Physiological effects of invasive ventilation with neurally adjusted ventilatory assist (NAVA) in a crossover study.

BACKGROUND: Neurally Adjusted Ventilatory Assist (NAVA) is a mode of assisted mechanical ventilation that delivers inspiratory pressure proportionally to the electrical activity of the diaphragm. To date, no pediatric study has focused on the effects of NAVA on hemodynamic parameters. This physiologic study with a randomized cross-over design compared hemodynamic parameters when NAVA or conventional ventilation (CV) was applied. METHODS: After a baseline period, infants received NAVA and CV in a randomized order during two consecutive 30-min periods. During the last 10 min of each period, respiratory and hemodynamic parameters were collected. No changes in PEEP, FiO2, sedation or inotropic doses were allowed during these two periods. The challenge was to keep minute volumes constant, with no changes in blood CO2 levels and in pH that may affect the results. RESULTS: Six infants who had undergone cardiac surgery (mean age 7.8 ± 4.1 months) were studied after parental consent. Four of them had low central venous oxygen saturation (ScvO2 < 65 %). The ventilatory settings resulted in similar minute volumes (1.7 ± 0.4 vs. 1.6 ± 0.6 ml/kg, P = 0.67) and in similar tidal volumes respectively with NAVA and with CV. There were no statistically significant differences on blood pH levels between the two modes of ventilation (7.32 ± 0.02 vs. 7.32 ± 0.04, P = 0.34). Ventilation with NAVA delivered lower peak inspiratory pressures than with CV: -32.7 % (95 % CI: -48.2 to -17.1 %, P = 0.04). With regard to hemodynamics, systolic arterial pressures were higher using NAVA: +8.4 % (95 % CI: +3.3 to +13.6 %, P = 0.03). There were no statistically significant differences on cardiac index between the two modes of ventilation. However, all children with a low baseline ScvO2 (<65 %) tended to increase their cardiac index with NAVA compared to CV: 2.03 ± 0.30 vs. 1.91 ± 0.39 L/min.m2 (median ± interquartile, P = 0.07). CONCLUSIONS: This pilot study raises the hypothesis that NAVA could have beneficial effects on hemodynamics in children when compared to a conventional ventilatory mode that delivered identical PEEP and similar minute volumes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01490710 . Date of registration: December 7, 2011.

A Nursing Survey on Nutritional Care Practices in French-Speaking Pediatric Intensive Care Units: NutriRéa-Ped 2014.

OBJECTIVES: Malnutrition in critically ill children contributes to morbidity and mortality. The French-speaking pediatric intensive care nutrition group (NutriSIP) aims to promote optimal nutrition through education and research. METHODS: The NutriSIP-designed NutriRéa-Ped study included a cross-sectional survey. This 62-item survey was sent to the nursing teams of all of the French-speaking pediatric intensive care units (PICUs) to evaluate nurses' nutrition knowledge and practices. One nurse per PICU was asked to answer and describe the practices of their team. RESULTS: Of 44 PICUs, 40 responded in Algeria, Belgium, Canada, France, Lebanon, Luxemburg, and Switzerland. The majority considered nutrition as a priority care but only 12 of the 40 (30%) had a nutrition support team, 26 of the 40 (65%) had written nutrition protocols, and 19 of 39 (49%) nursing teams felt confident with the nutrition goals. Nursing staff generally did not know how to determine nutritional requirements or to interpret malnutrition indices. They were also unaware of reduced preoperative fasting times and fast-track concepts. In 17 of 35 (49%) PICUs, the target start time for enteral feeding was within the first 24 hours; however, frequent interruptions occurred because of neuromuscular blockade, fasting for extubation or surgery, and high gastric residual volumes. Combined pediatric neonatal intensive care units were less likely to perform systematic nutritional assessment and to start enteral nutrition rapidly. CONCLUSIONS: We found a large variation in nursing practices around nutrition, exacerbated by the lack of nutritional guidelines but also because of the inadequate nursing knowledge around nutritional factors. These findings encourage the NutriSIP to improve nutrition through focused education programs and research.

Respiratory support by neurally adjusted ventilatory assist (NAVA) in severe RSV-related bronchiolitis: a case series report.

BACKGROUND: Neurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation controlled by diaphragmatic electrical signals. The electrical signals allow synchronization of ventilation to spontaneous breathing efforts of a child, as well as permitting pressure assistance proportional to the electrical signal. NAVA provides equally fine synchronization of respiratory support and pressure assistance varying with the needs of the child. NAVA has mainly been studied in children who underwent cardiac surgery during the period of weaning from a respirator. CASE PRESENTATION: We report here a series of 3 children (1 month, 3 years, and 28 days old) with severe respiratory distress due to RSV-related bronchiolitis requiring invasive mechanical ventilation with a high level of oxygen (FiO2 ≥ 50%) for whom NAVA facilitated respiratory support. One of these children had diagnosis criteria for acute lung injury, another for acute respiratory distress syndrome.Establishment of NAVA provided synchronization of mechanical ventilatory support with the breathing efforts of the children. Respiratory rate and inspiratory pressure became extremely variable, varying at each cycle, while children were breathing easily and smoothly. All three children demonstrated less oxygen requirements after introducing NAVA (57 ± 6% to 42 ± 18%). This improvement was observed while peak airway pressure decreased (28 ± 3 to 15 ± 5 cm H2O). In one child, NAVA facilitated the management of acute respiratory distress syndrome with extensive subcutaneous emphysema. CONCLUSIONS: Our findings highlight the feasibility and benefit of NAVA in children with severe RSV-related bronchiolitis. NAVA provides a less aggressive ventilation requiring lower inspiratory pressures with good results for oxygenation and more comfort for the children.