Anesthesia and analgesia
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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 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 TrialThe use of lidocaine for preventing the withdrawal associated with the injection of rocuronium in children and adolescents.
We designed this study to examine the incidence and degree of movement after the administration of rocuronium in children and adolescents and to measure the treatment effect of lidocaine for its prevention. One hundred patients (aged 5-18 yr) were randomly assigned to two groups. After general anesthesia was induced with 5 mg/kg thiopental sodium and manual occlusion of venous outflow was performed, one group of patients received 0.1 mL/kg 1% lidocaine i.v.. A second group received 0.1 mL/kg of isotonic sodium chloride solution as a placebo control. Venous outflow occlusion was held for 15 s, released, and immediately followed by the administration of rocuronium 1 mg/kg i.v.. The patient's response to rocuronium injection was graded using a 4-point scale. We observed that the incidence of withdrawal was 84% in the placebo group and was significantly decreased to 46% in patients pretreated with lidocaine (P < 0.001). This study demonstrates that the i.v. injection of rocuronium is commonly associated with a withdrawal reaction in anesthetized pediatric patients and that this reaction can be attenuated or eliminated by pretreatment with i.v. lidocaine. ⋯ Pain on injection of rocuronium in pediatric patients can be alleviated by pretreatment with i.v. lidocaine.
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Clinical TrialTramadol added to mepivacaine prolongs the duration of an axillary brachial plexus blockade.
Tramadol is an analgesic drug that is antagonized by alpha2-adrenoceptor antagonists, as well as opioid antagonists. We hypothesized that tramadol might produce effects on an axillary brachial plexus blockade similar to those of clonidine. We designed a prospective, controlled, double-blinded study to assess the impact of tramadol added to mepivacaine on the duration of an axillary brachial plexus blockade. After institutional approval and informed consent, 60 patients (ASA physical status I or II) scheduled for forearm and hand surgery after trauma under brachial plexus anesthesia were included in the study. Patients were randomly assigned to receive either 40 mL of mepivacaine 1% with 2 mL of isotonic sodium chloride solution (Group A, n = 20); 40 mL of mepivacaine 1% with 100 mg of tramadol (Group B, n = 20); or 40 mL of mepivacaine 1% with 2 mL of isotonic sodium chloride solution and 100 mg of tramadol i.v. (Group C, n = 20). Sensory block, motor block, and hemodynamics were recorded before and 5, 10, 30, 60, 120, 180, and 360 min after local anesthetic injection. Duration of sensory and motor block was significantly longer (P < 0.01; P < 0.05) in Group B (299 +/- 84 and 259 +/- 76 min) than in Group A (194 +/- 35 and 181 +/- 24 min) and Group C (187 +/- 35 and 179 +/- 16 min). There was no difference in onset of sensory and motor blockade among groups. Hemodynamics remained unchanged in all patients throughout the study period. We conclude that the addition of tramadol prolongs the duration of brachial plexus block without side effects. Tramadol may be an alternative to epinephrine or clonidine as an adjuvant to local anesthesia for an axillary block. ⋯ This study demonstrates that the admixture of 100 mg of tramadol with mepivacaine 1% for brachial plexus block provides a pronounced prolongation of blockade without side effects. Our data support a specific analgesic effect of tramadol on peripheral nerves.
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Comparative Study Clinical TrialComparison of sevoflurane with propofol for laryngeal mask airway insertion in adults.
We performed a prospective, randomized, controlled trial to compare the quality and ease of laryngeal mask airway (LMA) insertion after either rapid inhaled sevoflurane or i.v. propofol induction of anesthesia. Seventy-six unpremedicated ASA physical status I or II patients were anesthetized with either a single vital capacity breath of sevoflurane 8% or i.v. propofol 3 mg/kg, which produced equally rapid loss of consciousness (40.5 +/- 13.9 vs 37.7 +/- 9.9 s; P > 0.05). The LMA was inserted more rapidly in patients in the propofol group (74 +/- 29 vs 127 +/- 35 s; P < 0.01) and required fewer attempts (1.2 vs 1.6; P < 0.05) than the sevoflurane group. There was a greater incidence of initially impossible mouth opening in the sevoflurane group (45% vs 21%; P < 0.05). Once mouth opening was possible, the degree of attenuation of laryngeal reflexes was similar. The overall incidence of complications related to LMA insertion, especially apnea (32% vs 0%; P < 0.01), was more frequent in the propofol group (82% vs 26%; P < 0.01). There were four failures of LMA insertion in the propofol group and none in the sevoflurane group. Both groups had stable hemodynamic profiles and good patient satisfaction. We conclude that sevoflurane vital capacity breath induction compares favorably with i.v. propofol induction for LMA insertion in adults. However, prolonged jaw tightness after the sevoflurane induction of anesthesia may delay LMA insertion. ⋯ In this randomized, controlled trial, we compared the ease of insertion of the laryngeal mask airway in adults after induction of anesthesia with either a sevoflurane vital capacity breath technique or propofol i.v.. We conclude that sevoflurane compares favorably with propofol, although prolonged jaw tightness may delay laryngeal mask airway insertion.