Questions of the Week for 5/23/2023

Author: Christian Gerhart

1.    A healthy 3 yo male presents with the following rash. He is nontoxic appearing and has normal vital signs. The patient is tolerating PO intake and appears well hydrated. What is the most likely diagnosis and how is this typically managed? 

Images from Wikipedia

This is erythema multiforme (EM). Presence of oral lesions is a key distinguishing characteristic from urticaria which should not have mucosal lesions. Generally, topical steroids and oral antihistamines can be used to treat symptoms. Always consider SJS! Generally, SJS has macular lesions whereas the lesions in EM are papular. It can be hard to tell. If you don’t know for sure consider discussing with dermatology. 

2.      A healthy 3 yo male presents with a rash that you think is urticaria multiforme. Vital signs are normal and he is well appearing. There are no oral lesions. Per parents the lesions seem to migrate and be present for a few hours at a time. What symptomatic therapy is recommended? 

• Answer

  Antihistamine therapy. Urticaria multiforme is generally a benign disease, however more sinister diagnoses such as SJS must always be considered. H2 blockers such as cetirizine (Zyrtec) +/- H1 blockers such as diphenhydramine. Steroids can be used for refractory cases.

3.      You have a 41 yo male who was in an MVC who was intubated 15 minutes ago for altered mental status. Just after intubation his end tidal CO2 was 33. It has now increased to 55. The rest of his vitals are notable for tachycardia to 120, BP 150/100, T: 42C, RR 35 (breathing over the vent), 98% 50% FiO2. What diagnosis should be considered? 

• Answer

  Malignant Hyperthermia. This is rare but we must know about it and be suspicious of any patient who becomes febrile following intubation with succinylcholine. Volatile anesthetics used in the OR are another cause of this and patients may present from the OR or from outpatient surgery centers. An early sign of MH is an increase in end tidal CO2.

4.      What are the next steps in management for the patient above? 

• Answer

  Call for the MH cart from anesthesia. Initiate evaporative cooling with a target temp of 38C. Administer dantrolene. Aggressive supportive care with hyperkalemia management, IV fluids and close temperature monitoring.

  See https://emcrit.org/ibcc/mh/ for more.

5.      An 80-year-old patient with Parkinson’s disease presents with agitation and altered mental status. The patient becomes unsafe to themselves while trying to get out of bed and nearly suffers a fall. They are not redirectable and you feel they need to be chemically restrained for their safety. What agent is preferred in this scenario? 

• Answer

  There are no “good” options but probably the safest would be benzodiazepines in this scenario as it does not have dopamine antagonism properties. Patients with Parkinson’s disease are at high risk for acute Parkinsonian crisis if anti-dopaminergic agents such as Haldol or Droperidol are given. It may take weeks for the patient to return to their baseline if given these medications.

6.      A 35 yo male presents with acute agitation and altered mental status. He is diaphoretic and febrile to 39C. His BP is 200/140, HR 135, RR 33, 93% on RA. He has dilated pupils and normal reflexes. His EKG is show below. What is the most likely diagnosis and what would your initial therapy be? 

• Answer

  This is consistent with a sympathomimetic toxidrome, most likely cocaine toxicity. Remember that cocaine can act as a sodium channel blocker in toxicity. This patient has findings of sodium channel blockade with wide QRS, long QTc and a terminal R wave in aVR. Sodium bicarbonate can be used to address the sodium channel blockade. Benzodiazepines would be the treatment for his agitation.

7.      A 13 yo male with no medical history presents after ingesting an unknown substance with his friends to “have a good time”. He is picking at the air and appears to be hallucinating but is overall calm. His BP is 160/90, HR 120, RR 20, O2 sat 99% RA, T 38.2. He has dilated pupils, normal muscle tone and normal reflexes. He has dry skin. What is the most likely diagnosis and how can this be treated. 

• Answer

  This is an anticholinergic toxidrome with dry skin, hyperthermia, mydriasis, tachycardia, and relatively abrupt onset after ingestion. Benzodiazepines can be used for agitation. Physostigmine can be used as antidotal therapy. It acts to increase acetylcholine in the synapse but inhibiting acetylcholinesterase. There is currently a physostigmine shortage. Physostigmine is generally safe in healthy patients with an isolated anti-cholinergic toxicity without concern for TCA overdose and if the QRS is narrow. A rivastigmine patch can be applied though this is not as rapidly acting. These are the most commonly used agents as other acetylcholinesterase inhibitors do not cross the blood brain barrier.

8.      A 57 yo female with a history of anxiety/depression (she does not know her home medications as they were recently adjusted) who presents with fever and tachycardia. She is found to have a purulent cellulitis of her lower extremity and is started on linezolid since she has an allergy to vancomycin. Her home medications are resumed by the admitting and she later becomes increasingly tachycardic and her temperature increases to 40C overnight. What diagnosis should be considered? 

• Answer

  Serotonin syndrome. The history of anxiety/depression is meant to indicate that she is on serotonergic medications and the addition of linezolid in the context of sepsis and a recent medication adjustment could trigger serotonin syndrome. The hallmark of serotonin syndrome is clonus and hyperreflexia. The Hunter criteria is commonly used to assist in diagnosis. Benzodiazepines are commonly used for agitation. Precedex is an option for sick patients such as this. Cyproheptadine can be used generally for more mild cases. Aggressive supportive care to address hyperthermia and vital signs instability is key.

  https://emcrit.org/ibcc/serotonin/#causes_of_serotonin_syndrome

9.      An 87 yo male has a ground level fall where he strikes his head on the ground. He has some neck pain and abdominal pain. His CT head, cervical spine and C/A/P are negative for acute injury. He feels weaker than usual in his arms and on examination has some mild grip strength and tricep/bicep weakness. What diagnosis should be considered and what is the next best test? 

• Answer

  This is most consistent with a central cord syndrome. An MRI of the cervical spine (generally contrast isn't needed) is the next best test. Remember that the exam is crucial! CT is great for looking at the bones of the cervical spine, but we can miss ligamentous and cord injuries. If a patient has new neurologic changes, then consider an MRI.