Anesthesia and analgesia
-
Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Clinical TrialMaternal experience during epidural or combined spinal-epidural anesthesia for cesarean section: a prospective, randomized trial.
Epidural anesthesia (EA) and combined spinal-epidural anesthesia (CSEA) are popular anesthetic techniques for elective cesarean section. A randomized, blind study was conducted to compare maternal experiences during these regional anesthetics. EA was established using alkalinized 2% lidocaine with epinephrine and fentanyl, whereas spinal anesthesia was performed using 2.5 mL hyperbaric 0.5% bupivacaine and fentanyl via a single-space CSEA approach. Both patients and observers were blinded to the anesthetic technique allocation. One hundred twenty patients were enrolled; 6 were withdrawn (Group EA, n = 55; Group CSEA, n = 59). Of the two techniques, CSEA was associated with earlier onset times (P < 0.001), more intense motor block (P < 0.05), and greater ephedrine use (P < 0.01). Anxiety was significantly lower (P < 0.05) and satisfaction was higher (P < 0.05) before starting surgery with CSEA. Pain scores were lower pre- and intraoperatively with CSEA, a difference that became significant during block placement and at delivery (P < 0.05). There were no differences between groups in the incidence or severity of hypotension and nausea or analgesic supplementation rate; or for postoperative assessments of intraoperative pain, anxiety and satisfaction, and postpartum backache and headache. We conclude that maternal conditions and experience were good with both methods, although CSEA conferred several minor advantages. ⋯ Epidural and combined spinal-epidural anesthesia are often used for elective cesarean sections. Although the combined spinal-epidural anesthetic technique conferred minor advantages, both techniques were associated with low anesthetic failure rates, good operative conditions, and high maternal satisfaction levels.
-
Anesthesia and analgesia · Sep 1997
Comparative StudyA comparative study of the vasodilator effects of prostaglandin E1 in patients with pulmonary hypertension after mitral valve replacement and with adult respiratory distress syndrome.
To determine whether the vasodilator effects of prostaglandin E1 (PGE1) differ according to the etiology and pathophysiology of pulmonary hypertension, we studied 30 patients with pulmonary hypertension after mitral valve replacement (MVR) (n = 16) or with the adult respiratory distress syndrome (ARDS) (n = 14). PGE1 was administered to decrease the mean pulmonary artery pressure to below 30 mm Hg in both groups. Cardiac index and oxygen delivery tended to increase, whereas mean systemic artery pressure, mean pulmonary artery pressure, systemic vascular resistance index (SVRI), and pulmonary vascular resistance index (PVRI) significantly decreased in both groups. A vasodilatory index was defined in this study to allow evaluation of vasodilation relative to PGE1 dose: systemic vasodilatory index (VIs) = SVRI change/PGE1 dose; and pulmonary vasodilatory index (VIp) = PVRI change/PGE1 dose. The VIp was similar in both groups, but the VIs was significantly greater in the ARDS group compared with the MVR group (13.3 +/- 7.8 vs 4.8 +/- 5.1, P < 0.01). A good correlation was found between the pretreatment intrapulmonary shunt fraction (Qs/Qt [%]) value and PGE1 extraction rate in the lung (r = 0.60), and between the pretreatment Qs/Qt value and PGE1 concentration in the radial artery (r = 0.65) in an additional 15 patients. We conclude that the vasodilator effects of PGE1 on the pulmonary circulation are similar in the two groups, whereas the vasodilator effects on the systemic circulation are significantly greater in the ARDS group and that significant reduction in VIs in the ARDS group was associated with decreased PGE1 extraction in the lung. ⋯ Pulmonary hypertension after mitral valve replacement, or with adult respiratory distress syndrome, is a major medical problem. The authors found that administration of prostaglandin E1 significantly dilated the pulmonary circulation with a concomitant decrease in pulmonary artery pressure. Because the systemic vasodilatory effect was greater in the adult respiratory distress syndrome group, the authors concluded that prostaglandin E1 concentrations in the systemic circulation depend on the severity of lung injury.
-
Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialUse of the laryngeal mask airway as an alternative to the tracheal tube during ambulatory anesthesia.
We designed a prospective, randomized, multicenter study to compare anesthetic requirements, recovery times, and postoperative side effects when a laryngeal mask airway (LMA) was used as an alternative to the tracheal tube (TT) during ambulatory anesthesia. After induction of anesthesia with midazolam 2 mg, fentanyl 1 microg/kg, and propofol 2 mg/kg, 381 patients were randomly assigned to receive either an LMA (n = 207) or TT (n = 174) for airway management. In patients assigned to the TT group, succinylcholine 1 mg/kg or a nondepolarizing muscle relaxant was administered to facilitate tracheal intubation. Anesthesia was maintained with volatile anesthetics in combination with nitrous oxide 60% and oxygen. The average time to placement of the two airway devices (5 min) and the failure rates (1%) were similar in the two groups. Although there was a significant decrease in the intraoperative fentanyl requirement in the LMA group, the difference was of little clinical significance. Furthermore, there were no differences in the volatile anesthetic requirements. The time from end of surgery to removal of the airway device (5 min) was also similar in the two study groups. Although duration of the postanesthesia care unit stay and time to ambulation were significantly shorter in the LMA group, there were no differences in the times to "home readiness." The incidence of nausea and vomiting and the need for rescue antiemetic treatments in the postoperative period were similar in the two airway management groups. However, the incidence of postoperative sore throat was significantly greater in patients receiving the TT (versus the LMA). In conclusion, this study suggests that the LMA is a useful alternative to the TT for airway management during ambulatory anesthesia. ⋯ Use of the laryngeal mask airway can obviate the need for insertion of a tracheal tube for many ambulatory surgery procedures, and thereby decrease the incidence of postoperative sore throats.
-
Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Multicenter Study Clinical TrialTreatment of postoperative nausea and vomiting with single intravenous doses of dolasetron mesylate: a multicenter trial. Dolasetron Mesylate PONV Treatment Study Group.
This study was conducted to determine the efficacy and safety of four intravenous (I.V.) doses of dolasetron, an investigational 5-HT3 receptor antagonist, for the treatment of postoperative nausea and/or vomiting (PONV) after outpatient surgery under general anesthesia. This multicenter, randomized, double-blind trial compared the antiemetic efficacy of 12.5, 25, 50, or 100 mg I.V. dolasetron with placebo over 24 h using complete response (no emetic episodes and no rescue medication), time to first emetic episode or rescue medication, and patient nausea and satisfaction with antiemetic therapy as rated by visual analog scale (VAS). Of 1557 patients enrolled, 620 patients were eligible for treatment. Complete response rates for all dolasetron doses--12.5 mg (35%), 25 mg (28%), 50 mg (29%), and 100 mg (29%)--were significantly more effective than placebo (11%, P < 0.05). There was a significant gender interaction for complete response (P < 0.01). Of the patients in the 25-mg and 100-mg dose groups, 12% and 13%, respectively, experienced no nausea (VAS score < 5 mm) versus 5% in the placebo group (P < 0.05). There were no clinically relevant changes in vital signs or laboratory values and no trends with dose for adverse events. Dolasetron is effective for treating PONV and has an adverse event profile similar to that of placebo. The 12.5-mg dose was as effective as larger doses for complete response. ⋯ Nausea and vomiting are common problems for postsurgical patients. In this study of 620 patients undergoing surgery, a 12.5-mg dose of intravenous dolasetron, a new serotonin-receptor blocker, was significantly more effective than placebo in treating established postoperative nausea and vomiting. Dolasetron 12.5 mg was as safe as placebo.