Clinically, the incidence of
postoperative nausea and vomiting (
PONV) may be higher in mentally challenged patients than in normal healthy patients. The aim of this study was to investigate the risk factors for
PONV after
day care general anesthesia in mentally challenged patients undergoing dental treatment. We analyzed data on 231
day care general anesthesia cases involving mentally challenged patients undergoing dental treatment.
Anesthetic records for the past 5 years were investigated retrospectively. Ten items (age,
body weight, sex, duration of
general anesthesia, use of
propofol, use of
sevoflurane, use of
nitrous oxide, use of
neostigmine, treatment accompanied with
bleeding, and transfusion volume) were selected as risk factors for
PONV.
Postoperative nausea and vomiting was evaluated using the postoperative check sheet and linear discriminant analysis was performed to distinguish
PONV incidence using the 10 items as independent variables. The reliability of the linear discriminant function was evaluated using a misjudgment rate and information criteria (AIC).
Postoperative nausea and vomiting was observed in 13 cases out of 231 cases. The discriminant function with the smallest AIC (-25.0718) consisted of two independent variables: y=-0.077x(1)-0.001x(2)+0.0716(x(1)=use of
propofol, x(2)=age). The misjudgment rate was 31.6%. This result suggests that
PONV decreases when
propofol is used and that the incidence of
PONV decreases with age. To investigate other risk factors, an additional analysis was performed using 83 out of the 231 cases in which
sevoflurane was used as an
anesthetic agent. The results of the subgroup analysis suggest that the incidence of
PONV decreases in male patients and higher weight patients, although the patient's
body weight may be related to age, as the study cohort included many children. It is suggested that the major risks for
PONV in mentally challenged patients after
day care general anesthesia are no use of
propofol, lower age, female sex and lower weight.