Does continuous positive airway pressure (CPAP) during weaning from intermittent mandatory ventilation in very low birth weight infants have risks or benefits? A controlled trial. Successful extubation of newborn infants without preextubation trial of continuous positive airway pressure.
The purpose of this study was to evaluate three ventilator weaning strategies and to evaluate whether the use of continuous positive airway pressure (CPAP) via a nasopharyngeal or endotracheal tube would increase the likelihood of extubation failure in very low birth weight (VLBW) infants.
                We studied prospectively 87 preterm infants (mean +/- SD; birth weight: 1078 +/- 188 g; gestational age: 28.8 +/- 2.2 weeks) who were in the process of being weaned from intermittent mandatory ventilation (IMV). Infants were assigned by systematic sampling to one of the following three treatment groups: (1) direct extubation from IMV (D.EXT) (n = 30); (2) preextubation endotracheal CPAP (ET-CPAP) for 12-24 hr (n = 28); or (3) postextubation nasopharyngeal CPAP (NP-CPAP) for 12-24 hr (n = 29). Failure was defined as the need for resumption of mechanical ventilation within 72 hr of extubation due to frequent or severe apnea and/or respiratory failure (pH < 7.25, PaCO2 > 60 mm Hg, and/or requirement for oxygen FiO2 > 60%).
                There were no significant differences in failure rates among the three procedures. Failures were 2/30 (7%) in D.EXT; 4/28 (14%) in ET-CPAP; and 7/29 (24%) in the NP-CPAP. There were also no differences in FiO2, PaO2, and respiratory rates before and after discontinuation of IMV among the three groups. PaCO2 values were slightly higher in the NP-CPAP group 12-24 hr after weaning from IMV.
                We were unable to demonstrate a clear difference in extubation outcome by use of CPAP administered via an endotracheal or nasopharyngeal tube when compared to direct extubation from low-rate IMV in VLBW infants. Sixty newborn infants who had been mechanically ventilated through 3.0- or 3.5-mm endotracheal tubes were studied to examine the necessity of a preextubation trial of continuous positive airway pressure (CPAP). Thirty randomly assigned study infants were directly extubated from intermittent mandatory ventilation rates of six per minute; 30 randomly assigned control infants were extubated after a six-hour trial of continuous positive airway pressure of 3 cm H2O. Changes in respiratory rate, in PCO2, and in PO2/FIO2 were similar. All 30 study infants tolerated direct extubation without significant apnea or respiratory acidosis. Two study and eight control infants developed apnea during six hours after intermittent mandatory ventilation was discontinued (chi 2 = 4.3, P less than .05). Five control and no study infants had apneic episodes greater than or equal to 0.5 per hour (chi 2 = 5.5, P less than .02). The results of this study suggest that newborn infants may tolerate direct extubation from low intermittent mandatory ventilation rates without a preextubation trial of CPAP. A preextubation trial of CPAP appears to be unnecessary and may cause more frequent apnea in newborn infants if used for more than several hours.
Preterm infants no longer requiring endotracheal intubation and IPPV should be directly extubated without a trial of ETT CPAP.