Ventilation strategy using low tidal volumes, recruitment maneuvers, and high positive end-expiratory pressure for acute lung injury and acute respiratory distress syndrome: a randomized controlled trial.
BACKGROUND
Low-tidal-volume ventilation reduces mortality in critically ill patients with acute lung injury and acute respiratory distress syndrome. Instituting additional strategies to open collapsed lung tissue may further reduce mortality.


OBJECTIVE
To compare an established low-tidal-volume ventilation strategy with an experimental strategy based on the original "open-lung approach," combining low tidal volume, lung recruitment maneuvers, and high positive-end-expiratory pressure.


METHODS
Randomized controlled trial with concealed allocation and blinded data analysis conducted between August 2000 and March 2006 in 30 intensive care units in Canada, Australia, and Saudi Arabia.


METHODS
Nine hundred eighty-three consecutive patients with acute lung injury and a ratio of arterial oxygen tension to inspired oxygen fraction not exceeding 250.


METHODS
The control strategy included target tidal volumes of 6 mL/kg of predicted body weight, plateau airway pressures not exceeding 30 cm H2O, and conventional levels of positive end-expiratory pressure (n = 508). The experimental strategy included target tidal volumes of 6 mL/kg of predicted body weight, plateau pressures not exceeding 40 cm H2O, recruitment maneuvers, and higher positive end-expiratory pressures (n = 475).


METHODS
All-cause hospital mortality.


RESULTS
Eighty-five percent of the 983 study patients met criteria for acute respiratory distress syndrome at enrollment. Tidal volumes remained similar in the 2 groups, and mean positive end-expiratory pressures were 14.6 (SD, 3.4) cm H2O in the experimental group vs 9.8 (SD, 2.7) cm H2O among controls during the first 72 hours (P < .001). All-cause hospital mortality rates were 36.4% and 40.4%, respectively (relative risk [RR], 0.90; 95% confidence interval [CI], 0.77-1.05; P = .19). Barotrauma rates were 11.2% and 9.1% (RR, 1.21; 95% CI, 0.83-1.75; P = .33). The experimental group had lower rates of refractory hypoxemia (4.6% vs 10.2%; RR, 0.54; 95% CI, 0.34-0.86; P = .01), death with refractory hypoxemia (4.2% vs 8.9%; RR, 0.56; 95% CI, 0.34-0.93; P = .03), and previously defined eligible use of rescue therapies (5.1% vs 9.3%; RR, 0.61; 95% CI, 0.38-0.99; P = .045).


CONCLUSIONS
For patients with acute lung injury and acute respiratory distress syndrome, a multifaceted protocolized ventilation strategy designed to recruit and open the lung resulted in no significant difference in all-cause hospital mortality or barotrauma compared with an established low-tidal-volume protocolized ventilation strategy. This "open-lung" strategy did appear to improve secondary end points related to hypoxemia and use of rescue therapies.


BACKGROUND
clinicaltrials.gov Identifier: NCT00182195.
Meade
Maureen O
MO
Department of Medicine, McMaster University, Hamilton, Ontario, Canada. meadema@hhsc.ca
Cook
Deborah J
DJ
Guyatt
Gordon H
GH
Slutsky
Arthur S
AS
Arabi
Yaseen M
YM
Cooper
D James
DJ
Davies
Andrew R
AR
Hand
Lori E
LE
Zhou
Qi
Q
Thabane
Lehana
L
Austin
Peggy
P
Lapinsky
Stephen
S
Baxter
Alan
A
Russell
James
J
Skrobik
Yoanna
Y
Ronco
Juan J
JJ
Stewart
Thomas E
TE
D000328:Adult; D000368:Aged; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*; D012720:Severity of Illness Index; D016019:Survival Analysis; D013990:Tidal Volume