Prescription of low osmolar contrast to prevent nephrotoxicity in subjects with pre-existing renal impairment is costly and has not been clearly shown to be effective. We entered 249 subjects with a pre-contrast serum creatinine greater than 120 mumol/liter (1.35 mg/dl) having cardiac catheterization or intravenous contrast into a randomized controlled trial comparing high and low osmolar contrast. The outcome assessed was a rise in serum creatinine repeated 48 to 72 hours after contrast. A further 117 patients entered the non-randomized prospective arm of the study. In the randomized study the serum creatinine rose by at least 25% after contrast in 8 of 117 (6.8%) given high and in 5 of 132 (3.8%) given low osmolar contrast (P greater than 0.05, one-tailed 95% confidence interval for the difference 3 to 7.8%). More severe renal failure (greater than 50% increase in serum creatinine) after contrast was uncommon (3.4% with high and 1.5% with low osmolar contrast). A rise in serum creatinine after contrast was significantly associated with the severity of the pre-contrast renal impairment and the presence of diabetes mellitus, but not with type of contrast. Diabetics with a serum creatinine greater than 200 mumol/liter (2.25 mg/dl) pre-contrast had a highest risk of deterioration in renal function after contrast. We conclude that in patients with pre-existing renal impairment the incidence of contrast nephropathy was not significantly different comparing high osmolar and nonionic contrast. The potential benefit of nonionic contrast in moderate renal impairment is likely to be small, but trials in diabetics with severe renal impairment should be undertaken urgently.

Nonspecific symptoms are common in dialysis patients but few methods are available to measure their severity and their response to alteration in dialysis therapy. To determine the clinical features and measure the severity of the most important symptoms in end-stage renal disease (ESRD) patients, 97 dialysis patients were interviewed, 63 of whom were reinterviewed 1 year later. For comparison 82 transplant recipients were also interviewed. The six most important symptoms in dialysis patients (using the product of the patient’s perception of severity and prevalence) were tiredness, cramps, pruritus, dyspnea, headaches and joint pain. The symptoms were long-standing, occurred frequently, with little difference in prevalence between hemo- and peritoneal dialysis patients, and were often unrelated to a hemodialysis session. For each symptom, several dimensions of severity were assessed including frequency, duration, effect on sleep, daily living, activity, subjective quality of life and necessity for drug therapy. Often these dimensions did not correlate with patient’s perception of severity. For each symptom these items were combined to give an aggregate score with a range 0–10. Interobserver reproducibility for each symptom score was > 0.7 but intraobserver reproducibility was poor for 3 symptoms, because of the fluctuating nature of the symptoms. Construct validity was demonstrated by finding a significantly worse distribution of aggregate scores for tiredness, cramps, pruritus, dyspnea and nausea/vomiting in dialysis compared to transplant patients. Aggregate scores changed little after 1 year’s follow-up in stable dialysis patients but significant improvement in the aggregate scores for tiredness, dyspnea and nausea/vomiting were observed in 14 patients after successful transplantation. Multi-dimensional aggregate scores for individual symptoms should be useful in comparing the efficacy of various dialysis regimes and in determining the etiology of different symptoms, provided account is taken of the fluctuating nature of some of these symptoms.

Nonionic, low-osmolality contrast material is better tolerated during cardiac angiography than ionic, high-osmolality contrast material. Since cost constraints may prevent the universal use of nonionic contrast material, its selective use in patients with severe cardiac disease could be considered.

Somatic symptoms are common in patients on dialysis. Their causes are largely unknown and their therapy is unsatisfactory. To examine the relationship of psychological and clinical factors to these symptoms, 191 interviews were done in patients on hemo- and peritoneal dialysis. The severity of 8 somatic symptoms (tiredness, sleep disturbance, cramps, pruritus, headache, nausea, dyspnea, joint pain) of importance in dialysis patients was measured using previously validated scales. Indices of affect and quality of life were obtained, as was demographic, clinical and laboratory information. The severity of each symptom was significantly related to the indices of affect and quality of life. Using multiple logistic regression, poor affect score was the strongest correlate of each of the following somatic symptoms, tiredness, pruritus, sleep disturbance and cramps. It was ahead of any clinical or demographic variable and was also significantly correlated with the severity of the other smptoms. Indices of hyperparathyroidism were significantly associated with headache, joint pain, dyspnea and nausea. We conclude that the strongest correlate of common somatic symptoms in dialysis patients is affect disturbance, and that therapy aimed at improving the affect may improve the symptoms.