The Effects Of Different Limb Remote Ischemic Postconditioning On Serum Concentration Of Serum CTnT During And After Valve Replacement Surgery And Postoperative Recovery

Objective To investigate the effects of two methods of remote limb ischemicpostconditioning on serum cTnT, postoperative recover concentration duringvalve replacement surgery under cardiopulmonary bypass in adult patients. Toexplore myocardium protective effect of the two different limb remote ischemicpostconditioning. Methods Forty-eight Patients who are scheduled for valvereplacement surgery under cardiopulmonary bypass were enrolled andrandomly divided into three groups: controlled group(group C，n=16), rightupper limb remote ischemic postconditioning group(group S，n=16) and leftlower limb remote ischemic postconditioning group(group X, n=16).Premedicated with penehyclidine hydrochloride0.01~0.02mg/kg, all patientswere induced with intravenous sedative、analgesic、muscle relaxants followedby intratracheal Intubation and ventilation, and then maintained by continuousintravenous infusion of fentanly, midazolam and vecuronium, In addition toupper and lower limbs，In group C，no any treatment was processed, Theother methods and treatments are the same as the S group and X group. Ingroup S, immediately after aorta declamping, tourniquet fasten to the rightupper extremity was inflated (6cm wide, the lower edge2~3cm away fromelbow joint, pressure maintained at200mmHg), lasted for3minutes to blockthe bloodstream of the right upper limb, then deflated to reperfuse for3minutes.The above process repeated3times (18minutes in total). MAP maintained inrange of50~70mmHg during extracorporeal circulation. In group X, whenimmediate aorta declamped, tourniquets fasten to the left lower limb (8.0cm wide, lower edge3~4cm away from knee joint, maintain at250mmHg) wereinflated and lasted for3minutes to block bloodstream to the limb, then deflatedcuff to reperfuse for3minutes. The above process repeated3times (18minutesin total). MAP was kept in50~70mmHg during extracorporeal circulation.Continuous monitoring of ECG、HR、SBP、DBP、MAP、CVP、SpO2、PetCO2,and intermittent test of blood gas analysis, electrolytes, activated clotting time(ACT) were employed, and duration of CPB, aortic declamping time, automaticcardiac rebeating rate and arrhythmia during the clinical trial recorded. Results1. No significant differences in age, male/female ratio, weight (W), NYHAclassification, preoperative HR、 MAP、 SpO2, EF, single/double valvereplacement ratio existed among three groups (p>0.05)2. CPB time, aortablocking time, operation time in three groups of patients were not statisticalsignificance (p>0.05)3. In S group and X group, The automatic cardiacrebeating rates were significantly higher than that in C group (p<0.01) and nosignificant differences was found between S group and X group.4. The serumconcentrations cTnT concentration in three groups at T1is not significantlydifferent (p>0.05); At T2-5, the serum cTnT concentration in all groupscompared with their value at T1, increased significantly (p<0.01), but weresignificantly lower in S group and X group than that in group C (p <0.01).However, after aorta declamping, no difference was found in the serumconcentration of troponin-T between S group and X group (p>0.05).5. Thepostoperative ICU stay time, ventilation time, extubation time, time ofpostoperative vascular active drug use, hospitalization time in S group and Xgroup were significant shorter than in group C (p<0.01), and no difference wasfound between S group and X group. In S group, X group patients, no anyharmful effect occurred to conditioned limbs during hospital stay.6. There wereno differences in HR、MAP、CVP among all groups at T1、T2、T3、T4、T5.Comparing with T1, after aorta declamping, No differences were found inHR、MAP、CVP in each group. Conclusion1. Both the right upper limb ischemic postconditioning and left lower limb ischemic postconditioning caneffectively attenuate increase of serum cTnT concentration after aortadeclamping and improve the automatic cardiac rebeating rates, which revealedthat both methods are effective in myocardial protection.2. Both postconditionmethods can significantly and similarly reduce postoperative ICU stay time,time for use of vascular active drug, hospital stay time, postoperative extubationtime. It’s suggested that single upper or lower limb ischemia postconditioningcan be chosen, according to clinical convenience, to protection myocardium.3.During the investigation, no significant differences were found inhemodynamic parameters in all groups and any injury to limbs in S group andX group, which suggested that no harmful effect on stabilizing circulation andconditioned extremities. Remote ischemic limb postconditioning applied in thisstudy are effective, simple, practical, non-invasive, economic, feasible and safe.