Does pulmonary function change during whole-body deep hypothermia?

Whole-body deep hypothermia (DH) could be a new therapeutic strategy for asphyxiated newborn. Aim of this study was to describe how DH (core temperature 30-33°C) modifies the respiratory function if compared with mild hypothermia (MH; core temperature 33-34°C). This is an observational study. Results were obtained from a pilot study of safety of DH and topiramate in neonatal hypoxic-ischaemic encephalopathy. Fifty-seven newborns were enrolled: 29 patients in DH and 28 in MH. Recruitment criteria were moderate-severe hypoxic-ischaemic encephalopathy and gestational age ≥36 weeks. Mechanical ventilation was set to maintain SaO2 between 92% and 95%. Nineteen patients in DH and 18 in MH required mechanical ventilation. Of these patients, 10 and 12, respectively, did not required oxygen. No significant differences were observed in hours of oxygen and ventilation support, respiratory rate and PaCO2. Maximum FiO2, peak inspiratory pressure, positive end-expiratory pressure, minute ventilation and tidal volume during hypothermia were similar. Pulmonary function with different levels of hypothermia was similar.