The Value Of Lung Ultrasound Score Combined With Diaphragm Excursion In Predicting Extubation Outcome In Mechanically Ventilated Patients With ARDS

OBJECTIVE:To evaluate the value of lung ultrasound score and diaphragm ultrasound in patients with acute respiratory distress syndrome（ARDS）who are expected to weaning from mechanical ventilation,and to analyze whether they can be used as indicators for predicting weaning extubation in patients with ARDS.METHODS:A total of 40 ARDS patients who received oral intubation mechanical ventilation for less than 24 hours in the Intensive Care Unit,Yijishan Hospital from October 2021 to December 2022 were selected.The lung ultrasound score（LUS₁）was recorded by bedside ultrasound,and the general data such as intubation time,arterial blood gas analysis,heart rate,respiratory frequency,mean arterial pressure and tidal volume were recorded.The lung ultrasound score（LUS₂）was performed again before the spontaneous breathing test was performed in the department.The diaphragm excursion(DE₅and DE₃₀)was measured at the 5th and 30th minute of the spontaneous breathing test,and the difference was calculated(ΔDE_30-5).According to the results of SBT and extubation,the patients were divided into two groups:successful group（n=25）and failure group（n=15）.The clinical data and ultrasonic examination results of the two groups were statistically analyzed,and the indexes with statistical differences were analyzed by binary logistic regression.The receiver operating characteristic curve（ROC）was drawn,and the area under curve（AUC）was calculated to evaluate the value of lung ultrasound score and diaphragm excursion in predicting the outcome of extubation.RESULTS:1.There was no significant difference in sex,age,oxygenation index,APACHE II score,vital signs and ventilator parameters between the successful group and the failure group（P>0.05）.2.Compared with the successful group,the failure group had higher respiratory frequency and shallow fast breathing index（RSBI）,lower tidal volume and oxygenation index,and longer mechanical ventilation time during SBT.There was no significant difference in heart rate and mean arterial pressure between the two groups（P>0.05）.3.The lung ultrasound score before extubation,diaphragm excursion(DE₅and DE₃₀)andΔDE_30-5during SBT were compared between the two groups.Binary Logistic regression analysis showed that LUS₂（P=0.037,OR=0.664）and DE₃₀（P=0.015,OR=20.176）were the independent factors of extubation failure in ARDS patients.4.ROC curve analysis shows that when the AUC of LUS₂is 0.765（95%CI:0.615-0.916）with a cut-off value of 15.5,the corresponding sensitivity is 80.0%,the specificity is 60.0%,and the AUC of the change rate of LUS is0.800（95%CI:0.657-0.943）with a cut-off value of 0.275,the corresponding sensitivity is 76.0%,and the specificity is 80.0%.The AUC of DE₅is 0.704,the AUC of DE₃₀is0.839,and the AUC ofΔDE_30-5is 0.845.When with a cut-off value ofΔDE_30-5is0.233cm,the sensitivity is 88.0%and the specificity is 80.0%.The AUC of lung ultrasound score combined withΔDE_30-5was 0.861（95%CI:0.737-0.986）,the sensitivity of combined prediction was 84.0%,and the specificity was 80.0%.The AUC of lung ultrasound score change rate combined with DE₃₀was 0.885（95%CI:0.779-0.991）,and the sensitivity and specificity of combined prediction were 84.0%and 86.7%.CONCLUSION:The lung ultrasound score and diaphragm excursion add an accurate and simple non-invasive index for ARDS patients to extubation.It is suggested that it could be added to the parameters for predicting the outcome of weaning extubation.