Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2002
Comparative StudyThe effects of abdominal opening on respiratory mechanics during general anesthesia in normal and morbidly obese patients: a comparative study.
Morbid obesity has a profound effect on respiratory mechanics and gas exchange. However, most studies were performed in morbidly obese patients before or after anesthesia. We tested the hypothesis that anesthesia and abdominal opening could modify the elastic and resistive properties of the respiratory system. ⋯ Obese patients also presented higher resistances of the total respiratory system, lung and chest wall, as well as "additional" lung resistance. Mainly in obese patients, laparotomy provoked a significant increase in lung compliance and decrease in "additional" lung resistance 1 h after the peritoneum was opened, which returned to original values after the peritoneum had been closed (P < 0.005). In obese patients, low respiratory compliance and higher airway resistance were mainly determined by the lung component.
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Anesthesia and analgesia · Mar 2002
Prolonged neuromuscular block after rocuronium in postpartum patients.
Postpartum patients have not completely lost the weight gained during pregnancy. Drug dosing according to total body weight (TBW) can cause exaggerated effects and dosing by lean body mass (LBM) may provide a more consistent response despite the increased weight. We compared the duration of a rocuronium neuromuscular block in 22 women undergoing postpartum tubal ligation 31--79 h after delivery, with that in 22 women undergoing gynecological surgery. Anesthesia was induced and maintained with propofol and alfentanil. Half of the patients in each of the Postpartum and Control groups received a bolus dose of rocuronium 0.6 mg/kg TBW and the remaining half received rocuronium 0.6 mg/kg LBM. Neuromuscular block was monitored by electromyography and the ulnar nerve was stimulated transcutaneously using a train-of-four pattern. When rocuronium was given by TBW, median (range) duration of neuromuscular block until 25% recovery of the first twitch response was longer in the Postpartum group, 35.3 (29.7--48.7) min, compared with the Control group, 24.8 (21.5--28.6) min (P < 0.001). After dosing by LBM, the duration of block was similar between groups. The prolonged block with rocuronium in the Postpartum patients can be explained by relative drug overdose when dose calculation is based on their temporarily increased body weight. ⋯ Neuromuscular block is prolonged in the postpartum period after standard doses of rocuronium. Drug administration according to lean body mass will produce a more consistent duration of block.
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Anesthesia and analgesia · Mar 2002
Assessing sedation with regional anesthesia: inter-rater agreement on a modified Wilson sedation scale.
A valid and reliable means for measuring sedation during regional anesthesia would be valuable for both research and practice. Current methods of monitoring sedation include machine-, patient-, and observer-based assessment. The reliability of machine-based methods is limited at lower levels of sedation, whereas patient-based methods are impractical at higher levels. Observer-based methods offer the best alternative for assessing sedation during regional anesthesia; however, their reliability has not been adequately documented. We examined the interrater reliability of the Wilson sedation scale. Sedation was assessed by pairs of anesthesia care providers in 100 patients undergoing surgical procedures with regional anesthesia. On the basis of the findings, the scale was modified, and 50 additional patients were assessed. The study protocol called for a series of standardized stimuli administered by a research assistant. Raters were blinded to each other's ratings. Interrater reliability was assessed by using the kappa statistic, a measure of actual agreement beyond agreement by chance. When continuing checks on its operationalization and reliability are included, the modified Wilson scale provides a simple and reliable means by which to assess and monitor intraoperative sedation. ⋯ We evaluated the interrater reliability of the Wilson scale for measuring sedation during regional anesthesia. Paired anesthesia care providers' ratings of patient sedation indicated very good interrater reliability in both the original scale and a modified version. The modified Wilson scale provides a quick noninvasive means of monitoring sedation during regional anesthesia.
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Anesthesia and analgesia · Mar 2002
Spinal cord stimulation in postherpetic neuralgia and in acute herpes zoster pain.
We studied the effects of spinal cord stimulation (SCS) on postherpetic neuralgia (PHN). Data of 28 patients were prospectively investigated over a median period of 29 (quartiles 9--39) mo. In addition, four patients with acute herpes zoster (HZ) pain were studied simultaneously. After intractable pain for more than 2 yr, long-term pain relief was achieved in 23 (82%) PHN patients (median, 70 yr) during SCS treatment confirmed by a median decrease from 9 to 1 on the visual analog scale (P < 0.001). In five cases with serious comorbidity, the initial pain alleviation could not be stabilized. Spontaneous improvement was always confirmed or excluded by SCS inactivation tests at quarterly intervals. Eight patients discontinued SCS permanently because of complete pain relief after stimulation periods of 3--66 mo, whereas 2 reestablished SCS because of recrudescence after 2 and 6 mo. Considerable impairments in everyday life, objectified by the pain disability index, were also significantly improved (P < 0.001). In 4 patients with acute HZ pain, SCS was promptly effective and after periods of 2.5 (quartiles 2--3) months the pain had subsided. SCS seems to offer a therapeutic option for pharmacological nonresponders. ⋯ In many patients with postherpetic neuralgia and acute herpes zoster pain is not satisfactorily alleviated with pharmacological approaches. We report on 23 of 28 patients with postherpetic neuralgia and 4 of 4 with acute herpes zoster whose chronic pain was improved by electrical spinal cord stimulation.
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Anesthesia and analgesia · Mar 2002
A streamlined pharynx airway liner: a pilot study in 22 patients in controlled and spontaneous ventilation.
An inexpensive, single-use alternative device to the laryngeal mask and cuffed oropharyngeal airway appears useful in controlled and spontaneous ventilation. The hollow soft plastic airway may act as a sump for pooled secretions, possibly minimizing regurgitation risks. Without a cuff, important cost savings are likely.