Table 4 Bag/mask ventilation characteristics recorded from the newborn resuscitation monitor (n=644). Values are given as median (quartiles) or percentage (number)

 First HR (bpm)

98 (61–152)

95 (62–149)

88 (60–140)

0.699^a

 First HR under 100 bpm (%)

50.9 (112)

50.7 (136)

55.1 (86)

0.644^a

 HR after last ventilation (bpm)

153 (130, 171)

157 (134, 169)

160 (137, 170)

0.621^a

 HR 60 s after last ventilation (bpm)

160 (138, 176)

163 (145, 176)

160 (140, 175)

0.550^a

 Total BMV duration (seconds)

135 (66, 349)

127 (64, 266)

152 (82, 347)

0.234^a

 Total BMV pause (%)

27.9 (15.2, 44.8)

19.1 (8.2, 34.9)

15.7 (4.0, 31.2)

<0.001^a

<0.001^b

<0.001^b

0.077^b

 Tidal volume expired, (ml/kg)

7.6 (4.8, 11.8)

6.0 (2.9, 9.8)

6.3 (3.5, 10.4)

<0.001^a

<0.001^b

0.025^bc

0.137^b

 Mask leak (%)

38.0 (15.8, 57.0)

42.0 (18.5, 61.8)

38.8 (16.0, 60.0)

0.495^a

 Ventilation frequency, (1/min)

45.0 (36.0, 55.0)

48.0 (42.0, 54.0)

48.0 (42.2, 54.0)

0.006^a

0.009^b

0.005^b

0.542^b

 Peak inspiratory pressure (mbar)

36.0 (30.0, 39.0)

39.0 (36.0, 40.0)

38.0 (37.0, 40.0)

<0.001^a

<0.001^b

<0.001^b

0.498^b

 Minute volume (ml)

369 (225, 556)

287 (181, 459)

324 (198, 449)

0.005^a

0.001^b

0.049^bc

0.335^b

 Number of ventilations

61 (34, 159)

72 (38, 147)

85 (44, 208)

0.017^a

0.348^b

0.006^b

0.029^bc

 Static lung compliance, (ml/mbar)

0.93 (0.60, 1.40)

0.64 (0.38, 1.01)

0.67 (0.40, 1.02)

<0.001^a

<0.001^b

<0.001^b

0.630^b

 Total BMV pause during first minute (%)

31.1 (12.3, 56.6)

23.6 (8.3, 42.1)

15.1 (5.5, 38.7)

<0.001^a

0.003^b

<0.001^b

0.020^bc

 Tidal volume expired (ml/kg)

7.0 (3.5, 10.6)

4.2 (1.4, 8.1)

4.3 (1.9, 8.7)

<0.001^a

<0.001^b

<0.001^b

0.443^b

 Mask leak (%)

42.2 (21.0, 68.2)

52.8 (24.2, 74.5)

52.5 (26.0, 72.0)

0.068^a

 Ventilation frequency, (1/min)

46.0 (37.0, 58.0)

48.0 (42.0, 55.5)

49.0 (43.0, 55.0)

0.058^a

 Peak inspiratory pressure (mbar)

37.0 (32.0, 40.0)

39.0 (37.0, 41.0)

38.8 (37.0, 41.5)

<0.001^a

<0.001^b

<0.001^b

0.742^b

 Minute volume (ml)

317 (183, 494)

241 (113, 385)

247 (153, 387)

<0.001^a

<0.001^b

0.002^b

0.500^b

 Number of ventilations

30 (20, 40)

36 (27, 44)

39 (29, 44)

<0.001^a

<0.001^b

<0.001^b

0.190^b

 Static lung compliance (ml/mbar)

0.93 (0.61, 1.41)

0.65 (0.39, 1.04)

0.71 (0.41, 1.06)

<0.001^a

<0.001^b

<0.001^b

0.396^b