Anesthetic Management of the Hypertensive Patient: Part I

Safety of fecal microbiota, live-jslm (REBYOTA™) in individuals with recurrent Clostridioides difficile infection: data from five prospective clinical trials

Background

Microbiota-based treatments reduce the incidence of recurrent Clostridioides difficile infections (rCDIs), but prospectively collected safety data needed to broaden patient access and protect public health have been limited.

Objectives

We provide cumulative safety data from five prospective clinical trials evaluating fecal microbiota, live-jslm (RBL) - the first microbiota-based live biotherapeutic product approved by the US Food and Drug Administration - for preventing rCDI in adults.

Design

Integrated safety analysis includes three phase II trials (PUNCH CD, PUNCH CD2, PUNCH Open-Label) and two phase III trials (PUNCH CD3, PUNCH CD3-OLS) of RBL.

Methods

Trial participants were at least 18 years of age with documented rCDI who completed standard-of-care antibiotic therapy before treatment with RBL. Assigned study treatment regimen was one or two doses of RBL (or placebo) administered rectally, depending on the trial design. In four of the five trials, participants with CDI recurrence within 8 weeks after RBL or placebo administration were eligible for treatment with open-label RBL. Treatment-emergent adverse events (TEAEs) were recorded for at least 6 months following last study treatment; in PUNCH CD2 and PUNCH Open-Label trials, TEAEs and serious TEAEs were collected through 12 and 24 months, respectively.

Results

Among the five trials, 978 participants received at least one dose of RBL (assigned treatment or after recurrence) and 83 participants received placebo only. TEAEs were reported in 60.2% of Placebo Only participants and 66.4% of RBL Only participants. Only abdominal pain, nausea, and flatulence were significantly higher in the RBL Only group compared with the Placebo Only group. Most TEAEs were mild or moderate in severity and were most frequently related to preexisting conditions. There were no reported infections for which the causative pathogen was traced to RBL. Potentially life-threatening TEAEs were infrequent (3.0% of participants).

Conclusion

Across five clinical trials, RBL was well tolerated in adults with rCDI. In aggregate, these data consistently demonstrated the safety of RBL.

[Intraoperative management of potentially fatal arrhythmias after anesthesia induced by severe hypokalemia: A case report]

Severe hypokalemia is defined as the concentration of serum potassium lower than 2.5 mmol/L, which may lead to serious arrhythmias and cause mortality. We report an unusual case of potentially fatal ventricular arrhythmias induced by severe hypokalemia in a patient undergoing laparoscopic partial nephrectomy in Peking University Third Hospital due to irregular use of indapamide before operation. Indapamide is a sulfonamide diuretic with vasodilative and calcium antagonistic effects, which enhances sodium delivery to the renal distal tubules resulting in a dose-related increase in urinary potassium excretion and decreases serum potassium concentrations. The electrolyte disorder caused by the diuretic is more likely to occur in the elderly patients, especially those with malnutrition or long-term fasting. Hence, the serum potassium concentration of the patients under indapamide therapy, especially elderly patients, should be monitored carefully. Meanwhile, the potassium concentration measured by arterial blood gas analysis is different from that measured by venous blood or laboratory test. According to the previous research, the concentration of potassium in venous blood was slightly higher than that in arterial blood, and the difference value was 0.1-0.5 mmol/L. This error should be taken into account when rapid intravenous potassium supplementation or reduction of blood potassium level was carried out clinically. In the correction of severe hypokalemia, the standard approach often did not work well for treating severe hypokalemia. The tailored rapid potassium supplementation strategy shortened the time of hypokalemia and was a safe and better treatment option to remedy life-threatening arrhythmias caused by severe hypokalemia with a high success rate. Through the anesthesia management of this case, we conclude that for the elderly patients who take indapamide or other potassium excretion diuretics, the electrolyte concentration and the general volume state of the patients should be comprehensively measured and fully evaluated before operation. It may be necessary for us to reexamine the serum electrolyte concentration before anesthesia induction on the morning of surgery in patients with the history of hypokalemia. For severe hypokalemia detected after anesthesia, central venous cannulation access for individualized rapid potassium supplementation is an effective approach to reverse the life-threatening arrhythmias caused by severe hypokalemia and ensure the safety of the patients.

Maximum inferior vena cava diameter predicts post-induction hypotension in hypertensive patients undergoing non-cardiac surgery under general anesthesia: A prospective cohort study

Background

Inferior vena cava (IVC) ultrasonography is a reliable variable that predicts post-induction hypotension (PIH) in patients undergoing surgery under general anesthesia. However, in patients with hypertension, the predictive performance of ultrasound IVC measurements needs further exploration.

Methods

This is a prospective cohort study. Adult patients with existing hypertension scheduled to undergo non-cardiac surgery under general anesthesia were eligible. An abdominal ultrasound examination was conducted immediately prior to anesthesia induction (0.03 mg kg^–1 midazolam, 0.3 mg kg^–1 etomidate, 0.4 μg kg^–1 sufentanil, and 0.6 mg kg^–1 rocuronium). IVC collapsibility index (IVC-CI) was calculated as (dIVC_max–dIVC_min)/dIVC_max, where dIVC_max and dIVC_min represent the maximum and minimum IVC diameters at the end of expiration and inspiration, respectively. PIH was defined as a reduction of mean arterial pressure (MAP) by >30% of the baseline or to <60 mmHg within 10 min after endotracheal intubation. The diagnostic performance of IVC-CI, dIVC_max, and dIVC_min in predicting PIH was also examined in a group of normotensive patients receiving non-cardiac surgery under the same anesthesia protocol.

Results

A total of 51 hypertensive patients (61 ± 13 years of age, 31 women) and 52 normotensive patients (42 ± 13 years of age, 35 women) were included in the final analysis. PIH occurred in 33 (64.7%) hypertensive patients and 19 (36.5%) normotensive patients. In normotensive patients, the area under the receiver operating curve (AUC) in predicting PIH was 0.896 (95% confidence interval [CI]: 0.804–0.987) for IVC-CI, 0.770 (95% CI: 0.633–0.908) for dIVC_max, and 0.868 (95% CI: 0.773–0.963) for dIVC_min. In hypertensive patients, the AUC in predicting PIH was 0.523 (95% CI: 0.354–0.691) for IVC-CI, 0.752 (95% CI: 0.621–0.883) for dIVC_max, and 0.715 (95% CI: 0.571–0.858) for dIVC_min. At the optimal cutoff (1.24 cm), dIVC_max had 54.5% (18/33) sensitivity and 94.4% (17/18) specificity.

Conclusion

In hypertensive patients, IVC-CI is unsuitable for predicting PIH, and dIVC_max is an alternative measure with promising performance.

Clinical trial registration

[http://www.chictr.org.cn/], identifier [ChiCTR2000034853].

Anesthetic management of hypertensive patients

It is important for the clinicians to have a clear understanding of the anesthetic implications and increased risks due to hypertension to ensure safe surgical procedures in hypertensive patients. Preoperative hypertension is associated with greater intraoperative hemodynamic lability and an increased risk of perioperative cardiovascular complications. In addition to the patients’ baseline blood pressure (BP), the presence and severity of target organ damage and cardiovascular comorbidities should be evaluated preoperatively. Delaying surgery in hypertensive patients may be justified if there is an evidence of target organ damage that can be improved by such a delay. Further evaluation of suspected target organ damage before the surgery is also justified. Except withholding angiotensin-converting enzyme inhibitors/angiotensin receptor blockers 10 to 24 hours before the surgery, the continuation of preoperative antihypertensive therapy is generally recommended. Though maintaining perioperative BP within the range of 80%–90% to 110%–120% of the baseline BP (permissible BP decrease/increase ≤10%–20%) is generally recommended, an individualized and pathophysiology-based approach to control BP might be the best option throughout the perioperative period. In other words, BP targets in the perioperative period should be determined based on the type of surgery, patients’ baseline BP, risks of hypotension-related organ ischemia, and hypertension-related bleeding.