Phenotyping respiratory decompensation following definitive closure of the patent ductus arteriosus in preterm infants.

OBJECTIVE: To identify risk factors associated with high-frequency ventilation (HFV) following definitive closure of the patent ductus arteriosus (PDA). METHODS: We performed a retrospective study of premature infants (<37 weeks) who were mechanically ventilated before and after surgical or transcatheter PDA closure. Primary outcome was HFV requirement within 24 h of procedure. Logistic regression was used to estimate clinical associations with post procedure HFV requirement. RESULTS: We identified 110 infants who were mechanically ventilated before PDA closure, of which 48 (44%) escalated to HFV within 24 h after closure. In the multivariable model, surgical ligation (OR 21.5, 95% CI 1.6-284), elevated Respiratory Severity Score (RSS) 1 h post-procedure (OR 1.78, 95% CI 1.07-2.99) and 12 h post-procedure (OR 2.12, 95% CI 1.37-3.26) were independent predictors of HFV. CONCLUSION: Surgical ligation and elevated RSS values over the first 12 h after PDA closure are risk factors for HFV.

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

BACKGROUND: 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. METHODS: A single-center, retrospective review of infants who received HFJV was conducted. Subjects were enrolled if birthweight was ≤2,000 g and capillary PCO2 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 PCO2 was reduced by ≥10% after 1 h of HFJV. Data included peak inspiratory pressure, PEEP, capillary PCO2 , and oxygen saturation index (equal to mean airway pressure × FIO2 × 100/SpO2 ). 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. RESULTS: Thirty-four premature infants (n = 24 male) were studied. Twenty-five subjects were classified as responders and demonstrated a significant reduction of capillary PCO2 and FIO2 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 FIO2 requirements (0.6 vs 0.35, P = .038) at 4 h. CONCLUSIONS: We identified that lower postmenstrual age, improvements in capillary PCO2 and pH at 1 h, and a reduction of FIO2 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.