Reducing Pain Scores and Opioid Consumption After Total Knee & Hip Arthroplasty: A Ketamine Infusion Protocol
Opioids are frequently used to manage perioperative pain associated with TKA/THA despite being associated with negative sequalae.
- Total knee arthroplasty (TKA), and total hip arthroplasty (THA) are associated with moderate to severe, pain scores which can affect postoperative rehabilitation and patient satisfaction [1-2]
- Opioids are frequently used to manage perioperative pain associated with TKA/THA despite being associated with negative sequalae (e.g. nausea, respiratory depression, urinary retention, and constipation). [1-2]
- Multimodal pain relief regimens with non-opioid analgesics such as ketamine show superior pain relief and reduced opioid consumption after TKA/THA [1-2]
- lmplement an evidence-based interoperative ketamine infusion protocol for Certified Registered Nurse Anesthetists (CRNAs) to reduce intraoperative and postoperative opioid and administration as well as postoperative pain scores in TKA/THA patients.
- Setting: Small community hospital in rural Minnesota.
- Project team developed ketamine infusion protocol after a literature review.
- QI project deemed IRB exempt
- CRNAs, Post-anesthesia Care Unit (PACU) and med-surg RNs received education about protocol via PowerPoint presentation and information packets.
- CRNAs added ketamine infusion order to preop order set for TKA/THA patients.
- Coordinated with pharmacy to make pre-filled 2 mg/mL ketamine syringes for each patient with order.
Ketamine Infusion Protocol
- Verify patient is appropriate candidate for ketamine and consider lower dose for age >75.
- Ketamine bolus 0.25 mg/kg ideal body weight (IBW) after sedation initiation and prior to incision.
- Start ketamine infusion at 2.5 mcg/kg/min (IBW).
- Stop infusion 15 minutes prior to emergence.
- Average intraoperative fentanyl administration
- Average total PO morphine equivalents administered in PACU
- Average total PO morphine equivalents administered 24 hours postoperatively
- Average pain scores in PACU
- Average pain scores 24 hours postoperatively
- Data collected via chart review during three month implementation period and compared to same three month period one year prior.
- Decrease in average reported pain scores in PACU for TKA and 24 hours post-op for both TKA/THA after protocol implementation (Figure 1).
- Decrease in average PO morphine equivalents administered in PACU for TKA and 24 hours post-op for both TKA/THA after protocol implementation (Figure 2).
- Minimal decrease in intraoperative fentanyl use for TKA/THA
- Barriers to CRNA adoption of protocol included lack of infusion pumps and difficulty properly wasting large ketamine syringe.
- Project was implemented in the context of the COVID-19 pandemic.