Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study.
Class III obese patients have altered respiratory mechanics, which are further impaired in the supine position. The authors explored the hypothesis that preoxygenation in the 25 degrees head-up position allows a greater safety margin for induction of anesthesia than the supine position. ⋯ Preoxygenation in the 25 degrees head-up position achieves 23% higher oxygen tensions, allowing a clinically significant increase in the desaturation safety period--greater time for intubation and airway control. Induction in the 25 degrees head-up position may provide a greater safety margin for airway control.
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Comparative Study
Effect of sleep deprivation on righting reflex in the rat is partially reversed by administration of adenosine A1 and A2 receptor antagonists.
Similarities between naturally occurring sleep and general anesthesia suggest that the two states may interact physiologically. The authors have previously demonstrated that sleep deprivation potentiates anesthetic-induced loss of righting reflex (LORR) in rats. One possible mediator for this effect is adenosine, which accumulates in the brains of sleep-deprived animals and reduces anesthetic requirements. The authors tested in rats the hypothesis that potentiating effects of sleep deprivation on LORR can be altered by adenosine A1 and A2a receptor antagonists. ⋯ Both antagonists partially reversed the effect of sleep deprivation on anesthetic action. This result implies that deprivation-induced changes in adenosine receptor activity can alter LORR. Neither antagonist completely reversed this effect, suggesting possible non-adenosine-mediated effects of sleep deprivation.
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Comparative Study
Prolongation of QTc interval after postoperative nausea and vomiting treatment by droperidol or ondansetron.
At dosages above 0.1 mg/kg, droperidol induces a dose-dependent QTc interval prolongation. Although subject to controversy, low-dose droperidol has recently been suspected to induce cardiac arrhythmias. Hence, 5-hydroxytryptamine type 3 antagonists have become the first-line drug for management of postoperative nausea and vomiting. These drugs are also known to prolong the QTc interval at high dosages. This study describes QTc interval changes associated with postoperative nausea and vomiting treatment by droperidol or ondansetron at low doses. ⋯ Droperidol and ondansetron induced similar clinically relevant QTc interval prolongations. When used in treatment of postoperative nausea and vomiting, a situation where prolongation of the QTc interval seems to occur, the safety of 5-hydroxytryptamine type 3 antagonists may not be superior to that of low-dose droperidol.
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Comparative Study
Heart rate variability predicts severe hypotension after spinal anesthesia for elective cesarean delivery.
Hypotension due to vasodilation during subarachnoid block (SAB) for elective cesarean delivery may be harmful. Heart rate variability (HRV), reflecting autonomic control, may identify patients at risk of hypotension. ⋯ Retrospectively analyzed HRV of patients scheduled to undergo elective cesarean delivery during SAB showed significant differences depending on the severity of hypotension after SAB. Preliminary findings were prospectively confirmed. High LF/HF before SAB predicted severe hypotension. Preoperative HRV analysis may detect patients at risk of hypotension after SAB.
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Prolonged turnover times cause frustration and can thereby reduce professional satisfaction and the workload surgeons bring to a hospital. ⋯ Benchmarking sample mean turnover times among hospitals, without the use of confidence intervals, can be valid and useful. The authors successfully developed and validated a statistical method to estimate the percentage of turnover times at a surgical suite that are prolonged and occur at specified times of the day. Managers can target their quality improvement efforts on times of the day with the largest percentages of prolonged turnovers.