N Engl J Med. 2008 Nov 13;359(20):2095-104. Epub 2008 Nov 11.
Talmor D, Sarge T, Malhotra A, O’Donnell CR, Ritz R, Lisbon A, Novack V, Loring
SH.
Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess
Medical Center, Boston 02215, USA. dtalmor@bidmc.harvard.edu
BACKGROUND: Survival of patients with acute lung injury or the acute respiratory
distress syndrome (ARDS) has been improved by ventilation with small tidal
volumes and the use of positive end-expiratory pressure (PEEP); however, the
optimal level of PEEP has been difficult to determine. In this pilot study, we
estimated transpulmonary pressure with the use of esophageal balloon catheters.
We reasoned that the use of pleural-pressure measurements, despite the technical
limitations to the accuracy of such measurements, would enable us to find a PEEP
value that could maintain oxygenation while preventing lung injury due to
repeated alveolar collapse or overdistention. METHODS: We randomly assigned
patients with acute lung injury or ARDS to undergo mechanical ventilation with
PEEP adjusted according to measurements of esophageal pressure (the
esophageal-pressure-guided group) or according to the Acute Respiratory Distress
Syndrome Network standard-of-care recommendations (the control group). The
primary end point was improvement in oxygenation. The secondary end points
included respiratory-system compliance and patient outcomes. RESULTS: The study
reached its stopping criterion and was terminated after 61 patients had been
enrolled. The ratio of the partial pressure of arterial oxygen to the fraction of
inspired oxygen at 72 hours was 88 mm Hg higher in the esophageal-pressure-guided
group than in the control group (95% confidence interval, 78.1 to 98.3; P=0.002).
This effect was persistent over the entire follow-up time (at 24, 48, and 72
hours; P=0.001 by repeated-measures analysis of variance). Respiratory-system
compliance was also significantly better at 24, 48, and 72 hours in the
esophageal-pressure-guided group (P=0.01 by repeated-measures analysis of
variance). CONCLUSIONS: As compared with the current standard of care, a
ventilator strategy using esophageal pressures to estimate the transpulmonary
pressure significantly improves oxygenation and compliance. Multicenter clinical
trials are needed to determine whether this approach should be widely adopted.
(ClinicalTrials.gov number, NCT00127491.) 2008 Massachusetts Medical Society