A comparison of hemorheology between elderly and young patients with colorectal cancer during venous anesthesia

Objective To observe the changes of hemorheology during anesthesia in elderly patients with colorectal cancer.Methods 25 elderly patients(≥ 65 years old,n=25) and 25 young patients(18-64 years old,n=25) with colorectal cancer,ASA Ⅰ-Ⅱ,scheduled for elective radical surgery under general anesthesia,without diseases affecting the blood viscosity such as hypertension,coronary heart disease,diabetes,were enrolled.All patients received the same propofol venous anesthesia.Blood samples were taken at 4 different time points:T0,prior to the infusion and induction of anesthesia;T1,anesthesia reaching a steady state(BIS 40-60 and maintained 1 h) after intubations;T2,10 min before the end of operation;T3,into the PACU 30 min.Each time 5 mL bloods were taken from elbow vein used for the hemorheological measurements within 4 h.Blood viscosity was determined using an automatic reological examining machine.Results The change of hemorheology parameters:(1) comparisons between groups:Hηb,Mηb,Lηb of E group were higher than those of C group at all time points(P0.05).ηp was higher in E group at T1 than in C group(P0.05);Hct was higher in E group at T0,T1 than in C group(P0.05).In E group,the absolute values of EAI,EDI and ERI were higher than those in C group but without statistical significance(P0.05).(2)Comparisons within groups:compared with T0,all hemorheology parameters(Hηb,Mηb,Lηb,ηp,Hct,EAI,EDI,ERI) significantly declined at T1(P0.05),and continued decrease at T2(P0.05);at T3,these parameters began to ascend,but still lower than T1(P0.05).Conclusion The elderly patients with rectal cancer had higher hemorheology parameters than young adults in the perianesthesia period.In both two groups,hemorheology parameters increased in early stage in postoperative period,especially for elderly patients.