WAX ActiveLibrary: a tool to manage information overload.

WAX Active-Library (Cambridge Centre for Clinical Informatics) is a knowledge management system that seeks to support doctors' decision making through the provision of electronic books containing a wide range of clinical knowledge and locally based information. WAX has been piloted in several regions in the United Kingdom and formally evaluated in 17 GP surgeries based in Cambridgeshire. The evaluation has provided evidence that WAX Active-Library significantly improves GPs' access to relevant information sources and by increasing appropriate patient management and referrals this might also lead to an improvement in clinical outcomes.

A 3-month, double-blind, controlled trial of feeding with sucrose polyester in human volunteers.

Sucrose polyester (SPE) is a tasteless, odourless substance which reduces plasma cholesterol concentrations and may therefore be valuable as a fat substitute in human foodstuffs. It has recently been approved for use in snack foods by the United States Federal Drug Administration. The current study was designed to investigate its effects on gastrointestinal physiology and nutrient absorption in human subjects. A 6-month (2 x 3-month periods) double-blind, placebo-controlled, randomized, cross-over trial of SPE and control fat was performed in healthy free-living volunteers. Subjects consumed 20-40 g of SPE daily (mean 26.8 (SE 6.8) g) which reduced the intake of total and saturated fat but had no effect on energy intake or body weight. Plasma cholesterol and triacylglycerols were reduced. The frequency of bowel movements and their urgency were increased and anal leakage occurred in 7.2% of subjects. Abdominal pain was more frequent in subjects receiving SPE and was significantly greater than in the control group after 8 weeks feeding. The plasma concentrations of vitamin E and six carotenoids were significantly reduced. Routine haematology and biochemistry, other vitamins, intestinal biopsies, bile-salt retention, rectal prostaglandins, fractional Ca absorption and aminopyrine metabolism were unaffected. The ingestion of foods containing 20-40 g SPE daily provoked significant gastrointestinal problems. This intake is greater than that to be expected from the use of SPE in savoury snack foods, for which it has been approved by the United States Federal Drug Administration. However, the favourable effects on lipid profiles must be balanced against the reduction in the concentrations of vitamins and carotenoids, as these compounds may have beneficial effects on health through protection from free-radical oxidative stress.

Coherent exchange of healthcare knowledge in open systems.

This paper outlines design philosophies and methods for healthcare knowledge systems. Clinical priorities for knowledge are discussed in terms of temporal and individual needs. Book centred organisation of healthcare knowledge, which has proven effective in clinical practice, is proposed as the basis of virtual libraries available at the point of care for target groups of healthcare professionals.

Exchanging clinical knowledge via Internet.

The need for effective and efficient exchange of clinical knowledge is increasing. Paper based methods for managing clinical knowledge are not meeting the demand for knowledge and this has undoubtedly contributed to the widely reported failures of clinical guidelines. Internet affords both opportunities and dangers for clinical knowledge. Systems such as Wax have demonstrated the importance of intuitive structure in the management of knowledge. We report on a new initiative for the global management of clinical knowledge.

Subarachnoid haemorrhage of unknown cause: a long term follow-up.

Three hundred and sixteen patients who suffered a subarachnoid haemorrhage of unknown cause were followed up by questionnaire after 2 to 23 years, the average interval being 10 years. Two hundred and fifty one (79.5%) are known to be alive, 49 (15.5%) had died, and 16 (5%) patients were untraceable. The cumulative survival for the whole group after 22 years was 69%, the expected survival being 89%. The certified cause of death of 30 patients was from diseases of the circulatory system, mainly myocardial infarction and cerebrovascular disease, the expected number being 21.8. The results of this survey show a reduced life expectancy for both males and females and suggest that a more guarded view should be taken than is presently the case about the long term prognosis of these patients.

Small bowel obstruction: computer-assisted prediction of strangulation at presentation.

A multivariate computer analysis has been performed on the presenting data of patients with simple small bowel obstruction that settled with conservative treatment (n = 120) and of patients with viable strangulation small bowel obstruction (n = 38) and non-viable strangulation small bowel obstruction (n = 39) found at operation. Initially only 66 per cent of patients with viable strangulation and 46 per cent of those with non-viable strangulation had been treated by immediate surgery after resuscitation. The remainder had been treated conservatively for a median of 3.8 and 2.2 days respectively before undergoing surgery. The computer predicted on the basis of presenting symptoms and signs that 82 per cent of patients with viable strangulation and 97 per cent of those with non-viable strangulation had or would develop strangulation and should have undergone immediate surgery. We advocate that the computer can assist in the management of patients with small bowel obstruction.

Influence on patient management of general practitioner direct access to radiological services.

We have looked at the effect of open radiological access on patient management during a 2-year prospective study in the radiology department of a teaching hospital and two general practices. Five hundred and thirty consecutive requests for radiological examination were studied. Chest radiographs (29.8%) and barium meals (17.4%) were the investigations most commonly requested. At the time of referral general practitioners indicated that if open radiological access had not been available, 78% of the patients would have been referred to specialist clinics. They also indicated that with a normal initial radiological examination only 12% would need referral to a specialist department. Open access appears to save outpatient consultations.

Psychological and social evaluation in cases of deliberate self-poisoning seen in an accident department.

The outcome in 115 consecutive patients with mild self-poisoning seen by junior medical staff and discharged from the accident department was compared with that of 98 similar patients admitted to the medical wards. Psychiatrists saw only four patients in the accident department and 25 admissions. In making their assessments the junior medical staff considered psychosocial factors as well as the patients' physical condition. Most patients recommended for further care, and discharged from the accident department, subsequently received it. Repetition rates were similar in the two groups and there had been no suicides when patients were followed up at one year. It is feasible for junior staff in an accident department to decide whether patients with self-poisoning need admission or may be discharged with or without subsequent referral for psychiatric or social work help.

Cause of death in patients with rheumatoid arthritis with particular reference to azathioprine.

Three hundred and eleven patients with classical or definite rheumatoid arthritis were observed over an 11-year period. This group is of particular interest since 214 patients were given cytotoxic therapy, 203 were treated with azathioprine (52 of these also received chlorambucil or cyclophosphamide), and 11 were treated with cyclophosphamide or chlorambucil alone. Forty-six patients died. This is an excess mortality compared with the expected rate for the general population matched with respect to age and sex. The death rate was higher than expected in the age group 45-64 years but lower in those aged 75 years or over. There were more deaths from neoplasia and ischaemic heart disease in the younger age group. One patient died of lymphosarcoma; treatment had been with corticosteroids, gold, and chloroquine. No other tumours of the reticuloendothelial system were recorded, and no patient developed leukaemia.

Pharmacological screening of new chemical entities in human subjects and methods of data handling.

1 A system is described for screening new chemical entities in normal human subjects, which is designed to search for novel drug actions at an early stage of drug development. 2 In single (subject) blind experiments, doses are increased incrementally from one subject to next, with immediate feed-back of results from each dose. 3 As many physiological variables as possible are recorded, for which a purpose-designed apparatus system was constructed, and connected to a computer. 4 To overcome problems of inter-subject variability, the need for sensitivity, and to identify drug-related effects from the mass of data generated, a novel data management system was developed, and physiological profiles of volunteer subjects were built up to provide control data. 5 Results from a validation experiment in which isoprenaline was infused intravenously at different rates are presented and discussed.

Consultation-liaison scheme for self-poisoned patients in a general hospital.

In a prospective clinical trial 276 self-poisoned patients consecutively admitted to hospital were randomly allocated to medical teams or to psychiatrists for an initial psychiatric assessment and a decision about "disposal." Junior doctors and nurses received instruction in this work. While awaiting the outcome of the trial the randomisation was continued for 13 months and 729 allocations were made altogether. Physicians requested psychiatric opinions for roughly one in five of their patients. In other respects medical teams performed similarly to psychiatrists. Provided that due attention is given to teaching junior staff and to ensuring that psychiatric treatment and social-work support are available once patients have been assessed, such a consultation-liaison scheme could be adopted in other hospitals. This would help to change unfavourable attitudes towards self-poisoned patients and contribute to the general training of doctors and nurses.

The urinary excretion of radiocopper in presymptomatic and symptomatic Wilson's disease, heterozygotes and controls: its significance in diagnosis and management.

Radiocopper (64Cu, 67CU), given intravenously, has been used to study the pattern of excretion of copper in patients with presymptomatic, symptomatic and treated Wilson's disease, together with heterozygotes for the Wilson's disease gene and a control group of patients with a variety of neurological lesions mimicking Wilson's disease. Urine was collected for three periods after injection, 0 to 8 hours, 8 to 24 hours, at which time a test dose of penicillamine was given, and from 24 to 30 hours. Stable (endogenous) copper was also estimated on these samples and specific activity was determined. This was multiplied by a correction factor to allow for variations in dose and body weight. The findings for stable copper in urine were largely predictable. Controls and heterozygotes had the least copper excretion, the amounts rising in the presymptomatic to a peak in the symptomatic patients. Institution of therapy was associated with a fall in copper excretion pro rata with time. The most important radiochemical findings were as follows. Heterozygotes excreted less of the injected copper than controls both under basal conditions and after penicillamine. Presymptomatic patients excreted less radiocopper than heterozygotes after penicillamine although the excretion during the basal 24 hour period was very much greater. Patients with symptomatic Wilson's disease had by far the highest excretion of radiocopper in all three time periods which fell after treatment, pro rata with time, as had been found for stable copper. These results were subjected to computer analysis. There was no overlap between the various groups with the exception of a single control subject who had combined pyramidal and extrapyramidal system degeneration of obscure aetiology. This patient was classified by the computer study as 'heterozygote'. These findings lend further support to the hypothesis that the loss of a single gene for copper balance can be detected with a high degree of accuracy and also that presymptomatic patients can be selected from a sibship for prophylactic treatment without the risk of subjecting healthy heterozygotes to unnecessary and potentially hazardous long-term therapy.

Psychological and social evaluation in cases of deliberate self-poisoning admitted to a general hospital.

In a prospective clinical trial 312 cases of self-poisoning (276 patients) consecutively admitted to hospital were randomly allocated to medical teams or to psychiatrists for an initial psychiatric assessment and a decision as to "disposal." Junior doctors and nurses received some instruction in this work. Both groups of assessors asked for help from social workers when necessary. Once the medical teams had completed their assessments, psychiatrists provided most of the hospital treatment. Follow-up at one year showed no significant difference between the two groups of patients in the numbers who repeated their self-poisoning or self-injury (or both), or committed suicide. Provided junior doctors and nurses are taught to assess self-poisoned patients, we think medical teams can evaluate the suicidal risk and identify patients requiring psychiatric treatment or help from social workers, or both. Contrary to the Department of Health's recommendation that all cases of deliberate self-poisoning should be seen by psychiatrists, we have reached the conclusion that physicians should decide for each of their patients if specialist psychiatric advice is necessary.

Ventricular size following head injury: a clinico-radiological study.

A retrospective study of the records of 93 patients who had sustained a severe closed head injury was carried out to determine the relationship, if any, between the severity of the injury, the size of the cerebral ventricles and the residual disability. Ventricular size was expressed as a ventricular index. The callosal angle was also measured to see whether this was of value in the recognition of post-traumatic external obstructive hydrocephalus. A normal range of ventricular indices and callosal angles was obtained from a review of the air encephalograms of 56 patients matched for age and sex with the head injury group, and whose air studies were considered to be normal. The findings on the head injury group were subjected to detailed statistical analysis. The study showed that there was no statistically significant relationship between severity of injury, measured by duration of unconsciousness, and ventricular size expressed as a ventricular index. There was a relationship between ventricular size and residual disability as graded in this study. If age was taken into consideration, the relationship between ventricular size and disability was closer. It was not possible to predict residual disability of individual patients from ventricular size alone due to the wide range of values in any disability grade. Failure of air to pass from the basal cisterns over the cerebral convexities is a widely accepted sign of extraventricular obstruction. The shapes of the ventricles, the ventricular index and a callosal angle of 110 degrees or less provided supporting evidence of obstruction in this study. Recognition of an obstructive element in ventricular dilatation following head injury is important, since in a small carefully selected group of patients a ventricular shunting operation may favourably affect recovery.

The effects of maternal hypercapnia on foetal oxygenation and uterine blood flow in the pig.

1. The purpose of this investigation was to determine the effects of maternal hyperoxaemia and hypercapnia on the uterine vascular bed and foetal oxygenation in the large white sow at 80-90 days gestation. 2. When maternal hyperoxaemia was induced with 100% oxygen, there was a highly significant rise in the maternal arterial oxygen tension, but no other significant blood gas or vascular changes were observed. 3. When mild maternal hypercapnia was superimposed on maternal hyperoxaemia (oxygen plus 6% carbon dioxide), the oxygen tension and saturation of both the maternal uterine venous and foetal umbilical venous bloods were found when severe hypercapnia was induced (oxygen plus 50% carbon dioxide) but in this case all blood samples showed dramatic changes in PCO2 and pH. These changes were accompanied by an increase in the systemic blood pressure and uterine blood flow, and a decrease in uterine vascular resistance. 4. When mild hypercapnia was induced without hyperoxaemia (air plus 5% carbon dioxide) significant increases were recorded in the oxygen tension and saturation of uterine venous and foetal umbilical venous bloods. Systemic and uterine vascular resistance fell. 5. It was concluded that the increased foetal oxygen tension during maternal hypercapnia was the result of the increased uterine blood flow and greater mass delivery of oxygen to the placenta, so that once the oxygen requirements of the placental tissues themselves were exceeded there would be an increased oxygen gradient at the site of gas exchange. 6. Carbon dioxide concentration in arterial blood plays an important role in determining blood flow through the pregnant uterus in the sow.