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
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
Multicenter StudyThe Pediatric-Specific American Society of Anesthesiologists Physical Status Score: A Multicenter Study.
When applied to the pediatric population, the American Society of Anesthesiologists physical status (ASA-PS) classification has exhibited poor reliability due to its subjective and adult-focused definitions. This study was done to measure interrater agreement of a pediatric-adapted ASA-PS classification and to solicit multicenter perspectives to optimize the pediatric ASA-PS classification. ⋯ The pediatric-adapted ASA-PS classification had moderate interrater reliability among pediatric anesthesiologists. The lower reliability of scoring for ASA-PS II and III cases, in particular, supports the need for further ASA-PS definition refinement for pediatric populations.
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Anesthesia and analgesia · Mar 2021
Critical Care Medicine Practice: A Pilot Survey of US Anesthesia Critical Care Medicine-Trained Physicians.
This survey assessed satisfaction with the practice environment among physicians who have completed fellowship training in critical care medicine (CCM) as recognized by the American Board of Anesthesiology (and are members of the American Society of Anesthesiology) and evaluated the perceived effectiveness of training programs in preparing fellows for critical care practice. ⋯ This survey of CCM-trained anesthesiologists described a high rate of board certification, practice in academic settings, and participation in resident education. Areas of dissatisfaction with an anesthesia/critical care practice included burnout, work/life balance, and lack of respect. These results may increase recruitment of anesthesiologists into critical care and inform strategies to improve satisfaction with anesthesia critical care practice, fellowship training.