Influence of an anaesthetist on nurse-led, computer-based, pre-operative assessment.

Trained nurses using a rule-based computer program can successfully carry out pre-anaesthesia screening. All medical problems and abnormal laboratory results need to be reviewed by an experienced anaesthetist. Following the introduction of this system, there was a reduction in the frequency of cancellations of patients from elective orthopaedic operating lists from 4.8% to 1.8%, a difference that was statistically significant (p = 0.03, CI = [0.6%, 5.5%]). To minimise cancellations from booked operating lists, a booked admissions policy is essential, so that the anaesthetist who will eventually be responsible for patients with medical problems can be identified. Cancellations cannot be avoided completely because some abnormal conditions arise or deteriorate after completion of the screening process. The anaesthetist responsible for the patient's anaesthetic may have different views of the risks involved from those of the anaesthetist undertaking the screening process.

An audit of doctor's management of patients with chest pain in the accident and emergency department.

In a series of 604 patients attending an accident and emergency department with chest pain, the decisions made by casualty officers about admission to the coronary care unit were compared with the retrospective opinions of experienced clinical assessors who knew the results of any subsequent investigations. Of the 119 patients whom the assessors judged should have been admitted to the coronary care unit, 14 (11.8 per cent) were judged to have been discharged in error. Of the 485 patients whom the assessors judged should not have been admitted to the coronary care unit, 32 (16 per cent) were judged to have been advised admission unnecessarily. Misinterpretation of the electrocardiographic results was apparently the reason for five of the 14 false negative errors and four of the 32 false positive errors. The median time that patients who were eventually admitted to the coronary care unit spent in the accident and emergency department was 78 min.

The role of chest radiography in patients presenting with anterior chest pain to the Accident & Emergency Department.

The chest radiological findings and outcomes of 120 consecutive patients attending the Accident & Emergency Department with anterior chest pain were recorded prospectively to investigate the value of routine chest radiography in their management. Twenty-one patients (17.5%) were excluded because of incomplete information. Thirty-seven radiological abnormalities were identified in 33 (33%) of the remaining 99 chest X-rays. Seventeen of the abnormalities identified in 14 (14%) of the chest X-rays were clinically significant. The casualty officer's interpretation of 70 (70%) of the chest X-rays was correct, but 36 errors were made interpreting the other 29 chest X-rays. Of these errors, 19 were false negative errors, resulting in the mismanagement of two patients and 17 false positive errors, resulting in the mismanagement of four patients. It appears that a routine chest X-ray provides little information of practical value in the management of patients with anterior chest pain attending an Accident & Emergency Department, unless the training of medical students and junior doctors in the interpretation of chest X-rays is improved.

A probability-based aid for teaching medical students a logical approach to diagnosis.

In this paper we present a method of teaching medical students a logical approach to diagnosis. By using the independent Bayes method, commonly employed in decision aids, students can be made aware of how information on each new symptom affects what is likely in the light of what is known already. This approach is used for the diagnosis of thoracic symptoms in patients with normal chest X-rays and an example is given. Extensions of the system to incorporate information from investigations and error costs are discussed.

Quantitative assessment of the value of spirometry.

To determine the value of simple spirometric measurements in the diagnostic assessment of breathless patients, doctors requesting such tests were asked to predict the likely ventilatory abnormality, expressing these pretest predictions as probabilities. Comparison of these pretest predictions with the test results allowed an analysis of the doctors' ability to identify lung function abnormalities and an assessment of the diagnostic usefulness of the test. Predictions and spirometric measurements were made in 123 patients. Doctors expressed preference for a particular spirometric category in 112 cases, of which 13 were predicted to have a restrictive defect, 77 were predicted to have an obstructive defect, and 22 were predicted to be normal. Spirometry showed that nine patients had a restrictive defect, 79 had an obstructive defect, and 24 had normal indices. The study showed that 61% of the tests gave a result that doctors predicted as being unlikely. The study also showed that doctors had difficulty in identifying the reversibility of airflow obstruction in patients in whom they correctly predicted obstruction. Spirometry fulfils a useful role in the diagnosis of breathless patients.

North American blastomycosis in Africans.

Two young adults, one a native of Libya and one a Sudanese from Saudi Arabia, were referred at different times to the chest service at Westminister Hospital in London with a diagnosis of tuberculosis. They both had neurological deficits due to vertebral lesions. In spite of the fact that neither patient had ever been to North America, diagnoses of North American blastomycosis were established; both patients made remarkable recoveries on amphotericin B therapy.

Tropical splenomegaly syndrome (T.S.S.) in a European.

A case of tropical splenomegaly syndrome in a 66-year-old white man who had lived in Tanzania for 34 years is described. He had taken anti-malarial prophylaxis continuously and regularly. He had had malaria in 1955 but there was no history of alcoholism or jaundice. He was treated with proguanil hydrochloride and, after return to Tanzania, took paludrine as prophylactic. One year later he had no further complaints, the spleen was no longer palpable and the liver only just palpable.

Mathematics and medicine. Test reduction: III-Practical applications.

While there is no generally applicable method of test reduction, ways in which the problem can be tackled can usually be suggested. These include the examination of error rates of tests and the use of current statistical methods. When the cost-effectiveness of some more expensive test has to be measured, a model of the decision problem needs to be developed, with an attempted estimation of the values or utilities of the states of health that result from treatment.

Test reduction: I--Introduction and review of published work.

The word "test" is used in a more general sense to describe the process of eliciting evidence of any kind from a patient, and this paper explores the thesis that much evidence is unnecessary and that therefore much test reduction is possible. The value of test reduction can be measured by its efficiency--that is, its effect on the misclassification of disease--or, preferably, by some measure of its cost-effectiveness.

Airways obstruction in rheumatoid arthritis.

Owing to the report of an association between rheumatoid arthritis (RA) and obliterative bronchiolitis we have determined the prevalence of airflow obstruction in unselected patients with RA and normal chest radiographs. Spirometry was performed on 100 patients with rheumatoid arthritis and 84 control subjects matched for age, sex, and smoking habits. Patients with rheumatoid arthritis had significantly lower values for FEV1, FVC, FEV1/FVC, and MMEFR when compared with the controls: 39 patients had abnormal spirometry, and at least 32 showed airways obstruction. The prevalence of airflow obstruction is remarkably high, and we suggest that airway disease may be the commonest form of lung involvement in rheumatoid arthritis.

Comparison of reports on lung function tests made by chest physicians with those made by a simple computer program.

The numerical results of 60 sets of pulmonary function tests were submitted to five consultant chest physicians for independent reporting. The chest physicians' reports were compared with the reports generated by the on-line computer reporting system in routine use in the pulmonary function laboratory at Westminster Hospital. There was good agreement between the reports of the chest physicians among themselves and with the computer. The individual reports were compared with the consensus opinions of the physicians and the computer. The computer's decisions differed from the consensus opinion in 4.6% of instances. The comparable figures for the five physicians were respectively 2.9%, 2.9%, 2.9%, 4.0%, and 4.6%. Decisions differing from the consensus were due to mistakes or actual sustained disagreements of opinion. The physicians made more mistakes than the computer even though they were performing under test conditions. They made up for this, however, by producing fewer genuine disagreements from the consensus opinions. It is concluded that in routine day-to-day practice the computer report will be as consistently useful as the chest physicians' reports and more immediately available.