Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2000
Randomized Controlled Trial Clinical TrialSevoflurane, but not propofol, significantly prolongs the Q-T interval.
Prolongation of the Q-T interval may be associated with polymorphic ventricular tachycardia known as torsade de pointes, syncope and sudden death. Existing data show that isoflurane prolongs the Q-T interval, whereas halothane shortens it. The aim of this study was to determine whether sevoflurane or propofol affects the Q-T interval. Thirty female patients undergoing gynecologic surgery were randomly assigned to two groups, one receiving inhaled induction with sevoflurane and the other receiving total IV anesthesia with propofol. Before and 20 min after the induction, a six-lead electrocardiogram was recorded, and blood pressure was measured. The Q-T interval and heart rate adjusted Q-T interval (Q-Tc interval) were significantly prolonged during the administration of anesthesia with sevoflurane, while the Q-T interval was significantly shortened, and the Q-Tc interval was statistically unaffected during propofol anesthesia administration. We conclude that, in otherwise healthy female patients, sevoflurane prolongs the Q-Tc. ⋯ In this study, we evaluated the effect of sevoflurane induction and anesthesia versus propofol induction and anesthesia on the Q-T interval. Sevoflurane significantly prolonged the Q-T interval and the heart rate adjusted Q-T interval, whereas propofol shortened the Q-T interval but not the heart rate adjusted Q-T interval.
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Anesthesia and analgesia · Jan 2000
Meta AnalysisDexamethasone for the prevention of postoperative nausea and vomiting: a quantitative systematic review.
The role of dexamethasone in the prevention of postoperative nausea and vomiting (PONV) is unclear. We reviewed efficacy and safety data of dexamethasone for prevention of PONV. A systematic search (MEDLINE, EMBASE, Cochrane Library, hand searching, bibliographies, all languages, up to April 1999) was done for full reports of randomized comparisons of dexamethasone with other antiemetics or placebo in surgical patients. Relevant end points were prevention of early PONV (0 to 6 h postoperatively), late PONV (0 to 24 h), and adverse effects. Data from 1,946 patients from 17 trials were analyzed: 598 received dexamethasone; 582 received ondansetron, granisetron, droperidol, metoclopramide, or perphenazine; 423 received a placebo; and 343 received a combination of dexamethasone with ondansetron or granisetron. With placebo, the incidence of early and late PONV was 35% and 50%, respectively. Sixteen different regimens of dexamethasone were tested, most frequently, 8 or 10 mg IV in adults, and 1 or 1.5 mg/kg IV in children. With these doses, the number needed to treat to prevent early and late vomiting compared with placebo in adults and children was 7.1 (95% CI 4.5 to 18), and 3.8 (2.9 to 5), respectively. In adults, the number needed to treat to prevent late nausea was 4.3 (2.3 to 26). The combination of dexamethasone with ondansetron or granisetron further decreased the risk of PONV; the number needed to treat to prevent late nausea and vomiting with the combined regimen compared with the 5-HT3 receptor antagonists alone was 7.7 (4.8 to 19) and 7.8 (4.1 to 66), respectively. There was a lack of data from comparisons with other antiemetics for sensible conclusions. There were no reports on dexamethasone-related adverse effects. ⋯ When there is a high risk of postoperative nausea and vomiting, a single prophylactic dose of dexamethasone is antiemetic compared with placebo, without evidence of any clinically relevant toxicity in otherwise healthy patients. Late efficacy seems to be most pronounced. It is very likely that the best prophylaxis of postoperative nausea and vomiting currently available is achieved by combining dexamethasone with a 5-HT3 receptor antagonist. Optimal doses of this combination need to be identified.
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Anesthesia and analgesia · Jan 2000
Randomized Controlled Trial Clinical TrialThe effect of remifentanil on the bispectral index change and hemodynamic responses after orotracheal intubation.
In order to examine whether changes in the bispectral index (BIS) may be an adequate monitor for the analgesic component of anesthesia, we evaluated the effect of remifentanil on the BIS change and hemodynamic responses to laryngoscopy and tracheal intubation. Fifty ASA physical status I patients were randomly assigned, in a double-blinded fashion, to one of five groups (n = 10/group) according to the remifentanil target effect compartment site concentration (0, 2, 4, 8, or 16 ng/mL). The target-controlled infusion (TCI) of remifentanil was initiated 3 min after the TCI of propofol that was maintained at the effect-site concentration of 4 microg/mL throughout the study. After the loss of consciousness and before the administration of vecuronium 0.1 mg/kg, a tourniquet was applied to one arm and inflated above the systolic blood pressure in order to detect any gross movement within the first minute after tracheal intubation, which was performed 3 min after remifentanil TCI began. A BIS value was generated every 10 s. Arterial blood pressure and heart rate (HR) were measured every minute, noninvasively. Measures of mean arterial pressure (MAP), HR, and BIS were obtained before the induction, before the start of remifentanil TCI, before laryngoscopy, and 5 min after intubation. The relationships between remifentanil effect-site concentrations and BIS change or hemodynamic responses (changes in MAP and HR) to intubation were determined by logarithmic regression. BIS values were not affected by remifentanil before laryngoscopy. During this period, MAP and HR decreased significantly (P < 0.01) in the remifentanil 8 and 16 ng/mL groups. Changes in BIS, MAP, and HR were negatively correlated with remifentanil effect-site concentration (P < 0.0001). The number of movers in the remifentanil 0-, 2-, 4-, 8-, and 16-ng/mL groups was, respectively, 10, 9, 7, 1, and 0. Hypotensive episodes (MAP < 60 mm Hg) were noted in 1, 2, and 5 patients in the remifentanil 4-, 8-, and 16-ng/mL groups, respectively. We conclude that the addition of remifentanil to propofol affects BIS only when a painful stimulus is applied. Moreover, remifentanil attenuated or abolished increases in BIS and MAP after tracheal intubation in a comparable dose-dependent fashion. ⋯ Bispectral index change is as sensitive as hemodynamic responses after a painful stimulus for detecting deficits in the analgesic component of anesthesia. It may, therefore, be a useful monitor of the depth of anesthesia in patients who are incapable of HR and MAP responses to noxious stimuli because of medications or cardiovascular disease.
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Anesthesia and analgesia · Jan 2000
Randomized Controlled Trial Clinical TrialTape-recorded hypnosis instructions as adjuvant in the care of patients scheduled for third molar surgery.
As medical costs continue to escalate, there is willingness to consider the role played by nontraditional factors in health. We investigated the usefulness of tape-recorded hypnosis instruction on perioperative outcome in surgical patients in a prospective, randomized, and partially blinded study. Sixty patients scheduled for third molar surgery were studied. Patients were allocated to either an experimental group (E) or a control group (C). Group E received an audio tape to listen to daily for the immediate preoperative week, which guided the patients through a hypnotic induction and included suggestions on enhancement of perioperative well-being. Group C did not receive any tapes. The same surgeon administered local anesthesia and a standard regimen of sedation and performed the operation for all patients. The following variables were assessed 1 wk before surgery, immediately before and after surgery, and for 3 days after surgery by the indicated measurements: State anxiety by a Spielberger scale; nausea and pain by visual analog scales; number of tablets of the analgesics that were used; number of episodes of vomiting; and complications. In addition, the surgeon's assessment of ease of surgery was recorded. Two variables showed differences between the groups. First, Group C exhibited a mean increase of 11.7 points on the Spielberger scale from the screening to the presurgery period, while Group E showed only a mean increase of 5.5 points during the same period, P = 0.01. Second, the mean number of vomiting episodes was more in Group E, 1.3, than in Group C, 0.3, P = 0.02. In conclusion, anxiety was reduced before surgery by means of an audio tape containing hypnotic instructions; however, for no apparent reason, there was also an increase in the incidence of vomiting. ⋯ We administered hypnosis instructions to patients before third molar surgery. Anxiety was reduced, but there was an increase in the incidence of vomiting. Although an easy and cost-effective method, the value of this approach remains to be established.
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Anesthesia and analgesia · Jan 2000
Letter Case ReportsDual-plateau capnogram caused by cracked sample filter.