Hearing loss following spinal anaesthesia with bupivacaine.

The purpose of this study was to determine the incidence, degree and reversibility of hearing loss following spinal anaesthesia with bupivacaine and secondarily to see if there is a relationship between post-spinal headache and hearing loss. A prospective series of 35 patients admitted for elective Caesarean section under a standardized spinal anaesthetic was investigated. Otolaryngological examination and pure tone audiometry in the frequency range 250 Hz to 8 KHz were done on the day before surgery and on post-operative days 1 and 5. Five patients developed a reversible sensorineural hearing loss (mean loss 14.6 dB). This loss was either unilateral (3) or bilateral (2) and affected the low frequencies in all five patients. The demographic data for both groups (i.e. no change in hearing/sensorineural loss) was similar for age, weight, height, blood pressure change and level of sensory block. There was no association found with post-spinal headache.

A comparison of the effect on gastric emptying of either enflurane or propofol given during maintenance of anaesthesia for minor surgery.

Twenty patients scheduled for minor gynaecological surgery were studied. Anaesthesia was induced with propofol and maintained either with enflurane/oxygen/nitrous oxide or propofol/oxygen/nitrous oxide. The rate of gastric emptying was measured indirectly by the paracetamol absorption model. The results showed that there was no significant difference in gastric emptying rate between the two groups. Recovery in the propofol group was more rapid in that paracetamol ingestion occurred earlier in the recovery period compared with the enflurane group.

A comparison of the effect on gastric emptying of alfentanil or morphine given during anaesthesia for minor surgery.

Twenty patients, scheduled for minor gynaecological surgery, were studied. Anaesthesia was induced with propofol and maintained with oxygen, nitrous oxide and enflurane. Patients were randomly allocated to two groups: group 1 were given alfentanil 0.2 mg; group 2 were given morphine 5 mg. The rate of gastric emptying was measured indirectly by the paracetamol absorption technique. The results showed that morphine caused greater delay in gastric emptying compared with alfentanil (p < 0.05). The observed effect on gastric emptying rate may potentially affect the risk of peri-operative regurgitation and aspiration. This study provides further evidence that in short day-case procedures, when oral medication may be required postoperatively, alfentanil may be preferable to morphine as an intra-operative opioid.

Comparison of propofol with enflurane during hypotensive anaesthesia for middle ear surgery.

Forty patients undergoing middle ear surgery were allocated randomly to receive propofol induction and maintenance, or thiopentone induction and enflurane maintenance for anaesthesia. Both groups also received fentanyl, alcuronium, nitrous oxide and oxygen. If this did not reduce systolic arterial pressure to 70 mm Hg, labetalol, glyceryl trinitrate (GTN), or both, was administered. Fifteen control patients had enflurane anaesthesia without hypotension. Pre- and postoperative psychometric tests were performed in all groups. The propofol group received significantly more labetalol (P = 0.014) and GTN (P = 0.004) than the enflurane group. There was a greater increase in reaction times after operation in the study groups (P < 0.05) compared with controls. There was no difference between the propofol and enflurane groups in control of arterial pressure, recovery from anaesthesia or psychometric testing.

Continuous measurements of oxygen saturation during haemodialysis.

A new technique for recording and analysing continuous measurements of oxygen saturation (SpO2) by pulse oximeter during haemodialysis was used to compare changes in SpO2 in eight patients during two 4 h periods of dialysis using a cuprophane membrane, once using an acetate dialysate, and once using bicarbonate. The computer-derived patterns of SpO2 show whether hypoxaemia was caused mainly by extrapulmonary abnormalities (ventilatory control) or intrapulmonary abnormalities (V/Q distribution). The patterns of oxygen saturation were analysed for (i) stability, (ii) the lower median 20th centile of SpO2, and (iii) time below a SpO2 of 90%. Not all patients had reduced oxygenation during acetate dialysis. Three of eight patients had a stable pattern with acetate dialysis and six of eight were stable with bicarbonate. Five of eight patients had a lower SpO2 with acetate but one patient had a lower SpO2 with bicarbonate. Four patients had prolonged, clinically significant periods of oxygen desaturation with SpO2 less than 90%; two of these had particularly prolonged periods during acetate (62 min and 12 min), but one patient showed a longer period during bicarbonate than acetate dialysis (7 min). In two patients the SpO2 declined to less than 84%. The patterns of SpO2 suggested that the decrease in oxygen saturation was due more to extrapulmonary abnormalities causing an instability in ventilatory control rather than to venous admixture. It is recommended that pulse oximetry is used to identify patients at risk of hypoxaemia, to monitor these patients during haemodialysis, and to administer oxygen to those whose SpO2 falls below 90%, particularly if they have anaemia or cardiovascular disease.

Pneumomediastinum during general anaesthesia: a case report.

A case is reported of a pneumomediastinum which presented as an unexplained dysrhythmia during a routine general anaesthestic in a previously fit 19-year-old girl. The possible precipitating factors in this case are discussed along with a description of the signs and symptoms and an outline of its management.

A survey of anaesthetic charts.

This survey reviews the structure and content of all anaesthetic record charts in use in the 40 hospitals of the Yorkshire Regional Health Authority in the light of previous recommendations. Twenty-two different anaesthetic charts were used by 290 anaesthetists in this region. Some of the charts did not meet the ideal standard for size (A4) and the majority had no colour coding. Fourteen of the 22 charts omitted important headings concerned with patient identification and eight charts did not provide a record of the whole perioperative period. Some comprehensive forms are in use, chiefly in smaller hospitals, but there have been few changes in design in the last 10 years despite increasing medicolegal awareness.