Study On Severity And Outcome In Children With Acute Respiratory Distress Syndrome By Measurement Of Alveolar Dead Space Fraction

Objective:To investigate the role of alveolar dead space fraction?ADSF?on the severity and outcome among children with acute respiratory distress syndrome?ARDS?.Methods:Totally 20 children with ARDS in early stage were enrolled in this prospective study from December 2016 to November 2017 in PICU of Shengjing Hospital affiliated to China Medical University,and ADSF was measured by ADSF=?PaC0₂-PetCO₂?/PaCO₂.The general situation,critical severity score,duration of mechanical ventilation,length of hospital stay,and blood PH,PaO₂,PaCO₂,FiO₂,PetCO₂,oxygenation index?P/F,O/I?,mean airway pressure?MAP?,treatment and outcome were recorded and evaluated.These variables were analyzed by usingstudent's t-test,non-parametric test and ROC to analyse the relationship between the severity of ADSF and ARDS children,and the predictive value of the prognosis.Results:A total of 20 patients were divided into two groups according to the severity,one was mild to moderate group with 12 patients and another was severe group with 8patients.There were no significant differences in blood PH,PetCO₂,critical severity score,ventilation time,and length of hospital stay between the two groups?P>0.05?.Compared with the mild to moderate group,the PaO₂ and P/F value of the severe group was significantly decreased,and the FiO₂,PEEP,PaCO₂,OI and ADSF were significantly increased?P<0.05?.?2?Among the 20 cases,11 survived and 9 died.There were no significant differences in blood PH,critical severity scores and length of hospital stay between the death group and the survivor group?P>0.05?.Compared with the survival group,the PaO₂ and P/F value of the death group was significantly lower,the ventilation time,FiO₂,PEEP,PaCO₂,PetCO₂,OI and ADSF were significantly higher?P<0.05?.The area under the ROC judged by ADSF was 0.690?P<0.05?.If we take 0.338 as the critical value to evaluate the prognosis,the sensitivity and specificity for judging death were 0.704 and 0.634,respectively.The AUC of predicting the prognosis with OI was 0.720?P<0.05?.If we take 0.348 as the critical value to predict death,the sensitivity and specificity of 0.551 and 0.797 respectively.The area under the ROC judged by P/F was 0.256?P>0.05?.Conclusion:The ADSF on early stage was higher in children with severe ARDS than those with mild to moderate ARDS.The ADSF on early stage was higher in death group than that in survival group.ADSF is of guiding significance in the prognosis of ARDS.