Delirium symptoms during hospitalization predict long-term mortality in patients with severe pneumonia

Introduction Delirium is common in critically ill patients and impact in-hospital mortality in patients with pneumonia. The aim of the study was to evaluate the prevalence of delirium symptoms during hospitalization in patients with severe pneumonia and their impact on one-year mortality. Methods This was an observational, retrospective, cohort study of consecutive patients admitted to the respiratory high dependency unit of the San Gerardo University Hospital, Monza, Italy, between January 2009 and December 2012 with a diagnosis of severe pneumonia. A search through the charts looking for ten key words associated with delirium (confusion, disorientation, altered mental status, delirium, agitation, inappropriate behavior, mental status change, inattention, hallucination, lethargy) was performed by a multidisciplinary team. The primary endpoint was mortality at one-year follow-up. Secondary endpoint was in-hospital mortality. Results A total of 172 patients were enrolled (78 % males; median age 75 years). At least one delirium symptom was detected in 53 patients (31 %) during hospitalization. The prevalence of delirium symptoms was higher among those who died during hospitalization vs. those who survived (44 vs. 27 %, p = 0.049, respectively). Seventy-one patients (46 %) died during the one-year follow-up. The prevalence of at least one delirium symptom was higher among those who died than those who survived during the one-year follow-up (39 vs. 21 %, p = 0.014, respectively). At the multivariable logistic regression analysis, after adjustment for age, comorbidities and severe sepsis, the presence of at least one delirium symptom during hospitalization was an independent predictor of one-year mortality (OR 2.35; 95 % CI 1.13-4.90; p = 0.023). Conclusions Delirium symptoms are independent predictors of one-year mortality in hospitalized patients with severe pneumonia. Further studies should confirm our results using prospective methods of collecting data.