Ketamine Pharmacokinetics and Pharmacodynamics for Postpartum Depression and Pain After Cesarean Delivery

Peripartum Participants: Inclusion Criteria * Cesarean delivery * Adults 18 years and older * Term delivery ≥ 37 weeks gestation anticipated at time of delivery * ASA PS 2 or 3 * Able to provide informed consent * One of the following must be met for inclusion: Not planning to breastfeed OR ketamine use indicated for pain management plan. Exclusion Criteria * Patient going under general anesthesia for cesarean delivery * Allergy to study medication (ketamine) * ASA PS 4 + * Contraindications to neuraxial anesthesia * Preterm delivery (\<37 weeks gestation) * Anticipated fetal-neonatal complex care plan as indicated in the patient's chart * Patient history of ketamine or PCP abuse * Patient history of schizophrenia or psychosis * Patient history of liver or renal insufficiency * Patient history of uncontrolled hypertension, chest pain, arrhythmia, head trauma, or intracranial hypertension, uncontrolled hyperthyroidism, or other contraindications to ketamine * Participating in another pain or depression intervention trial * Undergoing hormonal or gender affirming therapies * Pre-eclampsia with severe features * Hemodynamic instability * Inability to participate in study procedures for any reason * Contraindicated medications use: oral antihypertensive medications (exclusion: hypertensive disorders of pregnancy), intravenous magnesium (exclusion: pre-eclampsia with severe features), ketamine/phencyclidine/psilocybins/any other psychedelics (exclusion: ketamine or PCP abuse), lithium/valproate/carbamazepine/lamotrigine/haloperidol/chlorpromazine/fluphenazine/aripiprazole/clozapine/other typical or atypical antipsychotic medications (exclusion: schizophrenia or psychosis) Control Participants Inclusion Criteria * Age 18 years and older * Sex: Male or Female * Able to provide informed consent * ASA PS 1, 2, or 3 Exclusion Criteria * Allergy to study medication (ketamine) * ASA PS 4 + * Inability to participate in study procedures for any reason * Patient history of ketamine or PCP abuse * Patient history of schizophrenia or psychosis * Patient history of liver or renal insufficiency * Patient history of uncontrolled hypertension, chest pain, arrhythmia, head trauma, intracranial hypertension, uncontrolled hyperthyroidism, or other contraindications to ketamine * Participating in another pain or depression intervention trial * Hemodynamic instability * Pregnant or pregnant within the last 6 weeks * Unwilling to provide urine sample for pregnancy testing (female controls) * Undergoing hormonal or gender affirming therapies * Contraindicated medications use: ketamine, phencyclidine, psilocybins, or other psychedelics (exclusion: ketamine or PCP abuse), lithium/valproate/carbamazepine/lamotrigine/haloperidol/chlorpromazine/fluphenazine/aripiprazole/clozapine, or other typical or atypical antipsychotic medications (exclusion: schizophrenia or psychosis)