British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of cricoid pressure on ease of insertion of the laryngeal mask airway.
We have evaluated the effects of cricoid pressure on laryngeal mask airway (LMA) insertion after an elective rapid sequence induction in 100 patients allocated randomly to two groups. An attempt was made to insert the LMA after application of cricoid pressure in one group and with no pressure in the other. The anaesthetist was blinded to the application of cricoid pressure. Insertion was successful in 45 of 50 patients in the cricoid pressure group and in 49 of 50 patients in the non-cricoid group (P < 0.1) We discuss the implications of these findings for failed intubation in the nonfasted patient.
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Randomized Controlled Trial Comparative Study Clinical Trial
Radiological examination of the intrathecal position of microcatheters in continuous spinal anaesthesia.
There have been few studies of the intrathecal position of spinal catheters in continuous spinal anaesthesia. This prospective study was designed to examine radiologically the intrathecal position of 28-gauge spinal catheters. ⋯ The intrathecal position of the catheters did not depend on the level of the lumbar puncture (P = 0.6246), but was dependent on the position of the patient during insertion of the catheter (P = 0.0093), and on the depth of insertion (P = 0.0099). Our study suggests that patients should be in a sitting position during insertion of a subarachnoid microcatheter and that the depth of insertion should not exceed 4 cm.
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Formation of atelectasis is one mechanism of impaired gas exchange during general anaesthesia. We have studied manoeuvres to re-expand such atelectasis in 16 consecutive, anaesthetized adults with healthy lungs. In group 1 (10 patients), the lungs were inflated stepwise to an airway pressure (Paw) of 10, 20, 30 and 40 cm H2O. ⋯ The final inflation (Paw = 40 cm H2O) virtually eliminated the atelectasis. We conclude that, after induction of anaesthesia, the amount of atelectasis was not reduced by inflation of the lungs with a conventional tidal volume or with a double tidal volume ("sigg"). An inflation to vital capacity (Paw = 40 cm H2O), however, re-expanded virtually all atelectatic lung tissue.
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Three months before this study, susceptibility for malignant hyperthermia (MH) had been tested in 15 pigs. In all pigs, MH was triggered by administration of 1% halothane. Brain electrical activity was examined during therapy of MH with and without administration of dantrolene. ⋯ All variables were measured over a period of 60 min after therapy: EEG, HR and MAP were recorded continuously and blood-gas tensions, arterial potassium and glucose concentrations and pH were measured every 150 s. In group I (no dantrolene) minor, transient improvements in EEG activity were noted, but all animals died within 15-25 min after the start of therapy. In dantrolene-treated animals, EEG total power and median frequency increased within 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)