Effect of Postoperative Pain Stress and Postoperative Analgesia on Platelet Function

Objective:To observe the effect of postoperative pain stress and postoperative analgesia on the platelet function of postoperative patients.Methods:40 ASAⅡ-Ⅲpatients aged from 45 to 68 years old undergoing elective abdominal surgery were randomly divided into epidural analgesia group(group E,n=20)and control group(group C,n=20).The patients in group E received the combined anesthesia of general anesthesia and epidural block plus postoperative epidural analgesia,and the patients in group C received general anesthesia plus postoperative intramuscular pethidine analgesia intermittently.VAS was used to assess pain intensity at the points of 8,24,36,48,60 and 72 h after surgery;blood samples were taken from peripheral vein before operation and on the 1~(st),2~(nd),3~(nd),4~(th)and 5~(th)postoperative days for determination of the expression of CD_(41)/CD_(61), CD_(62p),and CD_(63)of the glycoprotein on the platelet membrane surface and the platelet aggregation rate.Results:The patients in group E achieved good postoperative analgesic results,VAS at 8,24.36 and 48 h after the operation in group E were markedly lower than that in group C(P0.05,P0.01).Compared with the basic value before operation,the expression of CD_(41)/ CD_(61),CD_(62p),CD_(63)and platelet aggregation rate in the two groups were significantly increased on the 1~(st)postoperative day(P0.05,P0.01);the expression of CD_(41)/CD_(61)、CD_(62p)、CD_(63)and platelet aggregation rate in group C were all obviously higher than those in group E during the four postoperative days(P0.05,P0.01).Conclusion:Platelet aggregation rate shows a positive correlation with the expression of theglycoprotein on the membrane surface of platelet.Postoperative pain stress can promote platelet activation and platelet aggregation,enhance platelet function and blood agglutination,and put the patient in a relative hypercoagulable status.A good postoperative analgesia can help to inhibit the vicious stress response of the body,low er the platelet activity,decrease platelet aggregation,inhibit platelet function,lower blood agglutination,ameliorate the hyper- coagulable status,and therefore can act as one effective way to reduce the chances of postoperative thrombus complication and improve the patient's rehabilitation.