Mortality From Acute Respiratory Distress Syndrome Drops Dramatically

MedicalResearch.com Interview with:
Jared Radbel MD
Staten Island, New York

Medical Research: What are the main findings of the study?

Dr. Radbel: Using ICD 9 coding from the largest all-payer inpatient health care database in the United States, the National Inpatient Sample (NIS) database we identified 174,180 patients with Acute Respiratory Distress Syndrome (ARDS) from 1996-2011.  When expanded to estimate country-wide discharges, our data represents 856,293 patients.  We found a decrease in case fatality rate from 46.8% in 1996 to 32.2% in 2011. This corresponds to an absolute mortality reduction of 14.6% and relative reduction of 31%.

Medical Research: What was most surprising about the results?

Dr. Radbel: The most surprising finding in our study was the sharp decline in mortality from 2000-2005.  Over this time frame we found an absolute reduction in case fatality rate of 8.9%.  While mortality had been trending downward from 1996-2000, there was a statistically significant drop in mortality beginning in 2000.  Then in 2005, the decrease in mortality returned to its pre-2000 trend.  The ARDS Clinical Trials Network’s groundbreaking study, “Ventilation with lower tidal volumes as compared with traditional tidal 
volumes for acute lung injury and the acute respiratory distress syndrome,” published in 2000, demonstrated an absolute mortality reduction of 8.8%.  This absolute decrease is almost identical to the drop we discovered from 2000-2005.

Medical Research: What should clinicians and patients take away from your report?

Dr. Radbel: In the largest study to examine mortality trends in ARDS from 1996-2011, we demonstrate a clear decline in Acute Respiratory Distress Syndrome mortality.  Our study helps resolve discrepancies found in previous large meta-analyses studying ARDS mortality in similar timeframes.  We believe that collaborative advances in critical care medicine contributed to the overall decline. However, we assert that the sudden and sharp decrease in mortality from 2000-2005 may be attributed to low tidal volume ventilation.  Our results validate the changes that have been made to managing ARDS over the past couple of decades.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Radbel: I would recommend future studies examining the trends in mortality from ARDS after 2011.  It would be interesting to see if  current and future advances in the treatment of Acute Respiratory Distress Syndrome continue to improve survival from this often difficult to treat syndrome.

Citation:

CHEST 2014 abstract:

American College of Chest Physicians.
Dramatic decline in mortality rates for acute respiratory distress syndrome.