Intra-articular Ketamine reduces Post Operative Pain and Reduces Opioid usage
Ketamine's routine perioperative care has become popular since first being synthesized in 1962 by Calvin Stevens. The use of S-ketamine is increasing worldwide since the S(+)-enantiomer has been postulated to be a four times more potent anesthetic and analgesic than the R(-)-enantiomer and approximately two times more effective than the racemic mixture of ketamine.
In a recent study published in the American Journal of Physical Medicine & Rehabilitation, researchers have reported that the patients who received intra-articular ketamine generally reported lower pain scores and had lower postoperative opioid consumption after orthopedic joint procedures.
Ketamine is being explored for alternative treatment options for medical conditions such as headaches, depression, and chronic pain. Because of extensive first-pass metabolism, oral bioavailability is poor and ketamine is vulnerable to pharmacokinetic drug interactions. Sublingual and nasal formulations of ketamine are being developed, especially nasal administration produces rapid maximum plasma ketamine concentrations with relatively high bioavailability. However, ketamine is commonly used in the intravenous form for postoperative pain control but, its use as an intra-articular (IA) agent is fairly novel. Therefore researchers of Mayo Clinic, Minnesota, conducted a study to appraise the evidence from human clinical trials comparing postoperative pain scores and opioid consumption in patients receiving intra-articular ketamine versus other modalities of analgesia after orthopedic joint procedures.
It was a systemic review of seventeen studies from Embase, Scopus, and OVID Medline databases. From these studies, researchers compared patients receiving intra-articular ketamine versus other modalities of analgesia. The major outcome assessed was postprocedural pain score and total opioid consumption. Researchers also assessed the time to rescue analgesic medication request, active range of motion, time to mobilization, and adverse effects. Dosage of ketamine varied widely from 0.25 to 2 mg/kg.
Among 17 studies, researchers noted that 15 studies demonstrated decreased overall pain scores and decreased total postoperative opioid consumption in patients receiving intra-articular ketamine versus control groups. They also found that patients who received intra-articular ketamin generally demonstrated reduced time for mobilization and increased latency until rescue analgesic medication.
The authors concluded, "Patients who received intra-articular ketamine generally reported lower pain scores and had lower postoperative opioid consumption after orthopedic joint procedures".
They further added, "The findings suggest that the intra-articular route of ketamine delivery may be a useful analgesic modality, although future larger-scale trials should explore its pharmacokinetics, optimal dosing, safety, and cost-effectiveness".
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