Clinical Prediction Score for Nasal CPAP Failure in Pre-term VLBW Neonates with Early Onset Respiratory Distress

Abstract

We prospectively observed 62 pre-term very low birth weight neonates initiated on nasal continuous positive airway pressure (CPAP) for respiratory distress in the first 24 h of life to devise a clinical score for predicting its failure. CPAP was administered using short binasal prongs with conventional ventilators. On multivariate analysis, we found three variables-gestation <28 weeks [adjusted odds ratio (OR) 6.5; 95% confidence interval (CI) 1.5-28.3], pre-term premature rupture of membranes [adjusted OR 5.3; CI 1.2-24.5], and product of CPAP pressure and fraction of inspired oxygen ≥1.28 at initiation to maintain saturation between 88% and 93% [adjusted OR 3.9; CI 1.0-15.5] to be independently predictive of failure. A prediction model was devised using weighted scores of these three variables and lack of exposure to antenatal steroids. The clinical scoring system thus developed had 75% sensitivity and 70% specificity for prediction of CPAP failure (area under curve: 0.83; 95% CI 0.71-0.94).

Continuous Positive Airway Pressure Failure in Preterm Infants: Incidence, Predictors and Consequences

“…Another study in which infants on CPAP were intubated at an FiO 2 of 0.6 found that a lower intubation threshold would not have altered the numbers of infants intubated, but only delayed the time of intubation [9]. Despite the long documented observation of better oxygenation with higher airway pressures on CPAP [20], addition of CPAP level into the predictive modelling in the present study, either alone or as a product with FiO 2 [11], only marginally improved the goodness of fit.…”

“…The respiratory course for all infants managed initially on CPAP was defined from the intensive care charts. Data recorded included highest FiO 2 (sustained for at least 15 min), CPAP pressure and CPAP-FiO 2 product (= CPAP level in cm H 2 O × FiO 2 ) [11] in the first 2 h (25-28 weeks) or first 6 h (29-32 weeks), as well as highest PCO 2 in the first 6 h. For those failing CPAP, defined as the need for intubation before 72 h [7], the most recent physiological parameters prior to intubation were documented, and the radiological severity of RDS was categorised by one of the authors as mild, moderate or severe [12]. …”

“…Two recent observational studies examining the value of highest FiO 2 in the first hours of life as a predictor of later CPAP failure have yielded disparate results [9,10]. The product of CPAP level (in cm H 2 O) and FiO 2 has also been proposed as a potential predictor of CPAP failure [11], but this index may overestimate the effect of an incremental change in airway pressure on oxygenation.…”

The Stable Microbubble Test for Determining Continuous Positive Airway Pressure (CPAP) Success in Very Preterm Infants Receiving Nasal CPAP from Birth

“…Our FiO 2 (≥0.4) may be considered by some to be too low and result in more infants being classified as failing CPAP than if higher FiO 2 was used. Several studies have used FiO 2 >0.6 [2,3,4,18]. CPAP levels used at RWH are higher than those used by other groups [3,5] and these infants might have met CPAP failure criteria at other institutions.…”

Continuous Positive Airway Pressure to Prevent Neonatal Lung Injury: How Did We Get Here, and How Do We Improve?

“…51,68,69 Not surprisingly, both an increasing oxygen requirement (>40%) in the first hours of life and an increasing CPAP requirement (>6 cm H 2 O) predict failure. 51,[68][69][70] However, as most units include these factors as criteria for intubation, this association is necessarily confounded as a predictor of failure. A recent small study has shown that low tidal volume breaths, lower peak inspiratory flows, and increased oxygen requirement immediately after delivery can predict CPAP failure and deserves further study.…”