EEG Studies of Ketamine General Anesthesia

Electroencephalogram Studies of Induction and Recovery From Ketamine-Induced General Anesthesia

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.

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.

Inclusion Criteria:

• Between the ages of 18 to 45
• Normal body weight and habitus, BMI less than or equal to 30
• Non-smoker
• American Society of Anesthesiologists (ASA) physical status classification P1

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