Analysis of survival of end-stage renal disease patients

Traditional life-table analysis of differences in patient survival for various end-stage renal disease (ESRD) treatment modalities ignore the fact the ESRD patients face sequential risks because they frequently experience more than one mode of therapy. A modification of the usual life-table analysis is suggested as being more appropriate. This modified method takes into account the "time-to-treatment" bias, which, in this instance, is the time spent on the first modality of treatment (that is, center dialysis). The survival data of more than 2,000 ESRD patients in the State of Michigan during the 5-year period, 1974 to 1978, are used to illustrate this method.

Preservation of plasma volume during hemodialysis depends on dialysate osmolality

Hypotension is a major complication of hemodialysis and has been variously attributed not only to plasma volume loss which results from ultrafiltrative fluid removal, but also to extracorporeal blood circulation, osmolar changes or hemodynamic abnormalities which complicate the procedure. The present investigation demonstrates that plasma volume loss during ultrafiltrative fluid removal is reconstituted by mobilization of extravascular fluid, and that the rate of mobilization depends on dialysate osmolality. 7 subjects underwent 2 sessions of hemodialysis differing only in the NaCl concentration and osmolality of the dialysate, each session with ultrafiltration of fluid averaging about 1,800 ml over 3 h. Higher dialysate osmolality resulted in (1) less net decrease in plasma volume, -160 ml vs. -590 ml; (2) more mobilization of extravascular fluid, 1,670 ml vs. 1,150 ml, and (3) better control of hypotension. These results suggest that higher dialysate osmolality improves hypotension and dysequilibrium during hemodialysis by altering the movement between body fluid compartments and preserving normal hemodynamic mechanisms.

Hemorrhage during high-risk hemodialysis using controlled heparinization

The risk of worsening or commencement of bleeding in high-risk patients requiring hemodialysis has not been established. The present study of 300 dialyses in 51 patients with prospectively assessed increased risk for bleeding describes a method for limiting heparin administration by using the thrombin clotting time to assess heparin sensitivity before dialysis and to monitor heparin levels during dialysis. The procedure prevented clotting in the extracorporeal device and limited bleeding complications to 5% of cases overall. Patients with a higher risk for hemorrhage had a higher incidence of bleeding complication (26%), a larger fall in hematocrit, and more frequent requirement for blood replacement. We conclude that although hemodialysis poses a risk for actively bleeding patients, patients at risk but without active bleeding can be dialyzed with strict control of heparin administration.

Preventing hemorrhage in high-risk hemodialysis: regional versus low-dose heparin

Hemodialysis in patients with increased risk for hemorrhage can be accomplished with either a regional or a low, total dose of heparin. In a prospective study of 69 series of dialyses performed on an alternating schedule of heparinization for each patient, bleeding complications during and immediately following dialysis occurred in 23 of 122 dialyses (19%) with regional heparin compared to 13 of 133 dialyses (10%) with low-dose heparin (P less than 0.05). The incidence of hemorrhage correlated with the estimated degree of bleeding risk both at expected and at occult bleeding sites, and was the same or higher with regional heparin in all categories. Hemorrhage was not correlated with preexisting coagulation abnormalities, concurrent anticoagulant drugs, level of azotemia, or ability to successfully limit systemic heparinization during dialysis. The incidence of partial clotting of the dialyzer was 3 to 5% with both heparin protocols. We conclude that regional heparinization has no clinical or practical advantage over low-total-dose heparin in preventing bleeding associated with hemodialysis.

Renal failure following major angiography

Acute renal failure following angiography with contrast agents is known to occur, but the circumstances and frequency of its occurrence are not well described. A retrospective review of consecutive angiographic procedures performed over a six month interval revealed a 12 per cent incidence of renal failure following angiography. The degree of failure was severe in approximately 30 per cent of these cases and was associated with a significant mortality even though renal function usually recovered. The occurrence of renal failure was associated with the presence of renal insufficiency, impaired liver function, diabetes mellitus, hypoalbuminemia and proteinuria at the time of angiography to a statistically significant level. Furthermore, combinations of these factors, particularly preexisting combined renal insufficiency and impaired liver function, were associated with an increased incidence of acute renal failure. It is concluded that angiography poses a significant hazard to patients with underlying medical problems, particularly those involving the excretory routes of the contrast agent.

Correction of postoperative metabolic alkalosis and renal failure by hemodialysis

Three postoperative patients with oliguirc renal failure and hypochloremic metabolic alkalosis were treated with hemodialysis using a specailly prepared high-chloride, low-acetate dialysate. This mode of therapy corrected the metabolic abnormalities and was significantly more effective than treatment with commercially available high-acetate dialysate at increasing the serum chloride and hydrogen ion concentration. Furthermore, hemodialysis with high-chloride, low-acetate dialysate corrected the clinical sequelae of hypoventilation, cardiac arrhythmia, and neuromuscular irritability associated with metabolic alkalosis while treating uremia simultaneously.