Table 1

Changes in ventilation and oxygenation with changes in gas mixture in 10 infants with bronchiolitis on mechanical ventilation

Patient

Variable
 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
Age (months)
 9
 1
 1
 6
 4
 7
 2
 1
 4
 2
RSV positive
 No
 No
 Yes
 No
 Yes
 No
 Yes
 Yes
 Yes
 Yes
Ventilator rate
 20
 22
 18
 15
 28
 18
 15
 30
 20
 25
(breaths/min)









IT (s)
 1.0
 0.8
 0.8
 0.8
 1.0
 1.0
 1.0
 1.0
 1.0
 0.8
I:E
 1:2
 1:2
 1:3
 1:4
 1:1
 1:2
 1:3
 1:1
 1:2
 1:2
PaCO2(mmHg)









50/50 Nitrogen/
 45
 53
 44
 40
 47
 53
 65
 28
 35
 40
oxygen









50/50 Heliox
 43
 53
 41
 38
 46
 52
 62
 28
 39
 36
60/40 Heliox
 34
 51
 44
 39
 48
 45
 65
 26
 37
 38
70/30 Heliox
 35
 53
 44
 37
 45
 41
 69
 26
 34
 36
PaO2/FiO2









50/50 Nitrogen/
 183
 251
 246
 193
 174
 351
 395
 485
 167
 225
oxygen









50/50 Heliox
 190
 284
 182
 200
 232
 366
 364
 450
 188
 212
60/40 Heliox
 245
 220
 325
 200
 203
 370
 330
 445
 183
 230
70/30 Heliox
 237
 290
 303
 233
 190
 313
 240
 360
 213
 207
PaO2/PAO2









50/50 Nitrogen/
 0.30
 0.42
 0.39
 0.31
 0.28
 0.26
 0.35
 0.58
 0.68
 0.74
oxygen









50/50 Heliox
 0.30
 0.47
 0.29
 0.31
 0.37
 0.30
 0.33
 0.60
 0.62
 0.69
60/40 Heliox
 0.39
 0.38
 0.54
 0.33
 0.34
 0.29
 0.37
 0.62
 0.60
 0.69
70/30 Heliox
 0.40
 0.54
 0.54
 0.40
 0.34
 0.36
 0.35
 0.54
 0.50
 0.57

I:E, ratio of ventilator inspiratory to expiratory times; IT, ventilator inspiratory time; RSV, respiratory syncytial virus.

Gross et al. Critical Care 2000 4:188   doi:10.1186/cc692