SERUM CALCIUM AND BLOOD PRESSURE

493 circumference. My work showed in direct/indirect comparisons that the use of a long-bladdered cuff reduced random errors when compared with the standard cuff, but that cuff pressures tended to be higher and diastolic pressures lower than intra-arterial pressures. These opposing differences cannnot be minimised by selection of cuff design. In order to reduce arm

systematic errors with arm circumference I continue to recommend that the bladder in the standard cuff should be made much longer, extending perhaps to 42 cm. The final answer to this controversy can be given only by a largescale survey in which bladder length is a factor in experimental design or in studies aimed at giving a clearer understanding of the distribution of soft-tissue pressures in an arm compressed by a

blood-pressure cuff. Medical

College of Georgia

GEOFFREY E. KING

Augusta, Georgia 30912, U S.A.

SERUM CALCIUM AND BLOOD PRESSURE

SIR,-The work of Bulpitt,1 Kesteloot,and their colleagues led us

to

look

calcium and blood pressure data from from normotensive controls in an study3of the 45-64-year-old population of

at serum

and

hypertensives epidemiological 3 Renfrew, Scotland. 1.

Bulpitt CJ, Charles H, Everitt MG. The relationship between blood pressure and biochemical risk factors in a general population. Br J Prev Soc Med 1976; 30:

158-62. 2. Kesteloot H, Geboers J. Calcium and blood pressure. Lancet 1982; i: 813-15. 3. Hawthorne VM, Greaves DA, Beevers DG. Blood pressure in a Scottish town. Br Med J 1974; iii: 600-03.

The hypertensive group consisted of 63 men and 70 women; they screened twice and were found to have persistent hypertension. Patients on any kind of antihypertensive therapy (including diuretics) were not included. The controls were 52 men and 51 women, a 5% random sample ofnormotensives with diastolic blood pressure below90 mm Hg. The blood pressure measurements and blood sampling for serum calcium determination were done were

simultaneously. The mean serum calcium was slightly but significantly higher in the hypertensive group (p<0’ 00 1). A serum calcium of2’4 mmol/1 or more was found in 59% of hypertensives and in 22-3% of normotensives (p<0 001). When serum calcium was corrected for serum albumin,4 the trend persisted (p<0 02) (see figure). However, we did not find the significant correlation between serum calcium and systolic or diastolic blood pressure that has been reported by others,I,2 although the higher serum calcium values in our hypertensives support a calcium/blood pressure link. Frankly high serum calcium levels (>2 - 6mmol/1) were found in 8 -3% of hypertensives and 1070 of normotensives. However, the true prevalence of hypercalcaemia may not be reflected in our small series. University Department of Medicine, Dudley Road Hospital, Birmingham

A. K. SANGAL D. G. BEEVERS

ANGIOGRAPHY IN GASTROINTESTINAL BLEEDING

SIR,-The survey by Dr Allison and colleagues (July 3, p. 30) is impressive both in size and in its high incidence of positive angiographic findings. However, to interpret the results more information is required about the patients. The source ofbleeding was precisely located by angiography in 45 of 52 emergency procedures. The diagnosis had previously been made in 20 patients for whom the motivation for the procedure was therapeutic embolisation. If these cases are excluded, angiographic examination yielded a positive diagnosis in 25 of 32 instances- still a high percentage (78%) when compared with other series. 1,2 However, the indications for angiography can be further discussed. The failure of endoscopy to establish diagnosis (and possibly to provide treatment) in 3 cases of gastroduodenal ulcer and 2 cases of rectal tears is surprising. Broad indications for angiography could have resulted from a high incidence of failed endoscopic -

examinations. Another query is the degree of blood loss. The authors stated only that the patients were "judged clinically to be bleeding". One wonders whether there was any difference in the blood transfusion requirements between the 7 patients in whom the procedure was unsuccessful and the other patients. Such information could help to define more precisely the ideal cases for angiography. A bleeding rate of at least 3 ml/min is generally required to obtain a positive angiogram.In our hospital, angiographic examination is done only when the source of the gastrointestinal bleeding cannot be found after complete endoscopic examination. In the past two years, we performed 15 angiograms in 11 critically ill patients. A positive diagnosis was obtained in 9 episodes of bleeding from duodenum (11 patient), small bowel (5 patients), and colon (3 patients). In each instance, the bleeding rate was estimated to exceed 2 ml/min at the time of the procedure.

J. L. VINCENT C. DELCOUR R. J. KAHN J. STRUYVEN

Departments of Intensive Care and Radiology, Erasme Hospital, B-1070 Brussels, Belgium

4.

Total and albumin-corrected normotensives.

serum

calcium in

hypertensives

and

Payne RB, Walker BE. Serum calcium. Lancet 1979;

i: 1248.

1. Bar AH, De Laurentis DA, Parry CE, Keohane RB. Angiography in the management of massive lower gastrointestinal tract hemorrhage. Surg Gynecol Obstet 1980; 150:

226-28.

Dotted lines denote means. Serum albumin (and hnce albumin-corrected calcium) could not be traced in one normotensive female.

2.

Bergljung L, Hjorth S, Svendler CA, Oden B. Angiography in acute gastrointestinal bleeding. Surg Gynecol Obstet 1977; 145: 501-03.