Incidence and predictors of bulbar palsy after surgery for acoustic neuroma.

We present a retrospective review of the perioperative management and complications of 102 cases of acoustic neuroma operated on at an English teaching hospital over the last 9 years. Nine patients had a bulbar palsy postoperatively; five of those patients developed pulmonary complications. A bulbar palsy was more likely to occur in those with tumours > or = 3 cm. The occurrence of intraoperative bradycardias, present in nearly half of the bulbar palsy cases, did not help predict who would sustain this injury postoperatively. However, episodes of intraoperative hypotension served to better predict a bulbar palsy complication in conjunction with the presence of a large tumour. Post-operative airway management is an area of possible conflict of interest: the desire for early extubation to avoid the possibility of coughing and bucking on the endotracheal tube and the need to protect the airway of the patient with a lower cranial nerve deficit. Almost 10% of our patients did have such a deficit after surgery; and over half of them developed respiratory complications making this an important cause of postoperative morbidity. We recommend that the timing of extubation be judged on an individual basis for each patient. Those with tumours > or = 3 cm warrant particular concern. All patients should receive careful observation in a high dependency area for at least the first postoperative day.

Mucus glycoproteins from 'normal' human tracheobronchial secretion.

Mucous secretions were collected from tracheas of patients undergoing minor surgery under general anaesthesia with tracheal intubation, and mucus glycoproteins were isolated by using isopycnic density-gradient centrifugation in CsCl/guanidinium chloride. 'Whole' mucins were excluded from a Sepharose CL-2B gel, whereas subunits obtained after reduction were included. Trypsin digestion of subunits afforded high-Mr glycopeptides (T-domains), which were further included in the gel. The latter fragments are heterogeneous and comprise two or three populations, as indicated by gel chromatography and ion-exchange h.p.l.c. Rate-zonal centrifugation showed that the 'whole' mucins are polydisperse in size, with a weight-average Mr of (14-16) x 10(6). The macromolecules were observed by electron microscopy, as linear and apparently flexible thread-like structures. Subunits and T-domains had weight-average contour lengths of 490 nm and 160 nm respectively. It is concluded that mucus glycoproteins are present in secretions from the healthy lower respiratory tract. The 'whole' tracheal mucins are assembled from subunits, which in turn can be fragmented into high-Mr glycopeptides corresponding to the oligosaccharide domains typically found in mucus glycoproteins. The size and macromolecular architecture of the tracheal mucins is thus similar to that observed for mucins from human cervical mucus, chronic bronchitic sputum and pig stomach, providing yet another example of this general design of these macromolecules, i.e. subunits assembled end-to-end into very large linear and flexible macromolecules.

Effect of rate of injection on the neuromuscular block produced by vecuronium.

A subparalytic dose (0.015 mg/kg) of vecuronium bromide was administered to matched pairs of patients undergoing routine dental surgery under enflurane-nitrous oxide/oxygen anesthesia either as a rapid bolus injection or as a slow infusion over 5 min. It was demonstrated that bolus injection produced peak plasma levels of drug considerably greater than those following slow infusion. Time to maximum block was more rapid following bolus (368 +/- 84 [SD] sec) than by infusion (615 +/- 88 sec), but the maximum block produced, either demonstrated by the reduction in amplitude of T1 from control or the T1:T4 ratio on the integrated electromyogram (Datex IEMG), was similar in each group irrespective of rate of injection, T1 and T4 referring to the first and last twitch in a train of four series.

Anaesthesia for carotid body tumour resection in a patient with the Eisenmenger syndrome. A case report.

A patient with the Eisenmenger syndrome presented for removal of a carotid body tumour under general anaesthesia. The presentation and management of the case are described and some of the anaesthetic problems associated with these two uncommon conditions are discussed. The case is reported because of its rarity and because some of the complications of carotid body surgery may be particularly hazardous in the presence of the Eisenmenger syndrome. The importance of monitoring, of maintaining a stable heart rate and blood volume, and the danger of paradoxical systemic air embolism are stressed.