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

Abstract

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 P CO 2 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 2 was reduced by >10% after 1 h of HFJV. Data included peak inspiratory pressure, PEEP, capillary P CO 2 , and oxygen saturation index (equal to mean airway pressure ؋ F IO 2 ؋ 100/S pO 2 ). 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 P CO 2 and F IO 2 and increased pH within the first hour. The non-responders demonstrated a higher conventional ventilation peak inspiratory pressure (25 cm H 2 O vs 19 cm H 2 O, 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 2 requirements (0.6 vs 0.35, P ‫؍‬ .038) at 4 h. CONCLUSIONS: We identified that lower postmenstrual age, improvements in capillary P CO 2 and pH at 1 h, and a reduction of F IO 2 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.

Mortality Risk Factors in Preterm Infants Treated with High-Frequency Jet Ventilation

“…OSI (ie, mean airway pressure  F IO 2  100/S pO 2 ) has a strong linear correlation with the oxygen index and had been validated as a noninvasive method for assessing the severity of respiratory illness in infants and children. [26][27][28] Recently, Muniraman et al 29 demonstrated that the oxygen index derived from OSI was strongly correlated (r ¼ 0.89) and may provide reliable assessment of respiratory failure on a 12 Collectively, these findings suggest that OSI is a useful metric for guiding interventions, evaluating treatment response, and identifying risk stratification in premature infants, and our results support these findings. Our data suggest that ductal patency confers a survival benefit because subjects who did not have a patent ductus arteriosus demonstrated a nearly 8-fold increase in mortality.…”

“…Subjects were converted to HFJV in accordance with institutional guidelines, which have been described in a previous publication and are highlighted in Figure 1. 12 HFJV peak inspiratory pressure was primarily adjusted to maintain a pH $ 7.25 and capillary P CO 2 of 45-60 mm Hg. F IO 2 was titrated to maintain S pO 2 between 88% and 94%.…”

Therapeutic Effects and Outcomes of Rescue High-Frequency Oscillatory Ventilation for Premature Infants With Severe Refractory Respiratory Failure

“…Severe refractory respiratory failure was de ned when patients with a PaO 2 /FiO 2 ratio under 150 on two consecutive arterial blood gas (ABG) samples and/or had an initial oxygenation index (OI) ≥ 20 [21]. Poor response to conventional ventilation was de ned as failure to decrease PCO 2 > 10% and/or FiO 2 > 20% after 1 hour treatment by conventional ventilation (CV) at maximal settings [22,23]. Exclusion criteria were patients < 24 weeks of gestation, incomplete medical records, and patients with severe congenital anomalies (ex.…”

High-Frequency Jet Ventilation in Preterm Infants: Is There Still Room for It?

“…Current evidence does not allow recommendations for using HFJV routinely in preterm infants with respiratory distress syndrome, and its use is very restricted. 10 In a 4-y retrospective study, Wheeler et al 11 sought to identify measurable physiological factors to predict the successful use of HFJV as a rescue ventilation mode in subjects with acute hypercapnic respiratory failure. Lower gestational age, the use of lower peak inspiratory pressure in the previous conventional mechanical ventilation, reduction in F IO 2 and in capillary P CO 2 , and improvement in pH during the first hour of HFJV were predictors of better outcome.…”

“…Increases in the oxygen saturation index and F IO 2 in 4 h were associated with worse outcome to HFJV. According to the study by Wheeler et al, 11 an increase in the oxygen saturation index within 4 h under HFJV might be an indicator of the need for changes in the ventilation strategy, through either an increase in PEEP, an increase in mean airway pressure, or an unnecessary extension of the period of use of HFJV.…”