Adjustment of positive end-expiratory pressure to body mass index during mechanical ventilation in general anesthesia: BodyVent, a randomized controlled trial.

BACKGROUND: In patients requiring general anesthesia, lung-protective ventilation can prevent postoperative pulmonary complications, which are associated with higher morbidity, mortality, and prolonged hospital stay. Application of positive end-expiratory pressure (PEEP) is one component of lung-protective ventilation. The correct strategy for setting adequate PEEP, however, remains controversial. PEEP settings that lead to a lower pressure difference between end-inspiratory plateau pressure and end-expiratory pressure ("driving pressure," ΔP) may reduce the risk of postoperative pulmonary complications. Preliminary data suggests that the PEEP required to prevent both end-inspiratory overdistension and end-expiratory alveolar collapse, thereby reducing ΔP, correlates positively with the body mass index (BMI) of patients, with PEEP values corresponding to approximately 1/3 of patient's respective BMI. Thus, we hypothesize that adjusting PEEP according to patient BMI reduces ΔP and may result in less postoperative pulmonary complications. METHODS: Patients undergoing general anesthesia and endotracheal intubation with volume-controlled ventilation with a tidal volume of 7 ml per kg predicted body weight will be randomized and assigned to either an intervention group with PEEP adjusted according to BMI or a control group with a standardized PEEP of 5 mbar. Pre- and postoperatively, lung ultrasound will be performed to determine the lung aeration score, and hemodynamic and respiratory vital signs will be recorded for subsequent evaluation. The primary outcome is the difference in ΔP as a surrogate parameter for lung-protective ventilation. Secondary outcomes include change in lung aeration score, intraoperative occurrence of hemodynamic and respiratory events, oxygen requirements and postoperative pulmonary complications. DISCUSSION: The study results will show whether an intraoperative ventilation strategy with PEEP adjustment based on BMI has the potential of reducing the risk for postoperative pulmonary complications as an easy-to-implement intervention that does not require lengthy ventilator maneuvers nor additional equipment. TRIAL REGISTRATION: German Clinical Trials Register (DRKS), DRKS00031336. Registered 21st February 2023. TRIAL STATUS: The study protocol was approved by the ethics committee of the Christian-Albrechts-Universität Kiel, Germany, on 1st February 2023. Recruitment began in March 2023 and is expected to end in September 2023.

Does a combined intravenous-volatile anesthesia offer advantages compared to an intravenous or volatile anesthesia alone: a systematic review and meta-analysis.

BACKGROUND: In anesthesia, additive drug interactions are used for reducing dose and dose-dependent side-effects. The combination of propofol with volatile anesthetics is rather unusual but might have advantages compared to the single use regarding PONV, time to extubation, movement during surgery and postoperative pain perception. METHODS: We searched PubMed, Scopus, Web of Science, and CENTRAL for relevant studies comparing combined intravenous volatile anesthesia with total intravenous or balanced anesthesia. The studies identified were summarized in a meta-analysis with the standardized mean difference or risk ratio as the effect size. RESULTS: Ten studies provided data. The risk for PONV in the recovery room was significantly reduced for a combined anesthesia compared to a balanced anesthesia (RR 0.657, CI 0.502-0.860, p-value 0.002). There was no significant difference detected either in the time to extubation or in pain perception. Movement during surgery was significantly reduced for a combined compared to a total intravenous anesthesia (RR 0.241, CI 0.135-0.428, p-value 0.000). CONCLUSIONS: The combination of propofol and volatiles may have some advantages in the early occurrence of PONV compared to a balanced anesthesia. To sufficiently evaluate potential advantages of a combination of volatiles and propofol further high-quality trials are needed. TRIAL REGISTRATION: PROSPERO CRD42019126627 .

[Perioperative Drug Interactions - What Should Be Considered by Anesthetists]. / Perioperative Arzneimittelinteraktionen ­ was der Anästhesist wissen sollte.

Drug interactions cause numerous hospital admissions and even death. Administration of multiple therapeutic drugs increases the risk of relevant interactions. Pharmacologist consultation and also IT-based drug-interaction examination focus on this risk and may improve the safety and quality of the medical therapy. The perioperative period as well as for example post-surgery intensive care display a high-risk period for critical drug interactions because of the increased number of administered drugs at this time. This is highly challenging to the acting anesthetist. A detailed knowledge on possible drug-interactions is indispensable to maintain the highest duty of our faculty: patient's safety.Thus on the one hand modern narcosis uses drug interactions in performing "balanced anesthesia" and on the other hand it is essential to know about unwanted interactions that might arise of several mechanisms like chemical interactions as well as pharmacokinetic and pharmacodynamic ways. In this context, phenomena as the pharmaceutic influence on the QT-time have to be known as well as the so called serotonine syndrome for example. A detailed insight into the metabolism of administered drugs including elimination pathways like p-glycoprotein or enzymes of the cytochrome-p-450 family is helpful to maintain a basic survey.