Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Clinical TrialPreoperative oral dextromethorphan does not reduce pain or analgesic consumption in children after adenotonsillectomy.
In this randomized, double-blinded, placebo-controlled, prospective study, we evaluated the analgesic efficacy of dextromethorphan 0.5 mg/kg or 1.0 mg/kg p.o. 1 h before adenotonsillectomy in 57 children 6-12 yr of age. Anesthetic management was standardized. Morphine 0.075 mg/kg i.v. and acetaminophen 25-35 mg/kg p.r. were administered after anesthetic induction but before the start of surgery. A 4-point behavioral score (1 = asleep, 2 = awake and calm, 3 = awake and crying, 4 = thrashing) was recorded on admission to and discharge from the postanesthesia care unit (PACU). In the PACU, pain was assessed with Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and recorded every 15 min until the patient was transferred to the day surgery unit (DSU). In the DSU, patients rated their pain using a 10-cm baseline 0-10 visual analog pain scale (VAS) every 30 min until they were discharged home. A 24-h VAS was obtained by phone interview, and parental satisfaction was scored (yes/no) regarding their child's postoperative analgesia. Morphine 0.025 mg/kg i.v. was administered to children with CHEOPS score >6, who verbalized pain, or who were crying in any consecutive 5-min observation periods in the PACU. Total morphine consumption was recorded. The study groups were comparable with respect to demographic variables. We were unable to detect any differences between study groups with respect to postoperative morphine consumption, CHEOPS, behavior scores, VAS, or parental satisfaction. ⋯ Premedication with dextromethorphan 0.5 or 1.0 mg/kg p.o. does not improve postoperative analgesia in school-aged children who receive preemptive morphine 0.075 mg/kg i.v. and acetaminophen 25-35 mg/kg p.r. during nitrous oxide and desflurane anesthesia for adenotonsillectomy.
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Clinical TrialOptimization of the dose of intrathecal morphine in total hip surgery: a dose-finding study.
We designed this study to determine the optimal intrathecal dose of morphine in total hip surgery. The optimal intrathecal dose was defined as that providing effective analgesia and minimal side effects 24 h after total hip surgery. Patients (n = 143) scheduled for total hip surgery were randomized to four double-blinded groups with a standardized bupivacaine dose but different doses of intrathecal morphine (Group I = 0.025 mg, Group II = 0.05 mg, Group III = 0.1 mg, and Group IV = 0.2 mg). Pain scores, i.v. morphine intake (patient-controlled analgesia), and morphine-related side effects (respiratory depression, postoperative nausea and vomiting, itching, urinary retention) were recorded for 24 h after surgery. Excellent postoperative pain relief was present in all groups. The highest pain scores were found in Group I. The mean use of systemic morphine administered by patient-controlled analgesia infusion pump was 23.7, 17.8, 10.9, and 9.9 mg in Groups I-IV, respectively (P < 0.01 for Groups III and IV versus Group I). We conclude that 0.1 mg of intrathecal morphine is the optimal dose for pain relief after hip surgery with minimal side effects. ⋯ Earlier studies showed excellent postoperative pain relief after intrathecal morphine. However, the severity of side effects resulted in decreased enthusiasm for this anesthesia technique. In the present study, we show that an intrathecal dose of 0.1 mg of morphine can be used safely in total hip surgery with excellent postoperative pain relief.
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Comparative Study Clinical TrialHigh thoracic epidural anesthesia, but not clonidine, attenuates the perioperative stress response via sympatholysis and reduces the release of troponin T in patients undergoing coronary artery bypass grafting.
In this prospective study, we evaluated whether high thoracic epidural anesthesia (TEA) or i.v. clonidine, in addition to general anesthesia, affects the cardiopulmonary bypass- and surgery-associated stress response and incidence of myocardial ischemia by their sympatholytic properties. Seventy patients scheduled for elective coronary artery bypass graft (CABG) received general anesthesia with sufentanil and propofol. TEA was randomly induced before general anesthesia and continued during the study period in 25 (anesthetized dermatomes C6-T10). Another 24 patients received i.v. clonidine as a bolus of 4 microg/kg before the induction of general anesthesia. Clonidine was then infused at a rate of 1 microg x kg(-1) x h(-1) during surgery and at 0.2-0.5 microg x kg(-1) x h(-1) postoperatively. The remaining 21 patients underwent general anesthesia as performed routinely (control). Hemodynamics, plasma epinephrine and norepinephrine, cortisol, the myocardial-specific contractile protein troponin T, and other cardiac enzymes were measured pre- and postoperatively. During the preoperative night and a follow-up of 48 h after surgery, five-lead electrocardiogram monitoring was used for ischemia detection. Both TEA and clonidine reduced the postoperative heart rate compared with the control group without jeopardizing cardiac output or perfusion pressure. Plasma epinephrine increased perioperatively in all groups but was significantly lower in the TEA group. Neither TEA nor clonidine affected the increase in plasma cortisol. The release of troponin T was attenuated by TEA. New ST elevations > or = 0.2 mV or new ST depression > or = 0.1 mV occurred in > 70% of the control patients but only in 40% of the clonidine group and in 50% of the TEA group. We conclude that TEA (but not i.v. clonidine) combined with general anesthesia for CABG demonstrates a beneficial effect on the perioperative stress response and postoperative myocardial ischemia. ⋯ Thoracic epidural anesthesia combined with general anesthesia attenuates the myocardial sympathetic response to cardiopulmonary bypass and cardiac surgery. This is associated with decreased myocardial ischemia as determined by less release of troponin T. These findings may have an impact on the anesthetic management for coronary artery bypass grafting.
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Comparative Study Clinical TrialOnset time, recovery duration, and drug cost with four different methods of inducing general anesthesia.
We compared two conventional induction techniques (thiopental and propofol), an inhaled induction with sevoflurane using a circle system, and a rebreathing method. Fentanyl 1 microg/kg was given to women undergoing 10- to 20-min procedures. Anesthesia was induced (n = 20 each) with one of the following: 1) sevoflurane and N2O from a rebreathing bag (Sevo/Bag). A 5-L bag was prefilled with a mixture of sevoflurane 7% and N2O 60% in oxygen. The bag was connected between the normal circle system, separated by a spring-loaded valve; 2) sevoflurane 8% and N2O 60% from a circle system on a conventional anesthesia machine with a total fresh gas flow of 6 L/min (Sevo/Circle); 3) propofol 3 mg/kg as an i.v. bolus; 4) thiopental sodium 5 mg/kg as an i.v. bolus. Postoperative nausea and vomiting was treated with ondansetron. Induction times were comparable with each method. Recovery duration was shortest with sevoflurane, intermediate with propofol, and longest with thiopental. Induction drug costs were lowest with Sevo/Bag and thiopental, intermediate with Sevo/Circle, and highest with propofol. However, sevoflurane (by either method) caused considerable nausea and vomiting that required treatment. Consequently, total drug cost was least with thiopental, intermediate with Sevo/Bag and propofol, and greatest with Sevo/Circle. Thus, no single technique was clearly superior. ⋯ Anesthetic induction techniques influence awakening time, recovery duration, and drug costs. We tested two i.v. methods and two inhaled techniques. However, none of the four tested methods was clearly superior to the others.
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Clinical TrialPostoperative analgesia for outpatient arthroscopic knee surgery with intraarticular clonidine.
Intraarticular (i.a.) local anesthetics are often used for the management and prevention of pain after arthroscopic knee surgery. Clonidine prolongs the duration of local anesthetics. We designed this study to determine whether clonidine added to an i.a. injection would result in an analgesic benefit. Fifty patients were randomly assigned to one of five groups that received clonidine (either via the subcutaneous or i.a. route) or saline placebo with or without i.a. bupivacaine, as follows: Group 1 received 30 mL of 0.25% bupivacaine i.a.; Group 2 received 30 mL of 0.25% bupivacaine with clonidine (1 microg/kg) i.a.; Group 3 received 30 mL of 0.25% bupivacaine i.a. and subcutaneous clonidine (1 microg/kg); Group 4 received 30 mL of 0.25% bupivacaine with epinephrine (5 microg/mL) i.a.; and Group 5 received clonidine (1 microg/kg) in 30 mL of saline i.a.. The results of this study revealed a significant difference in analgesia from the i.a. administration of clonidine. The group who received a combination of i.a. bupivacaine and clonidine had a significantly decreased need for oral postoperative analgesics and an increased analgesic duration (P < 0.0001). We conclude that i.a. clonidine improved comfort in patients undergoing knee arthroscopy. ⋯ The intraarticular administration of clonidine along with bupivacaine results in a significant improvement in analgesia compared with either drug alone. There was an increased time to first analgesic request and a decreased need for postoperative analgesics.