Key Point

Researchers have recently found that certain cytokines are predictive of progression from hospital-acquired pneumonia to sepsis and septic shock.

BERLIN—Why do some postsurgical patients with hospital-acquired pneumonia (HAP) develop septic shock while others do not? A team of German researchers postulated that immune parameters differ between patients at diagnosis of pneumonia—before septic shock develops. They also considered the possibility that these parameters predict progression from pneumonia to septic shock.¹

The study included 76 ICU patients, all of whom had undergone surgery. Patients were assigned to one of two groups: HAP without septic shock or HAP that progressed to septic shock. Blood samples were collected at HAP diagnosis and measured for levels of immune mediators. In those who developed septic shock, blood samples were also taken within the first 12 hours of onset of shock and again at 72 to 96 hours.

Routine laboratory parameters were measured twice daily. Patient characteristics were documented, as well as APACHE III and multiple organ failure (MOF) scores. In the patients who developed septic shock, a pulmonary artery catheter was used for cardiovascular monitoring.

Routine laboratory parameters were measured twice daily. Patient characteristics were documented, as well as APACHE III and multiple organ failure (MOF) scores. In the patients who developed septic shock, a pulmonary artery catheter was used for cardiovascular monitoring.

AN INCREASED IMMUNE RESPONSE

Twenty-nine patients with HAP developed septic shock. Not surprisingly, the progression from HAP to septic shock was accompanied by a significant increase in APACHE III and MOF scores, as well as in leukocyte levels.

At diagnosis of HAP, levels of tumor necrosis factor a (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8, IL-10, and E-selectin were all elevated in patients who later developed septic shock. During late septic shock (72 or more hours after diagnosis), however, TNF-α, IL-1β, IL-6, and E-selectin all decreased.

According to the authors, the most important result of this study was the detection of an increased immune response in patients at the onset of HAP in those patients who progressed to septic shock.

“My personal opinion is that sepsis could be prevented in some patients if we intervene early enough,” said Claudia D. Spies, MD, Head of the Departments of Anesthesiology and Intensive Care Medicine at the University of Medicine in Berlin. “I also think that it is not difficult to predict risk in ICU patients—not only using biomarkers, but clinical data as well. However, these data must be reproduced in other hospitals to be sure that the risk prediction value of these parameters is really a useful tool in clinical practice,” stressed Dr. Spies. “Hospital-acquired pneumonia is our most frequent diagnosis of infection in critically ill patients after surgery, whereas other nosocomial infections are not that frequent and have not yet been investigated. This has been the focus of our research group within the last years,” she pointed out.

—Gale Jurasek

Reference
1. von Dossow V, Rotard K, Redlich U, et al. Circulating immune parameters predicting the progression from hospital-acquired pneumonia to septic shock in surgical patients. Crit Care. 2005;9:R662-R669.

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