Difficulty Controlling Sedation Level Using Processed Electroencephalography Monitoring in a Patient With Intellectual Disability, Fontan Circulation, and a Severe Gag Reflex
Patients with cardiovascular compromise are likely to develop hypotension upon receiving even small doses of sedatives. On the other hand, patients with severe dental phobias or with intellectual disability who have a severe gag reflex often require deeper levels of anesthesia. Thus, achieving an optimal level of anesthesia can be difficult in patients with cardiovascular compromise because of the relatively narrow range of sedative dosing capable of providing sufficient sedation to prevent the gag reflex without compromising hemodynamics. We present a patient with Fontan circulation, severe intellectual disability, and a severe gag reflex who underwent dental treatment using intravenous sedation. Processed electroencephalography (EEG) via a SedLine (Masimo Corporation) monitor was used to identify anesthetic depth, and propofol infusion rates were adjusted based on changes in Patient State Index (PSI) values. However, the PSI values fluctuated greatly in response to stimuli and changes in the depth of anesthesia. In summary, the indications for using feedback control of the sedation level by way of EEG analysis and adjusting propofol infusion rates might be limited in patients with cardiovascular compromise and severe gag reflex because such monitoring may be incapable of keeping pace with rapid changes in the balance between stimulation and the level of anesthesia.

Patient State Index Probes Attached to a Patient
Electroencephalography signals are obtained from the prefrontal cortex and processed to identify anesthetic depth.

Anesthetic Record for This Patient With Fontan Circulation and a Severe Gag Reflex
The propofol target-controlled infusion (TCI) was titrated according to the Patient State Index (PSI) values. ※ represents the time during which the PSI value was about 60 to 70, which was sufficient for allowing placement of a rubber dam. The PSI value was well controlled before the dental treatment started, but small increases in the propofol TCI rate caused an unexpected decline in PSI values. ×, duration of anesthesia; ⌾, duration of the surgery; a, active coughing reflex; b, active gagging reflex.
Contributor Notes