Pulmonary Disease - Volume 15, Part 3, December 2014

6 and 8 mL/kg of predicted body weight and PEEP
to FIO2 ratios consistent with the ARDS Network
low PEEP protocol is likely a safe and effective
strategy for the vast majority of intubated patients
with significant risk factors for developing ARDS.

IMPACT OF IMPROVED SUPPORTIVE CARE

A recent population-based, case-control study
from the Mayo Clinic in Rochester, Minnesota,
identified multiple potential hospital exposures re-
lated to the development of ARDS.108 Unique to this
study, patients were carefully matched by baseline
risk factors for developing ARDS, including their
LIPS score. Also, exposures were identified in a
blinded fashion and the screening window for risk
factor exposure was limited to the time from admis-
sion to 6 hours before developing ARDS both for
cases and an equivalent time period for controls. In
this rigorous design, inadequate empiric antimicro-
bials, hospital-acquired aspiration, transfusion of
blood products, and higher tidal volumes were par-
ticularly highly associated with developing ARDS.
Over the 10-year study period, there was a sig-
nificant decline in rates of exposures to these risk
factors that correlated with a marked decline in the
incidence of ARDS (Figure 4).109 Importantly, this
decline was due entirely to a decline in what the
study investigators identified as hospital-acquired
ARDS, without a drop in the number of patients
presenting to hospital with ARDS. The changes
implemented to improve standardization of care
at the Mayo Clinic included: implementation of

Figure 4. Declining incidence of hospital-acquired ARDS in Olmstead County. Trends in (A) incidence of community-acquired acute respiratory distress syndrome (ARDS) and (B) hospital-acquired ARDS from 2001–2008 in Olmsted County, Minnesota; dotted lines represent 95% confidence intervals. ALI = acute lung injury. (Adapted with permission from Li G, Malinchoc M, Cartin-Ceba R, et al. Eight-year trend of acute respiratory distress syndrome: a population-based study in Olmsted County, Minnesota. Am J Resp Crit Care Med 2011;183:59-66. Courtesy of the American Thoracic Society. Copyright 2012 American Thoracic Society.)