Nitrogen Balance And Protein Needs Of Critically Ill Patients Complicated With Proteins-Energy Wasting During Continuous Blood Purification Therapy

Objective To observate the nitrogen balance and protein needs by estimating the protein equivalent of nitrogen appearance of critically ill patients complicated with Proteins–Energy Wasting(PEW) during continuous blood purification therapy(CBPT).Method A descriptive study setting in a 12-bed medical intensive care unit(MICU) and a 9-bed surgical intensive care unit(SICU) in The First Affiliated Hospital of GuangXi Medical University. 92 patients treated with CBPT in the period of July,2008 to June,2009 were collected and divided into two groups by the PEW diagnosis based on the proposal of International Society of Renal Nutrition and Metabolism. Patients complicated with PEW during CBPT were in PEW group( n=52), the others in Control group (n=41). Using Leucine to draw the standard curve of amino acid and the concentrations of amino acid in the effluent were measured by Ninhydrin reaction hourly. To detect Urinary Nitrogen Appearant rate(UNA) 24-hour urine,drainage fluid and effluent were collected during CBPT day. Detecting concentrations of urinary nitrogen by Hitachi 7170 biochemical analyzer and Calculating the protein equivalent of nitrogen appearance(PNA) using Bergstr?m equation.Non-CBPT day's nitrogen balance and protein needs were used as Self-control.Rcording the basic information,nutritional implementation,and prognosis of the patients. Using SPSS13.0 software for statistical analysis.Results The UNA was 9.05±1.63g/d in PEW group,5.24±1.96g/d in Control group,P<0.05; The PNA was 69.90±12.06g/d in PEW group,52.81±13.42g/d in Control group,P<0.05; The estimated pretain needs was 84.2±12.7g/d in PEW group, 67.5±13.1g/d in Control group,P < 0.05;The UNA,PNA,and estimated pretain needs in PEW group are higher than the Control group. There is no statistically significant difference between two groups'nitrogen balance cumulatively(-42.29±11.68g vs. -40.04±10.77g,P=0.393) or daily( -10.29±2.00g/d vs.-9.98±2.40g/d,P=0.351). The mortality rate in ICU was 70.5% in PEW group,39.0% in control group, P<0.05; But there were no significant differences in the Kaplan-Meier survival curves between the two groups.Conclusions Critically ill patients complicating with PEW had a higher 24-hour UNA and protein needs than the others during CBPT days.