From the Guidelines
Low-dose ketamine is effective as an adjunct to opioid therapy for managing acute pain in critically ill adults, particularly in postsurgical patients.
Efficacy of Low-Dose Ketamine
- The use of low-dose ketamine (0.5 mg/kg IVP x 1 followed by 1-2 μg/kg/min infusion or 1–2 μg/kg/hr) as an adjunct to opioid therapy is suggested for reducing opioid consumption in postsurgical adults admitted to the ICU 1.
- Studies have shown that low-dose ketamine is associated with reduced morphine consumption, but it does not necessarily improve patients' self-reported pain intensity 1.
- The incidence of side effects, such as nausea, hallucinations, hypoventilation, pruritus, and sedation, is similar between the ketamine and opioid-alone groups 1.
Clinical Considerations
- The recommendation for using low-dose ketamine as an adjunct to opioids is conditional, with very low quality of evidence 1.
- Clinicians should consider the benefits and harms of using low-dose ketamine in critically ill adults, particularly in postsurgical patients 1.
- The use of low-dose ketamine may be beneficial in reducing opioid consumption, but its effect on patient-centered outcomes is still uncertain 1.
The FDA Drug Labels for ketamine (IV) do not address this question.
From the Research
Efficacy of Low-Dose Ketamine for Acute Pain Management
- The efficacy of low-dose ketamine for managing acute pain has been investigated in several studies 2, 3, 4, 5, 6.
- A systematic review and meta-analysis of randomized controlled trials found that low-dose ketamine may have higher or equivalent efficacy and safety compared to opioids for managing acute pain in the emergency setting 2.
- Another study found that low-dose ketamine can provide an opioid-sparing effect when used as an adjunct to opioid therapy, and that ketamine doses <0.5 mg/kg were not associated with significant side effects 4.
- A narrative review of 64 studies found that low-dose ketamine is a safe and effective option for acute pain treatment, and can be used as an alternative therapy to opioids or used in conjunction with them to reduce opioid exposure 4.
- A systematic review and meta-analysis of nine studies found that ketamine for immediate pain relief at 15 minutes could be an effective alternative to opioids, but its overall effect in comparison to opioids for improving pain has not shown a statistically significant difference 6.
Comparison to Opioids
- Studies have compared the efficacy of low-dose ketamine to opioids for acute pain management, with some finding that ketamine is non-inferior to opioids when used alone 4.
- A study found that higher adverse events were reported in opioids, but this was not statistically significant 6.
- Another study found that low-dose ketamine can be an effective and safe alternative to opioids in acute pain management 5.
Safety and Side Effects
- The safety and side effects of low-dose ketamine have been investigated in several studies, with some finding that ketamine doses <0.5 mg/kg were not associated with significant side effects 4.
- A study found that higher adverse events were reported in opioids, but this was not statistically significant 6.
- Another study found that low-dose ketamine can be an effective and safe alternative to opioids in acute pain management, with a low risk of side effects 5.