The Impact of Macro-and Micronutrients on Predicting Outcomes of Critically Ill Patients Requiring Continuous Renal Replacement Therapy

Abstract

Critically ill patients with acute kidney injury (AKI) who receive renal replacement therapy (RRT) have very high mortality rate. During RRT, there are markedly loss of macro- and micronutrients which may cause malnutrition and result in impaired renal recovery and patient survival. We aimed to examine the predictive role of macro- and micronutrients on survival and renal outcomes in critically ill patients undergoing continuous RRT (CRRT). This prospective observational study enrolled critically ill patients requiring CRRT at Intensive Care Unit of King Chulalongkorn Memorial Hospital from November 2012 until November 2013. The serum, urine, and effluent fluid were serially collected on the first three days to calculate protein metabolism including dietary protein intake (DPI), nitrogen balance, and normalized protein catabolic rate (nPCR). Serum zinc, selenium, and copper were measured for micronutrients analysis on the first three days of CRRT. Survivor was defined as being alive on day 28 after initiation of CRRT.Dialysis status on day 28 was also determined. Of the 70 critically ill patients requiring CRRT, 27 patients (37.5%) survived on day 28. The DPI and serum albumin of survivors were significantly higher than non-survivors (0.8± 0.2 vs 0.5 ±0.3g/kg/day, p = 0.001, and 3.2±0.5 vs 2.9±0.5 g/dL, p = 0.03, respectively) while other markers were comparable. The DPI alone predicted patient survival with area under the curve (AUC) of 0.69. A combined clinical model predicted survival with AUC of 0.78. When adjusted for differences in albumin level, clinical severity score (APACHEII and SOFA score), and serum creatinine at initiation of CRRT, DPI still independently predicted survival (odds ratio 4.62, p = 0.009). The serum levels of micronutrients in both groups were comparable and unaltered following CRRT. Regarding renal outcome, patients in the dialysis independent group had higher serum albumin levels than the dialysis dependent group, p = 0.01. In conclusion, in critically ill patients requiring CRRT, DPI is a good predictor of patient survival while serum albumin is a good prognosticator of renal outcome.

Energy and Protein in Critically Ill Patients with AKI: A Prospective, Multicenter Observational Study Using Indirect Calorimetry and Protein Catabolic Rate

“…However, excluding measurements obtained during fluid overload, the results were unchanged (all patients, patients not needing RRT, and patients undergoing RRT). Normalized PCR of 1.5–2.1 g/kg/day have been obtained by the urea kinetic method in small groups of patients with AKI on different modalities of RRT [ 10 , 17 , 18 , 19 , 20 , 21 ]. However, different BW were considered for protein intake normalization in these studies.…”

“…However, different BW were considered for protein intake normalization in these studies. In two studies the lowest BW measured during ICU stay was used [ 19 , 21 ], in another the actual BW [ 20 ], and in the remaining 3 studies no information was available on which was the reference BW [ 10 , 17 , 18 ]. Even Guidelines not always clearly specify which BW should be considered for protein needs estimation in critically ill patients with AKI (23–24).…”

“…Thus, the use of different BW could explain most of the differences in protein needs estimation, underlying the importance to obtain PCR in critically ill patients. As a matter of fact, recent studies suggest that adequate protein intake correlates to better outcomes in critically ill [ 26 , 41 , 42 , 43 ] and AKI patients [ 21 ]; in addition, negative nitrogen balance was identified as a predictor of death in AKI patients [ 44 ].…”

“…Moreover, data on their validity when applied to patients with AKI are scanty [ 16 ]. Regarding proteins, while PCR of patients on RRT has been investigated in the past by urea kinetic methods [ 10 , 17 , 18 , 19 , 20 , 21 ], no data are currently available on PCR in patients with AKI not on RRT.…”

Glutamina y antioxidantes en pacientes críticos con lesión renal aguda en terapia de reemplazo renal

“…En un estudio reciente en pacientes críticos con lesión renal aguda en TRRC se concluyó que los niveles séricos de antioxidantes no influyeron sobre la mortalidad, estancia prolongada tanto en la unidad de cuidados intensivos como hospital, y en duración de la TRR 8 . Oh y Cols.…”