The Effect Of Different Methods Of Analgesia On Postoperative Pain And Stress Response After Total Knee Arthroplasty

Objective: To study the effect of different methods of analgesia on postoperative painand stress response after total knee arthroplasty.Methods: Part one: Sixty patients undergoing elective total knee arthroplasty weredivided randomly into4groups (n=15each). Four groups of patients were treated withepidural combined spinal anesthesia. Group A was control group, groups B, C and D werereceived femoral nerve block before anesthesia. The drugs of Group B for femoral nervewere0.375%ropivacaine20ml. The drugs of Group C for femoral nerve were0.375%ropivacaine20ml and tramadol50mg. The drugs of Group D for femoral nerve were0.375%ropivacaine20ml and tramadol100mg. In the three days after operation, thefollowing parameters were measured: pain intensity (using VAS) at rest and during movingand frequent of side effects at the time of8h,12h,24h,48h and72h after operation (T1toT5). The maximal amplitude of knee flexion was measured during continuous passivemovement (CPM) on24h,48h and72h. Part two: Patients selection, anesthesia andanalgesia were same with the part one. Venous blood samples were taken before anesthesia(T0), at the end of operation (T1), and48h,72h after operation (T2, T3) for determinationof plasma IFN-γ, IL-10and cortisol.Results: Part one:1.The values of VAS were lower in groups B, C and D compared togroup A in rest or moving (P<0.05). The values of VAS on T1, T2, T3, T5point were lowerin group C compared to group B (P<0.05). The values of VAS on T4, T5point were lowerin group D compared to group C (P<0.05). The values of VAS on all time point were lowerin groups C and D compared to group B (P<0.05). The values of VAS on T4, T5were lower in group D compared to group C (P<0.05).2. There were no differences on onsettime of femoral nerve block in groups B, C and D (P>0.05). The duration of sensory blocktime and motor block time were longer in groups B, C, D compared to group A (P<0.05),and were longer in groups C, D compared to group B (P<0.05). There were no differencesof duration of sensory block time and motor block time in groups C and D (P>0.05).3. Thevalues of CPM were higher in groups B, C and D compared to group A on24h,48h and72h after operation (P<0.05). The values of CPM were higher in groups C and D comparedto group B on48h and72h after operation (P<0.05). The values of CPM were higher ingroup D compared to group C on72h after operation (P<0.05).4. There were nodifferences of headache, nausea, vomiting and itch of skin in four groups (P>0.05). Parttwo:1. There were no differences of the plasma cortisol concentrations before operation infour groups (P>0.05). The plasma cortisol concentrations were significantly increased atT1-3as compared to baseline value at T0in group A and B (P<0.05). The plasma cortisolconcentrations were significantly increased at T1and T2as compared to baseline value atT0in group C and D (P<0.05). The plasma cortisol concentrations were significantly lowerat T1-3in group C and D as compared to group A and lower at T2-3in group C ascompared to group B (P<0.05). There were no differences of the plasma cortisolconcentrations in groups C and D (P>0.05).2. There were no differences of the plasmaIFN-γ concentrations before operation in four groups (P>0.05). The plasma IFN-γconcentrations were significantly decreased at T2-3as compared to baseline value at T0ingroup A and B (P<0.05). The plasma IFN-γ concentrations were significantly decreased atT2as compared to baseline value at T0in group C and D (P<0.05). The plasma IFN-γconcentrations were significantly higher at T2in group B and T2,T3in groups C and D ascompared to group A (P<0.05). The plasma IFN-γ concentrations were significantly higherat T3in group C and D as compared to group B (P<0.05). The plasma IFN-γconcentrations were significantly higher at T3in group D as compared to group C (P<0.05).3. There were no differences of the plasma IL-10concentrations before operation in fourgroups (P>0.05). The plasma IL-10concentrations were significantly increased at T1-3as compared to baseline value at T0in group A, B and C (P<0.05). The plasma IL-10concentrations were significantly lower at T1, T2in group B and at T1-3in group C and Das compared to group A (P<0.05). The plasma IL-10concentrations were significantlylower at T3in group C and at T2-3in group D as compared to group B (P<0.05). Theplasma IL-10concentrations were significantly lower at T2, T3in group D as compared togroup C (P<0.05).Conclusion: Part one: Preoperative0.375%ropivacaine20ml with tramadol100mgfor femoral nerve block could significantly extend the time of sensory and motor nerveblock. Femoral nerve block and patient-controlled intravenous analgesia for total kneereplacement can effectively relieve postoperative pain, promote the recovery of function ofknee joint after operation. Part two: The use of ropivacaine and tramadol femoral nerveblock combined with intravenous analgesia could effectively reverse the expression of aftertotal knee arthroplasty. This method could effectively protect the immune function ofpatients undergoing.