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 FloTracâ„¢ 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.