Predictive Value Of Involuntary Cough Peak Flow On Reintubation In ICU Patients

Objective:To discuss the effect of involuntary cough peak flow on prediction of reintubation and prognosis in ICU patients with endotracheal intubation.Method:48 patients who were undergoing endotracheal intubation and ventilator assisted breathing for more than 24 hours were selected according to inclusion and exclusion criteria from November 2018 to March 2019 in the intensive care department of our hospital.All patients underwent cuff leak test when the primary disease was improved,and the positive patients were given40mg Methylprednisolone intravenously 24 hours before extubation.The Spontaneous Breathing Trial（SBT）was carried out using Pressure Support Ventilation（PSV）during daily sifting tests.After SBT,arterial blood gas analysis was performed.If SBT succeeded,involuntary cough peak flow would be measured in patients.The doctors decided whether to remove the endotracheal tube or not.The Acute Physiology And Chronic Heath Evaluation（APACHEII）,the Rapid Shallow Breathing Index（RSBI）,the involuntary cough peak flow,were compared during the variables of the successful extubation group and the failure group.Besides,the independent risk factors of the extubation failure were found out through Logistic regression analysis.Results:1.In all 48 cases of ICU patients through SBT,there were 29 males and19 females respectively.There were 38 successful extubation cases and 10failed extubation cases.In terms of demographic characteristics and prognosis,there were no significant differences in gender,age,Body Mass Index（BMI）,APACHEII score between the successful extubation group and the failed group（P>0.05）.The failure group had longer mechanical ventilation time,longer ICU stay,higher tracheotomy rate and higher mortality（P<0.05）.There was no significant difference in mental state and Glasgow Scale（GCS）between successful and unsuccessful extubation groups.In terms of blood flow dynamics and gas exchange parameters,success and failure group extubation cuff leakage,Maximal Inspiratory Pressure（MIP）,RSBI,the amount Of sputum,systolic pressure,diastolic blood pressure,heart rate,breathing,the value of PH,Partial Pressure Of Carbon Dioxide（PaCO₂）,oxygenation index had no significant difference.There were significant differences between the two groups in involuntary cough peak flow and Partial Pressure Of Oxygen（PaO₂）（P<0.05）.2.The analysis of independent risk factors in extubation failure and the predictive ability of extubation outcomeBinary Logistic linear regression analysis was performed on involuntary cough peak flow and PaO₂ with statistical significance in the univariate analysis.The results showed that both involuntary cough peak flow and PaO₂were independent risk factors for failure of extubation in patients with SBT mechanical ventilation（P<0.05）.Peak flow of involuntary cough was（OR=1.055,95%CI[1.004,1.110],P<0.035）,PaO₂（OR=1.135,95%CI[1.008,1.219],P<0.037）.ROC curve was drawn based on the relationship between measured values of reflected cough peak velocity,PaO₂,new variable Y and extubation results at 48h.It was found that the AUC of predicting extubation outcome with involuntary cough peak flow was 0.834,95%CI（0.689,0.979）.The optimal critical point was 71.15L/min.When the involuntary cough peak flow was under 71.15L/min,the specificity of extubation failure prediction was 90%,and the sensitivity was 78.9%.When used PaO₂ to predict the extubation outcome,AUC was 0.812,95%CI（0.667,0.957）.The optimal critical point was 71mmHg.When PaO₂ was under71mmHg,the specificity of predicting extubation failure was 60%,and the sensitivity was 92.1%.When both of them were used together to predict the outcome of extubation,the AUC of the new variable Y was more than that of the single index.Conclusion:1.Involuntary cough peak flow and PaO₂ have predictive value for reintubation in ICU patients undergoing mechanical ventilation via SBT.2.Involuntary cough peak flow and PaO₂ are independent risk factors for prediction of reintubation.