Patients are at risk for acute respiratory distress syndrome (ARDS) when they enter the hospital for surgery, and a team of researchers from the Mayo Clinic, as well as University of Texas Southwestern Medical Center and other institutions, are identifying the predictors of patients at highest risk. It is key to identify high-risk patients to prevent ARDS, the leading cause of respiratory failure after surgery, because many who develop the syndrome die or are affected for many years to come.
Currently, methods of prediction are unable to reliably identify patients at risk for ARDS, which is a problem because “[ARDS] is a very common reason for needing an extended course of breathing support after surgery, and approximately 20 to 25 percent of patients who develop the syndrome will die from it,” said Daryl Kor, MD, a Mayo Clinic anesthesiologist, in a press release. “It’s well-documented that those who develop this syndrome stay in intensive care longer and in the hospital longer, and the impact of the syndrome can persist for many years.” The team, led by Dr. Kor, identified nine risk factors that contribute to this lung disorder.
The study was published in Anesthesiology and was a multicenter cohort study. Records of 1,562-at risk patients from 19 hospitals were analyzed, and the team found 117 (7.5%) patients who developed ARDS. Nine independent predictors of ARDS were significant: sepsis, high-risk aortic vascular surgery, high-risk cardiac surgery, emergency surgery, cirrhosis, admission location other than home, increased respiratory rate (20 to 29 and ≥30 breaths/min), fraction of inspired oxygen (FIO2) greater than 35%, and oxygen saturation (SpO2) less than 95%. After identifying these nine factors, the team refined standing risk prediction models to be used in future ARDS prevention studies.
Operating room conduct changes slightly when patients at a higher risk for ARDS are admitted. “For example, we may be a bit more conservative in the way we transfuse blood products. We may also ventilate their lungs in a little different way than we might if their risk score was low,” said Dr. Kor. These measures are intended to prevent death and serious complications post-operation. Added Dr. Kor, “We also hope that by identifying these high-risk patients, we might be able to better select a study population for future studies that look at specific prevention strategies. Before, such studies really weren’t feasible because we couldn’t identify high-risk groups with any degree of accuracy.”
The study was conducted by physicians and researchers from Mayo Clinic in Rochester and Jacksonville, Fla., and from Beth Israel Deaconess Medical Center, Albert Einstein College of Medicine, University of Texas Southwestern Medical Center, Duke University Medical Center, Massachusetts General Hospital, Wake Forest University Health Sciences, Brigham and Women’s Hospital, University of Michigan School of Medicine and St. Joseph Mercy Hospital. The NIH-funded United States Critical Illness and Injury Trials Group collaborated on the study, and support was provided by a career development grant from the Foundation for Anesthesia Education and Research in Rochester; by National Institutes of Health grants U01-HL108712-01, UL1 TR000135 and KL2 TR000136; and by the Mayo Clinic Critical Care Research Committee.