Comparison of Ventilator’sWork of Breath Cased on Constant Flow Nasal CPAP Through Pressure Limited and Electronic Feedback Pressure Control Mechanisms in the Treatment of RDS in Neonates Weighing About 1000 Grams

Background: Continuous distending pressure (CDP) is considered as standard care in neonates with decreased pulmonary compliance. Concerns regarding the implementation of non-invasive CDP in a respiratory cycle in order to establish an optimal level of functional residual capacity (FRC) abound in the related literature. Examples include how to manage gas leakage in the interface, no imposed increased work of breath (WOB) on patients and prevention of applying trans-pulmonary pressure levels leading to metabolic acidosis. Following the development of autoflow hardware, pressure control (PC) respiratory pattern was defined in the field of mechanical ventilation (MV) in order to compensate for gas leakage in interface or compensate for pressure drop and increased CDP pressure level in respiratory phases of inspiration and expiration. Objectives: The study aimed at decreasing WOB in neonates with RDS using pressure control-nCPAP. Methods: This study was a retrospective clinical trial performed on 70 neonates weighing about 1000 grams with RDS. Participants were randomly assigned into two respiratory support groups based on the use of pressure limited nCPAP (PL-nCPAP) and pressure control nCPAP (PC-nCPAP). Each group consisted of 35 infants compared in terms of their demographic characteristics, duration of non-invasive respiratory support, rapid shallow breathing (RSB) index, ventilator’s WOB, need for MV, need for surfactant administration, chronic lung diseases, pneumothorax, intra-ventricular hemorrhage (IVH) and death. Results: No significant difference was observed between the mean time of non-invasive respiratory support and the need for MV, between the incidence of pneumothorax and IVH and also between the mortality rate and degree of involvement in chronic lung diseases in the two groups. The mean respiratory ventilation rate of ventilator’s WOB in PC-nCPAP group was significantly higher than that of PL-nCPAP group. The mean RSB index was also significantly higher in PL-nCPAP group than in PC-nCPAP group. Finally, the mean of surfactant administration in PL-nCPAP group was significantly higher than that in PC-nCPAP group. Conclusions: In this study, ventilator’s WOB in PC-nCPAP group, which was significantly higher than that of PL-nCPAP group, can be explained by significantly higher RSB index in PL-nCPAP group and significantly lower mean surfactant prescription in PC-nCPAP group.