الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Patients subjected for open heart surgery had higher incidence of perioperative morbidity and mortality . Among the most common etiology for these morbidity and mortality is incidence of bleeding and thromboembolic complications . The pervious literatures proved the relation between prostanoid release from platelets and platelet function represented by platelet aggregation as one of the major cause of the bleeding and thromboembolic complications . So, this study tried in a way to find the effect of anaesthetic technique applied and these factors aiming to find the most safe modality we can deliver to our patients .
This study was conducted on 60 adult patients . Patients were randomly allocated into three groups,20 patients each . The first group ( I ) received Fentanyl-Midazolam-relaxant, the second group ( II ) received fentanyl( low dose )-Isoflurane-Relaxant, and the third group ( III ) received Fentanyl ( high dose )-Relaxant based anaesthetic . Premedications ,CPB technique, weaning from CPB, and monitoring were the same for all groups . Blood samples were taken just before aortic cross clamping and before CPB weaning .
Aggregation study with optical aggregometer using ADP,Epinepherine,and Ristocetin was done to measure the platelet aggregation percentage . Prostanoids assay were obtained for TxB2 and PGE2 using ELISA reader at the same intervals .
The results of this study revealed that there is no strong relation between the release of PGE2 and TxB2 from AA metabolites derived from the platelet phospholipid membrane and platelet aggregation study . Hence, it is difficult to find strong correlation between the anaesthetic modality and platelet function represented by platelet aggregation study using the optical aggregometer without observation the other platelet parameters and mediators . But, the results proved that high dose opioid based anaesthesia (Fentanyl ) group ( III ) showed the highest platelet aggregation percentage even after CPB without symptoms and signs of thromboembolic complications as compared with the other groups , with the use of different aggregating agent .
Finally, this study can conclude that the high dose fentanyl group (III) showed the least TxB2 , highest PGE2 release, highest platelet aggregation percentage using ADP, Epinephrine, and Ristocetine as aggregating factors . Also this group ( III ) , showed the longest extubation time, the least amount of bleeding during the first 6 hours post-operatively, The least blood requirements during the first 24 hours post-operatively, and the shortest hospital stay as compared with the midazolam-fentanyl group ( I ), and the fentanyl-isoflurane group. On the other hand ,the results of this study revealed that there is no strong correlation between the prostanoid release represented by increase in TxB2 or decrease in PGE2 release and the increase in platelet aggregation using optical aggregometer in our time interval samples.