ABSTRACT
OBJECTIVE: The aim of this study was to evaluate the results of high frequency ventilation (HFV) used as a rescue strategy in newborn infants with severe lung disease who either failed conventional mechanical ventilation (CMV) or had an air block. PATIENTS AND METHODS: From April 1995 to June 1998, 241 infants with severe lung disease and managed according to a common protocol of HFV used as a rescue strategy were prospectively evaluated in the nine participating level III Spanish Neonatal Intensive Care Units. The most frequent diagnoses were respiratory distress syndrome (119), meconium aspiration (24), pneumonia (19) and congenital diaphragm hernia (18). RESULTS: Mean +/- SD gestational age and birth weight were 32.0 +/- 5.5 weeks and 1,187 +/- 1,071 g, respectively. All babies were previously manages with CMV for a mean of 59 hours. HFV was started at a mean postnatal age of 82 hrs, with a mean oxygenation index (OI) of 28.3 +/- 15.3 and an a/A DO2 of 0.10 +/- 0.08. Initial mean HFV settings were: mean airway pressure 12.8 +/- 3.4 mbar, frequency 8.3 +/- 1.4 Hz, amplitude 53 +/- 20 percent, tidal volume 2.2 +/- 0.7 ml/kg and FiO2 0.88 +/- 0.2. At two hours of HFV there was a significant increase in the mean PaO2 (from 48 to 80 mmHg), with a concomitant decrease in FiO2 (from 0.88 to 0.79), PaCO2 (from 60 to 46 mmHg) and OI (from 28 to 18). Mean a/A DO2 increased from 0.10 to 0.19; these changes remained similar thereafter. HFV was suspended after a mean of 95 hrs because of improvement in 70%, death in 19% and failure to improve the clinical condition in the remaining 19%. Intrahospital death rate was 32%. The following complications were observed: pneumothorax (10%), interstitial emphysema (4%), intraventricular hemorrhage grades III and IV (14.5%) and bronchopulmonary dysplasia (35%). CONCLUSIONS: HFV is an effective rescue strategy that improves pulmonary gas exchange within two hours of its initiation.
