EEG Studies of Ketamine General Anesthesia

Phase 2

Completed

Brief Summary: We are doing this research study to find out how and where ketamine acts in the brain. Ketamine is an anesthetic (a drug or agent used to decrease or eliminate the feeling of pain by putting you in an unconscious state). We will look at the brain using a machine that records the brain's electrical activity, called an electroencephalogram (EEG). We will assess how it impacts patient's pain responses.

Detailed Description: In this trial, participants will be given ketamine at a high enough dosage to induce general anesthesia. EEG recording will be conducted during this time. Cognitive assessments and pain monitoring will be administered at various points before and after ketamine induction.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Cardiovascular: myocardial infarction, coronary artery disease, peripheral vascular disease, arrhythmia, congestive heart failure, valvular disease, hypertension
Respiratory: bronchitis, chronic obstructive pulmonary disease, smoking, shortness of breath
Hepatic: hepatitis, jaundice, ascites
Neurologic: seizure, stroke, positive neurologic findings on neurologic examination, multiple sclerosis, Meniere's disease, Parkinson's disease, neuropathy, peripheral stenosis
Gastrointestinal: esophageal reflux, hiatal hernia, ulcer
Endocrine: diabetes, thyroid disease
Renal: acute or chronic severe renal insufficiency
Hematologic: blood dyscrasias, anemia, coagulopathies, on anticoagulant therapy
Musculoskeletal: prior surgery or trauma to head neck or face, arthritis, personal or family history of malignant hyperthermia
Psychiatric: history or treatment for an active psychiatric problem, depression
Reproductive: pregnancy, breast-feeding
Medications: regular use of prescription and non-prescription medications expected to affect CNS function, St. John's Wort
Allergies: labetalol, ondansetron, glycopyrrolate, ketamine, midazolam

Arm && Interventions

Group	Intervention	Description
Ketamine	Ketamine	15 subjects undergoing ketamine general anesthesia.

Primary Outcome Measures

Name	Time	Method
Average Pain Intensity Pre- and Post-Ketamine Induction	Approximately 125 minutes	Average Pain Intensity prior to ketamine induction, 30 minutes post ketamine, 60 minutes post ketamine, 75 minutes post ketamine, and 120 minutes post ketamine. PROMIS Pain Intensity 1a was used to assess pain delivered by a pre-calibrated pain cuff. Scale of 0 (no pain) to 10 (worst imaginable pain).

Secondary Outcome Measures

Name	Time	Method
Average Dissociation States Score Pre- and Post-Ketamine Induction	About 125 minutes	Patients were assessed for dissociation states prior to the induction of ketamine and at 60 minutes, 75 minutes, and 120 minutes after Ketamine was administered. The Clinician Administered Dissociation States Scale was used to measure dissociation. Each section is scored 0 (not at all) to 4 (extreme), and totaled. The minimum total score is 0 (best, no dissociation at all) and the maximum total score is 92 (worst, the most dissociation).
Difference of the Mean Clinician Administered Dissociative States Scale Before and After Midazolam Administration	About 60 minutes	Midazolam was administered approximately 60 minutes after the administration of Ketamine in order to reduce the effects of Ketamine on dissociation. Dissociation was measured using the Clinician Administered Dissociative States Scale. Each section is scored 0 (not at all) to 4 (extreme), and totaled. The minimum total score is 0 (best, no dissociation at all) and the maximum total score is 92 (worst, the most dissociation). The difference of the mean Clinician Administered Dissociative States Scale before and after Midazolam administration was found.