Inflammation, Cardiovascular Function and Weaning From Mechanical Ventilation

Mechanical ventilation is one of the most common interventions used to support critically ill patients. Up to one third of ventilated patients have difficulty establishing and maintaining independent spontaneous ventilation after a period of mechanical ventilation. Mechanical ventilation produces inflammation and inflammatory mediators are associated with cardiovascular dysfunction. Because cardiovascular instability is one mechanism that produces weaning failure, the effect of inflammation on cardiovascular function and subsequent weaning ability in ventilated patients requires study. Thus, the purpose of this study is to evaluate the effect of inflammation and cardiovascular function on ventilator weaning outcome. This study will use a predictive correlational design and non-probability sample of 60 ventilated medical intensive care patients. Data will be collected on study entry as the patient receives mechanical ventilation and during the initial pressure support weanmg tri al. Demographics, clinical status, inflammatory biomarkers and cardiovascular function measures will be made at the 2 time points. Repeated measures ANOV A will determine whether cardiovascular variables or inflammatory biomarkers differ by group (weaning success and failure) and across time (baseline and at end of weaning trial). Correlation coefficients will evaluate the association between cardiac function and inflammatory biomarkers. Logistic regression will evaluate the predictive power of inflammatory biomarkers and cardiovascular function for weaning success. This investigation will provide information about the role of inflammation and cardiovascular function in the ability to wean from mechanical ventilation.