Influential Factors Of High Frequency Oscillatory Ventilation Complicated With Hypocapnia In Newborns

Objective:To explore the influential factors related to hypocapnia in newborns treated by high frequency oscillatory ventilation?HFOV?.It will provide guide to rational use clinical practice and improve the prognosis of newborns.Methods:A retrospective study was conducted in 79 newborns whose were treated by HFOV in the department of neonatology from January 2016 to June 2018.Newborns were divided into hypocapnia group?44 cases?and non-hypocapnia group?35 cases?according to whether hypocapnia occurred after HFOV.The relationship between the general condition,the underlying disease,ventilator parameters:expiratory tidal volume/kg?VTe/kg?,amplitude??P?,mean airway pressure?MAP?,frequency?F?,fraction of inspired oxygen?FiO₂?and the occurrence of hypocapnia was analyzed.Results:Newborns in hypocapnia group?34.70±3.47?compared with non-hypocapnia group?36.31±3.52?had lower gestational age?P<0.05?and lower birth weight?P<0.05?.Newborns in hypocapnia group compared with non-hypocapnia group had more neonatal respiratory distress syndrome?NRDS??P<0.05?and more treated with pulmonary surfactant?PS??P<0.05?.The parameters of ventilator in the hypocapnia group?2.34±0.22,35.93±2.25,12.82±2.11,10.50±0.98?compared with non-hypocapnia group?2.10±0.26,34.43±2.60,10.97±2.18,11.20±1.55?had a higher VTe/Kg,?P,MAP?P<0.05?but lower F?P<0.05?.PaCO₂ in the hypocapnia group has a linear relationship with VTe/Kg and MAP,and establishes a regression quation by multiple linear regression:PaCO₂=-8.66VTe/Kg-0.86MAP+59.31?r=0.83,r²=0.69,P<0.05?.44 cases with hypocapnia after adjusting for ventilator parameters F,?P and MAP were were corrected and successfully withdrawn ventilator.Conclusion:Low gestational age,low birth weight,NRDS,treated with PS and ventilator parameters were related to hypocapnia in newborns after HFOV treatment.HFOV can improves CO₂ excretion by regulating F,?P,MAP and monitoring VTe to maintain PaCO₂ in the normal range.