Objective: To evaluate cardiorespiratory changes in hypothermic asphyxiated ventilated infants compared with controls.
Study design: Retrospective chart analysis with historical controls. Cardiorespiratory status of 10 asphyxiated newborns in hypothermia (H) (32 degrees-34 degrees C) (H group) was compared with that one of 11 asphyxiated newborns [control group, (C group)].
Results: 3/10 patients in H group needed an increased mean tidal volume (from 5.8 to 8 ml/Kg) during hypothermia when temperature reached a value of 32 degrees C, to maintain adequate gas exchange. Length of mechanical ventilation was similar in the two groups (H=5.4+/-4.4 vs C=2.8+/-2.7 days, p=ns). Heart rate, similar at the baseline (H group: 129+/-11 beats/min; C group: 129+/-12 beats/min), dropped to an average of 102+/-10 beats/min (p<0.05) during cooling in H group, while it remained stable in C group. Mean arterial blood pressure, comparable at birth, increased by a median of 8 mmHg during hypothermia (p=ns).
Conclusions: Hypothermia induces mild changes in cardiovascular status and in lung mechanics.