Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2001
Case ReportsIntraoperative monitoring of the recurrent laryngeal nerve during single-lung ventilation in esophagectomy.
We describe the use of a surface electrode attached to a double-lumen endobronchial tube to identify and monitor the recurrent laryngeal nerve during esophagectomy in single-lung ventilation. The technique is demonstrated in the case of a patient with carcinoma of the distal esophagus.
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Anesthesia and analgesia · Mar 2001
The analgesic interaction between intrathecal clonidine and glutamate receptor antagonists on thermal and formalin-induced pain in rats.
Clonidine, an alpha(2) adrenergic receptor agonist, inhibits glutamate release from the spinal cord. We studied the interaction of intrathecally administered clonidine and glutamate receptor antagonists on acute thermal or formalin induced nociception. Sprague-Dawley rats with lumbar intrathecal catheters were tested for their tail withdrawal response by the tail flick test and paw flinches produced by formalin injection after intrathecal administration of saline, clonidine, AP-5 (a N-methyl-D-aspartate receptor antagonist), or YM872 (an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist). The combinations of clonidine and the other two agents were also tested by isobolographic analyses. Motor disturbance and behavioral changes were observed as side effects. The ED(50) values of clonidine decreased from 0.26 microg (tail flick), 0.12 microg (Phase 1) and 0.13 microg (Phase 2) to 0.036 microg, 0.006 microg, and 0.013 microg with AP-5, and 0.039 microg, 0.057 microg, and 0.133 microg with YM872, respectively. Side effects were attenuated in both combinations. In conclusion, spinally administered clonidine and AP-5 or YM872 exhibited potent synergistic analgesia on acute thermal and formalin-induced nociception with decreased side effects in rats. ⋯ Combinations of a spinally administered alpha(2) adrenergic receptor agonist and an a N-methyl-D-aspartate receptor antagonist or an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist exhibited potent synergistic analgesia in acute thermal and inflammatory-induced nociception with decreased side effects.
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Anesthesia and analgesia · Mar 2001
Colforsin daropate improves contractility in fatigued canine diaphragm.
We studied the effects of colforsin daropate, a water-soluble forskoline derivative, on contractility in fatigued canine diaphragm. Dogs were randomly divided into 4 groups of 8 each. In each group, diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. Immediately after the end of a fatigue-producing period, Group 1 received no study drug, Group 2 was infused with small-dose colforsin daropate (0.2 microg. kg(-1). min(-1)), Group 3 was infused with large-dose colforsin daropate (0.5 microg. kg(-1). min(-1)), and Group 4 was infused with nicardipne (5 microg. kg(-1). min(-1)) during colforsin daropate (0.5 microg. kg(-1). min(-1)) administration. After the fatigue-producing period, in each group transdiaphragmatic pressure (Pdi) at low-frequency (20-Hz) stimulation decreased from baseline values (P < 0.05), whereas there was no change in Pdi at high-frequency (100-Hz) stimulation. In Groups 2 and 3, during colforsin daropate administration, Pdi to each stimulus increased from fatigued values (P < 0.05). The increase in Pdi was larger in Group 3 than in Group 2 (P < 0.05). In Group 4, the augmentation of Pdi by colforsin daropate was abolished in fatigued diaphragm with an infusion of nicardipine. The integrated diaphragmatic electric activity did not change in any of the groups. We conclude that colforsin daropate improves, in a dose-dependent manner, contractility in fatigued canine diaphragm via its effect on transmembrane calcium movement. ⋯ Diaphragmatic fatigue is implicated as a cause of respiratory failure in normal subjects and in patients with chronic obstructive lung disease. Colforsin daropate improves contractile properties during diaphragmatic fatigue.
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Multicenter Study Clinical TrialThe use of transcutaneous acupoint electrical stimulation for preventing nausea and vomiting after laparoscopic surgery.
Nonpharmacologic techniques may be effective in preventing postoperative nausea and vomiting (PONV). This sham-controlled, double-blinded study was designed to examine the antiemetic efficacy of transcutaneous acupoint electrical stimulation (TAES) in a surgical population at high risk of developing PONV. We studied 221 outpatients undergoing laparoscopic cholecystectomy with a standardized general anesthetic technique in this randomized, multicenter trial. In the TAES group, an active ReliefBand(Woodside Biomedical, Inc., Carlsbad, CA) device was placed at the P6 acupoint, whereas in the Sham and Placebo groups, an inactive device was applied at the P6 acupoint and at the dorsal aspect of the wrist, respectively. The ReliefBand was applied after completion of electrocautery and remained in place for 9 h after surgery. The incidence of PONV and need for "rescue" medication were evaluated at predetermined time intervals. TAES was associated with a significantly decreased incidence of moderate-to-severe nausea as denoted on the Functional Living Index-Emesis score for up to 9 h after surgery (5%-11% for the TAES group vs 16%-38% [P < 0.05] and 15%-26% [P < 0.05] for Sham and Placebo groups, respectively). TAES was also associated with a larger proportion of patients free from moderate to severe nausea symptoms (73% vs 41% and 49% for Sham and Placebo groups, respectively; P < 0.05). However, there were no statistically significant differences among the three groups with regard to incidence of vomiting or the need for rescue antiemetic drugs. We conclude that TAES with the ReliefBand at the P6 acupoint reduces nausea, but not vomiting, after laparoscopic cholecystectomy. ⋯ Transcutaneous acupoint electrical stimulation at the P6 acupoint reduced postoperative nausea, but not vomiting, in outpatients undergoing laparoscopic cholecystectomy procedures.
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of ropivacaine and bupivacaine for cervical plexus block.
We compared bupivacaine 0.5% and ropivacaine 0.75% for cervical plexus block (CB). Forty patients scheduled for carotid artery surgery were allocated randomly to undergo superficial and deep CB with 30 mL of one of the two anesthetic solutions. We evaluated the onset of anesthetic block; the requirement for supplementation during the surgery; the patients' satisfaction; postoperative pain on a visual analog scale at 1, 2, and 3 h; and the use of paracetamol as a rescue analgesic medication. Arterial blood was sampled immediately and 1, 3, 5, 10, 15, 30, 45, and 60 min after CB for measurements of bupivacaine or ropivacaine concentrations. Patients in both groups had equivalent onset of CB, local infiltration with lidocaine during surgery, and satisfaction scores. In the Bupivacaine group, visual analog scale scores were lower at 2 and 3 h, and the delay before paracetamol administration was prolonged. Observed peak concentrations were larger in the Ropivacaine group (4.25 [2.07-6.59 mg/L] vs 3.02 [0.98-5.82 mg/L]), but time to reach peak concentrations was comparable (5 [1-15 min] vs 5 [0-45 min] in the Ropivacaine and Bupivacaine groups, respectively). We conclude that ropivacaine has no advantage over bupivacaine for CB. ⋯ Compared with bupivacaine (150 mg), a larger dose of ropivacaine (225 mg) produces comparable features of cervical plexus block but less postoperative analgesia and larger plasma concentrations. There is no reason to favor ropivacaine in such a case.