Comparison of hemodynamic effects assessed by Functional Echocardiography between patients on Conventional Mechanical Ventilation and High Frequency-Oscillatory Ventilation

Abstract

Mechanical ventilation is one of the most common therapies in the newborn intensive care unit (NICU), and is associated with increased morbidity and mortality. The effects of positive pressure ventilation especially the HFOV on hemodynamic parameters are known to be complex and contradictory.

This aim of the present study was to compare the hemodynamic effects of the two modalities of assisted ventilation CMV and HFOV at the same mean airway pressure, assessed by Targeted Neonatal Echocardiography.

This randomized control study was conducted from January 2013 till May 2015 in the neonatal intensive care unit (NICU) of Pediatric Hospital, Ain Shams University, Cairo, Egypt. 58 neonates were included in our study, 29 on conventional mechanical ventilation and 29 on high frequency oscillatory ventilation.

Neonates included were those requiring ongoing intensive care and mechanical ventilation, whether preterms or full terms. Patients with Patent Ductus Arteriosus (PDA) were also included. Both groups were of matched gestational age, postnatal age, gender and surfactant administration.

Patients with major congenital cardiac malformations, who were early transfered to another unit, failed to get a parental consent or had no matched patient in the other group were excluded from our study. Patients who were shocked, if a preterm requires adrenaline infusion or if a term requires more than 2 boluses were also excluded from our study.

All patients were subjected to the following: • Full medical history • Thorough clinical examination • Laboratory investigations, CBG, CBC, CRP and Blood culture • Chest X-ray • Transcranial ultrasound • Targeted Neonatal Echocardiography

The studied neonates included 34 males and 24 females, 32 preterm and 26 full term. 10 of our patients were in the first 2 days of life while the rest were older than 2 days of life. 30 were born by spontaneous vaginal delivery and 28 by cesarean section.

We found that most of our patients were ventilated due to congenital pneumonia followed by post operative recovery and RDS. 29% of the patients had sepsis evidenced by positive blood culture, thrombocytopenia and elevated CRP level.

The patients were divided into 2 equal comparable groups, one on CMV and the other on HFOV. There was a significant decrease of pCO2 in neonates on HFOV versus those on CMV.

Cranial ultrasound revealed 11 of the enrolled patients had intracranial hemorrhage. There was a non-significant difference between CMV and HFOV as regards the presence of intracranial hemorrhage.

TNE results showed highly significant positive correlation between the LVEDD and weight. Most importantly, TNE results showed no signif