Podcast production, editing and sound design by Anton Helman
Podcast content, written summary & blog post by Anand Swaminathan, Brit Ling, Hania Bielawska and Anton Helman.
Edited by Anton Helman
Cite this podcast as: Helman, A. Swaminathan, A. Perry, J. Rosenberg, H. Bielawska, H, Long, B. Bridwell, R. Gottlieb M. Hensley, J. Murray, H. EM Quick Hits 19 Angioedema, SAH Decision Tool, Breastfeeding Myths, COVID-19 Neurology, Spider Bites, Skin Abscess Management. June, 2020. https://emergencymedicinecases.com/em-quick-hits-june-2020/. Accessed [date].
Management of Severe Angioedema
For the crashing patient with severe angioedema consider a Ketamine-Only Breathing Intubation (see KOBI), an alternative to awake intubation using dissociative dose ketamine (in a typical adult 100 mg over 30 seconds), and have a “double set up” with the neck prepared for cricothyrotomy
For the non-crashing patient with severe angioedema consider an awake intubationwith full topicalization and fiberoptic intubation
Medications for ACEi-associated angioedema such as icatibant, C1 esterase inhibitors and FFP are not evidence based and are generally not indicated
Consider tranexamic acid (TXA) 1g IV over 10 minutes based on a study of 33 patients in France
Beauchêne C, Martins-héricher J, Denis D, Martin L, Maillard H. [Tranexamic acid as first-line emergency treatment for episodes of bradykinin-mediated angioedema induced by ACE inhibitors]. Rev Med Interne. 2018;39(10):772-776.
Ottawa Subarachnoid Hemorrhage Rule and 6-Hour Computed Tomography Rule
The Ottawa SAH rule is recommended to assess whether or not a patient who presents with headache can be safely ruled out without any investigations.
Inclusion: GCS 15, ≥15 years old, new severe atraumatic headache, maximum intensity within 1 hour.
Exclusion: Patients with new neurologic deficits, prior aneurysm, prior SAH, known brain tumors, or chronic recurrent headaches (≥3 headaches of the same character and intensity for >6 months).
Neck pain or stiffness,
Witnessed loss of consciousness,
Onset during exertion,
Thunderclap headache (peaking pain within 1 second),
Limited neck flexion on examination
The Ottawa SAH rule was shown to have a 100% sensitivity for SAH in its validation, however it was 95% sensitive in the latest implementation study (note that there was only one true SAH miss in this study of a patient with profound anemia)
The Ottawa SAH 6-Hour Computed Tomography Rule is recommended to assess whether or not a patient who fails the Ottawa SAH rule can be ruled out with a plain CT done within 6hrs of headache onset without the need for further investigations (lumbar puncture, CTA).
Exclusion: 3 or more previous similar headaches (ie, same intensity/character as their current headache) over a period of >6 months (eg, established migraines), confirmed SAH before arrival at study ED, previously investigated with CT and LP for the same headache, papilledema, new focal neurological deficit, previous diagnosis of intracranial aneurysm or SAH, known brain neoplasm, cerebroventricular shunt, headache within 72 hours following a LP, headache described as gradual or peak intensity beyond 1 hour
Sensitivity = 95%, specificity=100%
The 6-hour-CT rule resulted in a 13% decrease in LP utilization following a normal early CT (26% vs 39%)
5 patients had SAH with the CT reported as normal: two unruptured aneurysms on CTA and presumed traumatic LP (as deemed by the treating neurosurgeon), one missed by the radiologist on the initial interpretation, one dural vein fistula (ie, non-aneurysmal), and one patient with sickle cell anemia with profound anemia (Hb, 63 g/L) with a 3 mm aneurysm
The Ottawa SAH 6hr rule for CT rule out should not be applied to patients who are known to be anemic with a serum Hb<90 g/L (9g/dL) at the time of the CT head because any blood will appear darker than usual on the CT scan making it more difficult to distinguish blood from brain tissue and hence can be missed on the CT.
Update 2022:A retrospective analysis of 347 patients with a subarachnoid hemorrhage found that the sensitivity of modern MSCT was 99.6% for aneurysmal SAH and 99% for all SAH at 48 hours after headache onset, and 100% for aneurysmal SAH at 24 hours after headache onset. There were no differences observed between 128-slice and 64-slice CT scanners. Abstract
Perry JJ, Stiell IG, Sivilotti ML, et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA. 2013;310(12):1248-55.
Bellolio MF, Hess EP, Gilani WI, et al. External validation of the Ottawa subarachnoid hemorrhage clinical decision rule in patients with acute headache. Am J Emerg Med. 2015;33(2):244-9.
Validation of the Ottawa Subarachnoid Hemorrhage Rule in patients with acute headache. CMAJ. 2018;190(6):E173.
Perry JJ, Sivilotti MLA, Émond M, et al. Prospective Implementation of the Ottawa Subarachnoid Hemorrhage Rule and 6-Hour Computed Tomography Rule. Stroke. 2020;51(2):424-430.
ED Breastfeeding Myths and Misconceptions
Physicians often confuse medication safety in lactation with that in pregnancy, or give overly cautious advice due to a concern for the infant’s safety; however, the vast majority of medications we use in the ED, as well as conditions we encounter, should not preclude ongoing breastfeeding
Not only can our well-meaning advice to avoid certain medications result in suboptimal care of the breastfeeding woman, suggesting that breastfeeding be interrupted or that a mom should express and dump her breast milk can result in a drop in milk supply and even unintended early weaning
When feeds are missed or replaced by formula, this can quickly result in less breast milk made by the mom, leading to a vicious cycle of a baby who is more hungry and fussy, who then gets more supplementation, spends less time at the breast, and eventually this can end breastfeeding altogether; other adverse consequences of missed feeds are plugged ducts and mastitis
The best opioid options for pain control in the breastfeeding mother are fentanyl and morphine; fentanyl levels in breast milk are nearly undetectable after 2 hours, while morphine has a short breast milk half-life, and is poorly absorbed by the child; hydromorphine, oxycodone and codeine are not recommended as hydromorphone has a long breast milk half life, oxycodone concentrates in the breast milk and codeine has an unpredictable metabolism
CT contrast administered to a breastfeeding mother is generally safe for the infant – the dose of CT iodinated contrast to the infant is less than 0.01% of the maternal dose and is thought to be inconsequential
Interruption of breastfeeding for 13 hours is required for VQ imaging because of the radioactive isotope; during that time however, the mom can still express her milk, and the milk is safe to feed to the infant once 13h has passed
Anesthetic medications such as propofol, etomidate, fentanyl and midazolam do not require any interruption in breastfeeding; the safety of ketamine is unknown, although it is likely to be safe, based on the principle of rapid redistribution from plasma
Breastfeeding is safe for most maternal infections; exceptions include Ebola, smallpox, HIV, rabies, active TB, herpes zoster of the breast
Black, A.D. Managing the Breastfeeding Patient in the Emergency Department. Ann Emerg Med. 2019. Aug 1-6.
Health Science Executive, Ireland. Section on Breastfeeding. How to tell if your newborn is getting enough breast milk’. Accessed at: https://www2.hse.ie/wellbeing/child-health/getting-breastfeeding-off-to-a-good-start/knowing-if-your-newborn-is-getting-enough.html
The Transfer of Drugs and Therapeutics Into Human Breast Milk: An Update on Selected Topics. Pediatrics 2013.
Reese-Stremtan et al. Academy of Breastfeeding Medicine Clinical Protocol #15. Analgesia and Anesthesia for the Breastfeeding Mother. Breastfeeding Medicine. 2017; 12 (9). Accessed at: https://abm.memberclicks.net/assets/DOCUMENTS/PROTOCOLS/15-analgesia-and-anesthesia-protocol-english.pdf
Wanderer et al. Anesthesia & Breastfeeding: More Often Than Not, They Are Compatible. Infographic. Anesthesiology: October 2017, Vol.127, A15.
Aljazafa et al. Pseudoephedrine: effects on milk production in women and estimation of infant exposure via breastmilk . 2003. Br J Clin Pharmacol, 56, 18–24
American Academy of Pediatrics. Policy statement – Breastfeeding and the Use of Human Milk. Pediatrics 2012;129;e827
Ontario Human Rights Commission. Pregnancy and Breastfeeding. 2012. http://www.ohrc.on.ca/sites/default/files/Pregnancy%20and%20breastfeeding_English_accessible.pdf
Neurologic associations with COVID-19
Neurologic complications have been observed to occur in 6-36% of patients with COVID, with hypoxic encephalopathy affecting 20% of patients in one series
Preexisting neurologic conditions have been associated with more severe infections, greater risk of ARDS, and mortality
The prevalence of ischemic stroke ranges from 2.5 to 5% of patients with COVID, and stroke has also been common in younger patients
Acute necrotizing encephalopathy is thought to be due to cytokine storm and damage to the blood-brain barrier; the most common areas affected include the thalamus, brainstem, cerebellum, and cerebral white matter
Guillain Barre Syndrome in patients with COVID-19 has been reported in China and Italy; CSF testing has been negative for SARS-CoV-2 thus far, and brain/spine MRI did not show changes in half of the patients at the time they were obtained.
Hemophagocytic lymphohistiocytosis (HLH) is most commonly linked with hematologic malignancy, immunosuppression, or critical infection, but it has been described in patients with SARS-CoV-2. Up to 1/3 of patients with HLH associated with COVID-19 have developed neurologic complications. Treatment includes steroids and tocilizumab.
Wu Y, Xu X, Chen Z, et al. Nervous system involvement after infection with COVID-19 and other coronaviruses. Brain Behav Immun. 2020.
Baig AM. Updates on What ACS Reported: Emerging Evidences of COVID-19 with Nervous System Involvement. ACS Chem Neurosci. April 2020.
Mao L, Wang M, Chen S, et al. Neurological Manifestations of Hospitalized Patients with COVID-19 in Wuhan, China: a retrospective case series study. medRxiv. February 2020:2020.02.22.20026500.
Aggarwal G, Lippi G, Michael Henry B. Cerebrovascular disease is associated with an increased disease severity in patients with Coronavirus Disease 2019 (COVID-19): A pooled analysis of published literature. Int J Stroke. April 2020:1747493020921664.
Wang HY, Li XL, Yan ZR, Sun XP, Han J, Zhang BW. Potential neurological symptoms of COVID-19. Ther Adv Neurol Disord. 2020;13.
Management of Spider Bites
The Recluse and Black Widow spiders are the only two spiders in North America that are venomous to humans each of which have different toxidromes
Recluse spider bites tend to occur indoors, initally be relatively painless, have a necrotoxin that dissolves tissues locally, and is classified into minor loxoscelism (localized skin erythema and edema that resolves spontaneously over 1 week) and cutaneous loxoscelism (the more severe form with cutaneous blisters and/or irregular echymosis and classically the red, white and blue sign – see below – which may develop a necrtotic eschar and heals over 6-8 weeks)
Red, white and blue sign of recluse spider bite with echymotic center, surrounded by ischemic blanching and erythema at the periphery
Treatment involves appropriate wound care and symptomatic treatment with anitrpruritic
Recluse spider bites can rarely cause systemic loxoscelism with hemolysis and myelonecrosis, petechial rash, fever, vomiting, acute renal failure, DIC requiring resuscitation supportive care with blood products
Black Widow spider bites are neurotoxic (acetylcholine mediated) causing intense sudden pain locally or regionally, localized diaphoresis, hypertension, agitation, fever, and can mimic an acute abdomen.
Treatment is supportive; there is an antivenom for black widow spider bites, however there is no evidence of clinical benefit with its use.
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.