Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2004
Randomized Controlled Trial Comparative Study Clinical TrialIsoflurane inhalation enhances increased physiologic deadspace volume associated with positive pressure ventilation and compromises arterial oxygenation.
Abnormally increased physiologic deadspace volume (Vd(phys)), consisting of alveolar deadspace volume and airway deadspace volume, is one of several causative factors predisposing to compromised arterial blood gas exchange. We compared the effects of two methods of general anesthesia on Vd(phys) when combined with positive pressure ventilation (PPV): total IV anesthesia (TIVA) and inhaled anesthesia with isoflurane. Forty patients with no history of pulmonary pathology undergoing elective surgery in the supine position were studied. ⋯ Furthermore, isoflurane inhalation (1.15% end-tidal concentration) resulted in impaired arterial oxygenation, as evidenced by a significant decrease in the Pao(2)/fractional inspired oxygen concentration ratio compared with baseline values from 387 +/- 35 to 310 +/- 70 (P < 0.05). Although significant increases in Vd(phys) resulted with PPV combined with TIVA, these adverse changes were much less compared with isoflurane inhalation and PPV. These findings may apply to subjects with compromised pulmonary function (i.e., acute respiratory distress syndrome or severe inhalational burn injury).
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Anesthesia and analgesia · Oct 2004
Randomized Controlled Trial Comparative Study Clinical TrialContinuous positive airway pressure versus noninvasive pressure support ventilation to treat atelectasis after cardiac surgery.
Atelectasis is common after cardiac surgery and may result in impaired gas exchange. Continuous positive airway pressure (CPAP) is often used to prevent or treat postoperative atelectasis. We hypothesized that noninvasive pressure support ventilation (NIPSV) by increasing tidal volume could improve the evolution of atelectasis more than CPAP. ⋯ There was no difference in oxygenation (Pao(2)/fraction of inspired oxygen at SICU discharge: 280 +/- 38 in the CPAP group versus 301 +/- 40 in the NIPSV group), pulmonary function tests, or length of stay. Minor complications, such as gastric distensions, were similar in the two groups. NIPSV was superior to CPAP regarding the improvement of atelectasis based on radiological score but did not confer any additional clinical benefit, raising the question of its usefulness for altering outcome.
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Anesthesia and analgesia · Oct 2004
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of single versus multiple injections on the extent of anesthesia with coracoid infraclavicular brachial plexus block.
Single-injection coracoid infraclavicular brachial plexus block produces inconsistent anesthesia of the upper limb. In this study, we sought to determine the number of injections needed to provide a reasonably complete anesthesia of the upper limb with this approach. Seventy-five patients were randomly assigned to receive a coracoid block guided by nerve stimulator with 42 mL of 1.5% mepivacaine with a single-injection (Group 1), dual-injection (Group 2), or triple-injection (Group 3) technique. ⋯ Significantly less complete paralysis for arm, wrist, and hand movements was found in Group 1 at 20 min. No significant difference was found between Groups 2 and 3. We conclude that dual and triple injection of local anesthetic guided by nerve stimulator increases the efficacy of coracoid block when compared with a single-injection technique.
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Anesthesia and analgesia · Oct 2004
Randomized Controlled Trial Clinical TrialLaryngotracheal topicalization with lidocaine before intubation decreases the incidence of coughing on emergence from general anesthesia.
Coughing on emergence can result in a number of undesirable side effects, including hypertension, tachycardia, tachyarrhythmias, increased intracranial pressure, and increased intraocular pressure. The efficacy of endotracheal spraying with lidocaine at the time of intubation in preventing coughing on emergence is unknown. ⋯ The incidence of coughing before tracheal extubation was less frequent in the lidocaine group (26%) than in the placebo group (66%, P < 0.01), as was the incidence after tracheal extubation (4% versus 30%, P = 0.022). This study supports the use of endotracheal lidocaine before intubation in patients undergoing general anesthesia for surgery <2 h duration where coughing on emergence is undesirable.
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Anesthesia and analgesia · Oct 2004
Randomized Controlled Trial Clinical TrialThe pharmacodynamic effects of rocuronium when dosed according to real body weight or ideal body weight in morbidly obese patients.
We investigated the pharmacodynamic effects of rocuronium on morbidly obese patients. Twelve morbidly obese female patients (body mass index >40 kg/m(2)) admitted for laparoscopic gastric banding were randomized into two groups. Group 1 (n = 6) received 0.6 mg/kg of rocuronium based on real body weight, whereas Group 2 (n = 6) received 0.6 mg/kg of rocuronium based on ideal body weight. ⋯ Recovery index tended to be longer in Group 1, but without a significant difference. In conclusion, in morbidly obese patients, the duration of action of rocuronium is significantly prolonged when it is dosed according to real body weight. Therefore, the dosage should be assessed on the basis of ideal rather than on real body weight in clinical practice.