Use of the RAM Cannula with Early Bubble Continuous Positive Airway Pressure Requires Higher Pressures: Clinical and In vitro Evaluations.

ABSTRACT

OBJECTIVE: Early bubble continuous positive airway pressure (bCPAP) in the delivery room (DR) reduces early intubation, mechanical ventilation, and bronchopulmonary dysplasia. The RAM cannula, adopted for ease of patient care, is a high resistance nasal interface that, when used with bCPAP, only transmits a portion of set pressures and attenuates the bubble effects. This study aimed to review early bCPAP pressures and bCPAP failure with the RAM cannula interface over a 6-year period. STUDY DESIGN: Retrospective, single-center study of infants delivered <1,250 g from 2013 to 2018 (n = 735) begun on bCPAP in the DR with the RAM cannula. In vitro testing of bCPAP pressure transmission was also performed for multiple nasal interfaces and nasal occlusion percentages. RESULTS: The percentage of infants intubated in the DR decreased over time (59 to 42%), while the average bCPAP pressure increased from 5.3 to 6.8 cmH2O. A total of 355 infants (48%) were admitted to the neonatal intensive care unit (NICU) from the DR on BCPAP. The failure rate for bCPAP in NICU within 72 hours decreased from 45 to 24% as the maximum CPAP increased from 5.8 to 7.6 cmH2O. Pneumothorax rates did not change. CPAP pressure transmission decreased with all sizes of the RAM cannula. CONCLUSION: When utilizing the RAM cannula for bCPAP, higher CPAP levels were associated with decreases in DR intubations and CPAP failure within the first 72 hours. If clinicians choose to use the RAM cannula for bCPAP, they will need higher set pressures to achieve lung inflation and the beneficial oscillatory effect will be diminished. KEY POINTS · The transmission of the pressure oscillations from bubble CPAP is diminished with the RAM cannula.. · Increasing set CPAP pressures was associated with a decreased delivery room intubation rate and a decreased CPAP failure rate within 72 hours.. · Clinicians using the RAM cannula for bCPAP will need to increase pressures to obtain adequate lung inflation or change to a nasal interface designed for bCPAP..