Table 2 Demographic and clinical characteristics for the 4 groups (spontaneous breathing, short-NIV, long-NIV or Surf > 24 h and Surf < 24 h) and for the 2 groups (Better and Worse Clinical Outcome) according to the subsequent clinical outcomes

Demographic

 N subjects

8

23

16

14

31

30

 Gestational age, weeks

32.7 [32.1; 33.3]

32.9 [32.1; 33.1]

30.0 [29.2; 30.6]*°

31.1 [30.4; 31.9]*

32.9 [32.1; 33.2]

30.4 [29.6; 31.3]^#

 (min.–max.)

(29.0; 33.6)

(29.0; 34.7)

(27.9; 32.7)

(27.8;34.1)

(29.0;34.7)

(27.8;34.1)

 Birth weight, g

1895 [1695;2215]

1720 [1411; 1997]

1220 [900; 1345]*°

1470 [1280; 1780]

1730 [1479; 2007]

1285 [1100; 1490]^#

(1090–2495)

(1180–2345)

(745–2375)

(900–1955)

(1090–2495)

(745–2375)

 Small for gestational age

0 (0)

3 (13)

4 (25)

0 (0)

3 (10)

4 (13)

 Female

3 (37)

9 (39)

10 (62)

10 (71)

12 (39)

20 (67)^#

 Twins

6 (75)

19 (83)

10 (62)

9 (64)

25 (81)

19 (22)

 Cesarian Section

6 (75)

19 (83)

16 (100)

14 (100)

25 (81)

30 (100)^#

 Antenatal steroids

7 (87)

22 (96)

16 (100)

14 (100)

29 (93)

30 (100)

 Resuscitation at birth

1 (12)

20 (87)°

16 (100)°

14 (100)°

21 (68)

30 (100)^#

 APGAR score at 5’

9 [9;10]

9 [8; 9]

9 [8; 9]

9 [8; 9]

9 [9; 9]

9 [8; 9]

 Arterial cord pH

7.31 [7.31; 7.33]

7.36 [7.35; 7.39]

7.37 [7.35; 7.40]

7.40 [7.36; 7.40]

7.30 [7.25; 7.32]

7.32 [7.27; 7.36]

Clinical characteristics

 Duration of non-invasive RS, days

0 [0; 0]

2[1.2; 3.4]

37.6 [29.4; 47.0]*°

8 [5.7; 25.3]*°

1.8 [0.1; 3.2]

29.4 [6.2; 44.0]^#

(0-0)

(0.5-7.1)

(1.5-108.3)

(1.5-59.2)

(0-7.1)

(1.5-108.3)

 Duration of mechanical ventilation, days

0 [0; 0]

0 [0; 0]

0 [0; 0]

0 [0; 0.4]

0 [0; 0]

0 [0; 0]

(0-0)

(0-0)

(0-14)

(0-4)

(0-0)

(0-14)

 Surfactant

0 (0)

0 (0)

3 (19)

14 (100)*°^§

0 (0)

17 (57)^#

 Second surfactant dose

0 (0)

0 (0)

1 (6)

2 (14)

0 (0)

3 (10)

 Air-leak

0 (0)

0 (0)

1 (6)

0 (0)

0 (0)

1 (3)

 Respiratory support at 36 weeks gestation

0 (0)

0 (0)

8 (50)*

2 (14)

0 (0)

10 (33)^#

 Sepsis

0 (0)

1 (4)

5 (31)

3 (21)

1 (3)

8 (27)^#

 Patent doctus arteriosus

0 (0)

1 (4)

3 (19)

4 (29)

1 (3)

7 (23)^#

 intraventricular haemorrhage

0 (0)

0 (0)

0 (0)

0 (0)

0 (0)

0 (0)

 Necrotizing Enterocolites

0 (0)

1 (4)

2 (12)

2 (14)

1 (3)

4 (13)

 Hospitalization, days

22 [18; 25]

28 [18; 40]

63 [51; 78]*°

36 [29; 61]

22 [18; 37]

55 [34; 71]^#

(12–53)

(7–61)

(25–178)

(18–101)

(7–61)

(18–178)