Aim: To assess the use of nasal high-frequency ventilation (HFV) to provide noninvasive ventilatory support for very low birthweight (VLBW) infants.
Study design: VLBW infants, >7 days of age on nasal continuous positive airway pressure (CPAP), were placed on nasal HFV for 2 h using the Infant Star high-frequency ventilator (Mallinckrodt, Inc., St. Louis, MO, USA). Mean airway pressure was set to equal the previous level of CPAP, and amplitude was adjusted to obtain chest wall vibration. Capillary blood was sampled before starting HFV and after 2 h to determine change in pH and partial pressure of carbon dioxide (pCO(2)).
Results: Fourteen subjects were studied, 10 males and 4 females. Gestational age was 26-30 weeks (median 27). Age at study was 18-147 days (median 30). Median birth weight was 955 g; median weight at study was 1605 g. Nasal CPAP pressure was 4-7 cm H(2)O (mean 5). Amplitude was 30-60 (median 50). After 2 h, PCO(2) (mean 45 torr) was significantly lower than initial PCO(2) (mean 50 torr) (p = 0.01), and pH had increased significantly (7.40 vs. 7.37, p = 0.04).
Conclusions: Nasal HFV is effective in decreasing pCO(2) in stable premature infants requiring nasal CPAP support. Long-term use of nasal HFV requires further study.