Ventilation strategies for patients with acute respiratory distress syndrome (ARDS) continue to be debated. However, a systematic review and meta-analysis, published recently in the journal Scientific Reports (2016;6:22855), appears to have identified the optimal technique.
The study was overseen by Enyou Li, MD, PhD, professor of anesthesiology in the Department of Anesthesiology at First Affiliated Hospital, Harbin Medical University, Harbin, China.
Analysis and Conclusions
“Thirty-six randomized controlled trials were included for meta-analysis, with a total of 6,685 patients randomized to receive one of the 26 ventilation strategies,” the researchers explained. “Compared with traditional meta-analysis, we subdivided the ventilation strategies into 26 ventilation strategies: different ventilation modes; same ventilation mode with different parameter settings; same ventilation mode and same parameter settings with different parameter value; and same ventilation mode and same parameter settings with different operational techniques.”
The reviewers analyzed direct and indirect evidence to compare the currently applied invasive mechanical ventilation strategies with respect to all-cause mortality in ARDS patients. They found that certain ventilation strategies—higher tidal volumes with fraction of inspired oxygen (FiO2)-guided lower positive end-expiratory pressure (PEEP), pressure-controlled ventilation with FiO2-guided lower PEEP, and lower tidal volumes with FiO2-guided lower PEEP and prone positioning—were associated with reduced mortality in these patients. The first of these strategies—higher tidal volumes with FiO2-guided lower PEEP—proved optimal.
“Permissive hypercapnia, recruitment maneuver, and low airway pressures were most likely to be the worst in terms of all-cause mortality. Compared with higher tidal volumes with FiO2-guided lower PEEP, pressure-controlled ventilation with FiO2-guided lower PEEP and lower tidal volumes with FiO2-guided lower PEEP and prone positioning ventilation are associated with lower mortality in ARDS patients,” the authors explained. First author Dr. Li did not respond to several requests for comment.
OK, but …
“The National Institutes of Health ARDSNet trial [N Engl J Med 2000;342:1301-1308] was the most compelling randomized, multicenter, controlled trial,” explained James Stoller, MD, MS, a pulmonologist and chair of the Education Institute at the Cleveland Clinic, which participated in the trial.
“The results support the use of 6 mL/kg tidal volume, based on ideal body weight. This is the strength of the literature, not just local anecdotal experience,” Dr. Stoller added. “Yet adoption of this experience is still incomplete in patients with acute lung injury or ARDS. Getting this across would have high impact, as the intervention was associated with a 28% survival benefit in the ARDSNet trial,” Dr. Stoller said in an interview with Anesthesiology News.
Dr. Stoller also holds the Jean Wall Bennett Professorship in Emphysema Research at the Cleveland Clinic Lerner College of Medicine.