Comparing High-Frequency Ventilation and Conventional Ventilation on Morphology of Brain, Kidney and Liver in Preterm Babies with Respiratory Distress

Abstract

Background: The increase in the ventilator rates by conventional mechanical ventilation (CMV) is limited by a minimum amount of time needed for a complete inspiration and expiration. In preterm babies with respiratory distress syndrome, it may not be sufficient to manage the hypercapnia and hypoxia associated. High-frequency ventilation (HFV) can be considered as a substitute for CMV in premature infants by increasing the ventilator rate further and reducing the tidal volume. The current study evaluates the efficacy and effects on brain, liver and kidney morphology of HFV in preterm babies with respiratory distress. Methods: This prospective and analytical study was conducted from December 2011 to January 2013 on 83 preterm babies’ with an initial provisional diagnosis of respiratory distress that needed respiratory support at birth or soon after admission. Initial and follow up blood gas (BG) and cranial U/S, and renal and hepatic function tests were done. Results: The study was conducted on 83 preterm babies, aged less than 37 weeks of gestation, who were divided into control (40) and study (43) groups. The study group showed significantly higher PEEP and PIP values than control in CMV and were shifted to HFV thereafter. The control group needed only CMV. After the intervention, statistically significant improvement in arterial blood gas parameters with respect to blood pH, pCO2 and pO2. The mean blood pH was found to be 7.386 ±0.039, with increase in mean pO2 (before shift =45.44±4.36 vs. after shift=40.56 ±2.597 mm Hg respectively, p= 0.01) and decrease in mean pCO2 (before shift= 38.23±0.03 vs. after shift=42.87 ± 6.915 mm Hg respectively, p=0.01). We can say that HFV helped to reduce acidosis, hypoxia, and hypercapnia in the neonates in the study group. In terms of renal functions, the serum sodium content marginally increased with HFV (After shift= 136.00±3.910 vs. before shift=135.00±5.686 mol/l, p=0.000), Significant increase in mean 24-hour urinary creatinine from their initial CMV values after subjecting them to HFV (before shift 14.509± 4.874 mg/dl vs after shift 15.340±7.054 mg/dl, p=0.002). In terms of hepatic functions, significant difference was observed after intervention was detected with higher PT in HFV group (0.01); on the other hand, no significant difference regarding ALT, PTT and fibrinogen between study and control groups was detected after HFV intervention. Brain ultra-sound scan (BUSS) results showed that the intraventricular haemorrhage (IVH) was reduced in the HFV group as compared to the CMV group. BUSS outcome also showed that there is a significant correlation between IVH and surfactant medication. Conclusion: Rescue HFV improved oxygenation, ventilation, lung recruitment and better oxygenation indices and there was no increased incidence of IVH. In addition, HFV had no deleterious effect on other organs such as the brain, kidney and liver.