Ingestion of stimulant medications does not alter BIS or clinical depth of anaesthesia at 1 MAC sevoflurane in children

Background/Aim: Children treated with stimulant medications for the behavioral management of attention deficit hyperactivity disorder (ADHD) may present for elective surgery. Stimulant medication is often continued until the morning of surgery to optimize perioperative behavior. It is unknown whether such stimulant drug ingestion can affect cerebral arousal and alter depth of anesthesia. A clinically relevant alteration in measured depth of anesthesia could form the basis for an evidence-based recommendation that children taking stimulant medications require a change in the amount of anesthetic delivered or that they require routine monitoring of depth of anesthesia. Materials and Methods: Thirty-four ASA 1 and 2 children aged between 5 and 16, presenting for elective day case surgery, were recruited. Seventeen had a diagnosis of ADHD and had taken stimulant medication on the day of surgery, and 17 were controls. A standard inhalational induction of anesthesia using air, oxygen, and sevoflurane by facemask was performed and maintained for 10 min at 1 MAC endtidal sevoflurane. During this time, no other stimulus was applied to the patient. Bispectral index (BIS) and other markers of depth of anesthesia were recorded after 10 min. Results: Children in both groups were of similar ages and weights. There were a higher percentage of boys in the stimulants group. Baseline physiological parameters were similar in both groups. After induction and equilibration for 10 min of anesthesia at 1 MAC endtidal sevoflurane, there was no significant difference in BIS or clinical markers of depth of anesthesia. Conclusions: Children taking stimulant medication for ADHD, and who ingest medication on the day of surgery, do not appear to have altered BIS or depth of anesthesia at 1 MAC of sevoflurane. These results do not support a recommendation for a change in anesthetic practice for children having ingested stimulants up to the day of surgery, either in terms of increasing the amount of anesthetic given or monitoring of depth