SMAC speeds blood tests

Press, 16 June 1979, Page 16

SMAC speeds blood tests

By

JOHN BROWN

It might seem a big gap between a test tube of blood and a computer. But a new $400,000 machine at Christchurch Hospital has linked the two. Its name is SMAC — a word which staff in the hospital’s biochemistry unit speak almost reverently. The new unit is the fastest and most efficient system of blood analysis in New Zealand. SMAC stands for Be<iuential Multiple Analysis and Computer. The

unit, which is number 677 in the world, is the first to be installed in a New Ze’land hospital. It has made possible the development at Christchurch Hospital of the country’s only centralised blood testing service. It will handie all oiouu tested from hospital patients in Christchurch. A case for the new machine was presented to the Department of Health in April, 1975, by the head of the Department of Clinical Biochemistry for the North Canterbury Hos-

pital Board, Professor Robin Carrell. Routine blood analysis requires about 20 to 25 separate tests. Until 1962 these had to be carried out manually and staff at. the

biochemistry department could handle only about 10 to 30 samples a day. The addition of automated equipment since the mid 1960 s on four separate

units made it possible for 70 samples to be tested every hour. Now, with SMAC, the testing process is combined and up to 6u(J b.uud samples a day can be processed. One side benefit to the patient is that only 5 mis of blood per sample are required, agains* .1 mis needed for previous test methods. The difference is of little significance to an adult but for a young baby the smaller requirement prevents many other problems. SMAC does not use “blood” as the layman knows it, but tests the almost colourless blood plasma which is extracted from each sample by centrifuge. Each sample is numbered and colourcoded. This information is fed into a small computer attached to SMAC through a keyboard in-put. Racks of blood samples are placed in front of SMAC’s computerised “laboratory.” A small light passes over each sample and “reads” the coding which is matched up with the material already recorded on the computer.

A fine metal tube then sucks up a small part, of each blood sample, which passes through fine plastic tubing to a central tube. This distributes each sample to 20 separate testing boxes, where the sample is subjected to a series of reagents to test for factors such as urea, calcium, cholesterol, protein and iron. The results of the 20 types of blood analysis carried out are recorded automatically by the computer against the samples’ coded record. To prevent the samples from getting mixed with each other, an air bubble separates each sample tested from the next. Professor Carrell, who

recently completed two years at Cambridge University Medical School and its teaching hospital is adamant that SMAC is a breakthrough for medical diagnosis in Christchurch. An advantage is that the larger amount of information from each blood sample might reveal unexpected abnormalities to the doctor, Professor Carrell believes. One disadvantage however might be that the sheer size of the results could be overwhelming. For this reason careful planning was needed to simplify presentation of the information to doctors so that any abnormal result is clearly evident. Blood testing is an essential tool of medical diagnosis and clinical management. Tests show how various drugs are working on patients and how management of patient care might need to be changed. SMAC makes it possible for this type of testing to be done much quicker, allowing more time for those specialised blood tests which are still subject to a large amount of manual control. SMAC’s pride of place in the biochemistry unit is a far cry from the makeshift-looking semiautomated units it replaces. The North Canterbury Hospital Board’s investment of almost $500,000 in SMAC and other modern equipment for the biochemistry unit is an important contribution to the re-development of Christchurch Hospital for its new role as one of the country’s major teaching hospitals. “Efficiency and effectiveness” is now the catchphrase in New Zealand medicine. SMAC will bring that one stage closer at Christchurch Hospital.