Opioids are a mainstay in the management of acute pain, but due to their side effects, physicians are under increased pressure to be more selective in their prescription. A recent review investigated if ketamine for pain management is a viable alternative in the emergency department.
The most common symptom during visits to the emergency department is acute pain. Managing this pain is a major aspect of initial care in hospital settings and opioids are an effective and widely available treatment option. However, there is an increased push from physician research groups to reduce overall prescriptions of opioids in emergency care settings while improving health outcomes for patients.
Ketamine for pain management has been recognized as a possible alternative. An inhibitor of NMDA receptors in nerve cells, ketamine can create dissociative anaesthetic states with hallucinatory sensations at higher doses. In the emergency department, ketamine is often administered at sub-dissociative doses as a sedative during procedures and for intubated patients.
Comparing ketamine to opioids for pain management
A team of researchers in the United States recently completed a systematic review comparing the effect of low-dose ketamine to opioids for adult pain management in the emergency department. Their full report was published in Academic Emergency Medicine.
Studies were included in the systematic review if they were randomized controlled trials comparing intravenous low dose ketamine to opioids in emergency department settings. They excluded pediatric studies, studies that were not placebo-controlled, did not report pain scores or co-administered additional medications.
Due to stricter selection criteria compared to previous reviews on the subject, the literature search and study selection yielded three studies totaling 261 patients. After extracting and pooling the pain scores from the selected studies, ketamine was found to be comparable in effectiveness to opioids in the treatment of acute pain.
Ketamine is comparable to opioids without the respiratory effects
Adverse events were associated with ketamine administration and were mainly related to lower urinary tract symptoms, including increased urinary frequency as well as the possibility of renal failure. Opioid administration was associated with side effects similar in severity but differing in nature, including nausea, vomiting, and respiratory depression. Ketamine administration may, therefore, be preferable to opioids in elderly patients or patients with pulmonary disorders where opioid use can cause respiratory depression or failure.
Concerns regarding addiction
Concerns over addiction have been one of the driving forces to find alternatives to opioids, but according to the study authors there is little evidence linking addiction with acute administration of opioids in the emergency department. With chronic use, ketamine has the potential to lead to addiction as well.
This systematic review suggests that ketamine for pain management is a viable alternative to opioids for in the emergency department. Due to the risks of prescribing opioids in certain patient subgroups, the authors maintain that ketamine can provide comparable levels of pain relief while avoiding respiratory side effects.
Written by Agustin Dominguez Iino, BSc
- Karlow N, Schlaepfer CH, Stoll CRT, Doering M, Carpenter CR, Colditz GA, Motov S, Miller J, Schwarz ES. A Systematic Review and Meta-analysis of Ketamine as an Alternative to Opioids for Acute Pain in the Emergency Department. Acad Emerg Med. 2018 Jul 17. doi: 10.1111/acem.13502. [Epub ahead of print]
- Pai A, Heining M. Ketamine. Continuing Education in Anaesthesia Critical Care & Pain. 7(2): 59-63. 2007 Apr 01. doi: 10.1093/bjaceaccp/mkm008.