[Future and Current Status of Monitored Anesthesia Care (MAC) in Japan: Preface and Comments].

American Society of Anesthesiologists defines that monitored anesthesia care (MAC) is a specific anesthesia service for a diagnostic or therapeutic procedure. Indications for monitored anesthesia care include the nature of the procedure, the patient's clinical condition and/or the potential need to convert to a general or regional anesthetic. In the USA, MAC is popular as an anesthesiologist service provided for an individual patient. MAC is also becoming increasingly popular in Japan. However, most Japanese anesthesiologists are not involved in MAC, and instead, physicians belonging to other departments such as internal medicine and pediatrics are in charge for MAC. Several guidelines for MAC during MRI in children and endoscopy in adults have recently been published in Japan. In the featured articles, we are dealing with the future and current status of MAC in Japan. Through the featured articles, I hope readers would know what to do next for us anesthesiologists in order to provide safe and useful MAC in Japan.