Development Of Mathematical Model And Metabonomic Study Of Blood Plasma For ICU Patients With Delirium

Objective To investgate the risk factors of the delirium and metabonomic study of blood plasma for ICU patients with delirium.Methods Our retrospective study included 223 patients(derivation group)who admitted to intensive care unit from September 2014 to January 2016 at Department of Critical Care Medicine,Yijishan Hospital,Wannan Medical College.The simplified Chinese version of the confusion assessment method(CAM-ICU)was administered to assess the patient twice a day.Multivariable logistic regression analysis was used to identify risk factors of delirium in ICU.A mathematical model was developed,and its reliability to predict delirium in ICU was assessed in 81patients(validation group)who admitted to intensive care unit from February 2016 to September 2016,the clinical data of validation group was prospectively collected.1H NMR analysis were performed to acquire the serum metabolic profiles between 18 deliriun patients and not deliriun patient.Results A total of 304 patients were included in this study.There were 233 patients in the derivation group and 81 patients in the validation group.Sixty four patients developed ICU delirium with incidence of 21.1%.Multivariable logistic regression analysis demonstrated six independent risk factors for ICU delirium:history of hypertension(RR=4.367;P = 0.020),hyoxemia(RR=3.382;P =0.018),use of benzodiazepines(RR=5.503;P=0.013),deep sedation(RR=3.339;P=0.048),infection(RR=3.480;P = 0.008)and mechanical ventilation(RR=3.547;P =0.037)in derivation group.The mathematical model predicted ICU delirium with an accuracy of0.862(P<0.001)in derivation group and 0.739(P<0.001)in validation group.There was no significant difference between predicted and observed cases of ICU delirium in the validation group.(P>0.05).Metabonomic analysis indicated that,compared with delirium group,blood concentrations of valine,leucine,alanine and acetoacetate increased significantly,while those of citrate decreased in not delirium group.Those metabolites were associated with amino acid metabolism,tricarboxylic acid and ketonebodies metabolism.Conclusions 1.The mathematical model is reliable for predicting development of ICU delirium.2.Amino acid metabolism,tricarboxylic acid and ketonebodies were disturbed in ICU patients with delirium.