Anesthesia and analgesia
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Anesthesia and analgesia · May 2004
ReviewA qualitative systematic review of the role of N-methyl-D-aspartate receptor antagonists in preventive analgesia.
We evaluated in a qualitative systematic review the effect of N-methyl-D-aspartate (NMDA) receptor antagonists on reducing postoperative pain and analgesic consumption beyond the clinical duration of action of the target drug (preventive analgesia). Randomized trials examining the use of an NMDA antagonist in the perioperative period were sought by using a MEDLINE (1966-2003) and EMBASE (1985-2003) search. Reference sections of relevant articles were reviewed, and additional articles were obtained if they evaluated postoperative analgesia after the administration of NMDA antagonists. The primary outcome was a reduction in pain, analgesic consumption, or both in a time period beyond five half-lives of the drug under examination. Secondary outcomes included time to first analgesic request and adverse effects. Forty articles met the inclusion criteria (24 ketamine, 12 dextromethorphan, and 4 magnesium). The evidence in favor of preventive analgesia was strongest in the case of dextromethorphan and ketamine, with 67% and 58%, respectively, of studies demonstrating a reduction in pain, analgesic consumption, or both beyond the clinical duration of action of the drug concerned. None of the four studies examining magnesium demonstrated preventive analgesia. ⋯ We evaluated, in a qualitative systematic review, the effect of N-methyl D-aspartate antagonists on reducing postoperative pain and analgesic consumption beyond the clinical duration of action of the target drug (preventive analgesia). Dextromethorphan and ketamine were found to have significant immediate and preventive analgesic benefit in 67% and 58% of studies, respectively.
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Anesthesia and analgesia · May 2004
Clinical TrialFiberoptic endotracheal intubation after topicalization with in-circuit nebulized lidocaine in a child with a difficult airway.
This case report describes the successful fiberoptic intubation of an uncooperative child with a difficult airway due to gross burn scarring in the facial and neck region by administering 4% end-tidal sevoflurane and simultaneously delivering 4% nebulized lidocaine via a small-volume nebulizer that was connected to the inspiratory limb of the circle system via a T-piece adapter. This case suggests that simultaneously administering a volatile anesthetic with nebulized lidocaine might be an alternative way to deliver lidocaine and might provide better topical anesthesia for uncooperative patients. ⋯ An in-circuit nebulization system to deliver topical lidocaine may facilitate fiberoptic-assisted intubation in anesthetized, spontaneously breathing children with compromised airways.
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Anesthesia and analgesia · May 2004
Electrocerebral silence by intracarotid anesthetics does not affect early hyperemia after transient cerebral ischemia in rabbits.
Evidence suggests that early postischemic hyperemia is mediated by both neurological and vascular mechanisms. We hypothesized that if neuronal activity were primarily responsible for reperfusion hyperemia, then electrocerebral silence induced by intracarotid anesthetics (propofol and pentothal) would attenuate the hyperemic response. New Zealand white rabbits were subjected to 10 min of cerebral ischemia using bilateral carotid occlusion and systemic hypotension. Subsequently, carotid occlusion was released, and the mean arterial blood pressure was increased to baseline values. In the control group, intracarotid saline was periodically injected during reperfusion. In the treatment groups, intracarotid propofol or thiopental was administered to maintain electrocerebral silence for 10 min. Physiological data were measured at baseline, during ischemia, and at reperfusion. Satisfactory data were available for 16 of 19 rabbits. Mean arterial blood pressure, end-tidal CO(2), and cerebral blood flows decreased significantly in both groups during carotid occlusion. During early reperfusion, a similar percent increase in cerebral blood flow from baseline values was observed in all 3 groups (192% +/- 76%, 218% +/- 84%, and 185% +/- 101% for saline, propofol, and pentothal, respectively). These results suggest that suppression of neuronal activity during reperfusion does not affect early hyperemia after transient cerebral ischemia. ⋯ Intracarotid injection of anesthetic drugs in doses that are sufficient to produce electrocerebral silence do not obtund early cerebral hyperemia after transient cerebral ischemia. This suggests that vascular, not neuronal mechanisms, are primarily responsible for early postischemic cerebral hyperperfusion.
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Anesthesia and analgesia · May 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe short- and long-term benefit in chronic low back pain through adjuvant electrical versus manual auricular acupuncture.
Acupuncture is an established adjuvant analgesic modality for the treatment of chronic pain. Electrical stimulation of acupuncture points is considered to increase acupuncture analgesia. In this prospective, randomized, double-blind, controlled study we tested the hypothesis that auricular electroacupuncture (EA) relieves pain more effectively than conventional manual auricular acupuncture (CO) in chronic low back pain patients with insufficient pain relief (visual analogue scale [VAS] > or = 5) treated with standardized analgesic therapy. Disposable acupuncture needles were inserted in the auricular acupuncture points 29, 40, and 55 of the dominant side and connected to a newly developed battery-powered miniaturized stimulator worn behind the ear. Patients were randomized into group EA (n = 31) with continuous low-frequency auricular EA (1 Hz biphasic constant current of 2 mA) and group CO (n = 30) without electrical stimulation (sham-electroacupuncture). Treatment was performed once weekly for 6 wk, and in each group needles were withdrawn 48 h after insertion. During the study period and a 3-mo follow-up, patients were asked to complete the McGill questionnaire. Psychological well being, activity level, quality of sleep, and pain intensity were assessed by means of VAS; moreover, analgesic drug consumption was documented. Pain relief was significantly better in group EA during the study and the follow-up period as compared with group CO. Similarly, psychological well-being, activity, and sleep were significantly improved in group EA versus group CO, the consumption of analgesic rescue medication was less, and more patients returned to full-time employment. Neuropathic pain in particular improved in patients treated with EA. There were no adverse side effects. These results are the first to demonstrate that continuous EA stimulation of auricular acupuncture points improves the treatment of chronic low back pain in an outpatient population. ⋯ Continuous electrical stimulation of auricular acupuncture points using the new point stimulation device P-stim significantly decreases pain intensity and improves psychological well-being, activity, and sleep in chronic low back pain patients.
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Anesthesia and analgesia · May 2004
Randomized Controlled Trial Clinical TrialPostcesarean analgesia with spinal morphine, clonidine, or their combination.
In this randomized, double-blind trial in 240 women, we investigated the analgesic efficacy and duration of subarachnoid fentanyl 15 microg with morphine, clonidine, or both morphine and clonidine for cesarean delivery. A dose-finding analysis showed similar postoperative efficacy and side effects for groups receiving morphine 100 microg with clonidine 60, 90, or 150 microg. Data from these groups were combined (MC60-150, n = 113) and compared with groups receiving morphine 100 microg (n = 39), clonidine 150 microg (n = 39), or morphine 100 microg plus clonidine 30 microg (n = 41). The four groups differed in the time to patient-controlled morphine use and cumulative morphine consumption (P < 0.0001 and P < 0.001, respectively), with the longest duration and smallest dose in MC60-150. Pain scores were significantly different among groups. Onset of sensory block, ephedrine requirement and incidence of hypotension, patient satisfaction, and recovery were similar. Groups receiving clonidine had greater sedation, those receiving morphine had more severe pruritus, and group MC60-150 showed a trend to more vomiting intraoperatively. Compared with morphine 100 microg or clonidine 150 microg alone, the combination of subarachnoid morphine 100 microg and at least 60 microg of clonidine was found to increase the duration of postcesarean analgesia, reduce opioid requirement, and increase intraoperative sedation. ⋯ A multimodal approach to postcesarean analgesia, using subarachnoid bupivacaine, fentanyl, morphine 100 microg, and clonidine 60 microg, improves pain relief compared with morphine 100 microg or clonidine 150 microg alone, but increases intraoperative sedation and may increase perioperative vomiting.