Perioperative handling of antiplatelet drugs. A critical appraisal.

Because of more and more accurate cardiovascular prevention programs and the increasing mean age of the general population, the use of antiplatelet treatments is progressively increasing in the last years. Moreover, the wide-spread use of bare-metal stents (BMS) and drug-eluting stents (DES) significantly increased the number of subjects with the need of a combined antiplatelet treatment: Aspirin (ASA) and Clopidogrel (CLO. Within the first year after coronary stenting, approximately 5% of patients needs to undergo non-cardiac surgery interventions. In such patients, current guidelines suggest to stop antiplatelet agents 7-10 days before surgery to avoid the risk of increasing blood loss. On the other hand, it has been shown that the risk of surgical bleeding, if antiplatelet drugs are continued, is lower than that of coronary thrombosis if they are withdrawn. Thus, an accurate stratification of the population according to the thrombotic risk is needed and the bleeding and the thrombotic risk should be considered in parallel. Although a growing amount of recommendations have been released by several Societies, the perioperative handling of antiplatelet drugs still represents a major concern in clinical practice. In this review we report the major literature data about the perioperative handling of antiplatelet drugs. Moreover, in order to describe future treatment perspectives and to identify valuable alternatives to current antiplatelet agents in the perioperative period, pharmacokinetic and pharmacodynamic characteristics of newer antiplatelet drugs are reported and analyzed.

Anesthetic management of a parturient with spinal muscular atrophy type II.

In the past, pregnancy was contraindicated in patients with spinal muscular atrophy. Recently, more cases are occurring because of improvement in survival and functional status. The goals for anesthetic management of these patients include satisfactory anesthesia during surgery and excellent postoperative analgesia with minimal compromise of respiratory function. Spinal anesthesia may be considered contraindicated due to spinal deformities, but successful spinal anesthesia was performed in a 37 year old parturient following magnetic resonance imaging of the spine.

Perioperative handling of patients on antiplatelet therapy with need for surgery.

The widespread use of metal stents and drug-eluting stents has shown the extent to which patients with unstable coronary perfusion depend on antiplatelet drugs, and how their risk of late thrombosis depends on the long-term use of agents such as clopidogrel. It has also been shown that the risk of surgical bleeding, if antiplatelet drugs are continued, is lower than that of coronary thrombosis if they are withdrawn. Thus, except for low-risk settings, the practice of withdrawing antiplatelet drugs 5-10 days prior to surgical procedures should be changed. The following suggestions are meant to provide a guideline in this respect. Most of the current surgical procedures may be performed while on low-dose aspirin treatment. Except when bleeding may occur in closed spaces (e.g. intracranial surgery, spinal surgery in the medullary canal, surgery of the posterior chamber of the eye) or where excessive blood loss is expected, where only clopidogrel should be discontinued; in all other cases the surgical procedures should be carried out in the presence of dual antiplatelet agents (if prescribed). Aspirin may be discontinued only in subjects at low risk of thrombosis, and at high risk of intraoperative bleeding. Operations associated with an expected excessive blood loss should be postponed unless vital. When prescribed for acute coronary syndrome or during stent re-endothelialization, clopidogrel should not be discontinued before a noncardiac procedure. For elective procedures, surgery should be postponed until the end of the indication for clopidogrel. After the operation, clopidogrel should be resumed within the 12-24 h. Cardiac procedures should be postponed for at least 4 days after clopidogrel withdrawal. The thrombotic risk of preoperative withdrawal of antiplatelet drugs overwhelms the benefit of regional or neuraxial blockade. Antiplatelet treatment replacement by heparin or low-molecular weight heparin does not provide protection against the risk of coronary artery or stent thrombosis. Haemostasis requires that at least 20% of circulating platelets have a normal function. As the effects of antiplatelet agents are not reversible by other drugs, fresh platelets are the only manner to rapidly restore normal haemostasis. Aprotinin decreases postoperative bleeding and transfusion rates in patients undergoing CABG and on clopidogrel during the days preceding surgery.