RESULTS
We selected 17 PTB32W patients out of the 106 infants included in the original study (16%), that had serial LU until 36 weeks’ PMA and received diuretics: 8 were included in the responders group, and 9 in the non-responders group (see figure 1). We performed a total of 108 LU, with a median number of LU per patients of 6 (IQR 5-8). The assistant neonatologists started diuretic therapy at a median age of 32 days (IQR 28-39) in our sample. The responders group had a median gestational age (GA) at birth of 26 weeks (IQR 25-28), and the non-responders were born at a median GA of 27 weeks (25-29) (p=0.78). The median birth weight in the responders group was 819g (575-1060 g), and it was 760g (602-920g) in the other group (p=0.65). The rest of clinical variables in each group are shown in table 1. Both groups were different in terms of: days of invasive mechanical ventilation (median days in responders group was 27 days (IQR 11-43 days), and it was 76 days (IQR 35-117 days) in the other group, p=0.03), RS at the beginning of diuretic treatment (4 patients (50%) in the responders group were on invasive mechanical ventilation, while 8 patients (89%) in the non-responders group were intubated, p=0.048), and BPD (2 patients (25%) in the responders group developed moderate-severe BPD, while 8 patients (89%) in the non-responders group were diagnosed as moderate-severe BPD, p=0.005).
After comparing LU scores in the different moments analysed (see image 2 and table 2), we found differences after the start of diuretics between the two groups, at A2 and A4. Although there was not a statistical significant difference in the other intervals of time after diuretics, the values obtained at A5 and A6 are markedly different between the groups: at A5, median LU score was 6 (IQR 3-8) in the responders group, and 12 (IQR 7-14) in the non-responders group, p=0.08; at A6, median LU score was 5 (IQR 4-6) in the responders group, and 12 (IQR 5-13) in the non-responders group, p=0.25.
However, in terms of RS, both groups had differences from the very first day they were began on diuretics. In the following time intervals analysed, these differences remained significant (see table 3).