Introduction
Off-pump coronary artery bypass
grafting (OPCABG) involves the use of a vascular conduit to bypass
atheromatous lesions in coronary arteries without the use of
cardiopulmonary bypass (CPB) under general anesthesia at lower
temperature, and need mechanical ventilation to aid breathing to
maintaining oxygen supply to vital organs of the body which is essential
for stability of respiratory and circulatory
system1-4. Be alien to
normal heart surgery by CPB, intraoperative anesthesia monitoring in
OPCABG is critical to the operation and postoperative morbidities such
as myocardial infarction, pulmonary and renal dysfunction, atrial
fibrillation, blood transfusion and mental
syndromes5-7. In
patients following OPCABG surgery, manipulation on beating heart and
calcified aorta, pain, anxiety and restlessness caused by critically
illness, surgical trauma, inflammatory response and a variety of
procedures and treatments often discourage the recovery of heart
function.
Delirium is a common neuropsychiatric syndrome in the patients following
OPCABG
surgery.6,8,9The hallmark of delirium is acute cognitive disturbance with fluctuation
in the level of consciousness and attention. The incidence of delirium
in critically ill patients is high. Delirium is particularly problematic
in patients receiving heart surgery because it increases the risk of
self-extubation and removal of other essential medical
devices10.
Previous studies show that postoperative sedation is important for
prognosis. Therefore, the ideal sedative treatment is beneficial to
reduce stress response in patients after cardiac surgery, reduce
man-machine confrontation, reduce oxygen consumption, stabilize
hemodynamics and reduce delirium or restlessness, to ensure the
completion of the invasive
operation11-14.
Some prophylactic strategies for the prevention of delirium have been
proposed, but not routinely implemented because of the lack of
convincing evidence15.
Surgical Apgar Score (SAS) system was initially validated in patients
undergoing general and vascular surgery and was subsequently expanded to
a majority of surgical
subspecialties16-21.
SAS relies on three variables (lowest heart rate, lowest mean arterial
pressure and estimated blood loss) that are easily obtained from the
anesthesia records. There was no study having investigated the
association between SAS score and prediction of risk of delirium
incidence in patients underwent OPCABG who is at high risk of emotional
incidents. This article aims to investigate the predictive value of SAS
score on delirium incidence following OPCABG surgery.