Minimizing Sedation and Early Mobilization
Deep sedation has repeatedly been associated with a higher risk for pneumonia, prolonged mechanical ventilation, delirium, and death.[32–34] Amongst 703 patients admitted to 42 ICUs, for example, there was a stepwise association between depth of sedation and more time to extubation, more delirium, and higher 180-day mortality risk. Similarly, immobility may lead to deconditioning, atelectasis, difficulty clearing secretions, and pneumonia. While most observational studies do adjust for patients' presenting conditions and severity of illness, it is difficult to disentangle the specific effects of sedation and immobility versus underlying disease on the ultimate risk of pneumonia, duration of mechanical ventilation, and mortality in observational analyses. It is therefore critical to evaluate the results of active intervention studies designed to reduce sedation and encourage mobilization to understand the true magnitude of their potential impact on nosocomial pneumonia, duration of ventilation, and mortality. Intervention studies not only assess the impact of these strategies on patient outcomes, but also lend insight into the practical feasibility of limiting sedation or mobilizing critically ill patients.
Reassuringly, the balance of studies suggests that protocols to limit sedation and mobilize patients are associated with less time to extubation, more hospital-free days, and possibly with lower VAP rates.[37–40] There is no clear mortality signal in randomized trials of sedation or mobility protocols, but some implementation studies have reported lower mortality rates, particularly with high adherence to integrated sedation and mobility bundles (although these observations are at risk of confounding as high bundle performance rates may be more feasible in less ill patients).[39–43]
One challenge in applying the evolving literature on sedation, mobility, and liberation from mechanical ventilation is that most studies of these interventions do not include HAP, VAP, or ventilator-associated events amongst their outcomes. This limits our capacity to directly relate lighter sedation and higher mobility to lower pneumonia rates. Nonetheless, the ultimate purpose in implementing prevention practices in the ICU is not to prevent VAP, HAP, or ventilator-associated events per se but to improve patient-centered outcomes. The emphasis then of sedation and mobility studies on time to extubation, ICU discharge, survivors' quality of life, and short- and long-term mortality is informative even in the absence of specific data on pneumonia.
Semin Respir Crit Care Med. 2019;40(4):548-557. © 2019 Thieme Medical Publishers