“Diffusion index”used to evaluate the prognosis of ARDS / 中华急诊医学杂志

ABSTRACT

Objective To propose the concept of “Diffusion Index”to replace Oxygenation Index as independent indicators to evaluate prognosis on ARDS patients under mechanical ventilation treatments,and comparison carried out between them preliminarily.Methods Calculation of “1 000 × (PaO2 /FiO2 /PEEP)”was taken as “Diffusion Index”.A total of 130 ARDS patients under mechanical ventilation support (MVS)were admitted to Peking Union Medical College Hospital ICU from July 2013 to July 2014.The data of these patients were retrospectively analyzed.Of them,15 patients were excluded because these patients refused invasive ventilation support.Respirator parameter setting and haemogas figures were recorded accordingly. Both Diffusion Index and Oxygenation Index were used separately to predict detachment of MVS from patients in 28 days,and the correlation between these two indexes and ARDS prognosis were determined.Results According to the outcomes of patients in 28 days,patients were divided into 3 groupsdetached group (n =44),failed to detach group (n =14)and death group (n =57).There was obvious difference in trend diagrams observed among three groups between diffusion index and oxygenation index.COX regression analysis of survival curve demonstrated that if Diffusion Index kept greater than 405.8,probability of detachment of MVS from patients was higher and the correlation was significant (P =0.009 ).Conclusions Compared with Oxygenation Index,“Diffusion Index” is a comprehensive indicator for ARDS prognosis with better reliability and validity.