Keywords: headache, back pain, misdiagnosis, stroke, intraspinal, epidural, abscess (PubMed Search)
Bottom Line: The rate of serious neurologic conditions missed at an initial ED visit is low. However, the potential harm of misdiagnosis can be substantial.
Keywords: kratom, adverse effects, poison center data (PubMed Search)
Kratom (Mitragyna speciosa) has been used for centuries in Southeast Asia to manage pain and opium withdrawal. It is increasingly being used in the U.S. for similar purpose. The U.S. DEA lists Kratom as a “drug of concern”.
Effects of Kratom leaves
A study reviewed National Poison Data System (2011 to 2017) to evaluate the clinical effects/outcomes of Kratom exposure.
Finding: (N=1807; single-substance: 1174; multiple-substance: 633])
Sara Post, Henry A. Spiller, Thitphalak Chounthirath & Gary A. Smith (2019): Kratom exposures reported to United States poison control centers: 2011–2017, Clinical Toxicology, DOI: 10.1080/15563650.2019.1569236
Category: Critical Care
Keywords: Airway management, acute respiratory failure, hypoxia, intubation, preoxygenation (PubMed Search)
The PROTRACH study recently compared preoxygenation with standard bag valve mask (BVM) at 15 lpm to preoxygenation + apneic oxygenation with high flow nasal cannula 60 lpm/100% FiO2 in patients undergoing rapid sequence intubation.
Guitton C, Ehrmann S, Volteau C, et al. Nasal high-flow preoxygenation for endotracheal intubation in the critically ill patient: a randomized clinical trial. Intensive Care Med. 2019. doi: 10.1007/s00134-019-05529-w. [Epub ahead of print]
Keywords: back pain, back emergency (PubMed Search)
Cauda Equina Syndrome (CES)
A recent pearl discussed CES. This is a very challenging diagnosis to make, especially on initial presentation
The 5 “classic” characteristic features are
Not all symptoms will be present in a given patient and there is no sign/symptom combination that either reliably diagnoses or excludes CES.
To illustrate how difficult this diagnosis is to make, a study looked at the predictive abilities of Neurosurgical residents.
Positive MRI for CES was accurately predicted by senior neurosurgical residents in approximately 50% of patients suspected of CES based on history and physical findings. As clinical certainty only becomes apparent with the classic symptoms (which are generally late findings) waiting to initiate MRI will delay decompressive surgery and can lead to worsened functional outcomes. This leads to increased MRI demand with more negative MRIs. Not surprisingly, only ~20% of MRI scans for suspected CES are positive.
Bell DA et al. Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning? Br J Neurosurg 2007;21:201-3.
Category: Critical Care
A True Tracheostomy Emergency
Przbylo JA, Wittels K, Wilcox SR. Respiratory distress in a patient with a tracheostomy. J Emerg Med. 2019; 56:97-101.
Category: Pharmacology & Therapeutics
Keywords: bleeding, epistaxis, tranexamic acid (PubMed Search)
Mechanism of Action
Tranexamic Acid (TXA) is an antifibrinolytic agent that is a competitive inhibitor of plasminogen activation, and a non-competitive inhibitor of plasmin
Inhibits the breakdown of fibrin mesh allowing clot formation
When is it Indicated?
Epistaxis/Oral Bleeds/Fistula Bleeds
Keywords: spinal cord, physical exam, assessment (PubMed Search)
Back pain with lower extremity symptoms can be concerning for cauda equina. Some pointers regarding the H&P:
None of these symptoms independently predicts cauda equina syndrome with an accuracy greater than 65%.
Bottom Line: do not depend on any one finding to reliably exclude or confirm cauda equina.
Shapiro S. Medical realities of cauda equina syndrome secondary to lumbar disc herniation. Spine (Phila Pa 1976). 2000;25(3):348-351; discussion 352
Gardner A, Gardner E, Morley T. Cauda equina syndrome: a review of the current clinical and medico-legal position. Eur Spine J. 2011;20(5):690-697. (Review article)
Bell DA, Collie D, Statham PF. Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning? Br J Neurosurg. 2007;21(2):201-203
Category: Critical Care
Keywords: ARDS, respiratory failure, ventilator settings, critical care (PubMed Search)
Despite ongoing research and efforts to improve our care of patients with ARDS, it remains an entity with high morbidity and mortality. Early recognition of the disease process and appropriate management by emergency physicians can have profound effects on the patient's course, especially in centers where ICU boarding continues to be an issue.
Recognition of ARDS (Berlin criteria)
*An ABG should be obtained in the ED if physicians are unable to wean down FiO2 from high settings, if oxygenation by pulse ox is marginal, or if the patient is in a shock state.
Tenets of ARDS Management:
*IBW Males = 50 + 2.3 x [Height (in) - 60] / IBW Females = 45.5 + 2.3 x [Height (in) - 60]
Strategies for Refractory Hypoxemia in the ED: You can't prone the patient, but what else can you do?
1. Escalate PEEP in stepwise fashion
2. Recruitment maneuvers
3. Appropriate sedation and neuromuscular blockade
4. Inhaled pulmonary vasodilators (inhaled prostaglandins, nitric oxide) if known or suspected right heart failure or pulmonary hypertension
Bottom Line: Emergency physicians are the first line of defense against ARDS. Early recognition of the disease process and appropriate management is important to improve outcomes AND to help ICU physicians triage which patients need to be emergently proned or even who should potentially be referred for ECMO.
Fielding-Singh V, Matthay MA, Calfee CS. Beyond Low Tidal Volume Ventilation: Treatment Adjuncts for Severe Respiratory Failure in Acute Respiratory Distress Syndrome. Crit Care Me.. 2018;46(11):1820-31.
Keywords: low back pain, analgesia (PubMed Search)
In patients with lower back pain, there is good evidence that muscle relaxants reduce pain as compared to placebo and that different types are equally effective. However, the high incidence of significant side effects such as dizziness and sedation limits their use. Muscle relaxants may be beneficial in an every bedtime capacity thereby limiting side effects.
If cyclobenzaprine is used during daytime hours, a lower dose schedule may work as well as a higher dose with somewhat less somnolence (5 mg three times a day vs 10 mg three times a day. In general, muscle relaxants should only be used when patients cannot tolerate NSAIDs but can tolerate the side effect profile.
We commonly add muscle relaxants to NSAIDs hoping for a larger analgesic effect. However, combination therapy does not appear to be better than monotherapy.
Adding cyclobenzaprine to high-dose ibuprofen does not seem to provide additional pain relief in the first 48 hours in ED patients with acute myofascial strain. Among an ED population with acute non radicular low back pain, a randomized trial found that adding cyclobenzaprine/other muscle relaxants to Naproxen did not improve functional outcomes or pain at one week or 3 months compared to naproxen alone.
Take home: Consider the limited usefulness use of muscle relaxants in ED patients with back pain
Friedman et al., 2015. JAMA.
Keywords: CCHD, congenital cardiac lesions, congenital heart disease (PubMed Search)
The hyperoxia-hyperventilation test (aka 100% Oxygen Challenge test) is used to differentiate the cause of central cyanosis in the sick neonate. The majority of neonatal cyanosis is caused by either cardiac or respiratory pathology.
Classically the test is performed as follows:
1. An ABG is obtained with the neonate breathing room air
2. The patient is placed on 100% FiO2 for 10 minutes
3. A repeat ABG is performed looking for an increase in PaO2 to >150 mmHg
- If the hypoxia is secondary to a respiratory cause, the PaO2 should increase to >150 mmHg.
- If the hypoxia is secondary to a congenital cardiac lesion (i.e. secondary to a right-to-left cardiac shunt) the PaO2 is not expected to rise significantly.
In practice, many physicians instead use pulse oximetry and monitor the SpO2 pre and post administration of 10 minutes of 100% FiO2.
- If after 10min of 100% FiO2, if SpO2 is not ? 95% (some resources use 85%) then the central cyanosis is likely secondary to intracardiac shunt.
- When this occurs, presume the sick neonate is symptomatic from a congenital cardiac lesion and initiate prostaglandin E-1 (PGE1) at 0.05-0.01 mcg/kg/min. Use caution as PGE1 may cause apnea.
Keywords: CT, Overdose, Pills (PubMed Search)
The primary tenet of poisoning treatment is to separate the patient from the poison. Gastric decontamination has been the cornerstone of poisoning treatment throughout history and methods include induced emesis, nasogastric suctioning, EGD or gastrostomy retrieval, activated charcoal, and whole bowel irrigation. Current guidelines for gastic decontamination are limited to few clinical situations. The detection of residual life threatening poisons in the stomach would be of value in predicting who might benefit from gastric decontamination in overdose.
Plain radiographs have variable sensitvity in detecting radioopaque pills. Computed tomography (CT) has been successful and gained wide acceptance in the detection of drug in body packers. In a recent study, authors studied the usefulness of non-contrast abdominal computed tomography for detection of residual drugs in the stomach in patients presenting over 60 minutes from acute drug overdose:
Non-contrast CT may help to predict which patients would benefit from gastric decontamination in acute life-threatening drug poisonings.
Position paper update: gastric lavage for gastrointestinal decontamination. Benson B, Hoppu K, et al. Clin Toxicol. 2013;51:140–146.
American Academy of Clinical Toxicology & European Association of Poisons Centres and Clinical Toxicologists (2005) Position Paper: Single-Dose Activated Charcoal, Clinical Toxicology, 43:2, 61-87.
Are ingested lithium sulphate tablets visible on x-ray? A one-year prospective clinical survey. Höjer J, Svanhagen AC. 2012. Clinical Toxicology, 50:9, 864-865.
The usefulness of non-contrast abdominal computed tomography for detection of residual drugs in the stomach of patients with acute drug overdose, Yong Sung C, Seung-Whan C, et al. 2019. Clinical Toxicology.
Category: Critical Care
Does This Patient Have Pericardial Tamponade?
Alerhand S, Carter JM. What echocardiographic findings suggest a pericardial effusion is causing tamponade? Am J Emerg Med. 2019; 37:321-6.
Keywords: Maintenance fluids, D5, NS, hyponatremia (PubMed Search)
Hyponatremia is the most common electrolyte abnormality in hospitalized patients, affecting approximately 15-30% of patients. Children have historically been given hypotonic maintenance IV fluids based off of theoretical calculations from the 1950s. Multiple studies have shown complications related to iatrogenic hyponatremia, including increased length of hospital stay, seizures and death.
The American Academy of pediatrics completed a systematic review and developed an updated clinical practice guideline:
Patient's age 28 days to 18 years requiring maintenance IV fluids should receive isotonic solutions with the appropriate amount KCl and dextrose.
Feld LG, Neuspiel DR, Foster BA, et al. Clinical Practice Guideline: Maintenance Intravenous Fluids in Children. Pediatrics. 2018;142(6):e20183083
Keywords: physostigmine, anticholinergic toxicity, adverse effects (PubMed Search)
Physostigmine is a cholinergic agent that can be administered to reverse delirium associated with anticholinergic toxicity. However, it is infrequenly used since the reports of cardiac arrest in patients with TCA overdose.
A recently published study reviewed 161 articles – involving 2299 patients – to determine the adverse effects and their frequency after the administration of physostigmine.
Adverse effects were observed in 415 patients (18.1%)
Specific adverse effects
Of 394 TCA overdose, adverse effects occurred in 14 patients (3.6%)
Arens AM et al. Adverse effects of physostigmine. J Med Toxciol. Feb 11. doi: 10.1007/s13181-019-00697-z. [Epub ahead of print] Review.
Category: Critical Care
Keywords: neutropenic fever, typhlitis, necrotizing enterocolitis, sepsis, septic shock (PubMed Search)
Neutropenic enterocolitis can occur in immunosuppressed patients, classically those being treated for malignancy (hematologic much more commonly than solid tumor). When involving the cecum specifically, it is known as "typhlitis."
It should be considered in any febrile neutropenic patients with abdominal pain or other symptoms of GI discomfort (diarrhea, vomiting, lower GI bleeding), and can be confirmed with CT imaging.
A recent study found that invasive fungal disease, most often candidemia, occurred in 20% of febrile neutropenic patients with CT-confirmed enteritis, a rate that increased to 30% if the patient was in septic shock.
1. Have a lower threshold for abdominal CT imaging in your patients with febrile neutropenia and abdominal pain/GI symptoms, especially if they are critically ill.
2. Consider addition of IV antifungal therapy if they are hemodynamically unstable with enterocolitis on CT.
Duceau B, Picard M, Pirrachio R, et al. Neutropenic enterocolitis in critically ill patients: Spectrum of the disease and risk of invasive fungal disease. Crit Care Med. 2019. [Epub ahead of print] doi: 10.1097/CCM.0000000000003687.
Keywords: Neck pain, radiculopathy (PubMed Search)
Spurling’s maneuver and modified Spurling’s maneuver aka neck compression test.
This maneuver is highly specific for the presence of cervical root compression
Can be used to reproduce radicular pain/symptoms.
Perform this maneuver with caution as it should not be performed in patients who have potential cervical spine instability.
Keeping the patient’s head in a neutral position pressing down on the top of the head. If this fails to reproduce the patient's pain, the test is repeated with the head extended, rotated and tilted to the affected side (the modified Spurling’s maneuver).
Reproduction of symptoms (limb pain or paresthesias) beyond the shoulder is considered positive. Neck pain alone is nonspecific and constitutes a negative test.
The test has a high specificity (0.89 to 1.00) but low sensitivity (0.38 to 0.97).
Meaning a positive test is helpful but a negative test does not rule out radicular pain.
This test should be used in conjunction with a thorough history and physical examination (strength, sensation and reflex testing)
Thoomes, Spine J 2018 Value of physical tests in diagnosing cervical radiculopathy: a systematic review.
Category: Critical Care
Management of Acute Variceal Bleeding
Boregowda U, et al. Update on the management of gastrointestinal varices. World J Gastrointest Pharmacol Ther. 2019; 10:1-21.
Keywords: older adults, CrCl, GFR, weight (PubMed Search)
Serum creatinine decreases with age with the decrease in lean body mass. However, the number of functioning glemeruli and kidney function decrease with age as well, making the creatinine an unreliable indicator of renal function in older adults.
The solution? Calculate the creatinine clearance (CrCl) (or GFR) for a more accurate assessment of the renal function. You can use simple equations such as the Cockroft-Gault equation which incorporate the body weight and age.
CrCl (mL/min) = (140-age) x lean body weight (kg) x (0.85 if female)
serum creatinine (mg/dL) x 72
Cockcroft DW, Gault H, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. doi:10.1159/000180580.
Wiggins J, Patel SR. Aging of the kidney. In: Halter J, Ouslander J, Studenski S, et al., eds. Hazzard’s Geriatric Medicine and Gerontology. 7th edition. New York, NY: McGraw-Hill; 2017. http://accessmedicine.mhmedical.com/content.aspx?bookid=1923§ionid=144525776.
Category: Pharmacology & Therapeutics
Keywords: hypoglycemia, hyperkalemia (PubMed Search)
Scott NL, Klein LR, Cales E, Driver BE. Hypoglycemia as a complication of intravenous insulin to treat hyperkalemia in the emergency department. Am J Emerg Med. 2019;37(2):209-213.
Keywords: Methylene Blue (PubMed Search)
Most clinicians are familiar with use of methylene blue for the treatment of methemoglobinemia, as a urinary analgesic, anti-infective, and anti-spasmodic agent, or for its use in endoscopy as a gastrointestinal dye, but this compound also has a role as a rescue antidote in life threatening poisonings causing refractory shock states and other shock states.
Methylene blue should be considered when standard treatment of distributive shock fails.
Methylene Blue for Distributive Shock: a Potential New Use of An Old Antidote. Jang DH, Nelson LS, Hoffman RS. J Med Toxicol. 2013;9(3):242-9.
Methylene blue used in treatment of refractory shock resulting from drug poisoning. Fischer J. Taori G. et al. Clin Toxicol 2014 Jan;52(1) 63-65.
Calcium channel antagonist and beta blocker overdoses: antidotes and adjunct therapies. Graudins A, Lee HM, Druda D. Br J Clin Pharmacol. 2016 Mar 81(3):453-61.
A Review of Methylene Blue Treatment for Cardiovascular Collapse. Lo A, Jean CY, et al. Journal of Emerg Med. May 2014. Vol 46 (6): 670-679.
A Systematic Analysis of methylene Blue for Drug-Induced Shock. Warrick BJ, Tataru AP, Smolinske S. Clin Toxicol 2016 Aug;54(7):547-55.