Abstract: Ｏｂｊｅｃｔｉｖｅ：To investigate association of shortterm change of hematocrit (HCT) ，mean platelet volume (MPV) with variation of volume status evaluated by bioimpedance analysis (BIA) in critically ill patients and their outcome.
Ｍｅｔｈｏｄｏｌｏｇｙ：Patients admitted to intensive care unit(ICU) of Jinling hospital from November 2020 to May 2021 were screened for enrollment. Patients with repeated measurements of BIA on the first and the third day of admission were enrolled, the total body water (TBW), extracellular water (ECW), intracellular water (ICW) obtained from BIA measurements were collected,and blood cell volume related indicators were collected. Bioelectrical impedance vector analysis (BIVA) was used for capacity grouping. The correlation between change rate of BIA volume index with change rate of blood cell volume were performed. The patients were divided into three groups according to the quartile and three quartile of the change rate. The prognosis of different group and combined scoring were anglyed with 90 days death as the end point.
Ｒｅｓｕｌｔｓ：A total of 198 patients were selected, including 137 males and 132 highvolume patients. The 90day mortality rate was 308％.The change rates of HCT and PCT had a low correlation with TBW, ECW and ICW, and the correlation coefficients were higher in the nonhigh volume group. KaplanMeier survival analysis showed a significant difference of survival rate between groups divided by change rate of HCT and MPV. The increased group had the highest death rate. A combination score integrated the change rate of HCT and MPV was found significantly linearly correlated with the overall mortality and the mortality (prediction equation: Y=0102X+0156,R2=0931,P=0008). COX multivariate regression analysis showed that the combination score was an independent risk factor for 90day mortality (HR 1322,95％CI 1068～1637,P=0010).
Ｃｏｎｃｌｕｓｉｏｎ：The dynamic changes of HCT, PCT and MPV have a certain correlation with the changes of BIA capacity index;Greater shortterm fluctuation of HCT and MPV (especially uprise) was correlated with the poor prognosis in critically ill patients; The combination score integrated the change rate of HCT and MPV is an independent risk factor for predicting the 90day mortality.