Factors influencing weaning from mechanical ventilation in elderly patients with severe pneumonia

The purpose of this study was to determine the factors that adversely affect the weaning of elderly patients with community-acquired pneumonia from mechanical ventilation.

This study retrospectively investigated the medical records of 71 elderly patients (65 years or older) who were admitted to the hospital because of community-acquired pneumonia and required mechanical ventilation between January 2003 and December 2007. The patients were divided into two groups: group A, which included 33 patients who were successfully weaned from mechanical ventilation, and group B, which included 38 patients who could not be weaned from mechanical ventilation. The study compared the patients' background, vital signs, and laboratory and bacteriological examinations at the beginning of mechanical ventilation. A multiple logistic regression analysis was performed to identify the factors associated with difficulties in weaning patients from mechanical ventilation.

In group B, there were significantly more smokers (P < 0.05) and more patients with emphysematous changes on thoracic CT (P < 0.05). In group A, the concentrations of total serum protein (P < 0.05) and albumin (P < 0.05) were significantly higher. A multiple logistic regression analysis revealed that patients with community-acquired pneumonia who showed emphysematous changes on thoracic CT (OR = 4.92, 95%CI 1.08-22.46) and/or a low concentration of serum albumin <3.0 g/dL (OR = 4.25, 95%CI 1.17-15.45) had difficulty being weaned from mechanical ventilation.

Our study suggests that elderly patients with community-acquired pneumonia with emphysematous changes on thoracic CT and/or a low concentration of serum albumin level have difficulty being weaned from mechanical ventilation.