Background Conscious sedation has been widely utilized in plastic surgery. However, inadequate
research has been published evaluating adequate drug dosage and depth of sedation.
In clinical practice, sedation is often inadequate or accompanied by complications
when sedatives are administered according to body weight alone. The purpose of this
study was to identify variables influencing the depth of sedation during conscious
sedation for plastic surgery.
Methods This prospective study evaluated 97 patients who underwent plastic surgical procedures
under conscious sedation. Serum aspartate aminotransferase (AST), alanine aminotransferase
(ALT), creatinine, and glucose levels were measured. Midazolam and ketamine were administered
intravenously according to a preset protocol. Bispectral index (BIS) recordings were
obtained to evaluate the depth of sedation 4, 10, 15, and 20 minutes after midazolam
administration. Associations between variables and the BIS were assessed using multiple
regression analysis.
Results Alcohol intake and female sex were positively associated with the mean BIS (P<0.01).
Age was negatively associated with the mean BIS (P<0.01). Body mass index (P=0.263),
creatinine clearance (P=0.832), smoking history (P=0.398), glucose (P=0.718), AST
(P=0.729), and ALT (P=0.423) were not associated with the BIS.
Conclusions Older patients tended to have a greater depth of sedation, whereas females and patients
with greater alcohol intake had a shallower depth of sedation. Thus, precise dose
adjustments of sedatives, accounting for not only weight but also age, sex, and alcohol
consumption, are required to achieve safe, effective, and predictable conscious sedation.
Keywords
Conscious sedation - Deep sedation - Hypnotics and sedatives - Consciousness monitors
