Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children

Abstract

Background: Acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in the pediatric age group. Positive pressure ventilation is currently the standard of care, though is known to be associated with complications. Continuous negative extrathoracic pressure ventilation (CNEP) or continuous positive airway pressure ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies.

Objectives: The primary objective of this review was to assess the effectiveness of CNEP and Ni-CPAP in pediatric patients with AHRF due to non-cardiogenic causes.

Search strategy: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005); MEDLINE (January 1966 to March 2005); EMBASE (1980 to March 2005); CINAHL (1982 to March 2005); published abstracts from the meetings of the American Thoracic Society and Pediatric Critical Care Meetings (1992 to 2005); and bibliographies of identified articles and asking the experts in the field.

Selection criteria: Randomized or quasi-randomized clinical trials of either CNEP or Ni-CPAP versus standard therapy (positive pressure ventilation) involving children (at least 1 month old and less than 18 years of age at the time of randomization) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported were included.

Data collection and analysis: The methodological quality of included study was assessed using the following criteria: concealment of randomization, blinding of intervention, completeness of follow up and blinding of outcome measurements. Data on relevant outcomes were abstracted and the effect size was estimated by calculating relative risk (RR) with 95% confidence intervals (CI) and risk difference (95% CI).

Main results: One eligible study was identified which was published in abstract format. Thirty-three infants (18 in the control group and 15 in the CNEP group) with a clinical diagnosis of bronchiolitis and fraction of inspired oxygen (FiO(2))()greater than 40% were studied. There was reduction in the FiO(2) (less than 30% within one hour of initiation of therapy) in four patients in the CNEP group compared to none in the control group (RR 10.7, 95% CI 0.6 to 183.9). One infant required positive pressure ventilation and one infant required nasal CPAP in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95% CI 0.02 to 9.06).

Implication for practice: There is a lack of well designed, controlled experiments of noninvasive modes of respiratory support in children with AHRF. Implication for research: Reduction of in-hospital mortality is an important outcome and even a small reduction could be beneficial. Studies assessing other outcomes such as avoidance of intubation and its associated complications, reduction in hospital stay and improvement in patient comfort are also valuable in gauging the overall impact of these strategies.