premature peripheral vascular disease-that necessitated a hospital stay of more than 30 days they took nearly as long as the elderly (aged 70 and over) to recover sufficiently to leave hospital (mean 50 5 days v 57 3 days). ConclusionsIf efficiency in a surgical service means a high throughput of patients and a low rate of cancellation we have three suggestions.(1) A surgical service might be provided with fewer beds if patients for elective operations were always admitted on the day of operation and discharged at the earliest opportunity and ifelderly patients with chronic illness were transferred to other care. The potential for such economy is, however, only 10% of the average number of beds occupied (3 * 5 of 34 5 in our study).(2) Numbers of beds should not be decreased further: physical removal of beds runs the risk that fluctuations in the need for beds can be accommodated only by cancelling elective admissions.(3) If all surgeons in a district were to increase their throughput the overall cost of health care would be increased and there would be a risk of bankrupting the district health authority. A new system of funding should be set up to encourage efficient surgical units with short waiting lists. Asthmatics with morning dipping had a history of nocturnal wheeze and a higher incidence of reflux symptoms, but measurement of oesophageal pH showed no significant difference in the amount or pattern of reflux when compared with "nondippers."Overall, 15 asthmatics had gastro-oesophageal reflux, and these participated in a randomised, double blind crossover trial of ranitidine versus placebo. No significant difference was found in the peak expiratory flow rates or subjective evaluation of well being of the patients.

The mini-Wright peak flow meter (MPFM) has been evaluated, and the results obtained from it show a strong positive correlation (r= 0-970) with the Wright's peak flow meter (PFM). MPFM measurements, however, were biased to be about 38 1/min higher than PFM measurements (95% confidence limits 31[0 1/min to 450 1/min). Between instrument variation was found (F-ratio 3 67 with 9 and 81 degrees of freedom: P<0 001). In practice this did not appreciably affect individual measurements greatly as 95% confidence limits on any individual measurements were increased from 241/min to 271/min. There was no significant day-to-day variability in measurements obtained with individual instruments. The MPFM is a pocket-sized, simple, cheap, and robust instrument for following changes in ventilatory function. In clinical trials and surveys, however, both the bias in favour of the MPFM compared to the PFM and inter-machine variation must be taken into account. As the manufacturers have altered the scale to remove the bias since this study was performed, it will be important to know whether the original or the modified meter is being used in future studies.

Fourteen patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) have been treated with demethylchlortetracycline (demeclocycline) 1200 mg daily. In 12 patients the underlying lesion was malignant. The serum sodium returned to normal (> 135 mmol/l) in all patients after a mean of 8-6 days (SD+5-3 days). Blood urea rose significantly from the pretreatment level of 4-2±2-3 mmol/l to 10-1±5-1 mmol/l at ten days (p<0 001). The average maximum blood urea was 13-4-6-8 mmol/l. In four patients the urea rose above 20 mmol/l, and in two of these demecyocycline was discontinued because of this rise. The azotaemia could be attributed to a combination of increased urea production and a mild specific drug-induced nephrotoxicity. Discontinuation of demeclocycline in six patients led to a fall in serum sodium, in one case precipitously, and return of the urea towards normal levels. Demeclocycline appears therefore to be an effective maintenance treatment of SIADH, and the azotaemia that occurs is reversible and probably dose dependent.

1 The effects of atenolol (50 mg and 100 mg) and oxprenolol (80 mg) on respiratory function were studied in ten patients with angina pectoris or hypertension complicated by chronic airways obstruction. 2 In patients with “fixed” airways obstruction, neither atenolol nor exprenolol significantly affected airways resistance. 3 In patients with “labile” airways obstruction, atenolol did not produce a significant increase in airways obstruction, whereas oxprenolol did. 4 Following isoprenaline challenge (1500 microgram by inhalation), atenolol permitted full bronchodilatation, whereas oxprenolol almost completely blocked the action of isoprenaline. 5 Partial agonist activity appears to be of less clinical importance than cardioselectivity.

In 1991 the West Midlands Pulmonary Function Audit Group examined the consistency between pulmonary function laboratories in the West Midlands. Three healthy subjects visited 22 centres and performed a standard set of pulmonary function tests. Demographic data on nine hypothetical subjects was also supplied for the laboratories to produce predicted values. Equipment was checked for accuracy using standard methods. The 1991 audit revealed significant inter-laboratory variability. Sources of error were identified and after consultation, recommendations were made to improve consistency. In addition, national and regional training workshops were organized for laboratory staff. In 1995 the audit was repeated using the same three subjects. Significant differences continued for all predicted results except for residual volume (RV) and forced vital capacity (FVC) and for all measured results except for functional residual capacity (FRC). However, improvements in the coefficient of variation were seen compared with 1991 for predicted forced expiratory volume (FEV1), total lung capacity (TLC), gas transfer (TLCO), FVC, FRC and RV. Similar improvements were seen in measured results for FEV1 and FVC. Increased variation was seen for predicted corrected transfer factor (KCO) and actual RV. The majority of variables in the 1995 audit had a coefficient of variation of less than 5% between laboratories. Analysis of the predicted results from the hypothetical subjects continued to show unacceptable variation reflecting continuing computer algorithm inconsistency. The improvements seen are encouraging and suggest that a regular audit programme is worthwhile.