A Combined Application Of Nutrition Risk Screening2002and Subjective Global Assessment In Patients Of Cardiac Valvular Replacement

Objective:To investigate the difference and complementarity of Nutrition Risk Screening2002and Subjective Global Assessment applied in patients of cardiac valvular replacement. To pursue one kind of or a set of nutritional screening tool that can validly predict poor clinical outcomes after surgery of patients undergoing cardiac valves replacement.Methods:Using a convenient sampling, a prospective cohort study design,137inpatients who would carry through cardiac valvular replacement underneath cardio pulmonary bypass(CPB) were enrolled from the department of cardiac surgery of a third-grade class-A hospital of Jinan City during July2012to December2013.Their nutritional status was assessed and classified by using NRS2002and SGA respectively within48h of hospital admission. On the basis of serum prealbumin, the sensitivity and specificity of NRS2002and SGA were compared. The correlation between the nutritional risk grade and cardiac function was analysed. Then complications, postoperative mechanical ventilation time and length of hospital were collected and compared during hospitalization. Patients were followed until discharge, hospital death or transfer to another department. Logistic regression and number needed to screen (NNS) were calculated to test the complementarity between the tools and their ability to predict very long length of hospital stay (VLLOS), complications, and death. Results:1. Of the patients screened,54patients (39.4%) were at nutritional risk (NRS+) and45patients (38.9%) were malnourished (SGA-B or SGA-C). The difference between them wasn’t statistically significant by matching χ2test(P=0.064). The kappa was0.701, explaining their percent of contact area was good. Taken Prealbumin (PA)<180mg/L as reference standard, the sensitivity of NRS2002and SGA were88.6%and80.0%and the specificity were77.5%and83.3%respectively.2. By Bivariate correlation it was found:there was significant negative correlation between NRS2002and PA as well as SGA and PA, the former correlation was better than the latter. There was significant positive correlation between NRS2002and cardiac functional grading as well as SGA and cardiac functional grading, correlation coefficient were0.689and0.619respectively.3. The incidence of postoperative complications of NRS+patients and NRS-patients were20.4%and7.2%separately, their mean hospital stays were20.9±5.4d and15.5±2.2d, mean postoperative mechanical ventilation time were28.8±16.0h and10.7±3.4h, all the difference were statistically significant(P<0.05). The incidence of postoperative complications of SGA-A, SGA-B and SGA-C patients were5.4%,20.5%and66.7%respectively, their mean hospital stays were15.6±2.0d,20.4±3.1d and33.4±6.7d, mean postoperative mechanical ventilation time were11.2±4.0h,28.2±14.5h and52.7±9.3h, the difference of each other were statistically significant(P<0.05).There were no significant differences in incidence of complications, mean postoperative mechanical ventilation time and mean length of hospital between the patients with malnutrition by SGA score(SGA-B or SGA-C) and ones with nutritional risk through NRS2002(NRS+)(P>0.05), the difference of postoperative mortality between them wasn’t statistically significant(P>0.05).4. The incidence of postoperative complications of NRS+&SGA-C and NRS+patients were66.7%and20.4%, their mean hospital stays were33.4±6.7d and20.9±5.4d, mean postoperative mechanical ventilation time were52.7±9.3h and28.8±16.0h, each of the difference was statistically significant(P<0.05). The incidence of postoperative complications of NRS+&SGA-B patients and NRS+patients were21.2%and20.4%, mean hospital stays were20.7±3.0d and20.9±5.4d, mean postoperative mechanical ventilation time were30.1±14.5h and28.8±16.0h, all the difference were not statistically significant(P>0.05). Mean hospital stays of NRS+&SGA-B and NRS+&SGA-A were20.7±3.0d and17.0±3.0d, their mean postoperative mechanical ventilation time were30.1±14.5h and15.5±5.1h, all the difference were statistically significant(P<0.05).5. This study found that the number needed to screen (NNT) in order to find out the same number of cases with poor clinical outcomes in different nutritional status was different. When poor clinical outcomes was the postoperative complications, the NNS of NRS+, SGA-B, SGA-C, NRS+&SGA-B and NRS+&SGA-C was respectively5、7、2、7、2; When poor clinical outcomes was VLLOS, the NNS of NRS+, SGA-B, SGA-C, NRS+&SGA-B and NRS+&SGA-C was respectively4、4.2、3、2.Conclusion:The probability of poor clinical outcomes that occurred in patients with nutritional risk or malnutrition before surgery was higher than in patients with normal nutritional status. NRS2002and SGA are applicable to the patients’nutrition screen before surgery. NRS2002mainly reflects the recent or acute changes in nutritional status. Because of surgical stress and the influence of age, the sensitivity of NRS2002is higher while the specificity is lower. SGA focuses on the change of chronic nutritional status, and isn’t conducive to find early malnutrition of patients. So its specificity is higher. The two nutritional screening tool can complenment each other.The concurrent application of SGA in patients with nutritional risk detected by NRS2002within48h of hospital admission is associated with increased ability to predict poor clinical outcomes for these tests, decreasing the risk of underestimating (by exclusive use of SGA) or overestimating (by exclusive use of NRS2002) the incidence of nutritional risk in cardiac valvular replacement, which is associated with poor clinical outcomes.