Summary Eight modes of administration of propofol were assessed in order to minimise the pain of injection. An intravenous bolus injection in the antecubital fossa was the only approach that caused no pain. When administered intravenously in the dorsum of the hand the pain score and the number of patients who experienced pain was reduced significantly by mixing the agent with lignocaine when compared with a bolus injection. Slowing the speed of injection caused the greatest discomfort. An indirect biochemical mechanism for the pain is proposed.

This report of a large number of patients undergoing emergency laparotomy in the UK confirms a remarkably high mortality by modern standards across the range. Very few pathologies or procedures can be considered anything other than high risk. The need for routine consultant involvement and critical care is evident, and the case distribution helps define the surgical skill set needed for a modern emergency laparotomy service. Preliminary data relating outcomes from emergency colonic surgery to surgical subspecialty require urgent further study.

SUMMARY1. Stretching the atrial appendages in anaesthetized dogs caused an increase in heart rate. This response was unrelated to changes in arterial blood pressure and left and right atrial pressures.2. The increase in heart rate was a reflex response; the afferent path was in the vagi and the efferent solely in the sympathetic nerves.3. The receptors involved in this reflex have been localized to the atrial appendages but there is no conclusive evidence as to their nature.

on behalf of the UK Emergency Laparotomy Network ABStRAct INTRODUCTION Emergency laparotomy is a common procedure, with 30,000-50,000 performed annually in the UK. This large scale study reports the current spectrum of emergency laparotomies, and the influence of the surgical procedure, underlying pathology and subspecialty of the operating surgeon on mortality. METHODS Anonymised data on consecutive patients undergoing an emergency laparotomy were submitted for a three-month period. The primary outcome measure was unadjusted 30-day mortality. Appendicectomy and cholecystectomy were among the procedures excluded. RESULTS Data from 1,708 patients from 35 National Health Service hospitals were analysed. The overall 30-day mortality rate was 14.8%. 'True' emergency laparotomies (ie those classified by the National Confidential Enquiry into Patient Outcome and Death as immediate or urgent) comprised 86.5% of cases. The mortality rate rose from 8.0% among expedited cases to 14.3% among urgent cases and to 25.7% among laparotomies termed immediate. Among the most common index procedures, small bowel resection exhibited the highest 30-day mortality rate of 21.1%. The presence of abdominal sepsis was associated with raised 30-day mortality (17.5% in the presence of sepsis vs 12.6%, p=0.027). Colorectal procedures comprised 44.3% and within this group, data suggest that mortality from laparotomy may be influenced by surgical subspecialisation. CONCLUSIONS This report of a large number of patients undergoing emergency laparotomy in the UK confirms a remarkably high mortality by modern standards across the range. Very few pathologies or procedures can be considered anything other than high risk. The need for routine consultant involvement and critical care is evident, and the case distribution helps define the surgical skill set needed for a modern emergency laparotomy service. Preliminary data relating outcomes from emergency colonic surgery to surgical subspecialty require urgent further study.

SummaryThe effects of intravenous morphine (10 mg/70 kg) on the ventilatory response to CO, were studied in two groups of subjects, young (18-29 years) and old (66-85 years), prior to elective surgery. In both groups morphine caused a signijcant depression of respiration as judged by a reduction in the slope of the COz response curve. a reduction in the calculated ventilation at an end tidal CO, tension of 7.3 kPa, a rise in resting end tidal C02 and a rise in the CO, threshold. There were no significant differences between the two groups in the changes produced by the drug, suggesting that acute respiratory depression after a single intravenous injection of morphine is similar in old and young people. Key wordsAnalgesics. narcotic; morphine. Measurement techniques; C 0 2 response.There is a widespread clinical impression that morphine causes greater respiratory depression in the old than in the young. Much experimental evidence fails to support this impression. Whilst breathing a C0,-enriched mixture after intravenous morphine administration, a group of elderly men achieved the same absolute ventilation as young men.' After intravenous or intramuscular morphine administration the changes in respiratory frequency u) and minute volume (p~) led to the conclusion that the aged did not possess the great sensitivity to morphine often attributed to them.2 After subcutaneous3 or intravenous4 morphine the changes in respiratory frequency, minute volume and end tidal COz tension (&'co2) were similar in young and old subjects.We have studied the effect of age on the ventilatory response to COz after intravenous administration of morphine by observing the changes in the C02 tension/ventilation curve and the calculated ventilation at a PE'CO, 7.3 kPa (v7.3). In addition, we observed the changes in the resting PE'co, and the 'CO, threshold' which is the level of PE'co, at which ventilation begins to increase from the basal level. MethodsTwo groups of 12 patients were studied. One Morphine in the elderly 91 1 group of six males and six. females was aged 66-85 years (mean 76 years) and the other group of six males and six females was aged 18-29 years (mean 25 years). The mean weight of the older group was 59 kg (43-85 kg) and the mean weight of the young group was 69 kg (51-86 kg). All patients were free from overt cardiorespiratory disease and gave informed consent for the study which was approved by the hospital ethical committee. Each patient was studied whilst lying comfortably on a trolley in the anaesthetic room prior to elective surgery. All subjects had been starved for at least 8 hours and had received no other drug. The measurement of ventilatory response to CO, was based on the method described by Read.5 The subject rebreathes into a small bag containing C02 at a partial pressure close to that of mixed venous blood. The progressive rise in Pco, within the bag stimulates respiration and the slope of the ventilation curve reveals information about the sensitivity of the respiratory centre.Each subject wore a nose cli...