To determine the efficacy of NAVA ventilatory mode in premature and term neonates and infants as measured by respiratory support needs and gas exchange; to describe the subset of patients to whom NAVA is successfully applied.
NAVA utilization in the neonatal intensive care unit was reviewed for the 9 month period after implementation of the modality (September 2010 to May 2011). Clinical data and markers of gas exchange were recorded at baseline before NAVA, at less than 12 hours and 12-36 hours of NAVA use. Student's paired t-test was used to compare patient response and support needs prior to and after the NAVA trial.
A total of 46 infants were ventilated utilizing NAVA. The mean gestational age at birth was 33 weeks (23-41) and postmenstrual age at time of NAVA was 39 weeks (27-61). 28/46 patients (61%) had a primary diagnosis of respiratory distress syndrome (RDS), meconium aspiration syndrome (MAS) or bronchopulmonary dysplasia (BPD). 10/46 (22%) had congenital heart disease. Other diagnoses included hypoxic-ischemic encephalopathy (HIE), congenital diaphragmatic hernia (CDH), congenital cystic adenomatoid malformation (CCAM) and surgical necrotizing enterocolitis (NEC). The first trial of NAVA for this patient population was continued for a median duration of 72 hours (1 to 1512). There was a significant difference in peak inspiratory pressure (PiP) before NAVA as compared to less than 12 hours and 12 to 36 hours after NAVA. Mean PiP before NAVA was 22 mmHg versus 18 mmHg at less than 12 hours and 12 to 36 hours of NAVA (n=41, p=.0004 and n=38, p=.003; respectively). Lower peak pressures after NAVA were not associated with an increased FiO2 need or a decrease in oxygen saturations. Mean FiO2 was .37 pre NAVA versus .35 at < 12 hours and .3 at 12 to 36 hours (p=NS). Mean saturations were 93% pre NAVA versus 94% at <12 hours and 93% at 12-36 hours. Blood gas measurements including pH and pCO2 were also similar prior to NAVA versus <12 hours and 12 to 36 hours after NAVA.
NAVA is an alternative mode of ventilator support that can be safely used in preterm and term neonates and young infants with a wide range of diagnoses. Utilization of NAVA results in lower peak inspiratory pressures while maintaining adequate ventilation and oxygenation without increased oxygen requirements. Even with the varied clinical diagnoses in the tertiary intensive care nursery, these findings are statistically significant.