RESUMO
BACKGROUND: High flow nasal cannula (HFNC) improves ventilation by washing out nasopharyngeal dead space while delivering oxygen. Heliox (helium-oxygen gas mixture), a low-density gas mixture, decreases resistance to airflow, reduces the work of breathing, and facilitates distribution of inspired gas. Excessive lung work and potential injury increases the workload on the immature diaphragm predisposing the muscle to fatigue, and can lead to inflammatory and oxidative stress, thereby contributing to impaired diaphragmatic function. We tested the hypothesis that HFNC with Heliox will decrease the work of breathing thereby unloading the neonatal diaphragm, and potentially reducing diaphragmatic injury. METHODS: Spontaneously breathing neonatal pigs were randomized to Nitrox (nitrogen-oxygen gas mixture) or Heliox, and studied over 4 hr following oleic acid injury. Gas exchange, pulmonary mechanics indices, and systemic markers of inflammation were measured serially. Diaphragm inflammation biomarkers and histology for muscle injury were assessed at termination. RESULTS: Heliox breathing animals demonstrated decreased respiratory load and work of breathing with lower pressure-rate product, lower labored breathing index, and lower levels of diaphragmatic inflammatory markers, and muscle injury score as compared to Nitrox. CONCLUSION: These results suggest that HFNC with Heliox is a useful adjunct to attenuate diaphragmatic fatigue in the presence of lung injury by unloading the diaphragm, resulting in a more efficient breathing pattern, and decreased diaphragm injury.
Assuntos
Lesão Pulmonar Aguda/terapia , Diafragma/lesões , Hélio/administração & dosagem , Oxigenoterapia/métodos , Oxigênio/administração & dosagem , Trabalho Respiratório , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Fadiga Muscular/efeitos dos fármacos , Nitrogênio/administração & dosagem , Distribuição Aleatória , SuínosRESUMO
BACKGROUND AND OBJECTIVE: Pneumothorax is common in very low birth weight (VLBW) infants. In our NICU, we noted an above average incidence of pneumothorax compared with similar NICUs based on Vermont Oxford Network benchmarking. The quality improvement project was designed to decrease the incidence of pneumothorax in VLBW infants in a tertiary care NICU. METHODS: The project was divided into 2 periods. During period 1, all VLBW infants were followed for 6 months for the presence of pneumothorax. A multidisciplinary team met regularly to review cases of pneumothorax and identify potential causes. High tidal volumes (VT) (>6 mL/kg) were noted around the time of occurrence of pneumothorax. Guidelines were developed for improved monitoring and rapid feedback of VT and peak inspiratory pressure between nursing staff and clinicians. During period 2, these guidelines were implemented and VLBW infants were again followed for 6 months. The incidence of pneumothorax was tracked. Run charts were used to monitor changes. RESULTS: The incidence of pneumothorax in VLBW infants decreased from 10.4% to 2.6% after the intervention (P = .04). By using process control, a reduction in pneumothorax was achieved in period 2. CONCLUSIONS: Increased vigilance and real-time monitoring of VT and peak inspiratory pressure decreased the incidence of pneumothorax in our population of VLBW infants. These interventions can be considered in other NICUs with an above-average risk adjusted incidence of pneumothorax in VLBW infants. Our data illustrate the benefits of comparative benchmarking and organized quality improvement in advancing patient care outcomes.