1.2 The laboratory in diagnosis
Different fields of laboratory research offered a range of new diagnostic techniques. Bacteriological research into the identity of disease-causing microorganisms provided practitioners with a new and accurate means of diagnosing cases of infectious disease. By the 1890s, specimens from patients suspected of suffering from tuberculosis or diphtheria were routinely cultured to confirm a diagnosis made on the basis of symptoms (Worboys, 2000, pp. 211–16, 252–7). Laboratory equipment used to explore physiological function in the healthy body was applied to reveal underlying physiological dysfunction and thus to diagnose disease. The electrocardiograph, for example, which was devised to explore the function of the heart, became a standard piece of hospital equipment used to diagnose heart conditions. It also helped to establish cardiology as a new specialty. Hospitals began to set up small biochemistry laboratories to analyse blood and urine samples taken from patients suffering from physiological diseases such as anaemia or diabetes. In new pathology departments, histological analyses were performed to check whether or not tissues removed during surgery were cancerous (Howell, 1995).
In the article mentioned in Section 1.1, Jewson assumes that clinical practitioners simply accepted that laboratory scientists – with their new and detailed knowledge of body function – possessed a special authority. Research on British medicine around the turn of the century, however, shows that there was conflict between the two groups, with some practitioners resisting the introduction of laboratory methods of diagnosis. Christopher Lawrence has shown how a group of elite London clinicians built their careers around a model of a gentleman practitioner, broadly educated, versed in the classics and with finely honed clinical skills. Such practitioners relied on attracting patients from the upper classes who shared this type of education and outlook. Far from being scientific reductionists inclined to see their patients simply in terms of diseased organs, these clinicians, like the eighteenth-century practitioners described by Jewson, saw the patient as a sick man, suffering from a unique and individual case of a disease, its course affected by lifestyle and environment. They prided themselves on their skills in clinical diagnosis based on observation and simple physical examination. Not surprisingly, they saw no value in bringing to the bedside the skills and knowledge acquired in the laboratory. One of the staff of St Bartholomew's Hospital was reported to have told his students, ‘When you enter my wards your first duty is to forget all your physiology. Physiology is an experimental science and a very good thing no doubt in its proper place. Medicine is not a science, but an empirical art’ (quoted in Lawrence, 1999, p. 426). Science was equated with specialism, and specialism with a narrow approach that might lead the practitioner to overlook clinical signs (Lawrence, 1985).
Resistance such as this was typical of a particular cohort of practitioners. Later generations of practitioners who had received training in laboratories as part of their medical degree were more willing to accept that there was a role for science at the bedside. In 1908, Thomas Horder (1871–1955), a distinguished clinician and a member of the London elite, wrote:
Though the days are past when the student entering the wards often received the superfluous advice to ‘forget his physiology’, the physiologist is still regarded a little suspiciously at the bedside. Perhaps he is in part himself to blame for that, for he is sometimes inclined to forget that observations made in the laboratory are not infallible, and are not necessarily more correct than clinical evidence … [P]hysiology can only come to the aid of medicine with becoming modesty, and without overweening dogmatism. There is no finality about either.
(Lawrence, 1999, p. 428)
Horder and other practitioners of his generation tried to strike a balance between the role of science and the clinical art. For them, observation still laid the groundwork for diagnosis. Measurement could then ascertain the severity of the condition. For example, a practitioner should be able to diagnose anaemia by observation and questioning: a blood count could measure the severity of the case and help to guide treatment. At all times, the laboratory and the bedside should be linked. The clinician should perform diagnostic tests, and thoroughly understand the implications of the results. Students and practitioners should not become so immersed in the specialised disciplines of the biomedical sciences that they lost sight of the patient as a person (Lawrence, 1999). There is good evidence that by the early twentieth century general practitioners working among the middle classes used laboratory tests to help their diagnosis. Similarly, the development and marketing of small ‘kits’ containing all the equipment necessary to perform simple analyses of blood and urine suggests that some general practitioners applied to their practice the skills learned in the medical-school laboratory.
Research has suggested that other practitioners were equally cautious about pathological examinations carried out in the laboratory. The first reading, by L.S. Jacyna, is taken from his case study on the role of the pathologist in Glasgow Western Infirmary, 1875–1910.
Read ‘The role of the laboratory in the hospital’, linked below. How do practitioners use the laboratory in their practice, and how does their use of the laboratory compare with that of the elite practitioners described by Lawrence?
Clickto open The role of the laboratory in the hospital.
Jacyna's account is about the use of a different sort of laboratory science: where Lawrence's practitioners are using physiological measurements, to judge the severity of cases, Jacyna's practitioners want a diagnosis based on a tissue sample. However, the Glasgow practitioners seem to share the London elite practitioners' feeling that the proper role of the laboratory should be strictly limited, and should come after an initial diagnosis has been made: the lab is used to confirm the cancerous nature of a tumour, or to decide which of the possible diagnoses of inflammation, tuberculosis and so on is correct. While practitioners accept that the laboratory has the technology, and that the pathologist has special skills which they lack, they do not immediately use the laboratory for diagnosis; nor do they use it to determine the course of treatment. The laboratory therefore has a strictly limited role – to refine or confirm an existing diagnosis. It assists practitioners in their clinical practice when dealing with a limited number of conditions.
While clinicians might be suspicious of the laboratory, practitioners working in laboratories actively promoted their skills as a means of serving local medical communities, and thus helping to build a niche for the laboratory. In Sheffield, for example, the established medical school added laboratories to its other teaching facilities in the 1890s. These were primarily intended to attract students, who might otherwise go to better-equipped schools for their training. However, the laboratories also provided services to the local medical community. The bacteriology laboratory conducted tests for local hospitals and the local authority, identifying cases of infectious disease. The physiology laboratory worked with local hospitals in carrying out research into occupational diseases linked to local industries, and into goitre – enlargement of the thyroid glands – which was prevalent in the area. The laboratory staff acquired a prominent position among local practitioners, and were seen as experts on particular conditions. General practitioners were therefore willing to refer on more difficult cases to these local experts, who could provide better diagnosis (Sturdy, 1992).