3. | RESULTS
We prospectively studied 32 infants: 17 receiving MD-nCPAP and 15
receiving bCPAP. Patient demographic and clinical characteristics are
summarized in Table 1 and Table 2. There were no significant differences
between the MD-nCPAP and bCPAP groups in any characteristic except
corrected GA (median corrected GA in MD-nCPAP = 32 (IQR: 31 to 33), in
bCPAP = 30 (IQR: 29 to 31), P = 0.006). Lung US Score (LUS), PEEP
and FiO2 were not different between the groups, suggesting that the
degrees of pulmonary impairment were similar.
Gastric emptying rates calculated as percentage emptied per minute
(%emptied/min) from the values obtained by both ACSA and spheroid US
methods at different time intervals were compared between MD-nCPAP and
bCPAP groups. There were no significant differences in the rates
measured by either ACSA or spheroid methods and between the MD-nCPAP and
bCPAP groups, either as the emptying rate across the entire feeding
duration or as individual early and late emptying rates (Figure 2a, 2b).
The ACSA method demonstrated significantly faster gastric emptying in
the early phase compared to the late phase in the 25+0 to 27+6 weeks GA
group (Bonferroni adjusted p-value = 0.0008) but not in the 28+0 to 34+6
weeks GA group (Bonferroni adjusted p-value = 1), irrespective of
ventilation group after accounting for multiple testing among paired
comparisons (Figure 2a) . The spheroid method rate
demonstrated significantly faster emptying in the early phase than in
the late phase (p < 0.0001) for all infants, irrespective of
ventilation group and GA group (Figure 2b).
Residual gastric contents prior to the next feeding were calculated to
be 42.4% in the MD-nCPAP group and 31.9% in bCPAP group when using
ACSA measurements, and 23.8% and 25.8% respectively when using
spheroid method. Comparison of these residual gastric contents showed no
significant difference between the MD-nCPAP and bCPAP groups by either
ACSA (Figure 3a) or spheroid method (Figure 3b). None of the studied
patients had emesis or measurable regurgitation.