Efficacy of intranasal ketamine for acute pain management in adults: a systematic review and meta-analysis.

This study aimed to compare the efficacy of intranasal (IN) ketamine for pain control with placebo and other analgesics in an emergency setting. Electronic databases of PubMed, Embase, and CENTRAL were searched for randomized controlled trials (RCTs) comparing IN ketamine with placebo or other analgesics up to 1st January 2021. Studies were to be conducted on adults and in an emergency setting. Pain outcomes and adverse events were compared. Seven RCTs were included. Three compared IN ketamine with placebo while others with opioids. Comparing IN ketamine with opioids, the pooled analysis demonstrated no significant difference in pain scores between the two groups at 15 minutes but better pain reduction with opioids at 30 minutes. Comparing IN ketamine with placebo, our analysis demonstrated a non-significant difference but a tendency for better pain relief with IN ketamine at 15 minutes and 60 minutes. Pain scores at 30 minutes were, however, significantly lower with IN ketamine as compared to placebo. The need for rescue analgesics was significantly lower with IN ketamine as compared to placebo. There was no significant difference in the incidence of dizziness and nausea/vomiting between IN ketamine and opioids. As compared to placebo, IN ketamine was associated with an increased incidence of dizziness but not nausea/vomiting. Emergence reactions were significantly increased with IN ketamine as compared to opioids and placebo. There may be a role of IN ketamine for acute pain management in adults in an emergency setting. There is a tendency for better pain control with IN ketamine as compared to control and the possibility of similar efficacy of IN ketamine as compared to opioids. However, the results are not unequivocal and are limited by the low number of studies in literature and limited pain indications studied. Further RCTs are required to strengthen the evidence.