Podcast production, editing and sound design by Anton Helman
Written summary & blog post by Sarah Reid and Anton Helman November, 2021
Cite this podcast as: Helman, A., Swaminathan, A., Khatib, N., Reid, S., H. Carr, D., Morgenstern J. EM Quick Hits 34 – Carr’s Case, Septic Arthritis vs Transient Synovitis, Managing Tracheostomies, Ethylene Glycol Poisoning, Ketamine for Agitation. Emergency Medicine Cases. November, 2021. https://emergencymedicinecases.com/em-quick-hits-november-2021/. Accessed [date].
Pediatric nontraumatic limp – differentiating transient synovitis from acute bacterial osteoarticular infection (septic arthritis, osteomyelitis)
Age and fever dictate differential for nontraumatic pediatric limp
Causes of non-traumatic limp by age/presence of fever
Workup to consider:
CBCD, CRP, blood culture if infection/inflammatory cause suspected to help distinguish between transient synovitis and osteoarticular infection
US (for effusion, soft tissues) if significant fever and/or elevation of inflammatory markers and/or severe pain
MRI with gadolinium is the most accurate noninvasive test for osteoarticular infection and should be considered for patients with persistent pain/fever
Differentiating transient synovitis and acute bacterial osteoarticular infection
Volume of blood matters when obtaining blood for culture and sensitivity which is essential, as hematogenous spread is common in children with osteoarticular infections
Peltola H. and Paakkonen M. Acute Osteomyelitis in Children. N Engl J Med. 2014;370:352-360.
Tu J, et al. Test characteristics of history, examination and investigations in the evaluation for septic arthritis in the child presenting with acute non-traumatic limp. A systematic review. BMJ Open 2020;10:e038088.
Ethylene glycol is a toxic alcohol found in engine coolants, cleaning products, radiator antifreeze, degreasing agents, foam stabilizers and metal cleaners that is intoxicating like ethanol
As the alcohol (which is nontoxic itself) is metabolized to an acid (which is toxic) patients develop hypotension, tachycardia, tachypnea, depressed level of awareness, renal failure and potentially seizures. The symptoms usually develop over 6-24hrs but can be delayed up to 4 days if ethanol is coingested.
Diagnostic clues to toxic overdose include tachycardia and tachypnea (in an attempt to blow off CO2), high anion gap metabolic acidosis with high osmolar gap, not sobering up as expected, low ethanol level in a highly inebriated patient
Early after ingestion an anion gap metabolic acidosis has not had time to develop but osmolality is expected to be high. Later after ingestion an anion gap metabolic acidosis is expected while the osmolality may be normal. Absence of an anion gap metabolic acidosis or high osmolar gap does not rule out toxic alcohol poisoning.
Coingestion of ethanol delays the toxic effects of ethylene glycol and can be used as an effective treatment when fomepazol antidote is not available.
Additional treatments besides fomepazol or ethanol includes pyridoxine, correction of acidosis with a bicarbonate infusion to target pH = 7.2, and dialysis
Evidence for ketamine for severe agitation and excited delirium
The first ever ED RCTs comparing ketamine to haloperidol + benzodiazepine for severely agitated patients were published in 2021
A randomized, single ED study of 93 patients compared ketamine (4 mg/kg IM or 1mg/kg IV) and haloperidol/lorazepam (haloperidol 5-10 mg IM/IV + lorazepam 1-2 mg IV/IM) with primary outcome of time to sedation, and found ketamine was significantly more effective at both 5 minutes and 15 minutes after medication administration with no statistically significant increase in adverse effects
Another single-centered, randomized trial of 80 patients comparing ketamine (5 mg/kg IM) and haloperidol/midazolam (5 mg for both), showed a significantly different mean time to sedation of 6 minutes for the ketamine group and 15 minutes for the haloperidol/midazolam group with no statistical difference in serious adverse events
While there were no statistical difference in serious adverse events, there was a trend toward more adverse events in the ketamine groups
=>Ketamine may be superior to haloperidol + benzodiazepine for rapid sedation of severely agitated patients but is associated with more serious adverse events, and should be considered in selected patients in the prehospital setting when rapid sedation is perhaps more important than in the ED
Barbic D, Andolfatto G, Grunau B, Scheuermeyer FX, Macewan B, Qian H, Wong H, Barbic SP, Honer WG. Rapid Agitation Control With Ketamine in the Emergency Department: A Blinded, Randomized Controlled Trial. Ann Emerg Med. 2021 Aug 2:S0196-0644(21)00433-9.
Lin J, Figuerado Y, Montgomery A, Lee J, Cannis M, Norton VC, Calvo R, Sikand H. Efficacy of ketamine for initial control of acute agitation in the emergency department: A randomized study. Am J Emerg Med. 2021 Jun;44:306-311
None of the authors have any conflicts of interest to declare
Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.