Anesthesia and analgesia
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Factor V Leiden (FVL) is the most common known inherited cause of thrombophilia; it is present in approximately 5% of the Caucasian population. Although the risk of venous thrombosis associated with this polymorphism in various medical settings is well described, its effect on perioperative risk is only beginning to be explored. ⋯ This review will describe the physiology of the FVL mutation, briefly clarify its risk in the nonsurgical setting, and assess current data regarding FVL in noncardiac and cardiac surgery. Finally, a summary of current clinical evidence and a plan for more detailed investigation of this potentially significant risk factor will be proposed.
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialIntrathecal midazolam II: combination with intrathecal fentanyl for labor pain.
Recent investigations have sought to improve intrathecal analgesia by combining opioids with other classes of analgesics. In this study we assessed the ability of intrathecal midazolam to increase the potency and duration of the analgesic effects of intrathecal fentanyl without causing adverse effects. Thirty parturients with cervical dilations 2-6 cm were randomized to receive either intrathecal midazolam 2 mg, fentanyl 10 micro g, or both combined to initiate analgesia. Pain scores were recorded before and at 5-min intervals for 30 min after the injection and then every 30 minutes until the patient requested further analgesia. The presence and severity of nausea, emesis, pruritus, headache, and sedation, in addition to arterial blood pressure, heart rate, respiratory rate, sensory changes to ice, motor impairment, cardiotocograph, and Apgar score were also recorded. The parturients were assessed after 2 days and 1 mo for neurologic impairment. Preinjection pain scores were unaltered by intrathecal midazolam alone and moderately decreased by fentanyl. Intrathecal midazolam increased the analgesic effect of fentanyl. No treatment altered cardiorespiratory variables or caused motor impairment. The addition of intrathecal midazolam to fentanyl did not increase the occurrence of any maternal adverse event or abnormalities on the cardiotocograph. We conclude that intrathecal midazolam enhanced the analgesic effect of fentanyl without increasing maternal or fetal adverse effects. ⋯ Treatment of labor pain with epidural injections of local anesthetic is complicated by decreases in arterial blood pressure and leg weakness. This study showed that a mixture of two drugs, fentanyl and midazolam, could provide powerful pain relief when the drugs were given together spinally without such side effects.
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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
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 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.