Medial Knee Unicompartmental Arthroplasty

Anesthesia Implications

Position: Supine, arms at side on armboards
Time: 1-2 hours (average)
Blood Loss: Low (10-50 ml)
Post-op Pain: High (7-10)
Maintenance Paralytic: Yes
Tourniquet Use: Yes
Blocks: Adductor Canal

High post-operative pain (general considerations): Plan ahead to treat pain in the postoperative period. If not contraindicated, consider hydromorphone or other long-acting analgesics along with adjuncts such as Ofirmev and/or toradol. Where possible, give during the operative period to limit pain in the postoperative period. Where applicable, consider peripheral nerve blocks and/or epidural interventions.

Tourniquet (general considerations): Antibiotics should be administered prior to tourniquet inflation. Tourniquet pain usually begins 45-60 minutes after inflation and is unresponsive to regional anesthesia and analgesics. Upper extremity pressure should be set to approximately 70-90 mmHg above systolic blood pressure (SBP). Lower extremity tourniquet pressure should be set to approximately 2 times SBP. Upon tourniquet release, there will be increases in End-tidal CO2 and metabolic acidosis, while decreases will be seen in core body temperature, blood pressure, and mixed venous oxygen saturation (SvO2)