Anesthesiology
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Clinical Trial
Forehead pulse oximetry: Headband use helps alleviate false low readings likely related to venous pulsation artifact.
This study investigated whether a tensioning headband that applies up to 20 mmHg pressure over a forehead pulse oximetry sensor could improve arterial hemoglobin oxygen saturation reading accuracy in presence of venous pooling and pulsations at the forehead site. ⋯ Application of up to 20 mmHg pressure on the forehead pulse oximetry sensor using an elastic tensioning headband significantly reduced reading errors and provided consistent performance when subjects were placed between supine and up to 15 degrees head-down incline (Trendelenburg position).
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Randomized Controlled Trial
Pharmacokinetics and pharmacodynamics of midazolam and metabolites in nonventilated infants after craniofacial surgery.
Because information on the optimal dose of midazolam for sedation of nonventilated infants after major surgery is scant, a population pharmacokinetic and pharmacodynamic model is developed for this specific group. ⋯ In nonventilated infants after major surgery, midazolam clearance is two to five times higher than in ventilated children. From the model presented, the recommended initial dosage is a loading dose of 1 mg followed by a continuous infusion of 0.5 mg/h during the night for a COMFORT-Behavior of 12-14 in infants aged 1 yr. Large interindividual variability warrants individual titration of midazolam in these children.
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A small surgical incision in mouse glabrous hind-paw skin induces short-lasting guarding behavior and mechanical and heat hyperalgesia-like behaviors, which imitate human postoperative pain. The increasing popularity of this animal model in drug discovery necessitates the understanding of genetic and sex influence on this animal model. ⋯ Although several studies postulated that mouse strain influences pain models, the authors' data indicate that such influence on incisional pain is negligible. This suggests that studies using an incision and knockout mice resulting from 129 strain mutation in a C57BL/6 strain background should have modest influence. The lack of sex differences in incisional pain may encourage researchers to use both male and female subjects in their studies.
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Mean body temperature (MBT) is the mass-weighted average temperature of body tissues. Core temperature is easy to measure, but direct measurement of peripheral tissue temperature is painful and risky and requires complex calculations. Alternatively MBT can be estimated from core and mean skin temperatures with a formula proposed by Burton in 1935: MBT = 0.64 x TCore + 0.36 x TSkin. This formula remains widely used, but has not been validated in the perioperative period and seems unlikely to remain accurate in dynamic perioperative conditions such as cardiopulmonary bypass. Therefore, the authors tested the hypothesis that MBT, as estimated with Burton's formula, poorly estimates measured MBT at a temperature range between 18 degrees and 36.5 degrees C. ⋯ The authors concluded that estimation of MBT from mean skin and core temperatures is generally accurate and precise.
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Preoperative clinics have been shown to decrease operating room delays and cancellations. One mechanism for this positive economic impact is that medical issues are appropriately identified and necessary information is obtained, so that knowledge of the patients' status is complete before the day of surgery. In this study, the authors describe the identification and management of medical issues in the preoperative clinic. ⋯ The preoperative evaluation can identify and resolve a number of medical issues that can impact efficient operating room resource use.