Relevant Factors Analysis And Intervention Measures Of The Noninfectious Hyperthermia After Cardiovascular Surgery

Background: Hyperthermia is very common after cardiac surgery. It was suggested that early postoperative fever is a manifestation of perioperative stress. Postoperative hyperthermia is known to be correlated with a greater degree of cognitive dysfunction after cardiac surgery. Furthermore, fever can exacerbate the extent of tissue injury if an overt stroke occurs. Body temperature plays an important role in ischemia-reperfusion injury of myocardial and cerebral.Objective: This study aimed to determine the incidence and the relevant factors of the postoperative noninfectious hyperthermia through a retrospective review of the database of 941 coronary artery bypass grafting surgery (CABG) cases .Methods: 941 cases chosen randomizedly in FuWai hospital and requested from 2007 to 2008 were entered into an electronic database for analysis, including 451 cases of coronary artery bypass grafting surgery undergoing extracorporeal circulation(CABG), and 490 cases of off-pump coronary artery bypass grafting surgery (OPCABG). Recorded data of patients's history, perioperative body temperature data at 10 time points and outcomes, analyzed the risk factors and protective factors by SPSS13.0 software for postoperative high temperature. Multiple linear regression was then used to identify independent predictors of maximum Tc at 8h after operation . Data are reported as mean±SD, and P less than 0.05 was used to define significance.Results: 1. There were 86.39% cases within 24h happened postoperative hyperthermia(≥38℃), the peak temperature was (38.2±0.66)℃at 8h after operation. 2. The group that patients who had higher temperature(≥38℃)had longer length of stay in ICU. 3. The temperature of OPCABG patients was higher than that of CABG patients within 48h after the operation. 4. Extracorporeal circulation, preoperative respiratory function abnormal, low ejection fraction(EF) were the risk factors for postoperative hyperthermia. 5. Hormone and postoperative analgesia were protective factors for postoperative hyperthermia.Conclusion: Postoperative hyperthermia had a high incidence after cardiac surgery, high body temperature hindered patients from postoperative recovery, Extracorporeal circulation, preoperative respiratory function abnormality, low EF were the risk factors of postoperative hyperthermia. Objective: To investigate the effects of flurbiprofen axetil and tramadol combined with fentanyl respectively on postoperative noninfectious hyperthermia and inflammatory mediators in patients undergoing cardiovascular surgery.Methods: This clinical trial was prospective randomized, controlled as a double-blinded study. 375 patients were divided into 3 groups equally with 125 cases each. Intravenous study drugs were administered twice respectively after jugular venous cannulation and before suture pericardium, the study drugs were flurbiprofen axetil 1mg/kg in group FF, tramadol 2mg/kg in group QF and fat emulsion 5 ml in group F. Patients received the intravenous drugs continuously(2ml/h) in the disposable syringer pump filled with the study drugs diluted to 96ml volume during 48h after the end of the operation. The disposable syringer pump was filled with flurbiprofen axetil 200mg mixed with fentanyl 1.0mg in group FF, tramadol 700mg mixed with fentanyl 1.0mg in group QF, and fentanyl 2.5mg in group F. Anti-emetic prophylactic regimen (tropisetron) was available to three groups at the end of the surgery. To randomly choose 30 cases from every group, and withdrawal 5ml venous blood after induction(before administered), at suture pericardium(before administered), 4h,20h and 24h after operation to check the concentrations of IL-1, IL-6, IL-10, TNF-α, PGE₂ in the plasma.Results 1. There were no significant difference in demography of the 3groups (p> 0.05); 2. At T8-T12, the temperature of all patients were significantly higher than TO (p <0.05); 3. FF group had significantly lower bladder temperature than that of QF group and F group at T8 (p <0.01); 4.The bladder temperature of FF and QF were significantly lower than that of Group F group at T9(p <0.01); 5. There was no significant difference among the concentration of cytokine of 3 groups at TO; 6. IL-1 of F group was significantly higher than those of FF and QF groups at T4 and T10(p< 0.05) 7. IL-6 of F group was significantly higher than those of FF and QF groups at T8 ; 8. The changes of IL-10 among all groups had no significant difference (p> 0.05), but compared the concentration of IL-10 at T0 and T4, the concentration of IL-10 of each group was significantly increased(p< 0.05) at T4; 9. Compared T8 with T0, TNF-αof FF and F groups were significantly higher than QF; TNF-αof FF and QF groups were significantly lower than that of F group at T11; 10. PGE₂ of all groups had increased significantly at T4 (p < 0.05), QF and FF groups were significantly lower than that of F group at T11(p <0.05); 11. VAS score among the three groups was similar, but F group needed more additional analgesic drugs than the other two groups (p <0.05); 12. FF Group had lower nausea score (p <0.05); 13.Baseline characteristics were equivalent among the 3 groups. (P> 0.05).Conclusions: The administration that intraoperative intravenous tramadol (2mg/kg), flurbiprofen axetil (1 mg/kg) combined with postoperative continuous intravenous infusion of tramadol 14.58mg/h, flurbiprofen axetil 4.17mg/h can effectively decrease the level of postoperative hyperthermia safely, inhibit a certain degree of inflammatory response, and provide good postoperative analgesia.