Ketamine versus etomidate as an induction agent for tracheal intubation in critically ill adults: a Bayesian meta-analysis.

BACKGROUND: Tracheal intubation is a high-risk intervention commonly performed in critically ill patients. Due to its favorable cardiovascular profile, ketamine is considered less likely to compromise clinical outcomes. This meta-analysis aimed to assess whether ketamine, compared with other agents, reduces mortality in critically ill patients undergoing intubation. METHODS: We searched MEDLINE, Embase, and the Cochrane Library from inception until April 27, 2023, for randomized controlled trials and matched observational studies comparing ketamine with any control in critically ill patients as an induction agent. The primary outcome was mortality at the longest follow-up available, and the secondary outcomes included Sequential Organ Failure Assessment score, ventilator-free days at day 28, vasopressor-free days at day 28, post-induction mean arterial pressure, and successful intubation on the first attempt. For the primary outcome, we used a Bayesian random-effects meta-analysis on the risk ratio (RR) scale with a weakly informative neutral prior corresponding to a mean estimate of no difference with 95% probability; the estimated effect size will fall between a relative risk of 0.25 and 4. The RR and 95% credible interval (CrI) were used to estimate the probability of mortality reduction (RR < 1). The secondary outcomes were assessed with a frequentist random-effects model. We registered this study in Open Science Framework ( https://osf.io/2vf79/ ). RESULTS: We included seven randomized trials and one propensity-matched study totaling 2978 patients. Etomidate was the comparator in all the identified studies. The probability that ketamine reduced mortality was 83.2% (376/1475 [25%] vs. 411/1503 [27%]; RR, 0.93; 95% CrI, 0.79-1.08), which was confirmed by a subgroup analysis excluding studies with a high risk of bias. No significant difference was observed in any secondary outcomes. CONCLUSIONS: All of the included studies evaluated ketamine versus etomidate among critically ill adults requiring tracheal intubation. This meta-analysis showed a moderate probability that induction with ketamine is associated with a reduced risk of mortality.

Severe Hypokalemia and Metabolic Alkalosis Caused by Licorice Discovered During the Treatment of Intraoperative Hypoxemia.

One of the causes of preoperative hypokalemia is the prolonged use of herbal medicines, especially licorice. Licorice can induce pseudo-aldosteronism, hypertension, metabolic alkalosis, and hypokalemia. An 87-year-old woman with a history of knee osteoarthritis was scheduled to undergo a total knee arthroplasty (TKA) under spinal anesthesia. She had also been prescribed herbal medicine for osteoarthritis of the knee two years before the surgery. During the surgery, the pulse oximeter showed hypoxemia. After the surgery was completed, arterial blood sampling showed hypoxemia, hypokalemia with electrocardiography (ECG) abnormalities, and metabolic alkalosis. The symptoms improved after the discontinuation of herbal medicines and administering potassium chloride. It is necessary to suspect electrolyte abnormalities as one of the causes of hypoxemia, hypertension, or ECG abnormalities in patients prescribed herbal medicines. Therefore, it is also important to ensure that patients on such drugs have their blood potassium levels assessed frequently in the perioperative period.