小剂量抑肽酶对体外循环中血小板的保护

Protective effect of low-dose aprotinin on human blood platelets during cardiopulmonary bypass

选择４５例心脏瓣膜置换术患者，其中２３例应用小剂量抑肽酶作为用药组，观察体外循环期间小剂量抑肽酶降低术后失血量的作用。结果显示：用药组术后失血量比对照组减少了５０．２％，输血量减少了６７．０％。抑肽酶可减缓血小板计数的骤然下降趋势，但并不阻止其下降。血小板聚集功能及粘附功能的下降在用药组明显较轻，而胞浆游离［Ｃａ２＋」ｉ、膜磷脂酶Ａ２和环氧化酶活性的上升明显被抑制。结论：小剂量抑肽酶可明显减少术后失血量及输血量，具有与大剂量抑肽酶同样的临床效果。对于血小板胞浆游离［Ｃａ２＋］ｉ及膜磷脂酶Ａ２、环氧化酶活性升高的抑制作用是抑肽酶作用机制的一个重要方面。

To assess the effects of low dose aprotinin on platelets during cardiopulmonary bypass(CPB), 45 Patients, aged 20 to 45 years, ASA grade Ⅱ to Ⅲ,undcrgoing elective operation of cardiac valve replacement under fentanyl-enflurane-atracurium anesthesia, were randomly allocated to receiving aprotinin 2 ×106 KIU (group I,n=23 ) or equivalent volume of normal saline as control (group Ⅱ,n= 22) res12ectively,at the same time as CPB began to work. The blood samples were collected after induction of anes- thesia. 5 mins prior to CPB. 5, 15, 30 and 60 mins following CPB,and immedialely before withdrawal of CPB.to measure such 1parameters of platelet as level of cytoplasmic free Ca2+ (CFCa2+),activities of phosphollpase A2 (PLA2) and cyclouoxygenase (PCO) in membrane,aggregation rate (AGR),adhesion rate (ADR ) and count Individually. The lotal blood volume of postoperative tho- racic drainage solution (TBV ) and the re(]uircd blood volume of transfusioll (RBVT) were recorded. The results ahoys(l that dur lug CP14,the levels of CFCa2+ and activitics of PLA2 and PCO increased significantly,and the AGR,ADR and count of plstclet decreased markedly in both groups (P<0. 05). As compared with the control values in group Ⅱ. the TBV and RBVJ: reduced by 50.2%; and 67 % separately (P<0.01 ). the platelet count rose obviously during 15 mind following CPc (P<0. 05 ), the level of CFCa2+ and activitics of PLA2 and PCO were descended drastically .and the AGR and ADR were ascended dramatically .in group Ⅰ during CPB (P<0. 05 ). These indicate that a low-dose aprolinin may be as effective as a higll-dose one in reducing foe postopera- tive blood loss,and this action may be closely related to aprotinin's depressing the concentration of Platelet CFCa2+ and activities of PLA2 and PCO in platclet membrane during CPB.