Relationship Between The Results Of Lung Ultrasound Examination And New Hypoxemia In PACU

Objective:the characteristics of lung ultrasound in patients undergoing abdominal surgery were observed in this study,to explore the ability of LUS examination results to predict the risk of new hypoxemia after extubation in Post-Anesthesia Care Unit patients.Methods:333 patients with elective abdominal surgery,aged 18～89 years,were examined by LUS before operation（T₀）,in PACU（T₁）and 20 minutes after extubation（T₂）,and the LUS scores were recorded respectively as LUSS₀,LUSS₁and LUSS₂.At T₂,the patient’s arterial blood gases was analyzed and the oxygenation index（Pa O₂/Fi O₂）was recorded.Pa O₂/Fi O₂≤300 is considered as hypoxemia,while Pa O₂/Fi O₂>300 non-hypoxemia group.The receiver operating characteristic curve was constructed to evaluate the ability of LUSS₁to predict the risk of hypoxemia after extubation,and explore the causes of hypoxemia.Results:1.Among 333 patients undergoing abdominal surgery,31 patients had new hypoxemia at T₂（9.31%）.24 cases（77.42%）of lung consolidation or atelectasis,3cases（9.68%）of extravascular lung water increase and 1 case（3.23%）of right pneumothorax were found by LUS examination.The rest 3 cases（9.68%）with hypoxemia had no obvious abnormal signs of LUS.2.Compared with T₀,LUSS of hypoxemia group and non-hypoxemia group increased significantly at T₁and T₂（P<0.05）.Compared with T₁,LUSS decreased slightly at T₂（P>0.05）with no significant difference in both group.3.At T₁,comparing LUSS₁between hypoxemia patients and non-hypoxemia patients,it was found that when LUSS₁<7,patients were less likely to have hypoxemia after extubation,while patients with LUSS₁>10 had higher risk of hypoxemia after extubation,and the blood oxygen did not improve until PACU.The area under the receiver operating characteristic curve（AUC）is 0.873.In addition,the risk of hypoxemia after extubation increased when the number of lung consolidation was more than or equal to 2 in LUS examination at T₁（P<0.001）.Conclusion:LUS examination can effectively predict the risk of hypoxemia after extubation,and provide a good diagnostic value for postoperative hypoxemia,which can be used for rapid assessment of pulmonary condition in perioperative patients.