Effects Of Acute Hypervolemic Hemodilution Or Combined With Controlled Hypotension Induced By Nicardipine On Hemodynamics And Troponin Ⅰ In Elderly Patients

Objective: To investigate the effects of acutehypervolemic hemodilution (AHH) or AHH combined withcontrolled hypotension (CH) induced by nicardipine onhemodynamics and cardiac troponin I (cTnI)in elderly patientsand evaluate their feasibility and safety in clinical use.Methods: This study include thirty ASA II patients(17male,13 female)without evident cardiac, pulmonary disease,without coagulation disorder and disturbance of electrolyteequilibrium ,age 65 ～79 yr , weigh 47 ～81kg, height150 ～175cm ,undergoing elective liver cancer, hepatichemangioma or pancreas duodenum operations during which theblood loss were expected to be over 15% of the patients'bloodvolume. The patients'preoperative hematocrit (Hct )wasbetween 35%～45% , hemoglobin (Hb) 120～150g·L^-1 andblood albumin 35～55g·L^-1. Thirty patients were randomlydivided into two groups: group I AHH (n=15) and group IIAHH+nicardipine CH (n=15). The patients were premedicatedwith intramuscular scopolamine 0.3mg and midazolam0.06mg·kg^-1. In both groups compound sodium aceteta injection10ml ·kg^-1 was infused after enterring operation room .Anesthesia was inducded by fentanyl 2～4μg·kg^-1, midazolam0.1 mg·kg^-1,propofol 1～2mg·kg^-1 , vecuronium 0.1mg·kg^-1and maintained with 1%～2% isoflurane and intermittent ivboluses of fentanyl and vecuronium .After trachealintubation ,the patients were mechanically ventilated . P_ETCO₂was maintained at 35～45mmHg .During operations BIS wasmaintained at 40～50 . The right internal jugular vein wascannulated for CVP monitoring and fluid administration ; thefemoral artery was cannulated with a special catheter for MAPmonitoring and blood sampling. Connected theNon-invasive Partial CO₂ Rebreathing System (NICO₂^TM) to theendotracheal tube . 6% HES (200/0.5) 15ml·kg^-1,30 ml·min^-1was infused before skin incision in the two groups in order toincreasing the patients'blood volume 20%. The blood loss wasreplaced by equal volume of 6% HES, the urinary volume andthe water vapoured from the trauma surface (6～8ml·kg^-1·h^-1)were replaced by equal volume of compound sodium acetetainjection so that the blood volume be maintained hypervolemic .Homologous blood was transfused when Hct was <24% and Hb<80 g·L^-1 in order to maintain Hct > 25%. When the operationfinished, diuretic was given .In group II, as soon as AHHbegan , nicardipine was infused at a rate of 1～4μg·kg^-1·min^-1and maintained MAP at 70% of the preoperative leavel(baseline). Continuous cardiac output (CO) ,SV ,CI , SVR ,CVP,MAP, ECG, SpO₂, HR and blood gases were monitored andrecorded before AHH(T0), AHH finished (T1),30min(T2) ,1h(T3) and 2h(T4) after AHH, cardiac troponin I wasmeasured at T₀ , T₁ and 4h after AHH(T5 ) .Results1 Two groups were no statistical significance with regard tosex ,age ,body weight ,height , types of operation and the valuesat T0 (P>0.05) ;2 Hb,Hct2.1 Results in the same group: Compared with the value at T0,Hb,Hct were decreased at T₁, T₂ ,T₃, T₄ (P<0.05) in bothgroups.2.2 Between two groups: Hb,Hct were no statistical significanceat T1, T2 ,T3, T4 (P>0.05);3 Hemodynamics values3.1 Results in the same group: Compared with the value at T0in group I :SV,CI,CO, CVP were increased (P<0.05), SVRwas decreased (P<0.05), MAP,HR were no statisticalsignificance at T₁, T₂ ,T₃, T₄ (P>0.05); Compared with thevalue at T0 in group II, SV,CI,CO, HR were increased (P<0.05),MAP, SVR were decreased (P<0.05),CVP was no statisticalsignificance at TT₁, T₂ ,T₃, T₄ (P>0.05);3.2 Beween two groups: Compared with group I, HR wasincreased at T₂ ,T₃, T₄ (P<0.05) ,MAP,CVP,SVR were decreased(P<0.05) ,CO,SV,CI at T₁, T₂ ,T₃, T₄ and HR at T1 were nostatistical significance in group II (P>0.05);4 cTnI...