Efficacy and adverse events of high-frequency oscillatory ventilation in adult patients with acute respiratory distress syndrome: a meta-analysis

Abstract

IntroductionTheoretically, high-frequency oscillatory ventilation (HFOV) achieves all goals of a lung-protective ventilatory mode and seems ideal for the treatment of adult patients with acute respiratory distress syndrome (ARDS). However, its effects on mortality and adverse clinical outcomes remain uncertain given the paucity of high-quality studies in this area. This meta-analysis was performed to evaluate the efficacy and adverse events of HFOV in adults with ARDS.MethodsWe searched PubMed, EMBASE and Cochrane Central Register of Controlled Trials through February 2014 to retrieve randomized controlled trials of HFOV in adult ARDS patients. Two independent reviewers extracted data on study methods, clinical and physiological outcomes and adverse events. The primary outcome was 30-day or hospital mortality. Risk of bias was evaluated with the Cochrane Collaboration’s tool. Mortality, oxygenation and adverse effects of HFOV were compared to those of conventional mechanical ventilation. A random-effects model was applied for meta-analysis.ResultsA total of five trials randomly assigning 1,580 patients met inclusion criteria. Pooled data showed that HFOV significantly improved oxygenation on day one of therapy (four studies; 24% higher; 95% confidence interval (CI) 11 to 40%; P <0.01). However, HFOV did not reduce mortality risk (five studies; risk ratio (RR) 1.04; 95% CI 0.83 to 1.31; P = 0.71) and two early terminated studies suggested a harmful effect of HFOV in ARDS (two studies; RR 1.33; 95% CI 1.09 to 1.62; P <0.01). Safety profiles showed that HFOV was associated with a trend toward increased risk of barotrauma (five studies; RR 1.19; 95% CI 0.83 to 1.72; P = 0.34) and unfavorable hemodynamics (five studies; RR 1.16; 95% CI 0.97 to 1.39; P = 0.12).ConclusionsHFOV improved oxygenation in adult patients with ARDS; however, it did not confer a survival benefit and might cause harm in the era of lung-protective ventilation strategy. The evidence suggests that HFOV should not be a routine practice in ARDS and further studies specifically selecting patients for this ventilator mode should be pursued.

Recruitment Maneuvers and PEEP Titration

“…These studies bring into question whether HFOV is a viable approach in adults with ARDS. 37 A sigh function was available on ventilators in the 1970s and 1980s. But interest in the use of sigh diminished, and this feature was removed from many ventilators.…”

HFOV in Pediatric ARDS: Viable or Vestigial?

“…Some of the reasons postulated for this lack of benefit with HFOV were timing of transition (early vs. late) and disease and patient related factors. Contrary to the postulated theoretical benefits, one meta-analysis in adults in fact showed abnormal hemodynamic profile and barotrauma related to HFOV [13].…”

High-frequency oscillation ventilation for hypercapnic failure of conventional ventilation in pulmonary acute respiratory distress syndrome

“…used an algorithm with initiating HFOV only if pH >7.25 in persistent severe ARDS, and ECLA if <7.25 [ 29 ]. The two recent meta-analyses again showed no significant difference in ventilation efficiency or PaCO 2 [ 11 , 30 ]. So in general, HFOV is not seen as a tool for ventilation failure.…”

“…In special circumstances however, HFOV may be beneficial, mostly as a rescue therapy in oxygenation failure [ 2 , 8 - 10 ]. A substantial improvement in oxygenation [ 7 , 11 ] and the safety of HFOV have been shown [ 12 , 13 ] even though barotrauma is reported in a substantial number of patients [ 9 , 14 ].…”