Medication, equipment, and supply costs for common interventions providing extended post- surgical analgesia following total knee arthroplasty in US hospitals

Aims: To estimate the cost to hospitals of materials (i.e. medications, equipment, and supplies) required to administer common interventions for post-surgical analgesia after total knee arthroplasty (TKA), including single-injection peripheral nerve block (sPNB), continuous peripheral nerve block (cPNB), periarticular infiltration of multi-drug cocktails, continuous epidural analgesia, intravenous patient-controlled analgesia (IV PCA), and local infiltration of bupivacaine liposome injectable suspension (BLIS). Materials and methods: This analysis was conducted using a mixed methods approach combining published literature, publicly available data sources, and administrative data, to first identify the materials required to administer these interventions, and then estimate the cost to the hospital of those materials. Medication costs were estimated primarily using the Wholesale Acquisition Costs (WAC), the cost of reusable equipment was obtained from published sources, and costs for disposable supplies were obtained from the US Government Services Administration (GSA) database. Where uncertainty existed about the technique used when administering these interventions, costs were calculated for multiple scenarios reflecting different assumptions. Results: The total cost of materials (i.e. medications, equipment, and supplies) required to provide post-surgical analgesia was $41.88 for sPNB with bupivacaine; $756.57 for cFNB with ropivacaine; $16.38 for periarticular infiltration with bupivacaine, morphine, methylprednisolone, and cefuroxime; $453.84 for continuous epidural analgesia with fentanyl and ropivacaine; $178.94 for IV PCA with morphine; and $319.00 for BLIS. Limitations: This analysis did not consider the cost of healthcare providers required to administer these interventions. In addition, this analysis focused on the cost of materials and, therefore, did not consider aspects of relative efficacy or safety, or how the choice of intervention for post-surgical analgesia might impact outcomes such as length of stay, re-admissions, discharge status, adverse events, or total hospitalization costs. Conclusions: This study provided an estimate of the costs to hospitals for materials required to administer commonly used interventions for post-surgical analgesia after TKA.