The Impact of Perioperative Ketamine Infusion on Surgical Recovery

Opioids are powerful analgesic medications that can reduce pain through action at the mu receptor. Unfortunately, activation of the mu receptor also results in undesirable side effects, such as respiratory depression, sedation, bowel ileus, nausea, itching, and tolerance. Therefore, in order to effectively treat pain with the least amount of opioids required, a multi-modal approach must include medications with different mechanisms of actions at alternative receptors. Some examples of non-narcotic pain medications include acetaminophen (Tylenol), anti-inflammatories (NSAIDS), muscle relaxants, local anesthetics, gabapentinoids (Lyrica), and ketamine, to name a few. In light of the opioid epidemic, medical providers at Vanderbilt University Medical Center (VUMC) are strategically combining these medications in a bundled pain-regimen after surgery. These regimens have been shown to decrease opioid consumption, improve surgical outcomes, and reduce hospital stays, thus coining the term 'enhanced recovery pathway' or enhanced recovery after surgery (ERAS). The combination of these medications has an indisputable synergistic effect. However, it is unknown how each medication contributes individually to the overall efficacy of the pathway. Ultimately, the investigators aim to perform a series of randomized controlled trials in which we isolate each component of the pathway to investigate its effects on length of stay, total opioid consumption, and surgical outcomes. The investigators will begin with studying ketamine.

Inclusion criteria

• 18 years old or greater
• presenting at VUMC for abdominal surgery on the colorectal, ventral hernia or surgical oncology services on a weekday.

Exclusion criteria

• allergy or contraindication to ketamine
• unable or refuse to receive a neuraxial or regional nerve block
• patient refusal
• direct transfer from operating room to intensive care unit with endotracheal tube placed
• treating team elects to exclude the patient prior to study drug administration
• abortion of planned surgical procedure