J Matern Fetal Neonatal Med, 2014; 27(S1): 436-7
Brief Introduction: Although bubble CPAP is seen to be superior to
continuous steady pressure CPAP, it is reported that its pressure
delivery system can be highly variable and unpredictable. CPAP has
been associated with gastrointestinal adverse effects – although
rarely. The CPAP belly syndrome is one such adverse effect characterised by gaseous
bowel-distension in infants treated with nasal CPAP.
The pressures transmitted from oropharynx to stomach during
BCPAP are not known. Intra gastric pressures in babies receiving
nasopharyngeal BCPAP have not been studied previously to the best
of our knowledge.
This study was done to study intra-gastric pressures in neonates
receiving bubble CPAP by nasopharyngeal prong.
Materials & Methods: 27 neonates were recruited for the study. Bubble
CPAP pressure of 6 cm water was used in all the neonates. A pressure
sensor (by sensoromedic was attached to a 5V regulated power
supply and the voltage drop across appropriate leads of the sensor
was proportional to the pressure difference,) was attached to
orogastric tube to measured the intra gastric pressure prior to
starting bubble CPAP and again after 30 to 90 minutes of CPAP. The
software for the data logging was provided by MECO 81 K -TRMS.
We routinely checked the calibration at different depths of water and
found it accurate with an error of less than 2%.
The clinical variables like Downe’s score, oxygen saturation,
venous blood gas pH, pCO2 and abdominal girth were recorded
alongside with pressure readings.
Clinical Cases or Summary Results: In our study there was statistical
improvement (p50.05) in parameters of respiratory distress like
Downe’s score (DS), oxygen saturation (SpO2), venous blood gas
parameters (pH, pCO2).
The mean intragastric pressure before starting BCPAP was
12.422 cm H2O, (95% CI 8.65 to 16.18) and during BCPAP it was
12.88 cm H2O (95% CI 10.48 to 15.29). The intragastric pressure always
remained positive and the overall change in intragastric pressure
recordings (paired t test) was 0.464 cm H2O (95% CI -5.11 to + 4.18,)
(p = 0.838).
Conclusions: We found that nasopharyngeal Bubble CPAP at pressure
of 6 cm water, decreased work of breathing, improved gas exchange
and improved Downe’s score. We found no significant increase in
intra gastric pressures and gastrointestinal complications such as
abdominal distention, NEC, perforation during our study.
Further multi centric studies with larger number of cases, are
required for predicting accurate changes in intragastric pressures.