We studied 20 patients undergoing thoracotomy, in a double-blind, placebo-controlled crossover trial of intercostal bupivacaine. Bupivacaine 0.25% was infused at 5 ml h-1 through each of two catheters placed in the intercostal space at operation. Mean (95% confidence limits) 24-h requirements for morphine from a patient-controlled analgesia device were 29 (22-37) mg during bupivacaine infusion and 44 (32-57) mg during saline infusion (P = 0.04). Patients also recorded significantly smaller visual analogue scores for pain during bupivacaine infusion. There were no adverse effects related to the intercostal infusion of bupivacaine. We conclude that bupivacaine, infused through catheters placed during thoracotomy in the adjacent intercostal spaces, is a useful adjunct to systemic opioid analgesia.

We describe the inadvertent subdural insertion of a lumbar extradural catheter in a primiparous woman in labour. A small quantity of local anaesthetic resulted in extensive motor and sensory block. Computed tomography performed after contrast injection demonstrated unequivocally that the catheter was in the subdural space. The catheter and injected fluid produced considerable displacement of the arachnoid within the thecal sac. We postulate that this could result in arterial compression or direct damage to the spinal nerve roots. Such a mechanism might explain some of the cases of permanent neurological damage associated with extradural analgesia.

A cross-over trial was performed in 12 volunteers to compare the relative potency of 25% nitrous oxide and 0.4% isoflurane when breathed for a period of 20 min. Oxygen was used as a control. The effects were observed for 35 min after drug administration. Choice reaction time, ability to tap two areas on a board and ability to perform mathematical problems were significantly impaired when inhaling nitrous oxide, the maximum effect being obtained within 5 min. With isoflurane, the effects were significantly greater than with nitrous oxide. The effect obtained after 15 min inhalation was greater than that at 5 min. Tests returned promptly to the base line after the discontinuation of the test agent. Subjective assessments were made using a series of eight visual analogue scales. Results of the scales represented by physical and mental sedation indicated that 0.4% isoflurane was more potent than 25% nitrous oxide. Significant effects were detected up to 15 min after the inhalation of the agent was stopped. Subanaesthetic concentrations of isoflurane warrant further study in patients undergoing dental treatment in which a rapid recovery from sedation is important.

The aim of the present study was to examine, in a double-blind, randomised manner, the effects of glycopyrronium 0.005 mglkg, atropine 0.01 mgikg or a placebo (normal saIine) on the frequency of bradycardia in 92 patients scheduled for major abdominal or gynaecological surgery. All patients received fentanyl. halothane and vecuronium. The frequency of bradycardia in the group that received saline was 18%. No cases occurred in either anticholinergic group. Mean heart rates intra-operativeIy were not signiJicantly different between the atropine and glycopyrronium groups. It is suggested that the routine use of pre-operative anticholinergic agents should be considered when a similar anaesthetic technique is employed.

SummaryWe assessed the hourly occupancy of our intensive care unit by high dependency patients over an 8-week period using the criteria established by the Working Group on Guidelines on Admission to and Discharge from Intensive Care and High Dependency Units published by the National Health Service Executive. High dependency patients accounted for 1914 bed hours (21.6%) out of a potential available total of 8880 hours. Measurement of Therapeutic Intervention Scoring System points and Acute Physiology and Chronic Health Evaluation II scores confirmed that categorising patients according to the new guidelines produced significantly different populations of patients. Mean (standard deviation) Therapeutic Intervention Scoring System points for intensive care status patients were 38.57 (10.40) compared to 21.66 (5.98) points for high dependency status patients (p`0.001). Median (range) Acute Physiology and Chronic Health Evaluation II score for intensive care status patients was 16 (1-45) compared to 11 (1-27) for high dependency status patients (p`0.0001). Calculating bed occupancy with different definitions for the whole of our intensive care unit population during the 8 weeks revealed a range of occupancies between 85.3% and 107.3%. We recommend that intensive care unit bed occupancy should be calculated in a standard manner nationally to allow comparison between units. We suggest that hourly occupancy be adopted as the universal method.Keywords Intensive care. ...................................................................................... Correspondence to: Dr P. Spiers Accepted: 2 October 1997 Following much adverse publicity about the transfer of patients needing intensive care between hospitals, the National Health Service (NHS) Executive has issued 'Guidelines on the Admission to and Discharge from Intensive Care and High Dependency Units' [1]. The authors felt that many patients remain on an intensive care unit (ICU) longer than necessary and that the development of high dependency units (HDUs) would mean that ICU resources would be used more appropriately. This sentiment has been echoed by other authors [2] who felt that the existence of an HDU would reduce the numbers of premature discharges from their ICU. We undertook this study in order to evaluate the amount of ICU resources that may be freed if an HDU were available, using the new guidelines [1] to categorise patients as either HDU or ICU status.Different ICUs use different definitions to calculate bed occupancy. A recent report of the British Transplantation Society Working Party on Organ Donation [3] collected information on bed occupancy from 173 units in the United Kingdom. Occupancy ranged from 25 to 137%, but the definition of bed occupancy was not stated and we suspect that each ICU had applied its own definitions, as we had done when completing the survey form. We are also aware that some ICUs include patients managed by the ICU team in other parts of the hospital in their occupancy figures. We therefore applied three different de...

SummaryThe aim of the present study was to examine, in a double-blind, randomised

Eisenmenger's syndrome consists of high pulmonary vascular resistance with reversed or bidirectional shunt at aortopulmonary, ventricular or atrial level. We describe the anaesthetic management of two adult females with Eisenmenger's syndrome admitted for laparoscopic cholecystectomy. One patient suffered post-operative complications, but the other case was uncomplicated. We used sevoflurane and total intravenous anaesthesia to provide general anaesthesia. Both techniques were tolerated.

Forty patients who had undergone coronary artery graft surgery and who required vasodilator therapy for postoperative hypertension were given infusions of either alfentanil or morphine together with bolus doses of midazolam for sedation and analgesia while ventilation was controlled artificially. Sodium nitroprusside (SNP) was administered to both groups using a computer-controlled closed loop system which adjusted the infusion rate to maintain a preset target arterial pressure. Target pressure +/- 5, 10, 15 and 20 mm Hg was maintained longer in the group receiving alfentanil. This group also required less SNP per hour. No difference was noted between the groups in the time taken to regain spontaneous ventilation and to extubation of the trachea, although the alfentanil group tended to be sedated more deeply during the infusion. The main advantage of alfentanil over morphine at doses used in this study was its superior ability to attenuate hypertensive responses to noxious stimuli, providing improved haemodynamic stability.