Cauda equina syndrome after continuous spinal anesthesia.

Four cases of cauda equina syndrome occurring after continuous spinal anesthesia are reported. In all four cases, there was evidence of a focal sensory block and, to achieve adequate analgesia, a dose of local anesthetic was given that was greater than that usually administered with a single-injection technique. We postulate that the combination of maldistribution and a relatively high dose of local anesthetic resulted in neurotoxic injury. Suggestions that may reduce the potential for neurotoxicity are discussed. Use of a lower concentration and a "ceiling" or maximum dose of local anesthetic to establish the block should be considered. If maldistribution of local anesthetic is suspected (as indicated by a focal sensory block), the use of maneuvers to increase the spread of local anesthetic is recommended. If such maneuvers prove unsuccessful, the technique should be abandoned.

Awake fibreoptic intubation in the patient at high risk of aspiration.

This report describes our experiences with 129 awake oral and nasal fibreoptic intubations in 123 patients considered to be at high risk of aspiration of gastric contents. I.v. sedation was used on all but six occasions. Local anaesthesia was applied to the larynx and trachea through the working channel of the fibrescope on 85 occasions, and by transtracheal injection on 29. Rigid laryngoscopy was necessary after fibreoptic laryngoscopy failed in one patient (with a bleeding peptic ulcer) who vomited a large amount of fresh and clotted blood. No other patient regurgitated during the procedure, and no patient developed evidence of aspiration.

Learning fibreoptic intubation: use of simulators v. traditional teaching.

This study compared a graduated training programme with that of a traditional teaching method to facilitate the learning of the technique of fibreoptic nasotracheal intubation. Thirty-two anaesthesia trainees were randomly assigned to two groups. The graduated programme involved: practice on a bronchoscopy teaching model; exposure of the epiglottis and vocal cords in patients recovering from general anaesthesia; performance of fibreoptic nasotracheal intubation in awake sedated patients. The traditional programme involved: demonstration (on a patient) of one fibreoptic nasotracheal intubation by the instructor; performance of fibreoptic nasotracheal intubation (by the trainee) in awake sedated patients. Nasotracheal intubation was accomplished significantly more often by the trainees in the graduated programme (86 out of 96 (89.6%) v. 64 out of 96 (66.5%) (P less than 0.01). The results demonstrate that trainees who undergo a graduated training programme using simulators are initially more successful at awake fibreoptic nasotracheal intubation than those who have learned in the traditional manner, and that the conditions of the investigation were acceptable to the trainees and patients.