A ketamine infusion is a continuous delivery of a low dose of ketamine, a disassociative anesthetic drug. It can be used for analgesia and anesthesia in medical procedures, but it cannot be used as the sole drug for this purpose and is most commonly seen in veterinary use. Experimental treatments with ketamine for the management of complex regional pain syndrome in humans have taken place in several nations, and peer-reviewed trials suggest the drug may have some promise in these applications.
This anesthetic drug can dull sensations of pain but does not induce skeletal muscle relaxation. One use for ketamine is in mild sedation for certain kind of procedures, or to induce anesthesia. In veterinary care, a clinician may give ketamine to help an animal calm down before starting anesthesia, in the interest of the safety of the animal and any handlers. For a long procedure where a single ketamine injection is not sufficient, the anesthesiologist may deliver another injection or could consider an infusion.
In a ketamine infusion, the drug is delivered intravenously through a drip at low doses. One benefit to this drug is a relatively large margin of safety. Patients have to receive a very high dose to experience dangerous side effects, and the anesthesiologist can easily adjust the dose if the patient starts to develop signs of distress. Some side effects can include irregular heart rate, delirium, jerking movements, or apnea, especially if the patient receives a high loading dose before a ketamine infusion.
In the treatment of complex regional pain syndrome and other chronic pain conditions, the ketamine infusion may be given on an inpatient or outpatient setting. Inpatients must spend several days in the hospital under monitoring while they receive the medication, while outpatients can receive a short infusion and then leave. The medication will induce analgesia and make the patient feel more comfortable.
Management of pain in general and chronic pain in particular has proved to be a significant challenge for health care providers. Patients often respond very differently to pain management even when they have what appears to be the same condition. One pain patient may find a ketamine infusion highly beneficial. Another may fail to respond or could find that the effects do not linger. Patients may benefit from seeing a pain specialist who can adjust dosages and explore other treatment options to see if it is possible to get the patient's pain under control.