Maximal haemostatic effect is attained in porcine skin within 7?min of the administration of a local anaesthetic together with epinephrine, refuting the need for a 30?min waiting time

摘要

ObjectiveBased on clinical experience gained over many years, the maximal haemostatic effect following administration of local anaesthetics containing epinephrine is generally believed to occur within 10?min. Surprisingly, it was found in a recent study, in which bleeding was quantified intraoperatively, that maximal haemostasis did not occur until 30?min. If this is indeed the case, then it would be necessary to extend the preoperative waiting time to minimize perioperative bleeding.We have carried out a carefully controlled study on the time delay between administration of a local anaesthetic containing epinephrine and maximal haemostasis in a surgical setting.MethodsLidocaine 20?mg/ml (2%) or lidocaine?+?epinephrine 12.5?μg/ml (1:80,000) was injected into the skin of eight pig flanks. Bleeding was induced after 3, 5, 7, 15 and 30?min by making a 10?mm incision at each injection site. Blood was collected for 1?min and weighed.ResultsA gradual reduction in bleeding was observed, with maximal reduction after only 7?min (54%,p?