Anesthesia and analgesia
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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
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
Multicenter StudyHeparin Anti-Xa Activity, a Readily Available Unique Test to Quantify Apixaban, Rivaroxaban, Fondaparinux, and Danaparoid Levels.
Despite their usefulness in perioperative and acute care settings, factor-Xa inhibitor-specific assays are scarcely available, contrary to heparin anti-Xa assay. We assessed whether the heparin anti-Xa assay can (1) be used as a screening test to rule out apixaban, rivaroxaban, fondaparinux, and danaparoid levels that contraindicate invasive procedures according to current guidelines (>30 ng·mL-1, >30 ng·mL-1, >0.1 µg·mL-1, and >0.1 IU·mL-1, respectively), (2) quantify the anticoagulant level if found significant, that is, if it exceeded the abovementioned threshold. ⋯ A unique simple test already widely used to assay heparin was also useful for quantifying these 4 other anticoagulants. Both clinical and economic impacts of these findings should be assessed in a specific study.
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Anesthesia and analgesia · Mar 2021
Observational StudyEffects of State Law Limiting Postoperative Opioid Prescription in Patients After Cesarean Delivery.
The impact of the Florida State law House Bill 21 (HB 21) restricting the duration of opioid prescriptions for acute pain in patients after cesarean delivery is unknown. Our objective was to assess the association of the passage of Florida State law HB 21 with trends in discharge opioid prescription practices following cesarean delivery, necessity for additional opioid prescriptions, and emergency department visits at a large tertiary care center. ⋯ Implementation of Florida Law HB 21 was associated with a lower total prescribed opioid dose and a shorter duration of therapy at the time of hospital discharge following cesarean delivery. These reductions were not associated with the need for additional opioid prescriptions or emergency department visits.