Myocardial protection during elective coronary artery bypasses grafting by pretreatment with omega-3 polyunsaturated fatty acids.

BACKGROUND/AIM: Despite recent advances in coronary artery bypass grafting (CABG), cardioplegic cardiac arrest and cardiopulmonary bypass (CPB) are still associated with myocardial injury. Accordingly, the efforts have been made lately to improve the outcome of CPB by glucose-insulin-potassium, adenosine, Ca(2+)-channel antagonists, L-arginine, N-acetylcysteine, coenzyme Q10, diazoxide, Na+/H+ exchange inhibitors, but with an unequal results. Since omega-3 polyunsatutated fatty acids (PUFAs) have shown remarkable cardioprotection in preclinical researches, the aim of our study was to check their effects in prevention of ischemia reperfusion injury in patients with CPB. METHODS: This prospective, randomized, placebo-controlled study was performed with parallel groups. The patients undergoing elective CABG were randomized to receive preoperative intravenous omega-3 PUFAs infusion (n = 20) or the same volume of 0.9% saline solution infusion (n = 20). Blood samples were collected simultaneously from the radial artery and the coronary sinus before starting CPB and at 10, 20 and 30 min after the release of the aortic cross clamp. Lactate extraction/excretion and myocardial oxygen extraction were calculated and compared between the two groups. The levels of troponin I (TnT) and creatine kinase-myocardial band (CK-MB) were determined before starting CPB and 4 and 24 h postoperatively. RESULTS: Demographic and operative characteristics, including CPB and aortic cross-clamp time, were similar between the two groups of patients. The level of lactate extraction 10 and 20 min after aortic cross-clamp time has shown negative values in the control group, but positive values in the PUFAs group with statistically significant differences (-19.6% vs 7.9%; p < 0.0001 and -19.9% vs 8.2%; p < 0.0008, respectively). The level of lactate extraction 30 minutes after reperfusion was not statistically different between the two groups (6.9% vs 4.2%; p < 0.54). Oxygen extraction in the PUFAs group was statistically significantly higher compared to the control group after 10, 20 and 30 min of reperfusion (35.5% vs 50.4%, p < 0.0004; 25.8 % vs 48.7%, p < 0.0001 and 25.8% vs 45.6%, p < 0.0002, respectively). The level of TnT, 4 and 24 h after CPB, was significantly higher in the control group compared to PUFAs group, with statistically significant differences (11.4 vs 6.6, p < 0.009 and 12.7 vs 5.9, p < 0.008, respectively). The level of CK-MB, 4 h after CPB, was significantly higher in the control group compared to PUFAs group (61.9 vs 37.7, p < 0.008), but its level, 24 h after CPB, was not statistically different between the two groups (58.9 vs 40.6, p < 0.051). CONCLUSION: Treatment with omega-3 PUFAs administered preoperatively promoted early metabolic recovery of the heart after elective CABG and improved myocardial protection. This study showed that omega-3 emulsion should not be considered only as a nutritional supplement but also as a clinically safe and potent cardioprotective adjunct during CPB.

Effect of pretreatment with omega-3 polyunsaturated fatty acids (PUfas) on hematological parameters and platelets aggregation in patients during elective coronary artery bypass grafting.

BACKGROUND/AIM: [corrected] Using omega-3 polyunsaturated fatty acids (PUFAs) in coronary artery bypass graft surgery (CABG) could provide protection against ischemic-reperfusion damage, prevention of postoperative arrhyth mia and attenuation of inflammatory response. However, omega-3 PUFAs inhibit cyclooxygenase (and thus decrease the synthesis of thromboxane A2 from arachidonic acid in platelets), which leads to decreased platelet aggregation. In cardiac surgery it is necessary to achieve a balance between inhibition and full platelets function. It is as well as im portant to closely follow hematological parameters, im paired by CABG itself. Therefore, the aim of the study was to establish the effects of pretreatment with omega-PUFAs on hematological parameters and plateletes aggre gation in patients with elective CABG. METHODS: This prospective, randomized, placebo-controlled, single-center trial was performed on parallel groups. The patients (n = 40) undergoing elective CABG were randomized receivin preoperative intravenous omega-3 PUFAs (Omegaven 10%) infusion (the PUFAs group) or the same volume of 0.9% saline solution infusion (the control group). Infusion was given a day before surgery and repeated four hours before starting extracorporeal circulation (CPB) via the pe ripheral vein at single doses of 100 mL (25 mL/h). Platelet function analysis was performed using multiple electrode aggregometry (MEA, multiplate-analyzer) before starting CPB and 2 h postoperatively for the patients of both groups. Results. There were no clinically relevant differ ences in baseline characteristics between the groups. He matological parameters were not significantly different between the groups pre-, intra- and postoperatively. Dur ing the first 24 h after surgery, the loss of blood was simi lar in the PUFAs and the control group (680 +/- 274 mL and 608 +/- 210 mL, respectively; p = 0.356). Postopera tively, platelet aggregation was not significantly different between the PUFAs and the control group in adenosine diphosphate (ADP) test (39 +/- 11 and 42 +/- 15, respec tively; p = 0.701), arachidonic acid (ASPI) test (64 +/- 24 and 70 +/- 27, respectively; p = 0.525) and trombin receptor-activating peptide (TRAP) test (68 +/- 25 and 75 + 26, respectively; p = 0.396), while their aggregation in collagen (COL) test was statistically significantly lower in the PUFAs related to the control group (32 +/- 15 and 47 +/- 20, re spectively; p = 0.009). Conclusion. Acute pretreatment with omega-3 PUFAs insignificantly affected the activity of platelets and did not influence postoperative blood loss.

[Pheochromocytoma as a challenge for the anesthesiologist]. / Feohromocitom kao izazov za anesteziologa.

INTRODUCTION: Pheochromocytoma is a tumour of adrenal chromaffin tissue which produces extreme amounts of catecholamines, and leads to significant haemodynamic disturbances. The anaesthesiologist has an important role in diagnostic procedures of pheochromocytoma (physical examination, biochemical analyses, pharmacological tests, tomographic, scintigraphic, and genetic examinations), and is included in the preparation of the patient for surgery, maintenance of anaesthesia during operation, and postoperative intensive care. RESULTS: We reviewed 268 patients with adrenal tumours, who were operated on in the Military Medicaf Academy in Belgrade over the period 1974-2002. In 93 (34.7%) patients pheocromocytoma was confirmed. Unilateral localization of tumours was noted in 75 patients (80.6%)), bilateral in 3 patients (3.2%), ectopic in 7 patients (7.5%), and multiple in 3 patients (3.2%). Malignancy was observed in 3 cases (3.2%), and recidivation in 2 cases (2.2%). The most frequent surgical approach was intercostal--by Turner Warvick (72.4%). During a retrospective analysis of complications in perioperative period, we found 3 cases (1.1%) of cardiac arrest, with lethal outcome in one patient (0.4%). In two patients (0.8%) we noted significant intraoperative bleeding (lesion of v.cavae and aortae). In five cases (2.0%) we recorded accidental pleural unilateral lesion, splenectomy in one patient (0.4%), and wound infection in 3 cases (1.1%). DISCUSSION: Pheochromocytoma is a rare disease but it is followed by numerous, significant, and very dangerous haemodynamic disturbances. This is the reason for necessity of a multidisciplinary approach in diagnostic procedures and treatment of the disease. Endocrinologists, anaesthesiologists, and surgeons must cooperate at the same time, and only then we can achieve a timely diagnostic, adequate preoperative preparation of the patient, surgical extirpation of tumours, and intensive postoperative care. Our retrospective study shows successful treatment of 268 patients with adrenal tumours and 93 patients with pheochromocytomas. CONCLUSION: Pheochromocytoma is a disease with high mortality rate. Surgical extirpation of tumour is the only way for a successful treatment. This tumour is a great challenge for anaesthesiologists, because of numerous disturbances of vital parameters in perioperative period. Low mortality rate in our study (0.4% in all patients, and 1.07% in patients with pheochromocytoma) is the result of an adequate perioperative treatment of our patients. Treatment of this tumour needs hospitalisation in greater clinical centres with adequate personnel and equipment.