RESUMO
The clinical histories of 27 neonates ventilated with high frequency respirators (Volumetric Diffusive Respirator VDR-2) have been analyzed in order to evaluate the efficiency of this type of ventilation in neonatal pathology. The average gestational age of these patients was 32 +/- 4 weeks. Most of them (70%) presented respiratory distress due to hyaline membrane disease. Of the remaining cases, three (11%) presented with congenital diaphragmatic hernia, two with pulmonary hypertension, two with meconium aspiration syndrome, one with Group B Streptococal sepsis/shock and one with case diaphragmatic agenesia. Between two and six hours after initiation of high frequency ventilation (HFV), pH, paCO2 and pO2 improved significantly in relationship to former values (p < 0.05- p < 0.001), reaching values in the normal range at 6.5 +/- 14 hours regarding pH, 30 +/- 50 hours regarding paCO2 and 6.5 +/- 10 hours regarding paO2. No hemodynamic modification could be attributed to this procedure. The principal complications were ectopic air (62%) and necrotizing tracheobronchitis (TBN) (25%). Bronchopulmonary dysplasia (BDP) was diagnosed in 20% of the cases, ductus (DAP) in 33% of the cases and intracraneal hemorrhage in 25% of the cases. Mortality was 70%. High frequency ventilation is an alternative procedure to conventional ventilation in this group of neonates. It produces an important number of favorable responses, but has complications that can not be overlooked.
PIP: Clinical records of 27 newborns treated with high frequency ventilation in a hospital neonatal service in Madrid were retrospectively studied. High frequency ventilation is a technique with specific indications that has recently been applied in some neonatal pathologies as an alternative to conventional ventilation. The respirators, model 2 Volumetric Diffusive Respirators, were used in 24 of the 27 cases because of failure of conventional ventilation. The 27 newborns weighed an average of 1850 +or- 944 g and ranged from 900 to 4000 g. Their average gestational age was 32 +or- 4 weeks, and the range was 26-42 weeks. 19 had respiratory difficulties stemming from hyaline membrane disease, 3 had congenital diaphragmatic hernias, 2 had pulmonary hypertension, and one each had meconium aspiration syndrome, septic shock from group B streptococcus, and diaphragmatic agenesia. 66% were delivered by cesarean. The pH, paCO2, and paO2 improved significantly between 2 and 6 hours after initiation of HFV treatment. Values in the normal range were reached at 6.5 +or- 14 hours for pH, 30 +or- 50 hours for paCO2, and 6.5 +or- 10 hours for paO2. No hemodynamic modifications were attributed to HFV. The most significant complications were ectopic air (62%) and necrotizing tracheobronchitis (25%). Broncopulmonary dysphasia was diagnosed in 20%, ductus in 33%, and intracraneal hemorrhage in 25%. The case fatality rate was 70%. Ten newborns improved definitively with HFV and proceeded to conventional ventilation. Two later succumbed to other causes. The study showed that HFV can lead to serious complications and should be applied with great prudence despite it great potential benefit.
