409

MEASURING BLOOD-PRESSURE

THE auscultatory method for measuring blood-pres-sure has been in continuous use since its introduction in

1905,1 with only minor modifications in technique andinstruments. Comparison with intra-arterial record-

ings’-" shows the method to be reasonably accurate andreliable, although large and unexplained discrepanciesmav arise in individual patients.’" Attempts to improvethe objectivity of the method by obscuring the mercurycolumn12 or by shifting the zero in random fashion"have been very successful, but the need for a humanobserver has always limited the frequency with whichobservations can be made. Replacement of the observerbv automatic mechanical inflation/deflation devices anda microphone to register the Korotkoff sounds14 has notbeen very successful, since the apparatus is necessarilycumbersome and subject to artifact. Ultrasound detec-tion of arterial-wall movement is another approachwhich has been carefully evaluated 15 but the apparatusis expensive and not portable. None of these instrumentshas much to offer the clinician with his inexpensive mer-cury manometer and stethoscope, but the whole picturehas changed with the upsurge of popular interest in

blood-pressure which has stemmed from increasing evi-dence that treatment of high blood-pressure may reducethe risk of cerebrovascular accidents and myocardial in-farction,’6 There is now great interest in mass screeningof blood-pressure17 and a natural outcome is the con-struction of instruments which will enable the doctor totake a blood-pressure rapidly and easily and may evenbe used by people with no training.18 19 A profusion ofautomatic and semi-automatic machines, many withattractive flashing lights to indicate systolic and diastolicpressure, are on offer in’the professional and lay Press.It has even been suggested that these instruments shouldbe installed in chemists shops next to the weighing-ma-chine, But whereas the auscultatory method of measur-ing blood-pressure has survived rigorous and repeatedexamination, there is very little information on the accu-racy and reliability of these new instruments. Seriousdeficiencies have been found in some which have beenexamined critically20 and little attention has been paidto the careful recommendations for evaluation laid down

by the American Heart Association.21 It is left to the in-tegrity of individual manufacturers and the enthusiasm

1 Korotkoff, M. S. Bull. imp. milit. Med. Acad. 1905, 11, 365.2. Ragan, C., Bordley, J. Bull. Johns Hopkins Hosp. 1941, 69, 504.3. Hamilton, W. F., Woodbury, R. A., Harper, H. I. J. Am. med. Ass. 1936,

107, 853.4. Steele, J. M. J. Mt Sinai Hosp. 1942, 8, 1042.5. Roberts, L. M., Smiley, J. R., Manning, G. W. Circulation, 1953, 8, 232.6 Berliner, K., Fujiy, H., Ho Lee, D., Yildiz, M., Garnler, B. Cardiologia,

Basel, 1960, 37, 118.7 Buhlmann, A. Direkte Blutkruckmessung Beimmenschen. Berlin, 1958.8 Holland, W. W., Humerfelt, S. Br. med. J. 1964, ii, 1241.9. Kotte, J. H., Iglauer, A., McGuire, E. Am. Heart J. 1944, 28, 476.10 Raftery, E. B., Ward, A. Cardiovasc. Res. 1968, 2, 210.11 Briet, S. N., O’Rourke, M. F. Aust. N.Z. J. Med 1972, 4, 485.12 Rose, G. A., Holland, W. W., Crowley, E. A. Lancet, 1964, i, 296.13 Wright, B. M., Dore, C. F. ibid. 1970, i, 337.14 Hinman, A. T., Engel, B. T., Bickford, A. F. Am. Heart J. 1962, 63, 663.15 Gundersen, J. Ahlgren, I. Acta anœsth. scand. 1973, 17, 203.16 Veterans Administration. J. Am. med. Ass. 1970, 213, 1143.17 Sackett, D. L. Lancet, 1974, ii, 1189.18 The Hi/Lo Baumanometer Blood-Pressure Kit. For physician-directed Home

Use. New Product Data Sheet. W. P. Baum Co Inc., New York.19 Owners Manual, Sphygmometrograph Blood-Pressure Recorder. Sears, Roe-

buck.

21 Labarthe, D. R., Hawkins, C. M., Remington, R. D. Am. J. Cardiol. 1973,32, 546,

22 Circulation, 1973, 48, suppl. 6.

of some investigators (see p. 398) to ensure that inaccur-ate and misleading instruments do not become freelyavailable. Perhaps it is time for the Committee on Safetyof Medicines to inspect and licence new medical instru-ments.

PROPIONIC-ACID DERIVATIVES

A NUMBER of anti-inflammatory drugs have beendevised in the hope of bypassing the side-effects ofaspirin, phenylbutazone, and indomethacin. Notable

among these are the propionic-acid derivatives: all havemuch less tendency to cause gastric side-effects thanaspirin, none causes important occult bleeding (thoughhxmatemesis has been reported), and all have analgesicpotency akin to that of aspirin. Some have rather lessanti-inflammatory activity and none reduces jointsize-a property regarded by some rheumatologists asthe hallmark of an anti-inflammatory drug.’ Clinical ex-perience suggests that, while they are well suited to mostrheumatic conditions, including osteoarthritis and soft-tissue rheumatism, they are not as effective as the tradi-

- tional anti-inflammatory agents in highly inflammatorydisorders such as gout, ankylosing spondylitis, and veryactive rheumatoid arthritis. Despite the lack of effect onjoint size, their anti-inflammatory potential is reflectedby improvement in morning stiffness (a cardinal symp-tom of inflammation which seems to have been over-looked by Celsus and Galen). These new compoundstherefore have more in common with the anti-inflamma-tory drugs than with simple analgesics. Huskisson2 classi-fies drugs for rheumatic disease under four headings-simple analgesics (e.g., paracetamol), analgesics withminor anti-inflammatory properties (e.g., ibuprofen),analgesics with major anti-inflammatory properties,(e.g., indomethacin) and pure anti-inflammatory drugs(corticosteroids).The propionic-acid derivatives fenoprofen,3 ibu-

profen,4 ketoprofen,5 and naproxen6 all have fewer side-effects than aspirin. According to Huskisson et al.7naproxen and fenoprofen seem slightly more effectivethan ibuprofen and ketoprofen; and naproxen and ibu-profen are less likely than the other two to cause gastricside-effects. But in this work the differences between in-dividual patients’ responses to one drug were great. Indi-vidual variation is of great practical importance. Ananti-inflammatory agent should be given for just longenough to see whether it will work; one or two weeks isenough. It may be necessary to try all the drugs to findthe best. For all but the most active cases of rheumatoidarthritis, and disorders such as gout in which inflamma-tion is prominent, propionic-acid derivatives can now beregarded as first-line treatment.

1. Boardman, P. C., Hart, F. D. Br. med. J. 1967, iv, 264.2. Huskisson, E. C. Reports on Rheumatic Diseases; p. 54. Arthritis and Rheu-

matism Council, London, 1974.3. Huskisson, E. C., Wojtulewski, J. A., Berry, H., Scott, J., Hart, F. D. Br.

med. J. 1974, i, 176.4. Huskisson, E. C., Hart, F. D., Shenfield, G. M., Taylor, R. T. Practitioner,

1971, 207, 639.5. Qutchi, D. W., Man, S., Bloch, M., Mason, R. M. Rheum. Rehab. 1973, 12,

62.6. Hill, H. F., Hill, A. G. S., Mowat, A. G., Ansell, B. M., Mathews, J. A.,

Seifert, M. H., Gumpel, J. M., Christie, G. A. Ann. rheum. Dis. 1974,32, 12.

7. Huskisson, E. C., Woolf, D. L., Balme, H. W., Scott, J., Franklyn, S. Br.med. J. 1976, i, 1048.