Category: Medical Education

Question Of The Day #16

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod16

Which of the following is the most appropriate next step in management for this patient’s condition?

  • A) Consult general surgery for exploratory laparotomy
  • B) Apply needle decompression of the chest
  • C) Apply Pericardiocentesis
  • D) Order CT scan of chest, abdomen, and pelvis

This patient sustained a penetrating traumatic injury to the left chest and presented to the emergency department with hemodynamic instability (tachycardic and hypotensive). Some differential diagnoses to consider on arrival include tension pneumothorax, cardiac tamponade, aortic injury, or aero-digestive tract injury. Prior to taking a detailed history on any trauma patient, a primary survey should be performed. The goal of the primary survey in a trauma patient is to identify and treat any life-threatening injuries as soon as possible. The primary survey is also known as the “ABCs.” Sometimes it is referred to as the “ABCDEFs.” This acronym stands for Airway, Breathing, Circulation, Disability, Exposure, and FAST exam (How to learn eFAST exam for free). Each letter is addressed and assessed in the order they exist in the alphabet. This creates a methodical, algorithmic approach to assist the practitioner in assessing the trauma patient for life-threatening injuries. The sonographic view shown in this question is the subxiphoid (cardiac) view and demonstrates the presence of free fluid. Free fluid on ultrasound appears black, or “anechoic” and is assumed to be blood in the setting of trauma. The free fluid is highlighted by red stars in the image below. The collapse of the right ventricle is shown by the yellow arrow in the below image.

cardiac tamponade - explained
SS Video 3 Pericardial Tamponade

In conjunction with hemodynamic instability and a history of penetrating chest trauma, this sonographic view strongly supports the diagnosis of cardiac tamponade. Consulting the general surgery team for exploratory laparotomy (Choice A) would be the correct course of action for a patient with hemodynamic instability and free fluid on the other abdominal views of the FAST exam. Needle decompression of the chest (Choice B) would be the correct initial treatment for a tension pneumothorax. The patient described in the case has clear bilateral lung sounds, no tracheal deviation mentioned, normal O2 saturation on room air, and sonographic demonstration of cardiac tamponade. A CT scan of the chest, abdomen, and pelvis (Choice D) would be indicated in this patient if he had normal vital signs and no free fluid on the FAST exam. A pericardiocentesis (Choice C) is the most appropriate next step in the management of this patient with cardiac tamponade to relieve signs of obstructive shock. It should be noted that this procedure has limitations and is not always effective. Pericardiocentesis is a temporizing treatment with pericardiotomy being the definitive therapy. Blood in an acute hemopericardium may clot and be unable to be aspirated with a large-bore needle. The procedure may injure surrounding organs, such as the liver, intestines, or heart itself. Ultrasound-guidance should be used whenever possible to avoid injury to surrounding organs. Emergent thoracotomy to relieve the cardiac tamponade should be performed on any patient with confirmed cardiac tamponade and cardiac arrest in the Emergency Department. Correct Answer: C

References

[cite]

You may want to read these

Pulmonary Embolism – https://iem-student.org/pulmonary-embolism/

Clinical Decision Rules – https://iem-student.org/clinical-decision-rules/

Question of The Day #6 – https://iem-student.org/2020/07/31/question-of-the-day-6/

Question Of The Day #15

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod 15 - pleuritic chest pain

Which of the following is the best course of action to further evaluate for a diagnosis of pulmonary embolism?

  • A) Perform a V/Q scan
  • B) Draw a D-Dimer test
  • C) Perform a CT Pulmonary Angiogram
  • D) Give lorazepam
Pulmonary embolism (PE) is a potentially lethal diagnosis evaluated by a combination of a thorough history, physical exam, and the use of risk stratification scoring tools. The Wells criteria and the PE rule-out criteria (PERC) are two well-accepted risk stratification tools for PE. These criteria are each listed below (Wieters et al., 2020).

Wells’ Criteria for Pulmonary Embolism

CriteriaPoint Value
Clinical signs and symptoms of DVT+3
PE is #1 diagnosis, or equally likely+3
Heart rate > 100+1.5
Immobilization at least 3 days, or Surgery in the Previous 4 weeks+1.5
Previous, objectively diagnosed PE or DVT+1.5
Hemoptysis+1
Malignancy w/ Treatment within 6 mo, or palliative+1
Interpretation
Score >4 = High probability
Score 2–4 = Moderate probability
Score <2 = Low probability

Pulmonary Embolism Rule Out Criteria

All Variables Must Be Present for <2% Chance of PE
Pulse oximetry >94% (room air)
HR <100
No prior PE or DVT
No recent surgery or trauma within prior 4 wk
No hemoptysis
No estrogen use
No unilateral leg swelling
The patient in this clinical vignette would have a Wells score of 1.5 (low risk) due to her persistent tachycardia of unknown etiology. The PERC rule can not be applied to this patient as she is over 50-years-old and has tachycardia. If the patient was low risk on Wells score and meet all the PERC rule criteria, she would have a less than 2% likelihood of her symptoms being due to a PE. It is important to note that only patients with a low-risk Wells score (low pretest probability for PE) can be subjected to the PERC rule. A low-risk Wells score (<2) is investigated with a D-Dimer test (Choice B), while moderate to high-risk Wells scores are investigated with a CT Pulmonary Angiogram (CTPA) (Choice C). A V/Q Scan (Choice A) is not a first-line test for the diagnosis of PE as it is less sensitive than a CTPA scan. Unlike a CTPA scan, a V/Q scan may be nondiagnostic in the setting of lung consolidation, effusions, or other airspace diseases. V/Q scans are second-line tests to CTPA when there are contraindications to a CTPA (i.e., renal failure). Lorazepam (Choice D) is a benzodiazepine that may be helpful in reducing tachycardia, which is secondary to anxiety. However, this therapy does not help further discern if the patient may have a PE. Correct Answer: B 

References

Wieters J, McDonough J, Catral J. Chest Pain. In: Stone C, Humphries RL. eds. CURRENT Diagnosis & Treatment: Emergency Medicine, 8e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2172&sectionid=165059275

Nickson, C. (2019). Pulmonary Embolism. Life in the Fastlane. Accessed on August 17, 2020. https://litfl.com/pulmonary-embolism/

[cite]

You may want to read these

Pulmonary Embolism – https://iem-student.org/pulmonary-embolism/

Clinical Decision Rules – https://iem-student.org/clinical-decision-rules/

Question of The Day #6 – https://iem-student.org/2020/07/31/question-of-the-day-6/

Question Of The Day #14

question of the day
~ Joseph Ciano, USA ~ Leave a comment
question of the day 14
40.1 - Pneumothorax 1

Which of the following is the most appropriate treatment for this patient’s condition?

  • A) Start anticoagulation
  • B) Perform needle decompression
  • C) Place small-bore chest tube in left chest
  • D) Start IV antibiotics

Anticoagulation (Choice A) would be the proper treatment for pulmonary embolism, NSTEMI/STEMI, and other conditions. This patient is dyspneic and hypoxemic on the exam, but his chest X-ray offers an alternative explanation for his symptoms. IV antibiotics (Choice D) would be helpful for pneumonia and COPD exacerbation, both of which are possible in this patient, but his chest X-ray offers an alternative explanation for his symptoms. Needle decompression of the left chest (Choice B) would be the appropriate initial treatment for a left-sided “tension” pneumothorax. This patient does have a large left-sided pneumothorax, but the X-ray lacks tracheal deviation, mediastinal shift, and left hemidiaphragm flattening, which can be attributed to tension pneumothorax. Most importantly, the patient lacks the hemodynamic instability that defines tension physiology (i.e. hypotension and tachycardia). In addition, the diagnosis and treatment of tension pneumothorax should be made clinically prior to chest radiography. Signs of hemodynamic instability along with tracheal deviation, absent unilateral lung sounds, and a history of trauma all support a diagnosis of tension pneumothorax. The treatment of a tension pneumothorax requires prompt recognition, needle decompression at the 3rd intercostal space at the midclavicular line, and a tube thoracostomy at the 4-5th intercostal space the anterior axillary line. The recommended needle decompression location is recently shifted to 4-5th intercostal space at the mid-anterior axillary line because the studies showed lower success rates in anterior – mid clavicular approach in adults. This patient has a spontaneous left-sided pneumothorax, not a tension pneumothorax. This is likely secondary to his coughing episodes and severe COPD. The treatment for this would be supplemental oxygen and the placement of a small-bore chest tube (i.e. “pig tail) in the left chest. Correct Answer: C. 

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Nickson, C. (2019) Pneumothorax CCC. Life in the Fastlane. Accessed August 17, 2020. https://litfl.com/pneumothorax-ccc/

[cite]

Question Of The Day #13

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod13

Which of the following is the most appropriate next step in management for this patient’s condition?

  • A) Cardiology consultation
  • B) Discharge home with prompt outpatient follow-up
  • C) Prescribe a benzodiazepine
  • D) Admission for cardiac stress testing

This patient presents to the emergency department after an atypical, brief episode of chest pain. The list of potential diagnoses that may have caused the pain episodes is extensive. The focus of the Emergency Medicine practitioner should not be to determine the diagnosis per say, but rather to be to identify the presence of any life-threatening conditions (i.e. Myocardial infarction, Aortic dissection, Esophageal Rupture, Pulmonary embolism, Tension pneumothorax, Cardiac tamponade, etc.). Many of these serious diagnoses can be evaluated with a detailed history, physical exam, and basic imaging and lab work if needed. Many risk stratification tools have been developed to evaluate the likelihood a patient has chest pain due to Acute Coronary Syndrome. One well-supported tool with international validation is the HEART score tool. The HEART score categorizes a patient as low (0-3), moderate (4-6), or high risk (7-10) for a Major Adverse Cardiac Event (MACE) based on the patient’s history, EKG, age, risk factors, and troponin level. The below chart from Wieters et al. (2020) outlines the HEART score categories and how to make clinical decisions based on a patient’s score.

HEART score for cardiac risk assessment of major adverse cardiac event (MACE).

CategoryScoreExplanationRisk Features
HistoryHigh-risk features
• Middle- or left-sided chest pain
• Heavy chest pain
• Diaphoresis
• Radiation
• Nausea and vomiting
• Exertional
• Relief of symptoms by sublingual nitrates

Low-risk features
• Well localized
• Sharp pain
• Non-exertional
• No diaphoresis
• No nausea and vomiting
Slightly Suspicious 0Mostly low-risk features
Moderately Suspicious+1Mixture of high-risk and low-risk features
Highly Suspicious+2Mostly high-risk features
ECG
Normal0Completely Normal
Non-specific Repolarization Disturbance+1Non-specific repolarization disturbance• Repolarization abnormalities
• Non-specific T wave changes
• Non-specific ST wave depression or elevation
• Bundle branch blocks
• Pacemaker rhythms
• Left ventricular hypertrophy
• Early repolarization
• Digoxin effect
Significant ST Depression+2Significant ST depression• Ischemic ST-segment depression
• New ischemic T wave inversions
Age
<450
45-64+1
≥ 65+2
Risk Factors• Obesity (Body-Mass Index ≥ 30)
• Current or recent (≤ 90 days)smoker
• Currently treated diabetes mellitus
• Family history of coroner artery disease (1st degree relative < 55 year old)
• Hypercholesterolemia

OR

Any history of atherosclerotic disease earn 2 points:
• Know Coroner artery Disease: Prior myocardial infarctions, percutan coronary intervention (PCI) or coronary artery bypass graft
• Prior stroke or transient ischemic attack
• Peripheral arterial disease
No known risk factors0
1-2 risk factors+1
≥ 3 risk factors or history of atherosclerotic disease+2
Initial Troponin
≤ normal limit0
1-3 x normal limit+1
> 3x normal limit+2

Score 0–3 = 2.5 % MACE over next 6 wk: Discharge home
Score 4–6 = 22.3% MACE over next 6 wk: Admit for observation
Score 7–10 = 72.7% MACE over next 6 wk: Admit with early invasive strategies

The patient’s HEART score in this question would be 2 (1 point for age and 1 point for hypertension as a risk factor). This categorizes the patient as low risk for a MACE over the next six weeks. The appropriate course of action for this patient would be discharge home with prompt outpatient follow-up (Choice B). Admission for cardiac testing (Choice D) would be warranted for a moderate-high risk HEART score. Prescribing a benzodiazepine (Choice C) would not be warranted as this patient is asymptomatic and the pain episode is vague and atypical. Benzodiazepines are sometimes useful in patients with chest pain due to anxiety. Cardiology consultation (Choice A) would not be warranted as the patient has a low HEART score, is currently asymptomatic with normal imaging, blood work and troponin, and a normal EKG. Correct Answer: B 

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Wieters J, McDonough J, Catral J. Chest Pain. In: Stone C, Humphries RL. eds. CURRENT Diagnosis & Treatment: Emergency Medicine, 8e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2172&sectionid=165059275

[cite]

Question Of The Day #12

question of the day
~ Joseph Ciano, USA ~ Leave a comment

Which of the following medications should be avoided to prevent worsening of this patient’s condition?

  • A) Aspirin
  • B) Ibuprofen
  • C) Antacids
  • D) Nitroglycerin

This elderly female patient presents with chest pain described as post-prandial burning, radiating to the shoulders, and with associated nausea and diaphoresis. Burning chest pain after eating supports diagnoses, such as peptic ulcer disease, gastritis, gastroesophageal reflux, or biliary disease. However, chest pain that radiates to both shoulders (2.58 likelihood ratio) or has associated diaphoresis (1.50 likelihood ratio) should be very concerning for acute myocardial infarction (Smith & Mahler, 2020). Associated symptoms that should raise concern for acute coronary syndrome are any radiation of the chest pain, pain worsened with exertion, associated nausea or vomiting, pain described as pressure or squeezing, pain with associated diaphoresis, and pain described as feeling similar to prior ischemic events. This patient’s EKG demonstrates an inferior ST-segment elevation myocardial infarction (STEMI). This is indicated by two or more inferior EKG leads (II, III, and aVF) showing ST-segment elevation greater than 1 mm and reciprocal ischemic changes indicated in lateral leads (I, aVL). Aspirin (Choice A) should be given to all patients with high suspicion for ACS, assuming there are no contraindications. This patient has a confirmed STEMI on her EKG and should receive Aspirin for its antiplatelet effects. Ibuprofen (Choice B) may help the patient’s pain, but likely would not acutely worsen the patient’s clinical condition. Antacids (Choice C) are relatively benign medications, and they would be unlikely to worsen the patient’s clinical condition. Nitroglycerin (Choice D) is often given in patients with anginal chest pain for pain relief. In many inferior STEMIs, nitroglycerin can cause a dangerous drop in blood pressure and should be avoided. These patients may have infarction of the right ventricle, which makes these patients sensitive to nitrates and prone to precipitous drops in blood pressure. IV fluids are the preferred initial therapy in the setting of hypotension. About 40% of patients with an inferior STEMI have concurrent right ventricular infarction. About 80% of inferior STEMIs are caused by occlusions in the right coronary artery (RCA) and about 18% are from an occlusion in the left circumflex artery (LCx). Occluded vessels in both territories can cause right ventricular infarction. Correct Answer: D  

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Burns, E. (2019) Inferior STEMI. Life in the Fast Lane. Accessed August 17, 2020. https://litfl.com/inferior-stemi-ecg-library/

[cite]

Question Of The Day #11

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod 11

Which of the following is the most appropriate next step in management for this patient’s condition?

  • A) IV antihypertensives and cardiothoracic consultation
  • B) IV heparin
  • C) Pericardiocentesis
  • D) IV Fluids, antibiotics, and surgical consultation

IV antihypertensives and CT surgery consultation (Choice A) would be the best treatment for a patient with aortic dissection. This diagnosis is characterized by severe tearing chest pain that radiates to the back, along with hypertension. Risk factors include tobacco smoking, uncontrolled hypertension, trauma (i.e. rapid deceleration), and connective tissue diseases (i.e. Marfan syndrome). Other than chest pain with radiation to the back, this patient lacks the other risk factors for aortic dissection, making Choice A less likely. IV heparin (Choice B) would be the correct choice for the treatment of pulmonary embolism and acute coronary syndrome (i.e. NSTEMI). Both of these diagnoses are possible, but a chest CT scan with PO water-soluble contrast is not the gold standard for diagnosing PE or ACS. A CT Pulmonary angiogram is ideal for PE diagnosis, and an EKG along with troponin levels are ideal for ACS diagnosis. Pericardiocentesis (Choice C) is the treatment for cardiac tamponade. The patient’s vitals show no evidence of obstructive shock, and there is no history of penetrating chest trauma, pericardial effusion, end-stage renal disease, HIV, lupus, cancer, or other risk factors for cardiac tamponade. Choice D outlines the best course of action to take in a patient with esophageal rupture, which is the disease described in the question stem. This condition can occur spontaneously after forceful vomiting causing high pressures in the esophagus (Boerhaave syndrome). In this situation, the chest pain typically begins after the onset of vomiting. Other etiologies of esophageal rupture include deceleration injuries and penetrating trauma (i.e. gunshot wounds, iatrogenic via esophagogastroduodenoscopy (EGD)). A “Hamman’s Crunch”, subcutaneous emphysema, fever, and signs of shock can be seen on exam. Diagnosis is confirmed by an esophagram or a CT scan of the chest with water-soluble oral contrast (i.e. Gastrograffin). Esophageal rupture is a life-threatening diagnosis as esophageal contents can spill into the mediastinum, causing mediastinitis and septic shock. The treatment is typically surgical with the repair of the perforated segment and drainage of fluid collections. Correct Answer: D  

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Nickson, C. (2019) Oesophageal Perforation. Life in the Fast Lane. Accessed August 17, 2020. https://litfl.com/oesophageal-perforation/

[cite]

Question Of The Day #10

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod10 palpitation

Which of the following is the most appropriate next step in management for this patient’s condition?

  • A) IV Adenosine 6mg
  • B) Synchronized cardioversion
  • C) IV Amiodarone 150mg
  • D) Vagal maneuvers

This patient has a narrow-complex tachycardia with a regular rhythm. A narrow QRS complex is defined as a QRS interval less than 120msec. This is a normal finding. The differential diagnoses for regular narrow complex tachycardia include sinus tachycardia, atrial tachycardia, atrial flutter, and supraventricular tachycardia (“SVT”). SVTs are typically associated with narrow QRS complexes, unless there is a concurrent bundle branch block, other aberrant conduction, or the existence of electrical accessory pathways as in Wolff Parkinson White (WPW) syndrome. The heart rate of an SVT can vary from 140-280 beats/min. Intravenous Adenosine (Choice A) is a hallmark of SVT treatment, however, Adenosine is given after vagal maneuvers have been attempted and have failed. Synchronized cardioversion (Choice B) is a last-ditch effort treatment in a patient with SVT. Vagal maneuvers and medications are attempted prior to using cardioversion. However, if the patient is hypotensive, cardioversion should be employed. Intravenous Amiodarone (Choice C), beta-blockers, calcium channel blockers, or other antiarrhythmics can be used to terminate SVTs if vagal maneuvers and adenosine are not effective. Vagal maneuvers (Choice D), such as the Valsalva maneuver (“bearing down”) or carotid massage, are the initial treatment for SVTs. Correct Answer: D 

References

Burns, E. (2019, March 30). Supraventricular Tachycardia (SVT). Life in the Fast Lane. https://litfl.com/supraventricular-tachycardia-svt-ecg-library/

Nickson, C. (2019, March 24). Narrow Complex Tachycardia. Life in the Fast Lane. https://litfl.com/narrow-complex-tachycardia/

[cite]

Question Of The Day #9

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod9

Which of the following is the most appropriate next step in management for this patient’s condition?

  • A) Give sodium bicarbonate
  • B) Give diazepam
  • C) Give physostigmine
  • D) Give naloxone

This patient is suffering from sympathomimetic toxicity. Signs of a sympathomimetic toxidrome include agitation, psychosis, delirium, tachycardia, hypertension, diaphoresis, mydriatic (dilated) pupils, and decreased bowel sounds. The features of anticholinergic toxidromes overlap with many features of sympathomimetic toxidromes. A clinical finding that can be used to differentiate the two toxidromes is diaphoresis. Diaphoretic skin supports a sympathomimetic ingestion, while dry, warm skin supports anticholinergic ingestion. Examples of substances that can cause a sympathomimetic toxidrome ae cocaine, amphetamines, synthetic cannabinoids, ketamine, bath salts, and ecstasy (MDMA). The treatment for this toxidrome is mostly supportive care, such as benzodiazepines and cooling. Cocaine can cause coronary artery vasospasm along with sodium-channel blockade, which can predispose to cardiac arrhythmia. For this reason, a 12-lead EKG is important in any patient with possible cocaine toxicity. Sodium bicarbonate (Choice A) would be beneficial in salicylate toxicity, tricyclic antidepressant toxicity, or cocaine toxicity if the QRS was widened. The EKG for this patient has a normal QRS interval (<120msec). Physostigmine (Choice C) is an acetylcholinesterase inhibitor. This medication would likely worsen the patient’s tachycardia. Physostigmine is the antidote for anticholinergic toxicity. However, physostigmine should not be used in TCA overdose as it may increase the risk of cardiac arrhythmia. Naloxone (Choice D) is the antidote for opioid toxicity. Signs of opioid overdose include miotic (constricted) pupils, respiratory depression, and CNS depression. This patient does not possess these symptoms on exam. Diazepam (Choice B) is the best treatment. Correct Answer: B

References

Greene S. General Management of Poisoned Patients. “Chapter 176: General Management of Poisoned Patients”. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9th ed. McGraw-Hill.

Donaldson, R. (2019). Cocaine toxicity. WikEm. https://www.wikem.org/wiki/Cocaine_toxicity

[cite]

Question Of The Day #8

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod 8 toxicology

Which of the following is the most likely cause of this patient’s condition?

  • A) Amitriptyline
  • B) Cocaine
  • D) Physostigmine
  • C) Diphenhydramine

This patient is suffering from an anticholinergic toxidrome. Symptoms of anticholinergic medication toxicity include altered mental status with agitation or delirium, tachycardia, hypertension, hyperthermia, mydriatic (dilated) pupils, hot and dry skin, decreased bowel sounds, and urinary retention. The sympathomimetic toxidrome is very similar to the anticholinergic toxidrome; however, patients with anticholinergic ingestions have dry skin while patients with sympathomimetic ingestions have diaphoretic skin. Some notable types of anticholinergics are atropine, antihistamines, Tricyclic antidepressants (TCAs), and Jimson weed. Amitriptyline (Choice A) is a TCA medication and can cause anticholinergic toxicity. When taken in high doses, a major adverse effect of TCAs is Na-channel blockade, resulting in QRS widening on EKG and cardiac arrhythmias. Therapy includes sodium bicarbonate and supportive care. This patient has a normal QRS interval on EKG, making this choice less likely. Cocaine (Choice B) is a sympathomimetic. Many features of the exam support sympathomimetic toxicity, but the presence of dry skin makes this choice less likely. Physostigmine (Choice C) is an acetylcholinesterase inhibitor which would have a cholinergic toxidrome if taken in excess. Features of this include bradycardia, bronchorrhea, bronchospasm, diarrhea, hypersalivation, sweating, and hyperactive bowel sounds. Treatment for cholinergic toxicity is atropine. Along with supportive care, physostigmine is the main treatment for anticholinergic toxicity. One exception is in TCA toxicity where physostigmine should be avoided. Diphenhydramine (Choice D) is an antihistamine with anticholinergic properties, and it is the most likely medication ingested in this case scenario. Correct Answer: D 

References

Greene S. General Management of Poisoned Patients. “Chapter 176: General Management of Poisoned Patients”. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9th ed. McGraw-Hill.

[cite]

Question Of The Day #7

question of the day
~ Joseph Ciano, USA ~ Leave a comment
qod7 - sepsis

Which of the following is the most appropriate next step in management for this patient’s condition?

  • A) Perform endotracheal intubation
  • B) Give more IV fluids
  • C) Start IV vasopressors
  • D) Give acetaminophen

This patient has a diagnosis of septic shock due to pneumonia. In all patients presenting to the Emergency Department, the initial assessment should involve the “ABCs” (assessment of Airway, Breathing, and Circulation). The patient is given supplemental oxygen for her hypoxemia with an improved oxygen saturation from 89% to 95%. Performing endotracheal intubation (Choice A) is too aggressive at this time as the patient is improving with non-invasive oxygenation techniques. The Centers for Medicare and Medicaid sepsis guidelines recommend a 30 mL/kg of isotonic crystalloid fluid bolus in patients with sepsis. However, there is limited data to support this recommendation, as some patients may benefit from less or more fluids than 30 mL/kg. The question stem indicates that an appropriate bolus of fluids has been given, so providing more IV fluids (Choice B) is not the best course of action. The use of passive leg raising or bedside ultrasonography to assess for Inferior Vena Cava (IVC) size may help a clinician discern if more or less fluids are required. For example, visualizing a flat, collapsible IVC on ultrasound indicates additional fluids may be helpful. An increase in blood pressure after a patient’s legs are raised above the level of the heart (“passive leg raise”) also supports the use of additional IV fluids. Giving acetaminophen (Choice D) will help reduce the patient’s fever and improve patient comfort. However, initiating vasopressor therapy (Choice C) is the more appropriate next course of action. Vasopressors (i.e. norepinephrine, epinephrine) are generally recommended after IV fluid boluses if a patient is persistently hypotensive with a MAP less than 65mmHg. Vasopressors help to maintain cerebral and organ perfusion in states of shock. They should be titrated to a dose that maintains a MAP of 65mmHg or above.  Correct Answer: C 

References

Nicks BA, Gaillard JP. Approach to Nontraumatic Shock. “Chapter 12: Approach to Nontraumatic Shock”. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9th ed. McGraw-Hill.

[cite]

Question Of The Day #6

question of the day
~ Joseph Ciano, USA ~ Leave a comment
sepsis abdominal pain

Which of the following is the most likely cause of this patient’s condition?

  • A) Cardiogenic shock
  • B) Obstructive shock
  • C) Distributive shock
  • D) Hypovolemic shock

This patient is in septic shock due to ascending cholangitis. Shock is a condition where the body is unable to deliver adequate perfusion to meet metabolic demands. Shock is often characterized by multiorgan dysfunction and hemodynamic changes (i.e. tachycardia, hypotension). Ascending cholangitis is a serious diagnosis that carries high mortality without prompt treatment and recognition. Causes of ascending cholangitis include choledocholithiasis, a biliary tract stricture, or compression by malignant disease. Some cases demonstrate Charcot’s Triad (fever, jaundice, right upper quadrant pain) or Reynolds’ Pentad (Charcot’s triad plus shock and altered mental status). This patient meets all 5 criteria of Reynolds’ Pentad. Rather than a gallstone obstructing the biliary tree, this patient has an underlying malignancy that is obstructing biliary outflow (hinted by weight loss and progressive jaundice over 3 months). Treatment includes antibiotics, IV fluids, and surgical management. The elevated white blood cell count, fever, history, and physical exam support the diagnosis of septic shock. Cardiogenic shock (Choice A) would be more likely in a patient with known baseline cardiac disease, a patient complaining of chest pain or shortness of breath, low ejection fraction seen on echocardiogram, and cold distal extremities. Conditions that can cause cardiogenic shock include STEMI, CHF, and myocarditis. Obstructive shock (Choice B) is seen in conditions, such as pulmonary embolism, tension pneumothorax, or cardiac tamponade. The patient’s history and physical do not support this diagnosis. Hypovolemic shock (Choice D) can be caused by severe dehydration or hemorrhagic shock (a type of hypovolemic shock). This patient likely has some component of dehydration, but septic shock is the primary condition in this patient. Septic shock is a form of Distributive shock (Choice C). Anaphylactic shock also is a type of Distributive shock. Correct Answer: C

References

Nicks BA, Gaillard JP. Approach to Nontraumatic Shock. “Chapter 12: Approach to Nontraumatic Shock”. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9th ed. McGraw-Hill.

Donaldson, R. (2020, May 2). Ascending cholangitis. WikEm. https://www.wikem.org/wiki/Ascending_cholangitis

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Better Decisions

Better Decisions
~ Sajan Acharya, Nepal ~ Leave a comment

Why is a physician working in the Achham district of Nepal worried when he finds that a patient tested positive for HIV, but a physician working in Humla district is worried but also skeptical? Why do we generally not prescribe high dose IV Vitamin C + Thiamine + Hydrocortisone when the combination has shown to provide a substantial mortality benefit in sepsis? Why do we encourage a patient, very rightly so, to get flu shots every year?

When making decisions, we think, we use our knowledge, weigh pros and cons, and make a choice. The variables, whose salient feature is that we barely think of them, are biases and heuristics. We are influenced by various medical journals we read, colleagues we work with, and even movies and advertisements we watch. Another, sometimes lethal feature of these decision influencers is that their influence is inversely proportional to the time we have to make a choice. This becomes relevant in ED, where split-second decisions are the norm.

So how do we make decisions that are backed more by studies and less by our implicit biases? How do we compare two tests that measure the same variable or two vaccines that work against the same infectious agent? There comes the role of statistics. Every physician, especially those making life-saving decisions in a fraction of seconds, should have an intuitive understanding of medical statistics. This will help us make decisions that are backed by our best understanding and understand our limitations.

Achham district of Nepal has the highest prevalence of HIV/AIDS in the country. When the disease’s prevalence is high, the chance that your patient has the disease given the positive result is high. This is the Positive Predictive Value (PPV). The same physician would want to re-run the test on asymptomatic patients if the test was negative. That is because, given the high prevalence, the Negative Predictive Value (NPV) of the test is low. One would also worry about the sensitivity and specificity of the test in question. Although these are properties intrinsic to the test and do not change with the prevalence of a disease in a population, their knowledge adds to the confidence with which we can prescribe a test to a patient.

One way of thinking about sensitivity is: among 100 diseased patients, how many will the test identify? You would want your screening test to have very high sensitivity so that you do not miss any diseased person. Specificity can be thought of as: among 100 healthy patients, how many will the test identify as negative for the disease? If a highly specific test tells you that a patient has a disease, chances are – he does. So the worried physician of Achham district probably used a very sensitive test and followed it with a highly specific test to confirm before talking to the patient about the result.

We encourage all patients to get the flu vaccine every year because of something called the Number Needed to Treat (NNT). It is the number of patients you need to treat to prevent one additional bad outcome e.g., severe flu, death, etc. Every 12 – 37 flu shots prevent one healthy adult from influenza when the vaccine is well-matched. That means the NNT of the flu vaccine is 12 to 37. [1]

The combination of high dose IV vitamin C + Thiamine + Hydrocortisone had shown to provide a substantial mortality benefit in a small retrospective study in 2016. We generally do not prescribe this in sepsis because we do not have a large RCT that supports the claim yet. The GRADE working group suggests a system for grading the quality of evidence. [2] When we say that evidence is graded 1A or 3B, we are commenting on the type, quality, and the number of studies that back the claim. Familiarizing ourselves with the grading system and hierarchy of evidence can be a good start in the world of evidence-based medicine.

References

  1. Kolber MR, Lau D, Eurich D, Korownyk C. Effectiveness of the trivalent influenza vaccine. Can Fam Physician. 2014;60(1):50.
  2. Petrisor B, Bhandari M. The hierarchy of evidence: Levels and grades of recommendation. Indian J Orthop. 2007;41(1):11-15. doi:10.4103/0019-5413.30519
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