Optimizing the Use of Ketamine to Reduce Chronic Postsurgical Pain

Inclusion Criteria:

Woman 18 years of age or older
Undergoing elective breast surgery for oncologic indication as follows: unilateral or bilateral mastectomy, prophylacticmastectomy, +/- lymph node dissection, +/- immediate or delayed reconstruction.
No distant metastases

Exclusion Criteria:

History of cognitive impairment or clinical signs of altered mental status (AMS) that may interfere with adherence to study procedures and/or participant safety. Clinical signs of AMS may include but are not limited to: confusion, amnesia, disorientation, fluctuating levels of alertness, etc.
Past ketamine or phencyclidine misuse or abuse
Schizophrenia or history of psychosis
History of post-traumatic stress disorder
Known sensitivity or allergy to ketamine
Liver or renal insufficiency
History of uncontrolled hypertension, chest pain, cardiac arrhythmia, stroke, head trauma, intracranial mass or hemorrhage, glaucoma, porphyria, uncontrolled thyroid disease, or other contraindication to ketamine
Lamotrigine, alfentanil, physostigmine, or 4-aminopyridine use
Currently Pregnant
Body mass index (BMI) greater than 35
Non-English or non-Spanish speaker
Currently participating in another pain interventional trial
Unwilling to comply with all study procedures and be available for the duration of the study
Patient is American Society of Anesthesiologists (ASA) physical status 4, 5, or 6
Patient has started or undergone hormone therapy for gender transition into male.
Patient scheduled for any bilateral (or greater) flap reconstruction