Intradialytic Parenteral Nutrition Does Not Improve Survival in Malnourished Hemodialysis Patients: A 2-Year Multicenter, Prospective, Randomized StudyNJM Cano, D Fouque, H Roth, et al, and the French Study Group for Nutrition in Dialysis Although intradialytic parenteral nutrition (IDPN) is a method used widely to combat protein-calorie malnutrition in hemodialysis patients, its effect on survival has not been thoroughly studied. We conducted a prospective, randomized trial in which 186 malnourished hemodialysis patients received oral nutritional supplements with or without 1 year of IDPN. IDPN did not improve 2-year mortality (primary end point), hospitalization rate, Karnofsky score, body mass index, or laboratory markers of nutritional status. Instead, both groups demonstrated improvement in body mass index and the nutritional parameters serum albumin and prealbumin (P < 0.05). Multivariate analysis showed that an increase in prealbumin of >30 mg/L within 3 months, a marker of nutritional improvement, independently predicted a 54% decrease in 2-year mortality, as well as reduced hospitalizations and improved general well-being as measured by the Karnofsky score. Therefore, although we found no definite advantage of adding IDPN to oral nutritional supplementation, this is the first prospective study demonstrating that an improvement in prealbumin during nutritional therapy is associated with a decrease in morbidity and mortality in malnourished hemodialysis patients.
Malnutrition is common in hemodialysis patients; the prevalence varies between 23% and 73%.1,2 In malnourished hemodialysis patients, the annual mortality rate is close to 30%.1,3 Inadequate nutrition intake is an important cause of malnutrition in patients with renal failure. Nutrition counseling, the use of oral nutrition supplements, and intradialytic parenteral nutrition (IDPN) are all methods that are used to treat malnutrition in these patients. IDPN is administered through an infusion pump during dialysis; the parenteral nutrition fluid is mixed with the patient's venous blood and returned to the body through the venous access.4 IDPN has previously been shown to improve nutrition and metabolic parameters, but prospective outcome data supporting the use of IDPN have been lacking. This is the first prospective, randomized study to address the benefits of IDPN on mortality and morbidity. This investigator-initiated, prospective, randomized, controlled study was designed to evaluate (via an intention-to-treat design) the effects of IDPN plus oral nutrition supplements given over 1 year on 2-year patient survival and morbidity. This study also aimed to define the determinants of outcome in malnourished maintenance dialysis patients who received nutrition therapies. In total, 186 patients were randomly assigned to receive either IDPN plus oral nutrition supplements (IDPN group, n = 93) or oral supplements alone (control group, n = 93) during 1 year, then followed during a subsequent year. The 2 groups were similar with respect to baseline characteristics with a nonsignificant trend to the IDPN group having more comorbidites. At months 3, 6, and 12, calories/kg and protein/kg provided by IDPN and oral supplements were statistically similar. Patients who actually received IDPN at months 3, 6, and 12 represented 87%, 79%, and 67%, respectively, of the IDPN group. Causes for IDPN discontinuation were nutrition status improvement, patients' wish, adverse events, and other reasons. In control and IDPN groups, mean compliance to oral supplementation was 72% and 69%, respectively, after 3 months; 68% and 75% after 6 months; and 70% and 61% after 12 months (NS).
Thirty-six patients died during the 2-year follow-up in the control group
and 40 in the IDPN group. Causes of death did not differ between groups. Mean
cumulative survival was 0.77 and 0.58 after 1 and 2 years, respectively;
survival was similar in IDPN and control groups. No difference appeared after
adjustment for diabetes, serum C-reactive protein levels, and comorbidities.
As compared with control subjects, patients with diabetes mellitus showed a
similar survival at month 12
( Karnofsky scores were similar in both groups at the start of the study and remained unaffected and similar in the 2 groups during the follow-up. All patients but 27 were hospitalized at least once during the follow-up. The median hospitalization length was 21 days. Hospitalization rate was 0.06 ± 0.10 and 0.06 ± 0.15 in control and IDPN groups from day 0 to month 12 and 0.06 ± 0.11 and 0.08 ± 0.16 from month 12 to month 24, respectively. There was no difference between the groups with regard to causes of hospitalization. More than 50% of patients received nutrition support after the 1-year randomized treatment as per the physician's decision. At months 18 and 24, oral supplements were given to 44% and 55% of control subjects and 54% and 50% of IDPN patients, respectively; IDPN was administered in 6% and 9% of control patients and in 13% and 17% of IDPN patients (NS). In both groups, spontaneous intake was stable during the follow-up period. Nutrition support was followed by an increase in body weight at months 3, 6, and 12 in IDPN patients and at month 3 in control subjects. In addition, both groups showed an increase in serum albumin and prealbumin concentrations from day 0 to month 3. Serum albumin levels remained elevated until month 18 and serum prealbumin until the end of the study. Multivariate analysis showed 4 independent predictors of the 2-year mortality: number of comorbidities (odds ratio [OR] = 1.53; 95% confidence interval [CI]: 1.14-2.05 per comorbidity), baseline serum albumin (OR = 0.93; 95% CI: 0.89-0.98 per g/L) and creatinine (OR = 0.98; 95% CI: 0.97-0.99 per 10 µmol/L), and serum prealbumin level increase >30 mg/L from day 0 to month 3 (OR = 0.46; 95% CI: 0.27-0.79). This study did not show whether IDPN truly affects patient outcomes as there was no group that received no nutrition intervention. What the study did show was that IDPN, when added to oral supplements, was no better than oral supplements at affecting outcomes. The authors justly argue that it would be ethically indefensible to have a group that received no nutrition intervention. They also calculated that based on their findings from this study, they would need an impractically large study with a total of 2700 patients to show a difference in mortality. The authors also found that an early increase in serum prealbumin levels during nutrition support independently predicted survival and decreased risk of hospitalization. These data underscore the prognostic value of changes in serum prealbumin concentrations during nutrition support. Diabetes mellitus did not alter the early response to nutrition support but was associated with a less sustained increase in serum albumin level. Patients with diabetes mellitus were characterized by an increased mortality during the second year of follow-up. In patients with diabetes mellitus, the early increase in serum prealbumin level did not predict an improvement of survival in patients. These data are consistent with an earlier report from the same authors which showed that survival of patients with diabetes mellitus was independent of nutrition status.5 From this study, we can infer that there is no advantage in adding IDPN to oral supplements. The question of what should be done with patients who do not tolerate their supplements was not addressed in this study. It seems prudent to propose that such patients should be given enteral nutrition support and, only after failing, be considered for IDPN. This study reaffirms that patients without diabetes mellitus benefit significantly from nutrition supplementation with a dramatic and sustained improvement in nutrition status. Finally, this study provides us with an additional prognostic marker for mortality and hospitalization risk in the form of increase in serum prealbumin levels during nutrition therapy. Praveen Goday, MBBS, CNSP
Contributing Editor—Praveen Goday, MBBS, CNSP Pediatric Gastroenterology and Nutrition, Division of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin
Nutrition in Clinical Practice, Vol. 23, No. 3,
343-344 (2008)
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
|
 |
|
Top
Comment
