The Effects Of PCA On Hemorheolgy In Early Stage Of Postoperative Period In Elderly Patients

Objective In early stage of postoperative period, pain results in strong stress response, and sympathetic excitation which could increase fibrinogen release and decrease its degradation, accordingly bridged erythrocytes inceased, then the blood viscosity increased, sometimes resulting in thrombosis, especially in elderly patients. Postoperative patient-controlled analgesia (PCA) could produce optimum analgesia and decrease adverse reaction caused by pain. To investigate the effects of PCA on hemorheolgy in early stage of postoperative period in elderly patients.Methods Twenty patients, physic status ASAⅠorⅡ, aged 60 to 75 (group E, n=20) undergoing major thoracic or abdominal surgery under general anesthesia, were randamly divided into elderly PCA group(Ep, treated with PCA)and elderly contol group(En), 10 in each group. Twenty patients, physic status ASAⅠorⅡ, aged 30 to 50(group Y, n=20), undergoing major thoracic or abdominal operation under general anesthesia, were randamly divided into youth PCA group (Yp, treated with PCA) and youth contol group(Yn), 10 in each group. PCA was administrated immediately after operation in PCA group.High shear blood viscosity(Hηb), low shear blood viscosity(Lηb), plasma specific viscosity(ηp), whole blood reductive viscosity(ηr), erythrocyte aggregation index(EAI), erythrocyte deformation index(EDI), erythrocyte rigidity index(ERI), erythrocyte sedimentation rate(ESR) and erythrocyte electrophoresis(EET) were measured at 5 minutes before anesthesia(T1),1h(T2),6h(T3),24h(T4),48h after operation(T5). Noninvasive blood pressure and heart reat were observed and recorded at T1-5. Visual analog pain scale scores(VAS) were observed and recorded at T2-5.Results (1) In group Ep, Hηb,Lηb,ηp,ηr,EET at T3,T4,T5 were lower than those at T1 (P<0.05), EAI,ERI at T5 was lower than those at T1 (P<0.05), ESR at T5 was higher than that at T1 (P<0.05), EDI at T5 was higher than that at T1, but without significance(P>0.05). (2) In group En, blood rheology indexes at T4,T5 were higher than those at T1, but without significance(P>0.05). (3) In group Yp, blood rheology indexes at T4,T5 were lower than those at T1, but without significance(P>0.05). (4) In group Yn, Blood rheology indexes at T5 were higher than those at T1, but without significnces(P>0.05).(5) Hηb,Lηb,ηr,EAI,ERI at T4,T5 in group Ep were lower than those in group En (P<0.05). (6) SBP and DBP at T3,T4,T5 were lower than those at T1 in group Ep (P<0.05). SBP and DBP at T3,T4 in group Ep were lower than those in group En (P<0.05). (7) VAS at T4,T5 were lower than those at T2 in group Ep (P<0.05). VAS at T3,T4 in group Ep were lower than those in group En (P<0.05).Conclusion (1) postoperative pain could increase blood viscosity in elderly patients, which manifested by increased plasma specific vicosity, erythrocyte aggregation and erythrocyte rigidity index. (2) PCA could improve blood viscosity in early stage of postoperative period in elderly patients.