Perioperative management of patients using antiplatelet agents The use of antiplatelet drugs for primary and secondary prevention of cardiovascular disease events is a common clinical practice. Antiplatelet therapy significantly decreases the incidence of cardiovascular disease events, including acute myocardial infarction and cerebrovascular accident. It is increasingly common to face patients on antiplatelet therapy who will undergo some surgical procedure, so it is essential to know the perioperative management of these drugs, to reduce the risks and complications associated with the suspension or maintenance of these therapies in the perioperative period. The most common antiplatelet agents used in Chile are acetylsalicylic acid and thienopyridines, of which clopidogrel is the most frequent one. The perioperative management of these drugs has to be based on the individual thrombotic risk of each patient and the risk of hemorrhage of each surgery. In noncardiac surgeries, it is suggested to maintain acetylsalicylic acid, except in patients with low to moderate thrombotic risk who will undergo surgeries with a high risk of bleeding, in which case it is recommended to suspend it 5 to 7 days before surgery. Clopidogrel is suggested to be discontinued 5 days before surgery, except in patients with high thrombotic risk who will undergo surgical procedures with low to moderate risk of hemorrhage. In myocardial revascularization surgeries, it is recommended to maintain acetylsalicylic acid and to suspend clopidogrel 5 days before the procedure. Once assuring adequate surgical hemostasis, it is suggested to reinitiate acetylsalicylic acid 6 hours after surgery and to reinitiate clopidogrel during the first 24 postoperative hours.

Obesity is a condition of excessive accumulation of body fat to a level that is harmful to health. The prevalence of obesity is increasing worldwide at an alarming rate. Therefore it is essential to know the perioperative management and specific considerations in this population. The majority of obese patients who undergo surgical procedures have few additional pathology, so their perioperative risk is similar to eutrophic patients. Obesity Surgery Mortality Risk Stratification Score OS-MRS is a validated scale for assessing the risk of perioperative mortality in these patients. It is essential to look for the presence of respiratory sleep disorders in these patients, and for this purpose, the STOP-BANG questionnaire is the most valid today. During anesthetic induction it is recommended to place the patient in the "ramp" position as it significantly improves the visualization of the glottis during laryngoscopy. Also, this position optimizes the oxygenation and ventilatory mechanics of these patients, increasing the time of safe apnea. Regarding airway management, orotracheal intubation with controlled ventilation is the technique of choice in this population. Anesthetic drug doses should be calculated based on adjusted weight or lean weight, depending on the type of drug chosen. Finally, complete and frequent postoperative monitoring is recommended in the recovery unit, transferring these patients to their room only when they meet the criteria included in the White and Song scale.