Causes of death in insulin-dependent diabetic patients treated with hemodialysis

Long-term outcomes of end-stage renal disease patients admitted to the ICU

BACKGROUND

End-stage renal disease (ESRD) patients admitted to the intensive care unit (ICU) have poor survival and high rates of readmission; however, little evidence exists on long-term outcomes. We set out to investigate the long-term (6 and 12 months) survival of ESRD patients admitted to the ICU and whether differential survival could be explained by dialysis modality and vascular access.

METHODS

We compared the admission characteristics, outcomes and readmission rates of 619 ESRD [95 peritoneal dialysis (PD), 334 hemodialysis with a catheter (HD CVC), 190 hemodialysis with an AV fistula (HD AVF)] patients admitted to 11 ICU's in Winnipeg, Manitoba, Canada. Parametric and nonparametric tests were used as appropriate to determine differences in baseline characteristics. Multivariable Cox and logistic regression was used to assess outcomes between the groups.

RESULTS

The 6- and 12-month crude survival was 62 and 52%, respectively. In a univariate model, modality and vascular access were associated with an increased hazard ratio (HR) of death [PD HR 1.60 95% confidence interval (CI) 1.20-2.13, HD CVC HR 1.55 95% CI 1.25-1.93] compared to patients on HD with an AVF. In three different multivariate adjusted models, this association persisted with HRs for death of 1.63-1.75 for PD and 1.50-1.58 for HD CVC.

CONCLUSIONS

Overall long-term survival of ESRD patients after admission to the ICU is poor. Being on PD or being dialyzed with a catheter was independently associated with an increased mortality.

Infectious complications of the hemodialysis access

Infectious complications of the vascular access are a major source of morbidity and mortality among hemodialysis (HD) patients. Numerous reports implicate the vascular access in up to 48 to 73% of all bacteremias in HD patients. The incidence of vascular access-related infection is highest when central venous dialysis catheters are employed. Native arteriovenous fistulas carry the lowest risk of infection. Unfortunately, prosthetic arteriovenous grafts, which represent the most common type of HD access in the United States, have been repeatedly shown to be a risk factor for bacteremic and nonbacteremic infections. Silent infection in old nonfunctional clotted prosthetic arteriovenous grafts has recently been recognized as a frequent cause of bacteremia and morbidity among HD patients. High proportions of infections related to the vascular access are caused by staphylococcal organisms, which carry high rates of mortality, recurrence, and metastatic complications. Management of vascular access-related infection has two aspects: The first relates to the choice, duration, and mode of administration of antibiotic therapy. Empiric antibiotic therapy, guided by demographic data and severity of illness, should be employed when the causative organisms are unknown. Prolonged administration of specific parenteral antibiotics is crucial in decreasing complications of infection, especially in cases of staphylococcal bacteremia. The second aspect relates to management of the vascular access. Efforts directed toward bacteriological cure should be concurrent with efforts to preserve native venous access sites whenever possible. Efforts to prevent vascular access-related infection should focus on increasing placement of arteriovenous fistulas and minimizing insertion of central venous dialysis catheters. Careful inspection and monitoring of the vascular access is of paramount importance in early detection of vascular access site-related infections. Several new approaches aimed at preventing catheter and prosthetic graft-related infection are being explored.

Hemodialysis in the diabetic patient with end-stage renal disease

Diabetes mellitus is now the most common cause of end-stage renal disease (ESRD) in the U.S., and the percentage of ESRD patients with diabetes is increasing yearly. One-year survival in such patients is poorer than in those with other etiologies of ESRD but has improved from 64% to 74% over the past decade. However, overall 5-year survival on dialysis is still less than 20% in this population. It is controversial whether hemodialysis or peritoneal dialysis (CAPD, CCPD) is the best choice. Advantages of hemodialysis include its ready availability and convenience for patients, who are frequently incapacitated by blindness, cerebrovascular disease, and/or amputations. However, patients may tolerate dialytic ultrafiltration poorly due to autonomic neuropathy. Maintenance of vascular access is difficult, which may contribute to inadequate dialysis in some patients. Cardiovascular disease remains the most common cause of death. Management of coronary artery disease is difficult because of the high prevalence of silent ischemia. Control of blood pressure is of paramount importance in preventing cardiovascular complications. Improved survival in diabetics who were dialyzed in a more intensive than usual fashion has been reported recently. In addition, much of the difference in survival rates between diabetics and nondiabetics can be accounted for by the poorer nutritional status in the former group. Thus attention to the dose of dialysis administered and assurance of adequate nutrition should result in improved survival of the diabetic patient on hemodialysis.

Diabetic nephropathy: new directions in management

Approximately 6 million people in the United States are known to be diabetic, with an estimated 4 million individuals having undiagnosed diabetes mellitus. The metabolic derangements of both insulin-dependent diabetes mellitus (IDDM) and noninsulin-dependent diabetes mellitus (NIDDM) result in widespread end-organ damage, including progressive kidney failure. Since its initial description in 1936, the incidence of diabetic nephropathy has progressively increased, and it is now the most common cause of newly diagnosed end-stage renal disease (ESRD) requiring renal replacement therapy in the United States. While basic research efforts into pathogenesis continue, there is significant interest in clinical interventions that may slow the progression of diabetic renal disease. In addition, the options available for renal replacement therapy have increased and improved substantially in recent years.