Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Clinical TrialUse of alfentanil and propofol for outpatient monitored anesthesia care: determining the optimal dosing regimen.
Propofol and alfentanil are both rapid and short-acting drugs that can be used for sedation and analgesia during monitored anesthesia care (MAC). This study was designed to determine the optimal infusion rates of propofol and alfentanil when administered during local anesthesia. In this randomized, double-blind study, we evaluated the effects of different propofol infusion rates on the alfentanil requirement, level of sedation, intraoperative recall, respiratory and cardiovascular variables, and recovery. Seventy-two consenting ASA physical status I or II female outpatients undergoing breast biopsy procedures with local anesthesia were randomly assigned to one of four treatment groups. All patients received midazolam, 2 mg intravenously (I.V.) for premedication. Propofol was infused at 0, 25, 50, or 75 microg x kg(-1) x min(-1) during the operation. Sedation was evaluated using the Observer's Assessment of Alertness/Sedation (OAA/S) scale at 5-min intervals by a blinded observer. Two minutes before the infiltration of the local anesthetic solution, a bolus of alfentanil, 2.5 microg/kg I.V., was administered, followed by a maintenance infusion of 0.5 microg x kg(-1) x min(-1). The alfentanil infusion rate was subsequently varied to maintain patient comfort and stable cardiovascular and respiratory function. Pictures were shown at the start of the propofol infusion, upon initiating the alfentanil infusion, and at 45 min after the skin incision to evaluate recall of intraoperative events. Propofol produced dose-dependent increases in the level of sedation (with median OAA/S scores of 2-4, P < 0.05). Higher infusion rates of propofol (50-75 microg x kg(-1) x min(-1)) produced significant amnesia, opioid-sparing effects (alfentanil 0.3 +/- 0.2 vs 0.6 +/- 0.2 microg x kg(-1) x min(-1)), and less postoperative nausea and vomiting (P < 0.05). However, episodes of transient hemoglobin oxygen desaturation were more common in the deeply sedated patients. Thus, in healthy outpatients premedicated with midazolam, 2 mg I.V., a propofol infusion of 25-50 microg x kg(-1) x min(-1) in combination with an alfentanil infusion of 0.2-0.4 microg x kg(-1) x min(-1) is recommended for sedation and analgesia during MAC in the ambulatory setting. ⋯ Sedation is often given during local anesthesia. This study demonstrated that administration of an intravenous anesthetic, propofol, in combination with an opioid infusion (i.e., alfentanil) to provide sedation analgesia and amnesia with a low incidence of side effects, such as nausea and vomiting and respiratory depression in outpatients premedicated with midazolam.
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Comparative Study Clinical TrialPretreatment with topical 60% lidocaine tape reduces pain on injection of propofol.
We determined whether pretreatment with topical 60% lidocaine tape reduced the incidence of pain on injection of propofol compared with mixing intravenous lidocaine with propofol. In a randomized, double-blind trial, 90 patients were allocated to one of three groups: pretreatment with a bioocclusive dressing and administration of a premixed solution of propofol 180 mg and 2 mL of normal saline (Group A); pretreatment with 60% lidocaine tape and a premixed solution of propofol and normal saline (Group B); or pretreatment with a bioocclusive dressing and a premixed solution of propofol 180 mg and lidocaine 40 mg (Group C). The incidences of pain in Groups A, B, and C were 86.7%, 33.4%, and 20%, respectively. Group B and Group C had a significantly lower incidence of pain than Group A. There was no significant difference in the incidence of pain between Group B and Group C. There was no significant difference in the distribution of site of pain on injection of propofol among the three groups. Pretreatment with topical 60% lidocaine tape reduced the incidence of pain on injection of propofol similar to that of intravenous lidocaine mixed with propofol. ⋯ Pretreatment with topical 60% lidocaine tape reduces the pain associated with injection of propofol, a frequently used intravenous anesthetic. This approach should increase patient comfort during induction of anesthesia.
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Clinical TrialSingle-dose ondansetron prevents postoperative vomiting in pediatric outpatients.
This randomized, double-blind, parallel-group, multicenter study evaluated the safety and efficacy of ondansetron (0.1 mg/kg to 4 mg intravenously) compared with placebo in the prevention of postoperative vomiting in 429 ASA status I-III children 1-12 yr old undergoing outpatient surgery under nitrous oxide- and halothane-based general anesthesia. The results show that during both the 2-h and the 24-h evaluation periods after discontinuation of nitrous oxide, a significantly greater percentage of ondansetron-treated patients (2 h 89%, 24 h 68%) compared with placebo-treated patients (2 h 71%, 24 h 40%) experienced complete response (i.e., no emetic episodes, not rescued, and not withdrawn; P < 0.001 at both time points). Ondansetron-treated patients reached criteria for home readiness one-half hour sooner than placebo-treated patients (P < 0.05). The age of the child, use of intraoperative opioids, type of surgery, and requirement to tolerate fluids before discharge may also have affected the incidence of postoperative emesis during the 0- to 24-h observation period. Use of postoperative opioids did not have any effect on complete response rates in this patient population. We conclude that the prophylactic use of ondansetron reduces postoperative emesis in pediatric patients, regardless of the operant influential factors. ⋯ Postoperative nausea and vomiting often occur after surgery and general anesthesia in children and are the major reason for unexpected hospital admission after ambulatory surgery. Our study demonstrates that the prophylactic use of a small dose of ondansetron reduces postoperative vomiting in pediatric patients.
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Comparative Study Clinical TrialProphylaxis for vomiting by children after tonsillectomy: dexamethasone versus perphenazine.
The effects of dexamethasone and perphenazine on vomiting after tonsillectomy in children were compared in 226 healthy children aged 2-12 yr. The study was randomized, stratified, blocked, and double-blind. Anesthesia was induced intravenously (I.V.) with propofol or by inhalation with halothane and N2O. Dexamethasone 150 microg/kg or perphenazine 70 microg/kg was administered I.V. after the induction of anesthesia in a double-blind fashion. Perioperative management of emesis, pain, fluids, and patient discharge was all standardized. The groups had similar demographic characteristics. Perphenazine significantly reduced the incidence of in-hospital vomiting compared with dexamethasone (13% vs 36%, P < 0.001). The incidence of out-of-hospital vomiting was almost identical. Overall, the incidence was significantly different for perphenazine vs dexamethasone (33% vs 46%, P = 0.04) using logistic regression analysis. Of note, sex and induction technique were significant predictors of postoperative vomiting (P < 0.05) using logistic regression analysis, with male patients and those patients undergoing I.V. induction vomiting less. In conclusion, perphenazine more effectively decreases vomiting by children after tonsillectomy in an ambulatory hospital setting compared with dexamethasone. ⋯ Postoperative vomiting can have many debilitating effects, and children undergoing tonsillectomy are at particular risk. We compared the effects of dexamethasone and perphenazine on vomiting after tonsillectomy in 266 children. We found perphenazine more effective than dexamethasone before discharge from hospital but that the two drugs have similar effects after discharge.
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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.