Current role of perioperative intravenous ketamine: a narrative review

The purpose of this review is to report on the perioperative uses of intravenous (IV) ketamine based on literature from the last five years (2018–2022). We searched MEDLINE, Embase and PubMed databases from 1st January 2018 till 15th September 2022. We primarily reviewed randomized control trials and systematic reviews with or without meta-analyses where IV ketamine was used as part of an anesthetic regimen perioperatively for general or regional anesthesia. We included studies with both pediatric and/or adult participants. We did not examine the quality of the randomized controlled trials (RCTs) included in our review. Perioperative IV ketamine consistently reduced postoperative opioid requirement especially in the early postoperative period, however, the duration of this effect was variable in different surgeries and patient populations. This effect was seen in breast, obstetric, bariatric, and orthopedic surgeries. The effect was minimal in pediatric and thoracic surgeries. It has a valuable role in multi-modal analgesic regimen, especially in orthopedic and spine procedures. Considerable heterogeneity was noted with regards to the dosage of IV ketamine. Bolus doses ranged from 0.15 to 1 mg·kg−1 and infusion doses ranged from 2 to 5 ug·kg−1·min−1. Its role in prevention of chronic post-surgical pain is still under investigation. Intravenous ketamine also reduced postoperative depressive symptoms in specific patient populations. It also reduced shivering associated with spinal anesthesia. It has a potential role in prevention of emergence agitation and postoperative delirium. In conclusion, IV ketamine has a versatile range of beneficial clinical effects in perioperative practice. The most widely studied are its analgesic effects which are of variable intensity amongst different surgical specialties and subset of patients. Despite its long history of use, fresh uses of IV ketamine continue to be reported. More trials are needed to better understand ideal dosing and patient subsets that will benefit most from these effects.