Assessing Initial Response to High-Frequency Jet Ventilation in Premature Infants With Hypercapnic Respiratory Failure

High-frequency jet ventilation (HFJV) has been used in conjunction with conventional ventilation for infants with respiratory failure. We sought to identify parameters that were associated with successful application of HFJV in patients with hypercapnic respiratory failure.

A single-center, retrospective review of infants who received HFJV was conducted. Subjects were enrolled if birthweight was ≤2,000 g and capillary P_CO was ≥55 mm Hg. Ventilator parameters and physiologic data were recorded at 1 h before HFJV initiation and at hours 1, 4, and 6 following conversion. Subjects were classified as responders if capillary P_CO was reduced by ≥10% after 1 h of HFJV. Data included peak inspiratory pressure, PEEP, capillary P_CO , and oxygen saturation index (equal to mean airway pressure × F_IO × 100/S_pO ). Because the data were not normally distributed, they are reported as median (interquartile range), and the Mann-Whitney test was used to assess differences in continuous data between groups. Categorical data were analyzed using a chi-square and Fisher exact test.

Thirty-four premature infants (n = 24 male) were studied. Twenty-five subjects were classified as responders and demonstrated a significant reduction of capillary P_CO and F_IO and increased pH within the first hour. The non-responders demonstrated a higher conventional ventilation peak inspiratory pressure (25 cm H₂O vs 19 cm H₂O, P = .005) and had a greater postmenstrual age (30 weeks vs 26.5 weeks, P = .01). This group had a higher oxygen saturation index (7.25 vs 3.36, P = .03) and F_IO requirements (0.6 vs 0.35, P = .038) at 4 h.

We identified that lower postmenstrual age, improvements in capillary P_CO and pH at 1 h, and a reduction of F_IO were associated with good response to HFJV. These data may help to identify patients who are likely to benefit from HFJV in the neonatal intensive care unit.