Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialEvaluation of the neuroprotective effects of S(+)-ketamine during open-heart surgery.
We compared the effect of S(+)-ketamine to remifentanil, both in combination with propofol, on the neurocognitive outcome after open-heart surgery in 106 patients. A battery of neurocognitive tests was administered before surgery and 1 and 10 wk after surgery. Fourteen patients (25%) in the control group and 10 patients (20%) in the S(+)-ketamine group had 2 or more tests with a cognitive deficit (decline by at least one preoperative SD of that test in all patients) 10 wk after surgery (P = 0.54). Z-scores were calculated for all tests. No significantly better performance could be detected in the S(+)-ketamine group, except for the Trailmaking B test 10 wk after surgery. We conclude that S(+)-ketamine offers no greater neuroprotection compared with remifentanil during open-heart surgery. ⋯ N-methyl-D-aspartic acid receptors play an important role during ischemic brain injury. We could not demonstrate that S(+)-ketamine resulted in greater neuroprotective effects compared with remifentanil during cardiopulmonary bypass procedures when both were combined with propofol.
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Anesthesia and analgesia · Jun 2004
Multicenter Study Comparative StudyAdverse gastrointestinal complications after cardiopulmonary bypass: can outcome be predicted from preoperative risk factors?
Adverse gastrointestinal (GI) outcome after cardiac surgery is an infrequent event but is a clinically important health care problem because of associated increased morbidity and mortality. The ability to identify patients at greatest risk before surgery may be helpful in planning appropriate perioperative management strategies. We examined the pre- and intraoperative characteristics of 2417 patients from 24 diverse United States medical centers enrolled in the Multicenter Study of Perioperative Ischemia Study who were undergoing cardiac surgery using cardiopulmonary bypass as predictors for adverse GI outcome. Resource utilization was evaluated for patients with and without adverse GI outcomes. Adverse GI outcomes occurred in 5.5% of patients (133 of 2417), increased in-hospital mortality 6.5-fold, prolonged the mean intensive care unit length of stay by 1 wk, and more than doubled the mean postoperative hospital stay (P < 0.0001). Predictors of adverse GI outcome included decreased left ventricular function, hyperbilirubinemia, thrombocytopenia, prolonged partial thromboplastin time, prior cardiovascular surgery, combined coronary artery bypass graft surgery and intracardiac or proximal aortic surgery, pharmacological cardiovascular support, and intraoperative transfusion. The literature suggests that adverse GI outcome after cardiac surgery is secondary to poor splanchnic perfusion, which many of these risk factors may predict. Therefore, patients deemed to be at risk before surgery may benefit from tightly controlled hemodynamic management and other strategies that optimize perioperative organ perfusion. ⋯ We identified the preoperative and intraoperative predictors associated with an increased incidence of postoperative gastrointestinal complications after cardiac surgery using cardiopulmonary bypass. Because these complications are associated with frequent morbidity and mortality, these predictors may be helpful in identifying patients at increased risk so that risk stratification can be modified and perioperative management can be appropriately adjusted.
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialComparison of percutaneous electrical nerve stimulation with transcutaneous electrical nerve stimulation for long-term pain relief in patients with chronic low back pain.
The long-term effect of percutaneous electrical nerve stimulation (PENS) on chronic low back pain (LBP) is unclear. We evaluated the number of sessions for which PENS should be performed to alleviate chronic LBP and how long analgesia is sustained. Patients underwent treatment on a twice-weekly schedule for 8 wk. Group A (n = 18) received PENS for 8 wk, group B (n = 17) received PENS for the first 4 wk and transcutaneous electrical nerve stimulation (TENS) for the second 4 wk, and group C (n = 18) received TENS for 8 wk. Pain level, degree of physical impairment, and the daily intake of nonsteroidal antiinflammatory drugs (NSAIDs) were assessed before the first treatment, 3 days after Week 2, Week 4, and Week 8 treatments, and at 1 and 2 mo after the sessions. During PENS therapy, the pain level decreased significantly from Week 2 in Groups A and B (P < 0.05 or 0.01), and physical impairment and required NSAIDs decreased significantly from Week 4 (P < 0.05 or 0.01) in Group A but only at Week 4 in Group B (P < 0.05 or 0.01). These effects were sustained until 1-mo follow-up (P < 0.01) in Group A but not in Group B; these effects were not observed at 2-mo follow-up even in Group A. In Group C, pain level decreased significantly only at Week 8 (P < 0.05). Our results indicate that repeated PENS is more effective than TENS for chronic LBP but must be continued to sustain the analgesic effect. ⋯ A cumulative analgesic effect was observed in patients with chronic low back pain (LBP) after repeated percutaneous electrical nerve stimulation (PENS), but this effect gradually faded after the treatment was terminated. Results indicate that although PENS is effective for chronic LBP, treatments need to be continued to sustain analgesia.
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe neuromuscular effects and tracheal intubation conditions after small doses of succinylcholine.
Succinylcholine 1.0 mg/kg usually produces excellent tracheal intubation conditions in 60 s. Recovery of respiratory muscle function after this dose, however, is not fast enough to forestall oxyhemoglobin desaturation when ventilation cannot be assisted. In this study, we investigated whether smaller doses of succinylcholine can produce satisfactory intubation conditions fast enough to allow rapid sequence induction with a shorter recovery time. Anesthesia was induced with fentanyl/propofol and maintained by propofol infusion and N(2)O in O(2). After the induction, 115 patients were randomly allocated to five groups according to the dose of succinylcholine (0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg, 0.6 mg/kg, or 1.0 mg/kg). Evoked adductor pollicis responses to continuous 1-Hz supramaximal ulnar nerve stimulation were recorded using acceleromyography. Tracheal intubation conditions were graded 60 s after succinylcholine administration. Onset time, maximal twitch depression, time to initial twitch detection after paralysis, and to 10%, 25%, 50%, and 90% twitch height recovery were recorded. Time to initial diaphragmatic movement as well as time to resumption of regular spontaneous respiratory movements were calculated. Onset times ranged between 82 s and 52 s, decreasing with increasing doses of succinylcholine but not differing between 0.6 and 1 mg/kg. Maximum twitch depression was similar after 0.5, 0.6, and 1 mg/kg (98.2%-100%). Recoveries of twitch height and apnea time were dose-dependent. Intubation conditions were often unacceptable after 0.3- and 0.4-mg/kg doses. Acceptable intubation conditions were achieved in all patients receiving a 0.5, 0.6, and 1 mg/kg dose of succinylcholine. Intubation conditions in patients receiving 0.6 and 1 mg/kg were identical, whereas times to T(1) = 50% and 90% and time to regular spontaneous reservoir bag movements were significantly shorter in the 0.6-mg/kg dose group (5.78, 7.25, and 4.0 min, respectively) versus patients receiving 1 mg/kg (8.55, 10.54, and 6.16 min, respectively). The use of 0.5 to 0.6 mg/kg of succinylcholine can produce acceptable intubation conditions 60 s after administration. The conditions achieved after 0.6 mg/kg are similar to those after 1.0 mg/kg. These smaller doses are associated with faster twitch recovery and shorter apnea time. ⋯ In normal healthy patients, succinylcholine 0.6 mg/kg produces clinical intubation conditions identical to the traditional 1.0-mg/kg dose but is associated with a shorter recovery time.
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialTime-related cuff pressures of the laryngeal tube with and without the use of nitrous oxide.
The Laryngeal tube (VBM Medizintechnik, Sulz, Germany), a new supraglottic airway, consists of an airway tube, two cuffs, and two distal apertures between the two cuffs. One concern with the use of this device is ischemic change to the oropharyngeal mucosa. We studied the time-course change of the intracuff pressure (which reflects the pharyngeal pressure) of the laryngeal tube during anesthesia with and without nitrous oxide. After insertion of a laryngeal tube, 24 patients were randomly allocated to 1 of 2 groups. In one group (group N or nitrous oxide group), 66% nitrous oxide was used, whereas in the other group nitrous oxide was not used (group A or air group). In both groups, sevoflurane was used to maintain anesthesia. Time-course changes of the intracuff pressure and postoperative airway complications were recorded. In group N, the intracuff pressure significantly increased over time (P < 0.001; the maximal pressure: 120 cm H(2)O), whereas in group A the intracuff pressure remained stable. The intracuff pressure was significantly higher in group N than in group A (P < 0.0001; 95% confidence intervals for difference: 6-20 cm H(2)O at 30 min). Postoperatively, two patients in group A and one patient in group N complained of mild sore throat. ⋯ Nitrous oxide may increase pharyngeal pressure by the cuffs of the laryngeal tube, and thus it is advisable to monitor and adjust the intracuff pressure of the laryngeal tube during anesthesia to minimize possible ischemic changes to the oropharynx.