The impact of neurally adjusted ventilatory assist mode on respiratory severity score and energy expenditure in infants: a randomized crossover trial.

OBJECTIVE: Examine respiratory severity scores (RSS) (mean airway pressure × fraction of inspired oxygen) and resting energy expenditure (REE) on neurally adjusted ventilatory assist (NAVA) compared with synchronized intermittent mandatory ventilation with pressure controlled and supported breath (SIMV (PC)PS). STUDY DESIGN: A randomized, crossover trial in a level IV neonatal intensive care unit. Twenty-four patients were ventilated with NAVA or SIMV (PC) PS for 12 h and then crossed over to the alternative mode for 12 h. The primary outcome (RSS) and additional secondary respiratory outcomes were analyzed. RESULTS: RSS and measured REE were not different between modes. On NAVA, peak inspiratory pressures were lower (17.8 vs 19.9 cmH2O (P<0.05)) without higher oxygen requirements. Respiratory rates were higher on NAVA (52 vs 39 (P<0.05)), estimated work of breathing (WOB) (0.01 vs 0.04 J l-1 (P<0.05)) was improved. CONCLUSION: NAVA mode can be safe without increase in RSS or REE. Although respiratory rates were higher, this was offset by lower peak inspiratory pressures and WOB during NAVA.

Factors leading to rehospitalization for tracheostomized and ventilator-dependent infants through 2 years of age.

OBJECTIVE: To identify factors leading to readmission for tracheostomized, ventilator-dependent infants <2 years of age. STUDY DESIGN: Retrospective cohort study of 117 tracheostomized, ventilator-dependent infants followed through 2 years of age. RESULTS: Home ventilator use (at hospital discharge, 6 and 12 months of age), inhaled steroid use (at 12 and 24 months of age), oxygen dependence (at 6 and 12 months of age) and tracheostomy (at discharge, 6 and 12 months of age) were increased risks for rehospitalization. Equipment malfunction throughout the first 2 years also contributed to readmissions. Viral infection, with rhinovirus/enterovirus the most commonly identified pathogen, was the most common etiology for rehospitalization. Diuretic use and initial comorbid diagnoses were not associated with increased risk of rehospitalization. CONCLUSION: The risk for rehospitalization for infants requiring tracheostomy and ventilator support was affected by prolonged oxygen use, prolonged ventilator dependence, inhaled steroid use and equipment malfunction, and was equally distributed throughout the first 2 years of life.

Infants born at <29 weeks: pulmonary outcomes from a hybrid perinatal system.

OBJECTIVE: To assess pulmonary outcomes of infants <29 weeks gestational age (GA), delivered at level I, II and III facilities, to identify potentially modifiable factors affecting bronchopulmonary dysplasia (BPD) severity and to assess the external generalizability of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) BPD Outcome Estimator. STUDY DESIGN: Outcomes for infants <29 weeks GA born during (2008-2010) and delivered either at an inborn level III center or in a level II or III metropolitan area hospital with transfer to a level IV center, or delivered in a distant level I or II center and then transported to a level IV center were assessed. BPD severity was compared with the NICHD Neonatal BPD Outcome Estimator. RESULT: Of 158 infants who comprised the cohort, 28 (17.8%) had no BPD, 39 (24.2%) had mild BPD, 45 (28.7%) had moderate BPD, 31 (19.7%) had severe BPD and 15 (9.6%) died at ≤36 weeks post menstrual age. Site of birth did not predict severe BPD or death. Receiver operator characteristic curves showed fair predictability for none/mild and severe BPD. CONCLUSION: BPD severity was not dependent on site of birth. The NICHD BPD outcome estimator provides fair prediction for extreme outcomes.

Ureaplasma urealyticum modulates endotoxin-induced cytokine release by human monocytes derived from preterm and term newborns and adults.

We previously observed that Ureaplasma urealyticum respiratory tract colonization in infants with a birth weight of < or =1,250 g was associated with increases in the tracheal aspirate proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-8 (IL-8) relative to the counterregulatory cytokine IL-6 during the first week of life (A. M. Patterson, V. Taciak, J. Lovchik, R. E. Fox, A. B. Campbell, and R. M. Viscardi, Pediatr. Infect. Dis. J. 17:321-328, 1998). We hypothesized that U. urealyticum alters the host immune response in the presence of a coinflammatory stimulus (e.g., bacterial infection or hyperoxia) by shifting the balance of cytokine expression towards the proinflammatory cytokines. To test this hypothesis, we compared the release of TNF-alpha, IL-8, IL-6, and IL-10 in vitro by unstimulated and U. urealyticum (with or without lipopolysaccharide [LPS])-stimulated human monocytes from adult peripheral blood and from term and preterm cord blood. U. urealyticum alone and in combination with LPS induced concentration- and development-dependent changes in cytokine release. In vitro inoculation with low-inoculum U. urealyticum (10(3) color-changing units [CCU]) (i) partially blocked the LPS-stimulated IL-6 release by all cells and reduced LPS-stimulated IL-10 release by preterm cells, (ii) stimulated TNF-alpha and IL-8 release by preterm cells, and (iii) augmented LPS-stimulated TNF-alpha release in all cells. In preterm cells, high-inoculum U. urealyticum (10(6) CCU) (i) stimulated TNF-alpha and IL-8, but not IL-6 or IL-10, release and (ii) augmented LPS-stimulated TNF-alpha and IL-8 release. High-inoculum U. urealyticum (i) stimulated release of all four cytokines in term cells and IL-8 release in adult cells and (ii) augmented LPS-induced TNF-alpha, IL-10, and IL-8 release in term cells but did not significantly affect LPS-induced cytokine release in adult cells. We speculate that U. urealyticum enhances the proinflammatory response to a second infection by blocking expression of counterregulatory cytokines (IL-6 and IL-10), predisposing the preterm infant to prolonged and dysregulated inflammation, lung injury, and impaired clearance of secondary infections.