Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Comparative Study Clinical TrialS(+)-ketamine for rectal premedication in children.
Our purpose for this prospective, randomized, and double-blinded study was to evaluate the anesthetic efficacy of S(+)-ketamine, an enantiomer of racemic ketamine, compared with a combination of S(+)-ketamine and midazolam, and plain midazolam for rectal premedication in pediatric anesthesia. Sixty-two children, ASA physical status I and II, scheduled for minor surgery, were randomly assigned to be given rectally one of the following: 1.5 mg/kg preservative-free S(+)-ketamine, a combination of 0.75 mg/kg preservative-free S(+)-ketamine and 0.75 mg/kg midazolam, or 0.75 mg/kg midazolam. Preoperative anesthetic efficacy was graded during a period of 20 min by using a five-point scale from 1 = awake to 5 = asleep. ⋯ Whereas the mask acceptance score was comparable in the three study groups, a 25% rate of complications during anesthesia induction via face was observed in the S(+)-ketamine study group (P < 0.05 versus other study groups). Our conclusions are that S(+)-ketamine for rectal premedication in the dose we chose shows a poor anesthetic effect and a frequent incidence of side effects during induction of anesthesia via face mask compared with the combination of midazolam/S(+)-ketamine and plain midazolam. Dose-response studies of S(+)-ketamine for rectal premedication in pediatric anesthesia may be warranted.
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Clinical TrialBupivacaine wound instillation via an electronic patient-controlled analgesia device and a double-catheter system does not decrease postoperative pain or opioid requirements after major abdominal surgery.
To assess the analgesic efficacy of patient-controlled bupivacaine wound instillation, 50 patients undergoing major intraabdominal surgery were enrolled into this prospective, placebo-controlled, double-blinded study. In all cases, a standard general anesthetic was administered. On completion of surgery, two multihole 20-gauge epidural catheters were tunneled through the proximal and distal apices of the surgical wound and placed above the fascia such that the tips were at the margin of the first and second thirds of the surgical wound, respectively. Postoperatively, a patient-controlled analgesia (PCA) device was connected to the instillation system. Either bupivacaine 0.25% (Bupivacaine Group) or an equal volume of sterile water (Control Group) was administered. The PCA device was programmed to deliver 9.0 mL with a 60-min lockout interval and no basal infusion. During the first six postoperative hours, a coinvestigator administered "rescue" morphine (2 mg IV). Thereafter, meperidine 1 mg/kg IM was administered on patient request for additional analgesia. Instillation attempts and actual number of injections were similar between the groups. The mean number of pump infusions and the mean "rescue" opioid requirements during the 24-h study period were similar between the groups. The total "rescue" morphine administered during the first six postoperative hours was 16 +/- 17 mg vs 18 +/- 14 mg for the Bupivacaine and Control Groups, respectively. The total meperidine administered during this period was 1.6 +/- 1.4 mg/kg and 2 +/- 1.2 mg/kg for the Bupivacaine and Control Groups, respectively. Preoperatively, hourly for the first six postoperative hours, and on removal of the instillation catheter, patient-generated visual analog scales for pain were similar at rest, on coughing, and after leg raise. In conclusion, bupivacaine wound instillation via an electronic PCA device and a double-catheter system does not decrease postoperative opioid requirements after surgery performed through a midline incision. ⋯ After major abdominal surgery performed through a 20-cm incision, repeated 0.25% bupivacaine wound instillation via an electronic patient-controlled analgesia device and a double-catheter system does not decrease postoperative pain or opioid requirements.
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of oral clonidine and oral midazolam as preanesthetic medications in the pediatric tonsillectomy patient.
We compared the effects of oral clonidine (4 microg/kg) and midazolam (0.5 mg/kg) on the preanesthetic sedation and postoperative recovery profile in children during tonsillectomy with or without adenoidectomy. In a double-blinded, double-dummy study design, 134 ASA physical status I-II children aged 4-12 yr were randomized to receive a combination of either clonidine and placebo (Group A), or placebo and midazolam (Group B) at 60-90 min and 30 min, respectively, before the induction of anesthesia. Children in the clonidine group exhibited more intense anxiety on separation and during induction of anesthesia via a mask as measured by the modified Yale Preoperative Anxiety Scores. They also had significantly lower mean intraoperative arterial blood pressures, shorter surgery, anesthesia, and emergence times, and a decreased need for supplemental oxygen during recovery compared with the midazolam group. However, the clonidine group had larger postoperative opioid requirements, maximum excitement and pain scores based on the Children's Hospital of Eastern Ontario scale in the Phase 1 postanesthetic care unit. There were no differences between the two groups in the times to discharge readiness, postoperative emesis, unanticipated hospital admission rates, postdischarge maximum pain scores, and 24 h analgesic requirements. The percentage of parents who were completely satisfied with the child's preoperative experience was significantly higher in the midazolam group. There were no differences in parental satisfaction with the recovery period. We conclude that under the conditions of this study, oral midazolam is superior to oral clonidine as a preanesthetic medication in this patient population. ⋯ We compared preanesthetic sedation and postoperative recovery after oral clonidine (4 microg/kg) and midazolam (0.5 mg/kg) in children during tonsillectomy. The clonidine group had greater preoperative anxiety and shorter surgery and anesthesia times, but required more postoperative analgesia. Delayed recovery and discharge times did not differ. Midazolam was superior to clonidine as oral preanesthetic medication for these patients.
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Comparative Study Clinical TrialOndansetron is no more effective than supplemental intraoperative oxygen for prevention of postoperative nausea and vomiting.
Supplemental oxygen maintained during and for 2 h after colon resection halves the incidence of nausea and vomiting. Whether supplemental oxygen restricted to the intraoperative period is sufficient remains unknown. Similarly, the relative efficacy of supplemental oxygen and ondansetron is unknown. We tested the hypothesis that intraoperative supplemental oxygen reduces the incidence of postoperative nausea and vomiting. Patients (n = 240) undergoing gynecological laparoscopy were given a standardized isoflurane anesthetic. After induction, they were randomly assigned to the following three groups: routine oxygen administration with 30% oxygen, balance nitrogen (30% Oxygen group), supplemental oxygen administration with 80% oxygen, balance nitrogen (80% Oxygen group), and Ondansetron 8 mg (immediately after induction), combined with 30% oxygen, balance nitrogen (Ondansetron group). The overall incidence of nausea and/or vomiting during the initial 24 postoperative h was 44% in the patients assigned to 30% oxygen and 30% in the Ondansetron group, but only 22% in those given 80% oxygen. The incidence was thus halved by supplemental oxygen and was significantly less than with 30% oxygen. There were, however, no significant differences between the 30% oxygen and ondansetron groups, or between the ondansetron and 80% oxygen groups. We conclude that supplemental oxygen effectively prevents postoperative nausea and vomiting after gynecological laparoscopic surgery; furthermore, ondansetron is no more effective than supplemental oxygen. ⋯ Supplemental oxygen reduces the risk of postoperative nausea and vomiting (PONV) as well or better than 8 mg of ondansetron. Because oxygen is inexpensive and essentially risk-free, supplemental oxygen is a preferable method of reducing PONV.
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Comparative Study Clinical TrialNegative pressure rewarming vs. forced air warming in hypothermic postanesthetic volunteers.
We compared changes in core temperature and systemic heat balance with a new negative pressure/warming device (Vital Heat(R) ) that uses negative pressure combined with heat to facilitate warming in vasoconstricted postoperative patients to those resulting from passive insulation or forced air. Seven healthy volunteers were anesthetized and cooled to a tympanic membrane temperature near 34 degrees C. Anesthesia was discontinued and shivering was prevented by using meperidine. ⋯ Core temperature increased no faster with Vital Heat warming (1.3 +/- 0.4 degrees C) than with a cotton blanket (1.2 +/- 0.4 degrees C). In contrast, core temperature increased more rapidly with forced air warming (2.6 +/- 0.6 degrees C). In this study we show that calories from a negative pressure rewarming device are largely constrained to the forearm and that heat does not flow to the core thermal compartment.