Contributor: Ricky Dhaliwal MD

Educational Pearls:

• Etomidate was previously the drug of choice for rapid sequence intubation (RSI)

• • However, it carries a risk of adrenal insufficiency as an adverse effect through inhibition of mitochondrial 11-β-hydroxylase activity

• A recent meta-analysis analyzing etomidate as an induction agent showed the following:

• • 11 randomized-controlled trials with 2704 patients

  • Number needed to harm is 31; i.e. for every 31 patients that receive etomidate for induction, there is one death

  • The probability of any mortality increase was 98.1%

• Ketamine is preferable due to a better adverse effect profile

• • Laryngeal spasms and bronchorrhea are the most common adverse effects after IV push

  • Beneficial effects on hemodynamics via catecholamine surge, albeit not as pronounced in shock patients

• 2023 meta-analysis compared ketamine and etomidate for RSI

• • Ketamine’s probability of reducing mortality is cited as 83.2%

  • Overall, induction with ketamine demonstrates a reduced risk of mortality compared with etomidate

• The dosage of each medication for induction

• • Etomidate: 20 mg based on 0.3 mg/kg for a 70 kg adult

  • Ketamine: 1-2 mg/kg (or 0.5-1 mg/kg in patients with shock)

• Patients with asthma and/or COPD also benefit from ketamine induction due to putative bronchodilatory properties

References

1. Goyal S, Agrawal A. Ketamine in status asthmaticus: A review. Indian J Crit Care Med. 2013;17(3):154-161. doi:10.4103/0972-5229.117048

2. Koroki T, Kotani Y, Yaguchi T, et al. Ketamine versus etomidate as an induction agent for tracheal intubation in critically ill adults: a Bayesian meta-analysis. Crit Care. 2024;28(1):1-9. doi:10.1186/s13054-024-04831-4

3. Kotani Y, Piersanti G, Maiucci G, et al. Etomidate as an induction agent for endotracheal intubation in critically ill patients: A meta-analysis of randomized trials. J Crit Care. 2023;77(April 2023):154317. doi:10.1016/j.jcrc.2023.154317

Summarized & Edited by Jorge Chalit, OMS3

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Contributor: Aaron Lessen MD

Educational Pearls:

• Pregnant patients at high risk of cardiac arrest, in cardiac arrest, or in extremis require special care

• A useful mnemonic to recall the appropriate management of critically ill pregnant patients is TOLDD

• T: Tilt the patient to the left lateral decubitus position

• • This position relieves pressure exerted from the uterus onto the inferior vena cava, which reduces cardiac preload

  • If the patient is receiving CPR, an assistant should displace the uterus manually from the IVC towards the patient’s left side

• O: Administer high-flow adjunctive oxygen

• L: Lines should be placed above the diaphragm

• • Lines below the diaphragm are ineffective due to uterine compression of the IVC

  • May consider humeral interosseous line vs. internal jugular or subclavian central line

• D: Dates should be estimated

• • > 20 weeks, can consider a resuscitative hysterotomy (previously known as perimortem c-section) to improve chances of survival

  • The uterus is palpable at the umbilicus at 20 weeks and 1 cm superior to the umbilicus for every week thereafter

• D: Call the labor and delivery unit for additional help

References

1. ACOG Practice Bulletin No. 211 Summary: Critical Care in Pregnancy. Obstetrics & Gynecology. 2019;133(5)

2. Fujita N, Higuchi H, Sakuma S, Takagi S, Latif MAHM, Ozaki M. Effect of Right-Lateral Versus Left-Lateral Tilt Position on Compression of the Inferior Vena Cava in Pregnant Women Determined by Magnetic Resonance Imaging. Anesth Analg. 2019;128(6):1217-1222. doi:10.1213/ANE.0000000000004166

3. Jeejeebhoy FM, Zelop CM, Lipman S, et al. Cardiac Arrest in Pregnancy. Circulation. 2015;132(18):1747-1773. doi:doi:10.1161/CIR.0000000000000300

4. Singh, Ajay; Dhir, Ankita; Jain, Kajal; Trikha, Anjan1. Role of High Flow Nasal Cannula (HFNC) for Pre-Oxygenation Among Pregnant Patients: Current Evidence and Review of Literature. Journal of Obstetric Anaesthesia and Critical Care 12(2):p 99-104, Jul–Dec 2022. | DOI: 10.4103/JOACC.JOACC_18_22

Summarized & Edited by Jorge Chalit, OMS3

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Contributor: Travis Barlock MD

Educational Pearls:

What is the ST segment?

• The ST segment on an ECG represents the interval between the end of ventricular depolarization (QRS) and the beginning of ventricular repolarization (T-wave).

• It should appear isoelectric (flat) in a normal ECG.

What if the ST segment is elevated?

• This is evidence that there is an injury that goes all the way through the muscular wall of the heart (transmural)

• This is very concerning for a heart attack (STEMI) but can be occasionally caused by other pathology, such as pericarditis

What if the ST segment is depressed?

• This is evidence that only the innermost part of the muscular wall of the heart is becoming ischemic

• This has a much broader differential and includes a partial occlusion of a coronary artery but also any other stress on the body that could cause a supply-and-demand mismatch between the oxygen the coronaries can deliver and the oxygen the heart needs

• This is called subendocardial ischemia

What else should you look for in the ECG to identify subendocardial ischemia?

• The ST-depressions should be at least 1 mm

• The ST depressions should be present in leads I, II, V4-6 and a variable number of additional leads.

• There is often reciprocal ST elevation in aVR > 1 mm

The most important thing to remember when you see subendocardial ischemia is…history

• Still, keep all cardiac causes on your differential, such as unstable angina, stable angina, Prinzmetal angina, etc.

• Also consider a wide array of non-cardiac causes such as severe anemia, severe hypertension, pulmonary embolism, COPD, severe pneumonia, sepsis, shock, thyrotoxicosis, stimulant use, DKA, or any other state that lead to reduced oxygen supply to the subendocardium and/or increased myocardial oxygen demand.

References

1. Birnbaum, Y., Wilson, J. M., Fiol, M., de Luna, A. B., Eskola, M., & Nikus, K. (2014). ECG diagnosis and classification of acute coronary syndromes. Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc, 19(1), 4–14. https://doi.org/10.1111/anec.12130

2. Buttà, C., Zappia, L., Laterra, G., & Roberto, M. (2020). Diagnostic and prognostic role of electrocardiogram in acute myocarditis: A comprehensive review. Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc, 25(3), e12726. https://doi.org/10.1111/anec.12726

3. Cadogan, E. B. a. M. (2024, October 8). Myocardial Ischaemia. Life in the Fast Lane • LITFL. Retrieved December 7, 2024, from https://litfl.com/myocardial-ischaemia-ecg-library/#:~:text=ST%20depression%20due%20to%20subendocardial,left%20main%20coronary%20artery%20occlusion.

Summarized by Jeffrey Olson, MS3 | Edited by Meg Joyce & Jorge Chalit, OMS3

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