Prediction Value Of Central Venous Oxygen Saturation Rate Combined With Diaphragm Ultrasonography In Patients With Mechanical Ventilation

Objective:At present,the indexes used to predict the outcome of withdrawal in clinical practice have defects such as low specificity,complex detection methods and low repeata bility.The change rate of central venous oxygen saturation（?ScvO₂）,diaphragm mobility-shallow rapid breathing index（DE-RSBI）,and diaphragm thickening-fraction-shallow rapid breathing index（DTF-RSBI）were measured during the spontaneous breathing test in critically critical patients in the ICU undergoing invasive mechanical ventilation.Further analysis evaluates whether the combined indexes between?ScvO₂,DE-RSBI,DTF-RSBI and?ScvO₂ and the others can predict the withdrawal outcome of patients with invasive mechanical ventilation.Methods:Patients who received invasive mechanical ventilation for at least 48hours in the Department o f Comprehensive Intensive Care Medicine of our hospital from September 2021 to October 2022 were selected as the subjects of this study.A total of 80 patients met the inclusion a nd exclusion criteria,including53 males and 27 females.According to the fin al withdrawal results,the subjects were divided into succe ssful group and failed group.Collect the research object of general clinical data,in cluding name,gender,age,history o f drinking,smoking,past medical history,acute physiology and chronic heal th evaluation（APACHEⅡ）,Chu Ru Yuan diagnosis,hospitalization,and using breathing machine time,Prognosis:heart rate,respiratory rate,tidal volume,and central venous oxygen saturation（ScvO₂）before withdrawal.Right diaphragm function was monitored by Philips CX50 portable color ultrasound at SBT30min.The liver was used as the window,and the measurement line was selected by two-dimensional ultrasound at the intersection of t he right midclavicular line and the right costal margin.Diaphragmatic moveme nt was monitored and recorded in this mode for at least three complete respiratory cycles.In addition,two-dimensional ultrasound was used to s elect measurement lines in the area between the right midaxillary line and the 8th to 10th ribs before switching to M-ultrasound mode.Diaphragmatic thickness was monitored and record ed in this mode for at least three complete respiratory cycles.After reco rding the above data through the formula to calculate?ScvO₂、DE-RSBI and DTF-RSBI.This experiment data are collected using SPSS27.0 software for statistics and analysis,for measurement data analysis:a normal distribution with mean standard deviation（`x±s）said,between groups use independent sample t-test,non-normal distribution using median M(P_{2 5},P₇₅)said that between groups using r ank and inspection.Count data using frequency,said the group between chi-square（c²）test;the correlation between DE-RSBI,DTF-RSBI and?ScvO₂ is analyzed by Pearson correlation.The combined index of DE-RSBI,DTF-RSBI and?ScvO₂ is analyzed by Logistic regression,the probability is saved,and the receiver operating characteristic curve（ROC）o f each parameter is plotted and the area under the receiver curve（AUC）is calculated.P<0.05 was considered statistica lly significant.Results:（1）A total of 80 p atients were included in this study,including 59 patients in the successful group a nd 21 patients in the failed group.The etiology of respiratory failure,gende r,age,APACHEⅡ,heart rate,respiration,mean arterial pressure,PH,Pa O_2,Pa CO₂,lactic acid,white blood cell count,neutrophil percentage,platelets,hemoglobin,albumin,creatinine,ALT,AST,potassium,sodium,chlorine and hypersensitive C-reactive protein at admission in the successful and failed withdrawal groups There was no statistical difference between ventricular ejection fraction and ventricular ejection fraction（P>0.05）.The duration of invasive ventila tor use and ICU stay in failed group were higher than those in successful group[13（11,17.5）vs 10（8,13）,（22.67±7.82 vs 12.02±4.75）,P<0.05].（2）In the successful group,the?ScvO₂ is lower than that in the failed group（4.15±1.10 vs 4.71±0.86,P<0.05）.DE-RSBI of successful group was lower than that of failed group（1.69±0.26 vs1.99±0.27,P<0.01）.The DTF-RSBI value of the successful group was lower than that of the fai led group（70.88±8.73 vs 82.44±6.74,P<0.01）.（3）ROC curve analysis is carried out on indexes of?ScvO₂、DE-RSBI and DTF-RSBI with statistical difference.The result indicates that the best cut-off value of?ScvO₂ is 4.23%,sensitivity is 56.7%,specificity is 79.0%and AUC is0.646.The optimal critical value,sensitivity,specificity and AUC of DE-RSBI were 1.77,86.4%,61.9%and 0.786 respectively.Tdf-rsbi had an optimal cut-off value of 76.57,sensitivity of 69.5%,specificity of 90.5%and AUC of 0.85.（4）Correlation analysis results showed that DE-RSBI was positively correlated with duration of?ScvO₂（r=0.822,P<0.01）,DTF-RSBI was positively correlated with duration of?ScvO₂（r=0.622,P<0.01）.（5）A binary logistic regression was used to calculate the joint index of?ScvO₂ and DE-RSBI、?ScvO₂ and DTF-RSBI,and to produce ROC curves for the two joint indexes:The best cut-off value for the combined index of?ScvO₂ and DE-RSBI was 0.26,with a sensitivity of 88.1%,specificity of 76.2%,and AU C of0.845;the best cut-off value for the combined index of?ScvO₂ and DTF-RSBI was 0.19,with a sensitivity of 71.2%,specificity of 95.2%,and AUC of 0.845.95.2%,and the AUC was 0.883.Conclusion:（1）?ScvO₂,DE-RSBI and DTF-RSBI are all good indexes to predict the outcome of machine withdrawal;（2）The prediction sensitivity and specificity of?ScvO₂ combined with DE-RSBI and?ScvO₂ combined with DTF-RSBI are higher than the three i ndexes when the single application is applied;（3）The prediction accuracy of?ScvO₂ combined DTF-RSBI to machine withdrawal outcome is higher than that of?ScvO₂ combined DE-RSBI,which can better guide machine withdrawal practice and is worthy of clinic al promotion.