Project Information

Proposal of intravenous ketamine use as an analgesic adjunct to GA in neurosurgical patients undergoing spine surgery and hence decrease the opioid use for intra operative and post-operative pain

Project Description: Pain is defined as “unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. Effective management of acute pain is a very important aspect of the optimal care of all patients undergoing surgery. Several recent surveys have shown that still a big amount of patients (around 70%) experience discomfort and moderate to severe pain after surgical procedures. The surgical stress results in increase in secretion of catabolically-acting hormones such as catecholamines, cortisol, ACTH, ADH, glucagon, and aldosterone, and a concomitant decrease in the secretion of the anabolically-acting hormones such as insulin and testosterone. These endocrine changes in turn cause a number of metabolic effects that ultimately result in a catabolic state. Therefore post-operative pain, unless effectively managed, can directly or indirectly cause impairment of the function of various organ systems (modern concepts of acute and chronic Pain management). The opioid epidemic has captured the attention of all the leading medical organizations in the country. Alternatives to opioids or techniques that markedly reduce opioids are highly desirable. Ketamine, an N-methyl-D-aspartate receptor antagonist, has emerged as such a drug because of its potent analgesia and lack of respiratory depression. Ketamine infusions can improve postoperative pain and decrease opioid consumption with the greatest benefit occurring during the most painful surgeries. (Ketamine a versatile tool in perioperative period and beyond) Ketamine, an anesthetic first developed in 1970, is one drug that has gained renewed interest as a part of the multimodal approach towards acute pain treatment. Intravenous ketamine, when added as an adjunct to general anesthesia, reduced postoperative pain and opioid requirements in a variety of settings, from outpatient surgery to major abdominal procedures (Ketamine for perioperative pain management). Ketamine can function as analgesic by blocking the NMDA receptors involved in nociceptive and inflammatory pain response. It is a potent antihyperalgesic agent. It can counteract opioid induced hyperalgesia and prevent the development of opioid tolerance. Ketamine has also been used to treat depression, CRPS, cancer pain, alcohol addiction, heroin addiction, asthma exacerbations, wheezing, and pain during propofol injection. Although it was first used purely as an anesthetic, ketamine is making a certain resurgence in the management of postoperative pain (Acute and perioperative pain section). IV Ketamine reduces opioid consumption by 40%. At one center, Division of Regional anesthesia and acute Interventional perioperative pain, low dose continuous IV infusion of Ketamine has been included as a standard of care for the management of post-operative pain in opioid tolerant patients since 2010 and noticed 40% reduction in opioid use(Acute and perioperative pain section). Meta-analyses of various clinical trials with IV Ketamine has shown the intra-operative boluses ranging from 0.15mg/kg to 1mg/kg and intra operative infusions ranging from0.12mg/kg/hr to 1.2mg/kg/hr to be effective in reducing opioid for intra operative and post-operative pain(Acute and perioperative pain). Ketamine has mind altering effects. Quiet, relaxed surroundings contribute to a reduced incidence of these side effects and when ketamine is administered alone, the prophylactic use of a sedative agent such as 3.75–7.5mg oral midazolam has generally decreased their incidence and severity. No severe physical symptoms have been reported with the use of low-dose ketamine; however, studies have reported benign effects of lightheadedness, headache, nausea, diplopia, drowsiness, and dizziness. These effects, unlike the psychotomimetic effects, tend to be dose-dependent. They are also limited to time of administration and a short time thereafter. Case series demonstrate a temporal link between ketamine abuse and urological symptoms, urinary tract damage, and renal impairment, with some but not all symptoms improving upon cessation of ketamine. Hepatotoxicity has been reported at anesthetic doses (≥1mg/kg) and patients receiving low-dose continuous infusion. Trials using single doses of ketamine <1mg/kg report no changes in liver function tests.

QPI: Venkata, Damalanka, (

Collaborators: Kelly, Flynn, (

Advisors: (

UF Health Big Aims: Increase Value None

MeSH Keywords: Acute and perioperative pain, Ketamine for peri-operative pain management, Multimodal analgesia,role of non opioid analgesics