Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Clinical TrialThe analgesic effect of interscalene block using clonidine as an analgesic for shoulder arthroscopy.
Used as the sole analgesic, clonidine produces analgesia after central neural blockade and intraarticular injection but not after axillary block. In this study, we sought to determine whether interscalene clonidine induces analgesia for shoulder arthroscopy. Forty patients scheduled for shoulder arthroscopy were prospectively included in this double-blinded study. Using a nerve stimulator technique, an interscalene catheter was inserted. The patients were randomly divided into two groups. The interscalene group (n = 20) received clonidine 150 micro g in 15 mL of saline through the catheter and 1 mL of subcutaneous saline, and the systemic group (n = 20) received 15 mL of saline through the catheter and clonidine 150 micro g (1 mL) subcutaneously. All patients underwent general anesthesia for surgery. On completion of arthroscopy, all patients received, via a patient-controlled analgesia, on demand a bolus of 8 mL of ropivacaine 0.2% through the catheter with a 1-h lockout period. Postoperative pain was measured every 4 h using the visual analog scale (VAS) for 24 h. Additional postoperative analgesia was available with parenteral nalbuphine if required until VAS < 3. VAS scores in the recovery room were significantly higher in the systemic group compared with the interscalene group (P < 0.0001). Analgesic duration was significantly longer in the interscalene group (P < 0.00001), and ropivacaine consumption was significantly less than in the systemic group (P < 0.0001). No significant difference was observed between groups for nalbuphine consumption. Side effects were comparable in the two groups. ⋯ Clonidine administered via an interscalene catheter enhanced analgesia compared with systemic administration. Nevertheless, the adverse effect of clonidine at this dose limits its use for routine management for postoperative analgesia.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialA comparative study of three warming interventions to determine the most effective in maintaining perioperative normothermia.
Perioperative hypothermia poses a challenge because of its deleterious effects on patient recovery. The current practice of applying two cotton blankets on patients during surgery is thought to be less ideal than using reflective insulation or forced-air warming. We studied 300 patients who underwent unilateral total knee replacement and were randomized equally to three groups: (a) the two-cotton-blanket group, (b) the one-reflective-blanket with one-cotton-blanket group, and (c) the forced-air-warming with one-cotton-blanket group. Tympanic temperature readings were taken before surgery in the induction room, on arrival at the recovery room, and at 10-min intervals until discharge from the recovery room. On arrival at the recovery room, the forced-air-warming group had significantly higher temperatures (adjusted for sex, age, and patient's induction room temperature) of 0.577 degrees C +/- 0.079 degrees C (95% confidence interval [CI], 0.427-0.726; P < 0.001) and 0.510 degrees C +/- 0.08 degrees C (95% CI, 0.349-0.672; P < 0.001) more than the reflective-blanket and two-cot-ton-blanket groups, respectively. The forced-air-warming group took a significantly (P < 0.001) shorter time of 18.75 min (95% CI, 13.88-23.62) to achieve a temperature of 36.5 degrees C in the recovery room as compared with 41.78 min (95% CI, 36.86-46.58) and 36.43 min (95% CI, 31.23-41.62) for the reflective-blanket and two-cotton-blanket groups, respectively. The reflective technology was less effective than using two cotton blankets, and the forced-air warming was most efficient in maintaining perioperative normothermia. ⋯ Perioperative hypothermia has deleterious effects on patient recovery. We found in patients having knee surgery that reflective technology was less effective than using two cotton blankets, whereas active surface warming with the forced-air method was most effective in maintaining normothermia.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of a left-sided Broncho-Cath with the torque control blocker univent and the wire-guided blocker.
Lung isolation can be accomplished in two ways: the first, a double-lumen endotracheal tube (DLT) and the second, a bronchial blocker (Univent or Arndt blocker). Previous studies have found that the DLT and the Univent are comparable when providing lung isolation. A new bronchial blocker, the wire-guided endobronchial blocker (Arndt blocker), has been introduced. However, there is no study to report its effectiveness with lung isolation during elective thoracic surgical cases. Therefore, we designed a prospective, randomized trial to compare the effectiveness of lung isolation among the 3 endotracheal tubes: the left-sided DLT Broncho-Cath Group A (n = 16 patients), the torque control blocker Univent Group B (n = 16 patients), and the wire-guided Arndt blocker Group C (n = 32 patients). The following variables were recorded: 1) time to initially position the assigned tube, 2) frequency of malpositions, 3) frequency of use of fiberoptic bronchoscope, 4) overall surgical exposure, and 5) tube acquisition cost. The Arndt blocker took longer to place (3:34 min/s) compared with the other 2 groups: the DLT group (2:08 min/s) or the Univent group (2:38 min/s) (P < 0.0004). There was no statistical difference in tube malpositions among the three groups: two for the DLT group, four for the Univent group, and nine in the Arndt group. Excluding the time for tube placement, the Arndt group also took longer for the lung to collapse (26:02 min/s), compared with the DLT group (17:54 min/s) or Univent group (19:28 min/s) (P < 0.0060). Furthermore, unlike the other two groups, the majority of the Arndt patients required suction to achieve lung collapse. Once lung isolation was achieved, overall surgical exposure was rated excellent for the three groups. Acquisition cost for the DLT group was $1663.20 (21 tubes opened), $2329.00 for the Univent group (17 tubes opened), and $3567.00 for the Arndt group (33 wire-guided blockers opened). This study demonstrates that the Arndt blocker takes longer to position and longer to deflate the isolated lung. For elective thoracic surgical cases, once the lung was isolated, the management seemed to be similar for all three tube groups. ⋯ We compared the latest design of double-lumen tubes Broncho-Cath, Univent, and Arndt blockers during lung isolation. Our results show that the Arndt blocker takes longer to position and longer to deflate the isolated lung. Once the lung was isolated, the management seemed to be similar for all three devices.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialPropofol-nitrous oxide anesthesia enhances the heart rate response to intravenous isoproterenol infusion.
Heart rate (HR) response to IV atropine is attenuated during propofol-nitrous oxide (N(2)O) anesthesia. We studied the effects of propofol-N(2)O anesthesia on isoproterenol-induced HR changes. The control group (n = 15) received no propofol and no N(2)O. Patients in the propofol-N(2)O group (n = 21) received IV propofol 2.5 mg/kg over 1 min followed by a continuous infusion of propofol 10 mg x kg(-1) x h(-1). After tracheal intubation, anesthesia was maintained with propofol 5 mg. kg(-1) x h(-1) and 67% N(2)O in oxygen. All patients in both groups received IV isoproterenol at incremental infusion rates (2.5, 5, 7.5, 10, 12.5, 15, and 17.5 ng x kg(-1) x min(-1) for 2 min at each dose) until HR increased more than 20 bpm from baseline values. At the end of each infusion period, hemodynamic data were collected. The HR response to isoproterenol 7.5 ng. kg(-1) x min(-1) was increased more in the propofol group than in the control group (20 +/- 5 versus 14 +/- 4 bpm; P < 0.05). During the isoproterenol infusion at 10 ng. kg(-1) x min(-1), HR increased by more than 20 bpm in all patients in the propofol group but in only 31% of patients in the control group (P < 0.0001). These results suggest that continuous isoproterenol infusion might be useful when a large dose of atropine is ineffective in restoring normal HR during propofol-N(2)O anesthesia. ⋯ We demonstrated that the heart rate response to IV isoproterenol infusion is enhanced during propofol-nitrous oxide anesthesia. This suggests that continuous isoproterenol infusion may be useful when a large dose of atropine is ineffective for restoration of normal heart rate in patients receiving propofol-nitrous oxide anesthesia.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Clinical TrialSupplemental oxygen does not reduce the incidence of postoperative nausea and vomiting after ambulatory gynecologic laparoscopy.
Supplemental 80% oxygen administration halves the incidence of postoperative nausea and vomiting (PONV) in inpatients. Whether it prevents PONV after ambulatory surgery is unknown. We tested the efficacy of supplemental 80% oxygen in decreasing the incidence of PONV after ambulatory gynecologic laparoscopy. One hundred patients were given a standardized sevoflurane anesthetic. They were randomly assigned to two groups: routine oxygen administration with 30% oxygen, balance nitrogen (Group A); and supplemental oxygen with 80% oxygen, balance nitrogen (Group B). Oxygen was administered during surgery and up to 1 h after surgery. The incidence of nausea and vomiting and the need for rescue antiemetics did not differ between the groups in the postanesthesia care unit, in the Phase II unit, or during the 24-h follow-up. The overall incidence of nausea and vomiting during the first postoperative 24 h was 62% in Group A and 55% in Group B (P = 0.486). There were no differences in the recovery profiles and patient satisfaction between the groups. In this study, supplemental oxygen did not prevent PONV in patients undergoing ambulatory gynecologic laparoscopy. ⋯ Supplemental 80% oxygen administration during surgery and until 1 h after surgery compared with 30% oxygen administration did not prevent postoperative nausea and vomiting after ambulatory gynecologic laparoscopy.