Fig. 1
Recorded parameters at 28 days of life (DOL) and at 36 weeks post menstrual age (PMA) in the two groups of infants during the three phases of the test. BL = Baseline; CH = Challenge; PT = Post-test; TcPCO2 = Transcutaneous partial pressure of CO2; ○ = Passed group; ● = Failed group. Bar shows the median value for each group. Mann Whitney test was applied for comparisons between the groups