Clinicians' approaches to mechanical ventilation in acute lung injury and ARDS.
OBJECTIVE
To examine clinicians' approaches to mechanical ventilation in patients with acute lung injury (ALI; PaO(2)/fraction of inspired oxygen [FIO(2)] <or= 300) and compare ventilator settings in patients with ARDS (PaO(2)/FIO(2) <or= 200) to settings in patients with milder oxygenation impairment (PaO(2)/FIO(2) of 201 to 300).


METHODS
Retrospective analysis of baseline data from prospective randomized trials conducted by the National Institutes of Health ARDS Network between 1996 and 1999.


METHODS
Ten clinical centers comprising 24 hospitals and 74 medical and surgical ICUs of the ARDS Network.


RESULTS
The most common mode of mechanical ventilation in both groups was volume-assist control (56%). Synchronized intermittent mandatory ventilation (SIMV) or SIMV with pressure support was used more often in patients with PaO(2)/FIO(2) of 201 to 300 than in patients with ARDS. The use of pressure-control ventilation was uncommon (10% overall), as was the use of permissive hypercapnia (6% of patients with ARDS and 3% of patients with PaO(2)/FIO(2) of 201 to 300). The mean +/- SD tidal volume was 10.3 +/- 2 mL/kg of predicted body weight or 8.6 +/- 2 mL/kg of measured weight for patients with ARDS, and was not significantly different for patients with PaO(2)/FIO(2) of 201 to 300. Plateau pressures (Pplats) were lower in the PaO(2)/FIO(2) of 201 to 300 group (27 +/- 7 vs 31 +/- 8 for the ARDS group; p = 0.0003) and were > 35 cm H(2)O in 26% of patients. Seventy-eight percent of patients with ARDS received <or= 10 cm H(2)O of positive end-expiratory pressure.


CONCLUSIONS
Physicians in ARDS Network centers caring for patients early in the course of ALI/ARDS used volume-targeted ventilation and selected tidal volumes that resulted in Pplats generally < 35 cm H(2)O. The average tidal volume was similar for patients with ARDS vs those with milder oxygenation deficits.
Thompson
B T
BT
Pulmonary and Critical Care Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. tthompson1@partners.org
Hayden
D
D
Matthay
M A
MA
Brower
R
R
Parsons
P E
PE
D000403:Airway Resistance; D002245:Carbon Dioxide / Q000097:blood; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008170:Lung Compliance; D015337:Multicenter Studies as Topic; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration; D016032:Randomized Controlled Trials as Topic; D012121:Respiration, Artificial / Q000379:methods* / Q000706:statistics & numerical data; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D013990:Tidal Volume
D002245:Carbon Dioxide; D010100:Oxygen