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Inspiratory and expiratory times for infants ventilator‐dependent beyond the first week
Author(s) -
Chan V,
Greenough A
Publication year - 1994
Publication title -
acta pædiatrica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 115
eISSN - 1651-2227
pISSN - 0803-5253
DOI - 10.1111/j.1651-2227.1994.tb12975.x
Subject(s) - medicine , gestational age , mean airway pressure , anesthesia , ventilation (architecture) , peak inspiratory pressure , oxygenation , respiratory rate , respiratory system , heart rate , blood pressure , tidal volume , pregnancy , mechanical engineering , genetics , biology , engineering
The aim of this study was to determine optimum inspiratory and expiratory times to be used for ventilation of infants older than one week of age. Each infant was studied at a rate of 30 breaths/min (inspiratory times (T I ) of 1.0, 0.67 and 0.5 s with expiratory times (T E ) of 1.0, 1.33 and 1.5 s, respectively) and at a rate of 60 breaths/min (T I 0.5, 0.33 and 0.25 s and T E 0.5, 0.67 and 0.75 s, respectively). Arterial blood‐gases were examined after 20 min on each setting. Fifteen infants with a median gestational age of 27 weeks were studied at a median postnatal age of 9 days and 10 infants with a median gestational age of 27 weeks at a median postnatal age of 24 days. All infants had type I chronic lung disease. Oxygenation did not consistently improve as T I was prolonged, elevating mean airway pressure but, particularly in older infants, was better at T I ± 0.5 s compared with T I < 0.5 s. In both groups, carbon dioxide elimination was better at 60 than at 30 breaths/min. Thus we suggest that in infants fully ventilator‐dependent beyond the first week of life, an inspiratory and expiratory time of 0.5 s should be used as the first choice.