Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2021
Relationship Between Propofol Target Concentrations, Bispectral Index, and Patient Covariates During Anesthesia.
Internationally, propofol is commonly titrated by target-controlled infusion (TCI) to maintain a processed electroencephalographic (EEG) parameter (eg, bispectral index [BIS]) within a specified range. The overall variability in propofol target effect-site concentrations (CeT) necessary to maintain adequate anesthesia in real-world conditions is poorly characterized, as are the patient demographic factors that contribute to this variability. This study explored these issues, hypothesizing that the variability in covariate-adjusted propofol target concentrations during BIS-controlled anesthesia would be substantial and that most of the remaining interpatient variability in drug response would be due to random effects, thus suggesting that the opportunity to improve on the Schnider model with further demographic data is limited. ⋯ Our hypothesis was confirmed. The variability in covariate-adjusted propofol CeT30 titrated to BIS in real-world conditions is considerable, and only a small portion of the remaining variability in drug response is explained by patient demographic factors. This finding may have important implications for the development of new pharmacokinetic (PK) models for propofol TCI.
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Anesthesia and analgesia · Mar 2021
Meta AnalysisAnesthesia and Long-Term Oncological Outcomes: A Systematic Review and Meta-analysis.
Propofol-based TIVA may be associated with improved overall survival after cancer surgery than volatile anaesthesia.
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Anesthesia and analgesia · Mar 2021
Randomized Controlled Trial Multicenter Study Comparative StudyHead Rotation Reduces Oropharyngeal Leak Pressure of the i-gel and LMA® Supreme™ in Paralyzed, Anesthetized Patients: A Randomized Trial.
This airway study is a neat little randomised-but-not-blinded study of the effect of head rotation on the oropharyngeal leak pressure of both the i-gel and LMA Supreme 2nd generation supraglottic airways.
The researchers investigated the leak pressure (OPLP) of the i-gel and LMA Supreme in paralysed patients with the head: 1. neutral, 2. rotated 30°, and 3. rotated 60°. They found that rotation of the head through 30° and 60° progressively increased OPLP by a clinically-significantly amount (0° vs 60° 5.5 cmH2O (3.3-7.8) & 6.5 cmH2O (5.1-8.0) respectively).
Before you get too excited...
The result however may not be reliably applicable to all populations, notably the study subjects were overwhelmingly small (x̄ ~160cm & 60kg) Japanese women (71%), receiving a TIVA muscle-relaxant anaesthetic (propofol, remifentanil, rocuronium). How well this improvement-with-rotation holds up among, for example, spontaneously ventilating large Caucasian males, is unclear.
Bottom-line
When using an i-gel or LMA Supreme 2nd generation supraglottic airway, careful head rotation to 60° may increased oropharyngeal leak pressure and so assist with ventilation troubleshooting. However head and neck rotation of anaesthetised, paralysed patients should be performed gently and cautiously – you are after all, not a chiropractor!
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Anesthesia and analgesia · Mar 2021
Pragmatic Clinical TrialPediatric Distraction on Induction of Anesthesia With Virtual Reality and Perioperative Anxiolysis: A Randomized Controlled Trial.
Perioperative pediatric anxiety is common and can have a negative psychological impact on children undergoing surgery and anesthesia. Studies have shown an incidence of anxiety at induction of up to 50%. Audiovisual distraction, including virtual reality (VR), is a noninvasive, nonpharmacological modality that may reduce perioperative anxiety. The goal of this study was to determine whether immersive audiovisual distraction with a VR headset during induction of general anesthesia (GA) in pediatric patients reduced preoperative anxiety. ⋯ This study demonstrates a reduction in pediatric preoperative anxiety with the use of VR. Preoperative VR may be an effective noninvasive modality for anxiolysis during induction of anesthesia in children.
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Anesthesia and analgesia · Mar 2021
Meta AnalysisThe Diagnostic Accuracy of Noninvasive Methods to Measure the Intracranial Pressure: A Systematic Review and Meta-analysis.
Although invasive monitoring is the standard method for intracranial pressure (ICP) measurement, it is not without potential for serious complications. Noninvasive methods have been proposed as alternatives to invasive ICP monitoring. The study aimed to investigate the diagnostic accuracy of the currently available noninvasive methods for intracranial hypertension (ICH) monitoring. ⋯ Our study showed several promising tools for diagnosing ICH. Moreover, we demonstrated that using multiple, readily available, noninvasive methods is better than depending on a single sign such as physical examination or CT alone.