Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2001
Meta Analysis Comparative StudyA lack of evidence of superiority of propofol versus midazolam for sedation in mechanically ventilated critically ill patients: a qualitative and quantitative systematic review.
Propofol and midazolam are often used for sedation in the intensive care unit. The aim of this systematic review was to estimate the efficacy and harm of propofol versus midazolam in mechanically ventilated patients. A systematic search (Medline, Cochrane Library, Embase, bibliographies), any language, up to June 1999 was performed for reports of randomized comparisons of propofol with midazolam. Data from 27 trials (1624 adults) were analyzed. The average duration of sedation varied between 4 and 339 h. In 10 trials, the duration of adequate sedation was longer with propofol (weighted mean difference 2.9 h; 95% confidence interval [CI], 0.2-5.6 h). In 13 trials (mostly postoperative), sedation lasted 4 to 35 h; in 9 of those, average weaning time from mechanical ventilation with propofol was 0.8-4.3 h; with midazolam it was 1.5-7.2 h (weighted mean difference 2.2 h [95% CI, 0.8 to 3.7 h]). In 8 trials, sedation lasted 54 to 339 h; there was a lack of evidence for difference in weaning times. Arterial hypotension (relative risk 2.5 [95% CI, 1.3 to 4.5]; number-needed-to-treat, 12), and hypertriglyceridemia (relative risk 12.1 [95%CI, 2.9 to 49.7]; number-needed-to-treat, 6) occurred more often with propofol. The duration of adequate sedation time is longer with propofol compared with midazolam. In postoperative patients with sedation <36 h, weaning is faster with propofol. ⋯ The duration of adequate sedation time is longer with propofol compared with midazolam. In postoperative patients with sedation < 36 h, weaning is faster with propofol.
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Anesthesia and analgesia · Apr 2001
Meta AnalysisThe effects of an increase of central blood volume before spinal anesthesia for cesarean delivery: a qualitative systematic review.
We evaluated in this qualitative systematic review the efficacy of increasing central blood volume on the incidence of hypotension after spinal anesthesia for elective cesarean delivery. Randomized controlled trials investigating any method of increasing central blood volume before the initiation of obstetric spinal anesthesia were sought by using MEDLINE (1966-2000), Embase (January 1988-April 2000), and the Cochrane Library (Issue 1, 2000). Additional reports from retrieved and review articles, hand searching of non-MEDLINE journals, and abstracts of major anesthesia meetings (1994-1999) were located. The primary outcome was the incidence of hypotension. Secondary outcomes included: ephedrine use, Apgar scores, umbilical cord pH values, and maternal nausea and vomiting. Twenty-three articles met our inclusion criteria with the use of crystalloid preload, colloid preload, and mechanical methods of increasing central volume. Crystalloid preload was inconsistent in preventing hypotension, whereas colloid appeared to be effective in all but one study. Leg wrapping and thromboembolic stockings decreased the incidence of hypotension compared with leg elevation or control. Few differences in fetal outcomes or maternal nausea and vomiting were reported. Increasing central blood volume by using colloid and leg wrapping decreases but does not abolish the incidence of hypotension before spinal anesthesia for elective cesarean delivery. ⋯ We performed a systematic review to determine whether fluid loading reduced the incidence of low blood pressure after spinal anesthesia for cesarean delivery. Although no technique totally eliminates the occurrence of hypotension, colloid administration (starch or gelatin containing fluids) and leg wrapping were the most effective.