ARDS Patients More Likely to Survive in High-Volume ICUs

Patients have a better chance of surviving acute respiratory distress syndrome (ARDS) when they’re admitted to high-volume intensive care units (ICUs), according to a study presented at the 2017 American Thoracic Society (ATS) International Conference.

ARDS is a common disease that affects about 10% of patients admitted to ICUs and is associated with a crude ICU mortality ranging from 30% to 40%. It occurs when fluid builds up in the tiny, elastic air sacs in the lungs. The buildup reduces oxygen levels in the bloodstream, which deprives organs of the oxygen they need to function.

“As the management of ARDS patients requires a complex, well organized, and technically sophisticated level of care, we aimed at investigating whether there is or there is not a relationship between patient’s outcomes and case-volume ICUs,” researchers wrote. “A secondary objective was to assess trends in patients’ characteristics, outcomes and management between 2000 and 2014.”

Led by Martin Dres, MD of the AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumonologie et Réanimation Médicale in Paris, France, researchers looked at data for 316,000 ICU stays that took place between 2000 and 2014. They assessed the difference in ARDS severity using the Simplified Acute Physiology Score (SAPS2) scoring method and looked at ARDS-related mortality at low, moderate and high patient volume ICUs.

“Our study is the first to look at a large and regional database that suggests patients with ARDS admitted to centers caring for a large number of people with ARDS may have better prognoses than in centers with a lower case volume,” Dres said.

Overall, Dres and colleagues were able to identify 18,022 ARDS-related ICU stays during the 14-year study period. High volume ICUs (>68 ARDS admissions annually) had 51.5% mortality, moderate volume ICUs (38-67 ARDS admissions annually) had 54% mortality, and low volume ICUs (<37 ARDS admissions annually) had 55.2% mortality rates.

High-volume ICUs also had the shortest periods of patient admittance, with average length of stay clocking in at around 15 days, versus 17 days for moderate-volume ICUs and 18 days for low-volume ICUs.

Notably, researchers found that in the 35 ICUs studied, ICU mortality decreased despite increases in ARDS severity. Over the 14-year trial, severity scores grew from an average of 52 to 58, with 52 representing a 50% mortality rate. However, ICU mortality rates decreased concurrently from 57.9% to 45.5% and hospital mortality decreased as well, from 59.1% to 48.4%.

“Further studies are warranted to confirm and delineate our results and determine whether regionalization of patients with ARDS should be recommended,” Dres said. “We hope our research fuels further discussion regarding global quality of care and global management in the setting of ARDS.”

Read the full American Thoracic Society release.