Silent myocardial ischaemia in diabetic patients after general anaesthesia with 24h intravenous opioids or with epidural analgesia

AbstractObjectiveTo evaluate the effect of general anaesthesia with either continuous i.v. opioids (G/O) or thoracic epidural analgesia (G/EP) on postoperative transient myocardial ischaemia (TMI) in type 2 diabetic patients undergoing open cholecystectomy.MethodologyThis randomised controlled study was conducted on 50 patients with D.M. Patients were divided into G/O group or G/EP group. All patients had negative stress exercise test and at least two cardiac risks preoperatively. Epidural analgesia was established by 15ml of ropivacaine 0.2% with fentanyl 2μg/ml followed by 5–8ml/h of ropivacaine 0.1% with fentanyl 1μg for 24h postoperatively. Both studied groups received same general anaesthesia. Continuous i.v. fentanyl 100μg/h was given intraoperatively in group G/O followed by i.v. morphine PCA. Primary outcome measured postoperative TMI using 24h continuous ST segment analysis, endothelin-1(ET-1), troponin T, creatine kinase MB (CK-MB), and CKMB/CK preoperatively, 8h and 24h postoperatively. Second outcome measured dynamic stress (perioperative heart rate, blood pressure and postoperative pain).ResultsEndothelin-1 was above cutoff level preoperatively and rose up dramatically postoperatively in both studied groups. G/EP attenuated ET-1 elevation than G/O. Troponin T and CK-MB did not rise postoperatively in both studied groups. Postoperative CK-MB/ CK ratio was higher than 10% in 12 and eight patients in group G/O and G/EP, respectively. Twelve cardiac ischaemic events were noticed in four patients in group G/O and four events in two patients in group G/EP without significant difference in total duration of ischaemia between groups. G/EP lowered HR more significantly intraoperatively and gave better pain control for 4h postoperatively. In conclusion, D.M was associated with high ET-1 level. Upper abdominal surgery increased ET-1 release. G/EP attenuated ET-1 release more than G/O and produced more stable haemodynamic parameters and less postoperative pain. No superior cardioprotective effect was noticed in G/EP over G/O

The effect of multimodal balanced anaesthesia and long term gabapentin on neuropathic pain, nitric oxide and interleukin-1β following breast surgery

AbstractObjectivesTo evaluate the effect of multimodal balanced anaesthesia and gabapentin (6months) on neuropathic pain qualities, nitric oxide (NO) and interleukin 1-beta (IL-1β).MethodologyThis randomized study was conducted on 50 women scheduled for conservative breast surgery for cancer followed by chemotherapy and/or radiotherapy. Women enrolled into two groups; either to receive balanced general anaesthesia (GA) (control group) or ultrasound guided thoracic paravertebral with GA, multimodal balanced anaesthesia, (intervention group). Nociceptive pain was evaluated for 24h. Neuropathic pain was evaluated using pain questionnaire 1month postoperatively and neuropathic pain scale at 1, 3, 6 and 9months. Gabapentin was prescribed to women reporting neuropathic pain 1month postoperatively and for 6months. NO and IL-1β were measured before operation, 1, 3, 6 & 9months, postoperatively. Their relationship with neuropathic pain was assessed.ResultsNociceptive pain was less in intervention group than control group immediately post operative, 4h after surgery at rest and 8h with movement. Neuropathic pain started few days postoperatively, in both groups. Its onset, sites, duration and precipitating factors did not differ between the groups. Sensitive, hot pain and unpleasantness reduced significantly 1month postoperatively, in intervention group. Two months later, itchy, dull and sharp pain was significantly less in intervention group. At 6months, most of neuropathic pain items except sharp and deep pain lowered significantly in intervention group. At 9months, hot and superficial pain was still less in intervention group. NO decreased significantly 1 and 3months postoperatively, while IL-1β was significantly lower through different times, in intervention group. IL-1β correlated well with neuropathic pain intensity and unpleasantness.ConclusionBreast surgery for cancer was associated with neuropathic pain that continued for 9months after surgery. Multimodal balanced GA had positive impact on acute nociceptive and neuropathic pain. Gabapentin reduced almost all neuropathic pain qualities