Early versus delayed initiation of continuous distending pressure for respiratory distress syndrome in preterm infants

Premature babies often lack the substance, surfactant, a detergent like substance produced by the lung. This causes their lungs to fail to expand properly at birth, and breathing in requires a big effort. If left untreated, breathing difficulty progressively worsens and it may cause damage to the lung. Continuous distending pressure (CDP) improves the expansion of the lung making it easier for the premature baby to breath. It is applied through a face mask, or into the nostrils or by a partial vacuum outside the chest. When applied early, it may also reduce the lung damage that causes chronic lung disease. Different ways of using CDP were assessed in six controlled trials (four randomized), and it was found that fewer infants who received early CDP had to go on to be treated with intermittent positive pressure ventilation. No adverse effect of early use of CDP was found in these trials. However, there were several limitations to information from the studies, as the number of infants was small and the mean age ranged from seven to eighteen hours old when CDP was applied. Practice has changed from when these studies were done. CDP interventions are applied earlier, and surfactants are commonly given as well. Corticosteroids are given to the fetus before birth (antenatally) to prepare their lungs for birth.

Authors' conclusions: 

Early application of CDP has a clinical benefit in the treatment of RDS in that it reduces subsequent use of IPPV and thus may be useful in preventing the adverse effects of this treatment. However, many of the trials were done in the 1970s and 1980s and re-evaluation of the strategy of early CDP in the era of antenatal steroid use and early surfactant administration is indicated focusing on administration methods.

Read the full abstract...

The application of continuous distending pressure (CDP) has been shown to have some benefits in the treatment of preterm infants with respiratory distress syndrome (RDS). CDP has the potential to reduce lung damage particularly if applied early before atelectasis has occurred. Early application of CDP may better conserve an infant's own surfactant stores and consequently be more effective than CDP applied later in the course of RDS.


To determine if early compared with delayed initiation of CDP results in lower mortality and reduced need for intermittent positive pressure ventilation in preterm infants with RDS.

Search strategy: 

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Oxford Database of Perinatal Trials, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2006), MEDLINE (1966 to September Week 4, 2006), previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, journal hand searching mainly in the English language.

The electronic search was updated in November 2009.

Selection criteria: 

Trials which used random or quasi-random allocation to either early or delayed CDP in spontaneously breathing preterm infants with respiratory distress syndrome.

Data collection and analysis: 

Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used, including independent assessment of trial quality and extraction of data by two authors.

Main results: 

In six studies on a total of 165 infants, early CDP was associated with a significant reduction in subsequent use of intermittent positive pressure ventilation (IPPV), (typical RR 0.55, typical RD -0.16, NNT 6), but there was no evidence of effect on overall mortality. There was no evidence of effect on the rates of pneumothorax (five studies) or bronchopulmonary dysplasia (one study). Early CDP resulted in a reduction in duration of oxygen therapy in the single study reporting this outcome.