After approval by the internal review board of the institution where the study was done, the patients were identified in the preoperative assessment consultation. There 308 patients with an ASA I or II physical status scheduled for ambulatory surgery were included.
Previa autorización por el comité de ética de la institución donde se realizó el estudio, se captaron en consulta preanestésica 308 pacientes ASA I y II clasificación de la Sociedad Americana de Anestesiólogos programados para cirugía ambulatoria.