Discussion
In our present case, the patient showed decreased cardiac function that was thought to be caused by coronary artery stenosis, and hence great attention was paid to the patient’s hemodynamics during anesthesia induction. Thus, it was necessary to select sedatives with minimal circulatory depression during anesthesia induction to avoid circulatory collapse. Careful determination of the dosage of the sedatives was also required. The same applied to the administration of analgesics. Recently, a short-acting benzodiazepine called remimazolam was approved for use in Japan [1]. This drug has a shorter half-life than midazolam, which is also a benzodiazepine, but has the advantage of a faster onset of action and enables the evaluation of the presence or absence of consciousness using electroencephalography [3,4]. Another advantage of this drug is that it does not cause vascular pain, unlike propofol [4]. Before the approval of remimazolam, total intravenous anesthesia with propofol was commonly used for sedation during surgery. However, propofol has a strong circulatory suppression effect [5], which makes it difficult to use in patients with decreased cardiac function, indicating a disadvantage. On the other hand, it has been reported that remimazolam causes less circulatory depression, and its use has enabled the maintenance of stable circulatory dynamics even in patients with heart failure [6-8]. In our present case, circulatory management was carried out using FloTrac™ to continuously monitor variables, such as cardiac output and SVV, and both cardiac output and SVV showed stable values without any events of circulatory failure. Our present case indicates that the use of remimazolam is effective in the anesthesia management of patients with decreased cardiac function undergoing cardiac surgery. Furthermore, recent reports suggest that compared to propofol, anesthesia management with remimazolam reduces the surgical stress response and the effects of anesthetics on respiratory function, and is superior in reducing anesthesia-associated side effects [9]. In addition, remimazolam has been shown to potentially decrease the incidence of postoperative delirium [10], and its use is believed to be effective for patients with respiratory abnormalities and older patients at high risk of postoperative delirium.