By Will Boggs, MD
Transfusion factors and patient characteristics contribute to the risk of acute lung injury (ALI) following blood transfusions in critically ill patients, according to a report in the November 1st issue of the American Journal of Respiratory and Critical Care Medicine.
"Critically ill patients, their families, and physicians need to be aware that life support therapies such as blood transfusions or ventilators, while often necessary and life-saving, are not without risks," Dr. Ognjen Gajic told Reuters Health. "Our study suggests that specific transfusion factors have an important role in many critically ill patients who develop acute lung injury in the intensive care unit."
Dr. Gajic and colleagues from the Mayo Clinic College of Medicine, Rochester, Minnesota investigated the incidence, risk factors, and outcome of ALI that develops within 6 hours after the transfusion of blood products in patients admitted to the medical ICU.
Seventy-four of 901 patients (8%) developed ALI within 6 hours of transfusion, the authors report.
Patients with sepsis, liver disease, and a history of chronic alcohol abuse were more likely than other patients to develop ALI, as were patients who received plasma-rich blood products, blood products from female donors, and larger volumes of plasma from female donors.
Donors to patients who subsequently developed ALI had a higher number of pregnancies and tested positive for anti-leukocyte antibodies more often than donors to patients who did not develop ALI.
IL-8 concentrations and storage age of red blood cell products did not differ between patients who developed ALI and matched controls, the investigators say, but the concentration of lysophosphatidylcholine was significantly higher in blood products given to ALI case subjects than to control subjects.
Hospital mortality was significantly higher in patients who developed ALI (41%) than in matched controls (23%).
"The association between specific donor and transfusion characteristics and subsequent development of ALI has important implications relative to both the etiology and prevention of this syndrome," the investigators conclude.
"If the true incidence of this syndrome is even half of that estimated by this study, the associated morbidity and mortality occurring in the more than 4 million estimated recipients of blood products each year is enormous," write Dr. Timothy R. Watkins from the University of Washington, Seattle, Washington and Dr. Avery B. Nathens from University of Toronto, Ontario, Canada in a related editorial.
"Future studies should focus on other at-risk cohorts, including those with severe trauma, sepsis, and GI-related hemorrhage," the editorial concludes.
"Mayo Clinic is a part of an ongoing (year 2 out of 5) NIH-funded collaborative study with the University of California, San Francisco, designed to comprehensively address the incidence and mechanisms of transfusion-related acute lung injury among all patients exposed to transfusion (major surgery, trauma; not only medical critically ill patients as in our previous study)," Dr. Gajic said. "This research will allow for better understanding of underlying mechanisms and for development of novel strategies for prevention of acute lung injury and its consequences."
Am J Respir Crit Care Med 2007;176:886-891,839-840.
