The Effective Concentration Of Sevoflurane Which Influences The Left Heart Systolic Function By Cardiac Ultrasound

Objective:This essay aims to study the influence of sevoflurane at different concentrationlevels on left heart systolic function by cardiac ultrasound monitoring. It also furtherexplores the effective concentration of sevoflurane which influences the left heartsystolic function.Method:The first part: Choose40patients undergoing elective surgery which usessevoflurane inhalation to induce general anesthesia endotracheal intubation. Thesepatients are aged30to50, ASAI-class II with no cardiovascular and lung diseases. Therandom number table method are used. The patients are divided into4groups accordingto minimum alveolar concentration (MAC).(â… -â…£ group, n=10). The sevofluraneconcentration is1.0MAC,1.5MAC,2.0MAC,2.5MAC, Use multi-functional anesthesiamonitor to record noninvasive arterial systolic pressure(SP), diastolic pressure(DP),heart rate(HR), prior to the induction(T0) and after3min(T1),5min(T2),8min(T3),10min(T4) of reaching the target concentration. At the same time, continue monitoringthe left ventricular with systolic cardiac ultrasound, and record the left ventricularend-diastolic diameter(Dd), end systolic diameter(Ds), left ventricular ejectionfraction(EF), left interior diameter shortening rate(FS), cardiac output(CO). Calculatethe concentration Dd, Ds, EF, FS, the change of CO at various time points.The second part: Choose75patients undergoing elective surgery which uses sevoflurane inhalation to induce general anesthesia endotracheal intubation. Thesepatients are aged30to50, ASA I-class II with no cardiovascular and lung diseases.The random number table method are used. The patients are divided into5groupsaccording to the results of the first part and minimum alveolar concentration (MAC),(â… -V group, n=15). The sevoflurane concentration is1.0MAC,1.5MAC,2.0MAC,2.5MAC, Use multi-functional anesthesia monitor to record noninvasive arterialsystolic pressure(SP), diastolic pressure(DP), heart rate(HR), prior to the induction(T0)and after5min(T1) of reaching the target concentration. At the same time, continuemonitoring the left ventricular with systolic cardiac ultrasound, and record the leftventricular end-diastolic diameter (Dd), end systolic diameter(Ds), left ventricularejection fraction(EF), left interior diameter shortening rate(FS), Calculate theconcentration Dd, Ds, EF, FS, the change of CO at various time points. Calculate thechange of the Ds, EF, FS of each concentration group in T1time and the probability ofconcentration of EF, FS decreasing>10%, and20%in T1time. Use the probability unitregression analysis method[1]to calculate EC50, EC95at the end of the breathingcaused by sevoflurane-inducing left ventricular EF, FS decreasing>10%, and20%andthe corresponding95%confidence interval(CI).Results:The first part:(1) compared with T0, â… group and T1, T2, T3, T4point of SP andDP were significantly decreased, the difference was statistically significant (P <0.05);(2) compared with the T0, II group, T1, T2, T3, T4time point of EF, FS, SP and DP weresignificantly lower, the difference was statistically significant; CO in T2time decreasedobviously, the difference was statistically significant (P <0.05);(3) compared with T0,T1, group III, T2, T3, T4time point of Ds increased significantly, the difference wasstatistically significant; T2, T3, T4time point of EF, FS decreases obviously, thedifference was statistically significant; Compared with T0, T2, T3, T4time points of COdecreases obviously, difference was statistically significant and compared with T1, andCO in T2time decreased obviously, the difference was statistically significant; Compared with T2, T4time point of EF, FS increased obviously, the difference wasstatistically significant; Compared with T0, T1, T2, T3, T4time points of SP and DPdecreased obviously, the difference was statistically significant; Compared with T1, T2,T3, T4time SP decreased obviously, the difference was statistically significant (P <0.05);(4) compared with T0, T1, IV group T2, T3, T4time point of Ds increasedsignificantly, the difference was statistically significant; T2, T3, T4time point of EF, FSdecreases obviously, the difference was statistically significant; Compared with T0, T2,T3, T4time points of CO decreases obviously, difference was statistically significant andcompared with T1, and CO in T2time decreased obviously, the difference wasstatistically significant; Compared with T0, T1, T2, T3, T4time points of SP and DPdecreased obviously, the difference was statistically significant; Compared with T1, T2,T3, T4time SP decreased obviously, the difference was statistically significant (P <0.05). In group IV, changes of SP and DP in T1time are mainly caused by decreasingperipheral vascular resistance; in T2, T3time, the decrease in SP and DP are caused bydual function between peripheral vascular resistance and cardiac function inhibition;While by T4time, the decrease of SP, DP are mainly caused by decreasing peripheralvascular resistance.The second part: â… -IV group, the concentration of EC50at the end of thebreathing when concentrations concentration of EF decreases>10%is1.68MAC and95%confidence interval is1.51-1.82MAC; the EC95is2.31MAC and95%confidenceinterval is2.11-2.71MAC; the concentration of EC50at the end of the breathing whenconcentrations concentration of EF decreases>20%is2.33MAC and95%confidenceinterval is2.19-2.57MAC, the EC95is2.95MAC and95%confidence interval is2.67-3.69MAC; the concentration of EC50at the end of the breathing whenconcentrations concentration of FS decreases>10%is1.51MAC and95%confidenceinterval is1.29-1.64MAC; the EC95is2.10MAC and95%confidence interval is1.92-2.52MAC; the concentration of EC50at the end of the breathing whenconcentrations concentration of FS decreases>20%is2.28and95%confidence intervalis2.12-2.56MAC, the EC95is3.06MAC and95%confidence interval is2.72-3.95MAC. Conclusion:The first part:(1) Within the concentration range of this study, the higherconcentration of sevoflurane has certain inhibitory effect on the left heart function, andit is associated with sevoflurane concentration at the end of the breathing.(2) Theconcentration range of my study, sevoflurane has a small effect on heart rate, but hasobvious inhibitory effect on the blood pressure and indicators of cardiac function withthe concentration increased significantly and achieves maximum effect in5min ofreaching the target concentration.(3) In group â…£, the decrease in SP and DP havesignificant correlation with inhibition of cardiac function after the sevoflurane at the endof the breath reaching target concentration5min and8min later.The second part: The concentration of EC50at the end of the breathing whenconcentrations concentration of EF decreases>10%is1.68MAC and EF decreases>20%is2.33MAC; the concentration of EC50at the end of the breathing whenconcentrations concentration of FS decreases>10%is1.51MAC and FS decreases>20%is2.28MAC.