Risk factors for nosocomial nontraumatic coma: sepsis and respiratory failure.

Background: Coma's are a major cause of clinical deterioration or death. Identification of risks that predispose to coma are important in managing patients; however, the risk factors for nosocomial nontraumatic coma (NNC) are not well known. Our aim was to investigate the risk factors in patients with NNC.

Methods: A retrospective case-control design was used to compare patients with NNC and a control group of patients without coma in a population-based cohort of 263 participants from the neurological intensive care unit in Shuyang County People's Hospital of Northern China. Coma was diagnosed by a Glasgow Coma Scale score ≤8. Adjusted odds ratios for patients with NNC were derived from multivariate logistic regression analyses.

Results: A total of 96 subjects had NNC. The prevalence of NNC was 36.5% among the subjects. Among these, 82% had acute cerebrovascular etiology. Most of the NNC usually occurred at day 3 after admission to the neurological intensive care unit. Patients with NNC had higher hospital mortality rates (67.7% vs 3%, <0.0001) and were more likely to have a central herniation (47.9% vs 0%, <0.001) or uncal herniation (11.5% vs 0%, <0.001) than those without NNC. Multiple logistic regression showed that systemic inflammatory response syndrome-positive sepsis (odds ratio =4, 95% confidence interval =1.875-8.567, <0.001) and acute respiratory failure (odds ratio =3.275, 95% confidence interval =1.014-10.573, <0.05) were the factors independently associated with a higher risk of NNC.

Conclusion: Systemic inflammatory response syndrome-positive sepsis and acute respiratory failure are independently associated with an increased risk of NNC. This information may be important for patients with NNC.