Anesthesia and analgesia
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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.
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Comparative Study Clinical TrialThe analgesic effect of sufentanil combined with ropivacaine 0.2% for labor analgesia: a comparison of three sufentanil doses.
The combination of opioids with local anesthetics is commonly used for epidural labor analgesia. We examined whether increasing sufentanil in doses of 5, 10, and 15 microg prolonged the duration of labor analgesia produced by ropivacaine. One hundred healthy parturients in the first stage of labor who requested epidural analgesia were enrolled. Parturients were randomized to receive 12 mL ropivacaine 0.2% alone or with sufentanil 5 microg, sufentanil 10 microg, or sufentanil 15 microg. The duration of analgesia, pain score, degree of motor blockade (using a four-point Bromage scale), heart rate, blood pressure, respiratory rate, oxygen saturation, and incidence of nausea and pruritus were recorded. The mean duration of epidural analgesia was 96 +/- 32 min for patients without sufentanil, 134 +/- 27 min for Group 5 (p < 0.01 versus control), 135 +/- 33 min for Group 10 (p < 0.01 versus control), 130 +/- 33 min for Group 15 (p < 0.01 versus control) without differences among sufentanil groups. Between 30 and 90 min, the sufentanil groups (5 microg, 10 microg, and 15 microg) had lower pain scores than the control group (p < 0.01 versus control) but there were no differences among the sufentanil groups. No patient in any group had a Bromage score more than 1. No significant difference was found for opioid-related side effects. We conclude that 5-10 or 15 microg sufentanil induced a similar prolongation of analgesia when combined with ropivacaine 0.2% for initiation of labor analgesia. ⋯ We studied the effect of adding one of three possible sufentanil doses to epidural ropivacaine 0.2% for labor analgesia. Adding sufentanil increased the duration of analgesia but there was no advantage in adding more than 5 microg of sufentanil.
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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 TrialPatient-controlled interscalene analgesia with ropivacaine 0.2% versus bupivacaine 0.15% after major open shoulder surgery: the effects on hand motor function.
We compared the effects of patient-controlled interscalene analgesia with ropivacaine 0.2% and patient-controlled interscalene analgesia (PCIA) with bupivacaine 0.15% on hand grip strength after major open shoulder surgery. Sixty patients scheduled for elective major shoulder surgery were prospectively randomized to receive in a double-blinded fashion either ropivacaine or bupivacaine through an interscalene catheter. Before surgery, all patients received an interscalene block (ISB) with either 40 mL of 0.6% ropivacaine or 40 mL of 0.5% bupivacaine. Six h after ISB, the patients received a continuous infusion of either 0.2% ropivacaine or 0.15% bupivacaine for 48 h. In both groups, the PCIA infusion rate was 5 mL/h plus a bolus of 4 mL with a lockout time of 20 min. Strength in the hand was assessed preoperatively, 24 h, and 48 h after ISB and 6 h after stopping the infusion of local anesthetic. The presence of paresthesia in the fingers was checked. Pain relief was assessed using a visual analog scale; side effects were noted, and the patients rated their satisfaction 54 h after the block. A significant decrease of strength in the hand was observed in the Bupivacaine group 24, 48, and 54 h after ISB (P < 0.05). Paresthesia was more frequently reported in the Bupivacaine group for the second and third fingers 48 h after ISB (P < 0.05) and in the first three fingers 6 h after discontinuation of the local anesthetic infusion (P: < 0.05). The pain score was similar in the two groups at all times, and patient satisfaction was comparable between the two groups. We conclude that the use of the PCIA technique with ropivacaine 0.2% or bupivacaine 0.15% provides a similar pain relief after major shoulder surgery. However, ropivacaine 0.2% is associated with better preservation of strength in the hand and less paresthesia in the fingers. ⋯ We compared the patient-controlled interscalene analgesia technique with ropivacaine 0.2% and bupivacaine 0.15% after major open shoulder surgery. For similar pain control ropivacaine is associated with better preservation of strength in the hand and less paresthesia in the fingers.
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Anesthesia and analgesia · Jan 2001
Randomized Controlled Trial Comparative Study Clinical TrialTramadol added to lidocaine for intravenous regional anesthesia.
Sixty volunteers, divided into four groups of 15 each, received IV regional anesthesia of the upper limb with 40 mL tramadol 0.25%, sodium chloride 0.9%, lidocaine 0.5%, or 100 mg tramadol-containing lidocaine 0.5%. By using a double-blinded method, we tested the onset and recovery of sensory block at six sites of the forearm and hand as well as onset of complete motor block. The symptoms after deflation of the tourniquet were recorded. The onset and recovery of sensory block and the onset of motor block were similar in the tramadol and saline groups. However, in the Tramadol-Lidocaine Group, the speed of onset of sensory block was faster than in the Lidocaine Group. In the Tramadol and the Tramadol-Lidocaine Groups, the incidence of skin rash and painful or burning sensation at the injection site was increased. We conclude that tramadol 0.25% does not have a local anesthetic effect when used as a sole drug for IV regional anesthesia, but might modify the action of local anesthetic, providing a shorter onset time of sensory block. ⋯ Tramadol, a centrally acting analgesic, might have local anesthetic properties, as do some opioid drugs. We demonstrated that 0.25% tramadol solution containing 100 mg tramadol is not effective as a sole drug, but may improve the action of 0.5% lidocaine for intravenous regional anesthesia. The increased incidence of side effects may limit the clinical use of tramadol.