Improved nutritional outcomes with neurally adjusted ventilatory assist (NAVA) in premature infants: a single tertiary neonatal unit\u2019s experience

Abstract

During neurally adjusted ventilatory assist (NAVA)/non-invasive (NIV) NAVA, a modified nasogastric feeding tube with electrodes, monitors the electrical activity of the diaphragm (Edi). The Edi waveform determines the delivered pressure from the ventilator. Infant breathing is in synchrony with the ventilator and therefore is more comfortable with less work of breathing. Our aim was to determine if infants on NAVA had improved nutritional outcomes compared to infants managed on conventional respiratory support. A retrospective study was undertaken. Infants on NAVA were matched with two conventionally ventilated controls by gestational age, birth weight, sex, antenatal steroid exposure, and whether inborn or transferred ex utero. NAVA/NIV-NAVA was delivered by the SERVO-n® Maquet Getinge group ventilator. Conventional ventilation included pressure and volume control ventilation, and non-invasive ventilation included nasal intermittent positive pressure ventilation, triggered biphasic positive airway pressure, continuous positive airway pressure and heated humidified high flow oxygen. The measured outcome was discharge weight z scores. Eighteen “NAVA” infants with median gestational age (GA) of 25.3 (23.6–27.1) weeks and birth weight (BW) of 765 (580–1060) grams were compared with 36 controls with GA 25.2 (23.4–28) weeks (p = 0.727) and BW 743 (560–1050) grams (p = 0.727). There was no significant difference in the rates of postnatal steroids (61% versus 36% p = 0.093), necrotising enterocolitis (22% versus 11% p = 0.279) in the NAVA/NIV NAVA compared to the control group. There were slightly more infants who were breastfed at discharge in the NAVA/NIV NAVA group compared to controls: breast feeds (77.8% versus 58.3%), formula feeds (11.1% versus 30.6%), and mixed feeds (11.1% versus 11.1%), but this difference was not significant (p = 0.275). There was no significant difference in the birth z scores 0.235 (−1.56 to 1.71) versus −0.05 (−1.51 to −1.02) (p = 0.248) between the groups. However, the discharge z score was significantly in favour of the NAVA/NIV-NAVA group: −1.22 (−2.66 to −0.12) versus −2.17 (−3.79 to −0.24) in the control group (p = 0.033).Conclusion: The combination of NAVA/NIV-NAVA compared to conventional invasive and non-invasive modes may contribute to improved nutritional outcomes in premature infants.What is known about this topic:• Neurally adjusted ventilatory assist (NAVA) ventilation enables synchronisation of both the start and end of an inflation breath and allows the neonate to initiate their own breath and regulate.What this study adds: • NAVA when offered to extremely premature infants may have additional benefit of improved nutritional outcomes.