Prophylactic aluminium hydroxide and hyperaluminaemia in intensive care.

Prophylactic antacid therapy is widely used in intensive care units. We show that significant hyperaluminaemia may occur during the course of prophylaxis with aluminium hydroxide in patients with compromised renal function. Since a significant proportion of patients in intensive care have, or are at risk of developing, renal failure we suggest that the routine use of aluminium hydroxide should be avoided.

Hypercalcaemia in Cleveland: a hospital-based survey.

Over a period of six months all reports in the South Tees Health District of serum calcium levels greater than 2.70 mmol/l were extracted and patient records examined to establish the associated diseases and patterns of management. A total of 235 reports were evaluated, and after exclusion of doubtful cases 196 patients were included in the study. No cause had been identified in 57 (29%). Many of these were elderly females in whom hypercalcaemia may have been due to primary hyperparathyroidism, but parathyroid hormone levels had not been measured. Of those in whom a diagnosis had been made, 62 (45%) were associated with malignancy and 50 (36%) with chronic renal failure. 72% of cases of hypercalcaemia reported to general practitioners and 13% of those reported to hospital doctors were not investigated further. Despite the inclusion of serum calcium estimation on routine biochemical profiles, many cases of hypercalcaemia are being ignored or not investigated further. The study emphasizes the need for a reliable screening test for primary hyperparathyroidism.

Cardiac troponin levels in patients with impaired renal function.

Cardiac troponins are important indicators of myocardial damage. Recent studies have shown that serum cardiac troponin levels are raised in at least 50% of patients with renal disease. The mechanisms and implications of these findings are discussed.

A comparison between atenolol and metoprolol in respect of central nervous system side effects.

A double-blind crossover study was performed to compare the incidence of central nervous system (CNS) side effects with atenolol and metoprolol. Eleven women and 6 men who had previously developed such side effects on lipophilic beta-blockers were identified by means of a preliminary questionnaire. A 30-item psychiatric questionnaire was then used to detect changes in psychological status and possible CNS side effects. Discontinuation of the original lipophilic beta-blocker produced a significant improvement in quality of sleep, dreams, concentration, memory, energy and anxiety. Introduction of atenolol did not result in any significant CNS effects. With metoprolol, however, some effects occurred but not to the extent experienced prior to study on other more lipophilic beta-blockers. Blood pressure control was identical with both drugs.

Circadian variations in urine excretion in chronic renal failure.

The pattern of urine excretion over 24 hours has been studied in nineteen patients with stable chronic renal failure of varying severity and due to a variety of renal disorders. The patterns were compared with those in eighteen health control subjects of similar age. The 24 hour urine volume was not significantly greater in the patients (1608 +/- 112 compared with 1710 ml +/- 169). A lower urine concentration (341 +/- 79 mOsm compared with 430 +/- 160 mOsm/kg) was associated with a lower total 24 hour solute excretion (596 +/- 224 compared with 699 +/- 169 mOsm/24 hours). Frequency of micturition, expressed in relation to periods of 24 hours, was similar (6.8 +/- 0.6 compared with (6.4 +/- 0.5). There was an alteration in the normal pattern of urine flow, with more urine at night and less in the day. Nocturia, a consistent feature of the patients with renal failure is due to reversal of the normal pattern and not to an increased volume of urine or increased frequency of micturition. The time of onset of decreased urine excretion during the day was associated with the change from recumbency to activity. The morning antidiuresis, and the nocturnal diuresis, are associated with, and probably the result of, changes in sodium and total solute excretion. The circadian rhythm of potassium excretion remained normal in chronic renal failure, except in very severe renal failure when it was reversed. Alterations in sodium, total solute and water excretion were associated with changes in creatinine excretion and were observed even in mild renal failure. In some patients, studied just before commencing regular dialysis, renal function would have been adequate for reasonable health had the rates of excretion observed at night persisted throughout the 24 hours. Nocturia, in nineteen patients with chronic renal failure, was due to a change in the circadian pattern of urine flow; it is suggested that this results, at least in part, from an inability to respond normally to changes from recumbency to activity.

Management of the patient with multiple myeloma and renal failure.

Renal impairment is a common feature of multiple myeloma. Management of these patients requires an understanding of some of the basic principles of haematology and nephrology.