[Analysis of death risk factors for nosocomial infection patients in an ICU: a retrospective review of 864 patients from 2009 to 2015].

OBJECTIVE: To investigate the mortality risk factors of nosocomial infection patients in intensive care unit (ICU), and to guide clinicians to take effective control measures.

METHODS: A retrospectively cohort study was conducted. The relevant information of patients with nosocomial infection treated in ICU of Hengshui Harrison International Peace Hospital Affiliated to Hebei Medical University from June 2009 to December 2015 was analyzed. The patients who admitted to ICU again, with length of ICU stay less than 48 hours, without first etiology of screening within 48 hours of ICU admission, or without complete pathogenic information were excluded. The gender, age, diagnosis, length of ICU stay, invasive operation, nutritional status, acute physiology and chronic health evaluation II (APACHEII) score, sequential organ failure assessment (SOFA) score, distribution and drug resistance of the pathogens, and procalcitonin (PCT) levels at 7 days after nosocomial infection were recorded. The risk factors leading to death in patients with nosocomial infection were analyzed by logistic regression, and the receiver operating characteristic curve (ROC) was drawn to evaluate the predictive value of all risk factors on the outcome of patients with nosocomial infection.

RESULTS: In 864 enrolled patients with male of 54.75% and mean age of (63.50±15.80) years, 732 (84.72%) patients survived and 132 (15.28%) died. Compared with survivors, the non-survivors had higher age (years: 65.47±15.32 vs. 58.15±13.27), incidence of urgent trachea intubation (32.58% vs. 22.81%), deep venous catheterization (83.33% vs. 63.25%), and multiple drug-resistant infection (65.91% vs. 33.20%), longer length of ICU stay (days: 13.56±4.29 vs. 10.29±4.32) and duration of coma (days: 7.36±2.46 vs. 5.48±2.14), lower albumin (g/L: 23.64±8.47 vs. 26.36±12.84), higher APACHEII score (19.28±5.16 vs. 17.56±5.62), SOFA score (8.55±1.34 vs. 6.43±2.65), and PCT (μg/L: 3.06±1.36 vs. 2.53±0.87, all P < 0.05). There was no significant difference in gender and urinary tract catheterization between survivors and non-survivors (both P > 0.05). The low respiratory tract was the most common site of infection followed by urinary tract and bloodstream in both groups. It was shown by logistic regression analysis that prolonged ICU stay [odds ratio (OR) = 2.039, 95% confidence interval (95%CI) = 1.231-3.473, P = 0.002], APACHEII score (OR = 1.683, 95%CI = 1.002-9.376, P = 0.000), SOFA score (OR = 2.060, 95%CI = 1.208 -14.309, P = 0.041), PCT (OR = 2.090, 95%CI = 1.706-13.098, P = 0.004), and multi-drug resistant pathogens infection (OR = 5.245, 95%CI = 2.213-35.098, P = 0.027) were independent risk factors for ICU mortality in patients with nosocomial infection. The area under ROC curve (AUC) of length of ICU stay, APACHEII score, SOFA score, and PCT level for predicting death of nosocomial infection patients was 0.854, 0.738, 0.786, and 0.849, respectively, the best cut-off value was 16.50 days, 22.45, 6.37 and 3.38 μg/L, respectively, the sensitivity was 83.6%, 90.0%, 81.1%, and 89.6%, and the specificity was 70.3%, 75.6%, 71.3%, and 85.4%, respectively.

CONCLUSIONS: Prolonged ICU stay, nosocomial infection with secondary sepsis and multiple organ dysfunction syndrome were the leading causes of death for nosocomial infection patients in ICU. Prolonged ICU stay, APACHE II score, SOFA score, and PCT level could effectively predict death risks for nosocomial infection patients.