Ketamine in Patients Undergoing TEVAR Procedures Receiving NCI (2020Ketamine)

A Randomized, Double-blind, Placebo-controlled, Study to Identify the Opioid-sparing Effects, and Pain-reduction Potential of Low Dose Ketamine on Patients Undergoing TEVAR Procedures Receiving NCI

The objective of this study is to identify the opioid-sparing effects, and pain-reduction potential of low dose, sub-dissociative ketamine on patients undergoing thoracic endovascular aortic repair (TEVAR) procedures receiving naloxone continuous infusion (NCI).

Patients undergoing descending aortic repair often experience post-operative pain, and have high post operative opioid requirements. That pain is partially due to the use of naloxone continuous infusion (NCI). NCI is part of a bundled approach used in the first 48 hours post-operatively to prevent spinal cord ischemia, a devastating complication associated with surgical repair of the descending aortic. Data indicate that patients receiving NCI experience elevated post-operative pain scores and increased opioid requirements during the 48-hr post-operative NCI administration, compared to patients not receiving NCI. Ketamine is an FDA-approved N-methyl D-aspartate (NMDA) antagonist that has been shown to provide adjunctive analgesia and opioid-sparing effects in post-operative surgical patients. At low doses, ketamine provides analgesic benefit without the anesthetic effects seen at higher doses. These doses are commonly referred to sub-dissociative. This study will evaluate whether use of sub dissociative ketamine (SDK) in patients undergoing aortic procedures with the use of NCI will lead to decreased post-operative opioid consumption, and produce improved pain scores in the first 48 hours.

Participants in this group will receive standard of care as well as a saline infusion during the study period.

Participants in this group will receive standard of care as well as a continuous ketamine infusion at the induction of anesthesia and for 48 hours postoperatively.

Continuous ketamine infusion at a dose of 0.2 mg/kg/hr, initiated at the induction of anesthesia and continued for 48 hours postoperatively.

Pain will be assessed using a 10-Point Numerical Pain Scale (as part of standard of care) every hour for the first 24 hours and every two hours for the next 24 hours. Scores range from 0-10; higher scores indicated higher levels of pain.

Ketamine-induced delirium will be monitored via the Confusion Assessment Method (CAM-ICU) survey every 8 hours for 48 hours. The CAM-ICU assesses four diagnostic features of delirium and the result is a binary (yes or no) determination.

Uncontrolled hypertension is defined as a systolic pressure of 160 mmHg despite 3 intravenous antihypertensive agents.

Inclusion Criteria: willing to give informed consent scheduled for elective thoracic aorta repair or thoracoabdominal aortic repair requires naloxone continuous infusion for spinal prophylaxis Exclusion Criteria: allergy to ketamine, acetaminophen, or fentanyl diagnosis of schizophrenia history of hydrocephalus or central nervous system mass incarcerated individuals pregnant or lactating individuals