved in this Maritimes Emergency Medicine Conference. EMS tracks, Pediatrics, Trauma, Crowding. Special rates for Nurses, Paramedics, Residents etc. https://caepconference.ca/registration/
A 90-year-old female
presented to the emergency department after a fall. Her vitals were stable and
a chest x-ray demonstrated three posterior rib fractures. She was keen to be
managed at home and had the necessary supports in place. She was discharged
with a prescription for analgesics and instructions to return to the ED if her
condition changed.
4 days later, the same
patient returned to the emergency department with shortness of breath and
increased work of breathing. Auscultation revealed decreased air entry on the
left. A pneumothorax was at the top of the differential.
PoCUS for Pneumothorax
Lung ultrasound has been found to be more sensitive than chest x-ray for detecting pneumothorax.1 To begin scanning, it is best to have the patient in a supine or semi-recumbent position. The high frequency linear array transducer provides excellent near-field imaging and may be used to better appreciate Lung Sliding, however both the phased array or curvilinear probe may also be used. The probe should be positioned in the longitudinal orientation, with the marker towards the patient’s head, on the anterior chest. Scanning through various rib spaces on both sides completes the exam.
In a normal healthy
lung, the visceral and parietal pleura slide against each other creating a
distinct shimmering effect known as Lung Sliding. The presence of Lung Sliding
rules out pneumothorax with nearly 100% sensitivity in the area directly under
the probe.2*
Lung sliding
Absent lung sliding
Comet-tails are
another normal feature of a healthy lung. This is an artifact caused by the
reverberation between the parietal and visceral pleura. Comet-tails are seen as
bright, vertical lines that fade quickly. The detection of comet tails allows
you to rule-out pneumothorax.3
The Seashore Sign is a
normal finding in M-mode of a healthy lung. The sliding of the parietal and
visceral pleura creates a sand like pattern directly deep to the pleural line.
In a pneumothorax, there is air between the parietal and visceral pleura and
thus the ultrasound beam is scattered deep to the parietal pleura. In this
case, an artifact known as the Barcode Sign may be seen where a reflection of
the chest wall is seen below the parietal pleura.5*
The most specific finding
of pneumothorax is the Lung Point Sign. This is the point where the visceral
pleura begins to separate from the parietal pleura indicating the boundary of
the pneumothorax. Although pathognomonic for pneumothorax it is not always
present – the sensitivity is 66%.4
Lung Point
In summary
PoCUS for pneumothorax
can be performed quickly at the bedside and is more sensitive than chest x-ray.
Look for the absence of Lung Sliding, the absence of Comet-tails and try to
locate the Lung Point Sign.
A 20-year-old African male presented to the emergency department with black, tarry stool for the past two days. He appeared hemodynamically stable. He was treated for peptic ulcer disease (PUD) due to Helicobacter pylori infection eight months ago after an episode of severe hemorrhage. His medications included ferrous sulfate and Pepto-Bismol. He did not have a primary care provider.
What diagnoses
should be considered?
90% of melena is due to upper gastrointestinal (GI) hemorrhage proximal to the ligament of Treitz, but the pharynx and small bowel may sometimes be involved.2 Major causes of upper GI bleeding include PUD, varices, Mallory-Weiss tear, or neoplasms.1 Life-threatening hemorrhage, varices, ulcerations, arteriovenous malformations, and malignancy must also be considered.1
It is important to distinguish between dark stool from blood, known as melena, and dark stool from other causes, such as iron or bismuth. Liquid consistency, shininess, and foul smell are distinct features of melena. 5
What questions
should this patient be asked?
Symptoms can help determine the severity and etiology.1 Upper abdominal pain is common with peptic ulcer. Dysphagia combined with weight loss and early satiety is characteristic of malignancy. Significant coughing or retching may lead to Mallory-Weiss tear.2
Comorbidities and prior episodes of upper GI bleeding should be asked. History of liver disease and alcoholism are associated with variceal hemorrhage. Abdominal aortic aneurysm is associated with an aortoenteric fistula. A history of H. pylori infection and NSAID use are risk factors for PUD.2
The use of NSAIDs, antiplatelets, or anticoagulants must be identified. Medications that can induce pill esophagitis (i.e. bisphosphonates) also need to be identified. Bismuth and iron can both lead to harmless darkening of the stool.2
Are any
investigations required?
Physical exam begins with an assessment of the patient’s hemodynamic stability.2 Signs of any co-morbidities should be noted. Laboratory tests should include complete blood count, liver function tests, and serum electrolytes. The hemoglobin level may be unchanged from baseline for the first 24 hours.1
Is fecal occult blood test required?
The FOBT has only been validated for use in asymptomatic patients for colorectal cancer (CRC) screening.5 For symptomatic (i.e. melena) patients with high pre-test probability of GI bleeding, the FOBT has a high false positive rate.5
Foods with peroxidase
activity (i.e. red meat), vitamin C, antiplatelets and anticoagulants can influence
the FOBT results,5
therefore dietary and medication restriction for
three days is needed.3 Therefore,
the FOBT is unsuitable for emergency rooms despite common use in this setting
as a point-of-care (POC) test.3 The newer immunochemical FOBTs do
not require dietary restriction and have shown improved accuracy as POC testing
for CRC, but its accuracy in evaluating black-coloured stools remains unclear.3,
7
There is speculation that FOBT may be used for patients with dark stools on iron supplementation.3 However, melena is usually well-characterized by its liquid consistency, shininess, and foul smell. Importantly, the FOBT has never been validated for such use to distinguish between melena and other causes of dark stool.3, 5
How should
this patient be managed?
A hemodynamically stable patient should be promptly categorized according to rebleeding and mortality risk, using the Glasgow Blatchford Score (GBS) or Rockall Score. They are validated tools based on information such as the patient’s blood pressure, hemoglobin level, and co-morbidities.4, 6
Although pre-endoscopic empiric therapy with PPI is recommended for all patients, this is based on the excellent safety profile of PPIs rather than evidence regarding their efficacy.4 Histamine-2 receptor antagonists are ineffective as preendoscopic therapy.4, 6
Endoscopy within the first 24 hours of presentation is recommended for suspected GI bleeding,1,4 although patients with very low GBS Score (i.e. zero) are unlikely to benefit.5
Generally, all patients with upper GI bleeding require gastroenterology consult. In cases where endoscopy is not suitable, surgical consultation is needed.2
Case revisited
Physical exam and lab results were
unremarkable except low hemoglobin, which yielded a total GBS Score of 2 for
this patient. Since this is considered high risk1, gastroenterology
was consulted. The patient was given an infusion of IV PPI.
Although the patient is on iron and bismuth, he had been on these medications for many months, and, given his history of severe hemorrhage due to PUD without a family physician to provide follow-up care, it was deemed appropriate to investigate further.
References
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Kim B, Li B, Engel A, Samra J, Clarke S, Norton I et al. Diagnosis of
gastrointestinal bleeding: A practical guide for clinicians. World Journal of
Gastrointestinal Pathophysiology. 2014;5(4):467.
2.
Cappell M, Friedel D. Initial Management of Acute Upper Gastrointestinal
Bleeding: From Initial Evaluation up to Gastrointestinal Endoscopy. Medical
Clinics of North America. 2008;92(3):491-509.
3.
Ip S, Sokoro A, Buchel A, Wirtzfeld D, Konrad G, Fatoye T et al. Use of Fecal
Occult Blood Test in Hospitalized Patients: Survey of Physicians Practicing in
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Canadian Journal of Gastroenterology. 2013;27(12):711-716.
4.
Barkun A, Fallone C, Chiba N, Fishman M, Flook N, Martin J et al. A Canadian
Clinical Practice Algorithm for the Management of Patients with Non-Variceal
Upper Gastrointestinal Bleeding. Canadian Journal of Gastroenterology.
2004;18(10):605-609.
5.
Narula N, Ulic D, Al-Dabbagh R, Ibrahim A, Mansour M, Balion C et al. Fecal
Occult Blood Testing as a Diagnostic Test in Symptomatic Patients is not
Useful: A Retrospective Chart Review. Canadian Journal of Gastroenterology and
Hepatology. 2014;28(8):421-426.
6.
Barkun A. International Consensus Recommendations on the Management of Patients
With Nonvariceal Upper Gastrointestinal Bleeding. Annals of Internal Medicine. 2010;152(2):101.
7.
Huddy JR, Ni MZ,
Markar SR, Hanna GB. Point-of-care testing in the diagnosis of gastrointestinal
cancers: Current technology and future directions. World Journal of
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