Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2003
Randomized Controlled Trial Clinical TrialHyperbaric bupivacaine 2.5 mg prolongs analgesia compared with plain bupivacaine when added to intrathecal fentanyl 25 microg in advanced labor.
We investigated the effect of sequential administration of intrathecal (IT) hyperbaric bupivacaine (after the initial administration of IT hypobaric fentanyl) on the duration of spinal analgesia. Thirty-seven nulliparous parturients with a cervical dilation >/= 5 cm were randomized to receive either IT fentanyl 25 micro g and plain bupivacaine 2.5 mg (group P; n = 19) or IT fentanyl 25 micro g and hyperbaric (with 8% glucose) bupivacaine 2.5 mg (group H; n = 18). The two components of the IT injectate were administered sequentially (fentanyl 25 micro g diluted in 2 mL of normal saline, immediately followed by 0.5 mL of 0.5% bupivacaine). ⋯ Group H also had a more limited dermatomal spread (median highest sensory level of T8 versus T4 in group P; P < 0.05). The side-effect profile was similar. Under these circumstances, hyperbaric bupivacaine conferred an increased duration of IT analgesia compared with plain bupivacaine.
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Anesthesia and analgesia · Sep 2003
Clinical TrialPerioperative continuous peripheral nerve blocks with disposable infusion pumps in children: a prospective descriptive study.
Continuous peripheral nerve blocks (CPNB) after pediatric major orthopedic surgery are not widely used. We conducted a prospective descriptive study to evaluate the effectiveness of disposable elastomeric pumps for CPNB in children. After inducing general anesthesia, 25 consecutive children scheduled for major orthopedic surgery received a 0.5-mL/kg bolus of a mixture of 1% lidocaine with epinephrine and 0.25% bupivacaine in axillary, femoral, or popliteal catheters. ⋯ Sensory and motor block were noted at H1 and decreased from the sixth hour. No adverse events were noted. We concluded that the use of elastomeric disposable pumps for CPNB in children was an effective technique.
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Anesthesia and analgesia · Sep 2003
Randomized Controlled Trial Comparative Study Clinical TrialContinuous infraclavicular perineural infusion with clonidine and ropivacaine compared with ropivacaine alone: a randomized, double-blinded, controlled study.
Although clonidine has been shown to increase the duration of local anesthetic action and prolong postoperative analgesia when included in single-injection nerve blocks, a controlled investigation of the efficacy of this practice to improve analgesia for continuous perineural local anesthetic infusion has not been reported. In this study, ambulatory patients (n = 34) undergoing moderately painful upper extremity orthopedic surgery received an infraclavicular brachial plexus block (mepivacaine 1.5%, epinephrine 2.5 micro g/mL, and bicarbonate 0.1 mEq/mL) and a perineural catheter before surgery. After surgery, patients were discharged home with a portable infusion pump delivering either ropivacaine 0.2% or ropivacaine 0.2% plus clonidine 1 micro g/mL via the catheter for 3 days (basal, 8 mL/h; patient-controlled bolus, 2 mL every 20 min). ⋯ Adding clonidine to ropivacaine resulted in a statistically significant decrease in the number of self-administered 2-mL bolus doses on postoperative Days 0 and 1 (P < 0.02), but this decreased actual local anesthetic consumption by an average of only 2-7 mL/d (P < 0.02). There were no statistically significant differences between the two groups for any of the other variables investigated, including sleep quality or oral analgesic requirements. We conclude that adding 1 micro g/mL of clonidine to a ropivacaine infraclavicular perineural infusion does not provide clinically relevant improvements in analgesia, sleep quality, or oral analgesic requirements for ambulatory patients having moderately painful upper extremity surgery.
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Anesthesia and analgesia · Sep 2003
Doxapram produces a dose-dependent reduction in the shivering threshold in rabbits.
Dopamine is a thermoregulatory neurotransmitter that provokes hypothermia when injected in or near the hypothalamus. Doxapram stimulates release of dopamine from carotid bodies, but is known to have central effects that are probably, at least in part, similarly mediated. We thus tested the hypothesis that doxapram produces a substantial, dose-dependent reduction in the shivering threshold in rabbits. ⋯ The control rabbits shivered at 36.3 degrees +/- 0.3 degrees C, those given 0.25 mg x kg(-1) x h(-1) doxapram shivered at 34.8 degrees +/- 0.5 degrees C, and those given 0.50 mg x kg(-1) x h(-1) shivered at 33.7 degrees +/- 0.6 degrees C. All the shivering thresholds significantly (P < 0.001) differed from one another. The magnitude of this inhibition, if similar in humans, would be clinically important.
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Anesthesia and analgesia · Sep 2003
Randomized Controlled Trial Comparative Study Clinical TrialHemispheric synchronized sounds and intraoperative anesthetic requirements.
Hemispheric synchronization is currently promoted as a treatment for preoperative anxiety and for reduction of intraoperative anesthetic and analgesic consumption. We designed this study to examine the effect of Hemisync sounds on anesthetic hypnotic depth. After obtaining informed consent, we randomized subjects undergoing general anesthesia and outpatient surgery into two groups: the treatment group received Hemisync sounds (n = 31), and the control group received a blank cassette tape (n = 29). ⋯ We found no differences in the amount of propofol used during the induction of anesthesia (2.49 +/- 0.59 mg/kg versus 2.60 +/- 0.59 mg/kg; P = 0.48) or the maintenance of anesthesia (0.141 +/- 0.02 mg x kg(-1) x min(-1) versus 0.146 +/- 0.04 mg x kg(-1) x min(-1); P = 0.62) between the Hemisync and control groups. We also found no differences between the Hemisync group and the control group for participants with high state anxiety (P = not significant). We conclude that Hemisync sounds do not reduce the hypnotic component of the anesthetic state of patients undergoing general anesthesia and surgery.