SAN FRANCISCO – The work environment for nurses and the physician staffing model in the intensive care unit influence patients’ likelihood of acquiring ventilator-associated pneumonia (VAP), based on a cohort study of 25 ICUs.
Overall, each 1-point increase in the score for the nurse work environment – indicating that nurses had a greater sense of playing an important role in patient care – was unexpectedly associated with a roughly sixfold higher rate of VAP among the ICU’s patients, according to data reported in a session and press briefing at an international conference of the American Thoracic Society. However, additional analyses showed that the rate of VAP was higher in closed units where a board-certified critical care physician (intensivist) managed and led care rather than an open unit where care is shared.
“We think that the organization of the ICU is actually influencing nursing practice, which is a really novel finding,” commented first author Deena Kelly Costa, PhD, RN, of the University of Michigan School of Nursing in Ann Arbor. “In closed ICUs, when you have a board-certified physician and an ICU team managing and leading care, even if the work environment is better, nurses may not feel as empowered to standardize their care or practice.”
“ICU nurses are the ones who are primarily responsible for VAP preventive practices: they keep the head of the bed higher than 45 degrees, they conduct oral care, they conduct (patient) surveillance. ICU physicians are involved with writing the orders and ventilator setting management. So how these providers work together could theoretically influence the risk for patients developing VAP,” Dr. Costa said.
“We need to be thinking a little bit more critically about not only the care that’s happening at the bedside... but also at an organizational level. How are these providers organized, and can we work together to improve patient outcomes?”
“I’m not suggesting that we get rid of all closed ICUs because I don’t think that’s the solution,” Dr. Costa maintained. “I think from an administrative perspective, we need to be considering what’s the organization of these clinicians and this unit, and [in a context-specific manner], how can we improve it for better patient outcomes? That may be both working on improving the work environment and making the nurses feel more empowered, or it could be potentially considering other staffing models.”
Some data have already linked a more favorable nurse work environment and the presence of a board-certified critical care physician independently with better patient outcomes in the ICU. But studies of their joint impact are lacking.
The investigators performed a secondary, unit-level analysis of nurse survey data collected during 2005 and 2006 in ICUs in southern Michigan.
In all, 462 nurses working in 25 ICUs completed the Practice Environment Scale of the Nursing Work Index, on which averaged summary scores range between 1 (unfavorable) and 4 (favorable). The scale captures environmental factors such as the adequacy of resources for nurses, support from their managers, and their level of involvement in hospital policy decisions.
The rate of VAP during the same period was assessed using data from more than 1,000 patients from each ICU.
The summary nurse work environment score averaged 2.69 points in the 21 ICUs that had a closed physician staffing model and 2.62 points in the 4 ICUs that had an open physician staffing model. The respective rates of VAP were 7.5% and 2.5%.
In adjusted analysis among all 25 ICUs, each 1-point increase in an ICU’s Practice Environment Scale score was associated with a sharply higher rate of VAP on the unit (adjusted incidence rate ratio, 5.76; P = .02).
However, there was a strong interaction between the score and physician staffing model (P less than .001). In open ICUs, as the score rose, the rate of VAP fell (from about 16% to 5%), whereas in closed ICUs, as the score rose, so did the rate of VAP (from about 3% to 14%).
Dr. Costa disclosed that she had no relevant conflicts of interest. The parent survey was funded by the Blue Cross Blue Shield Foundation of Michigan.