Total Knee Arthroplasty

Anesthesia Implications

Position: Supine, arms extended
Time: 1-2 hours (average)
Blood Loss: Moderate (50 – 200 ml)
Post-op Pain: Moderate (3-6)
Maintenance Paralytic: No
Tourniquet Use: Yes
Blocks: Adductor Canal, Popliteal

Spinal or epidural – these are very good considerations for these cases as they been shown to provide both analgesia and reduce blood loss. For spinals, the addition of lidocaine (10 mg), epinephrine (15 mcg), and fentanyl (25 mcg) has been shown to be very effective at both reducing postoperative pain and discharge times.

Blood loss – You may be asked by physician to keep blood pressures low to reduce blood loss (Systolic ~ 90-110).

TXA – Anticipate administration of tranexamic acid (TXA). Timing for administration of TXA is highly variable, so ask for the preference of the surgeon.

Bone cement – Anticipate the use of bone cement and prepare for bone cement implantation syndrome (this syndrome primarily causes hypoxia and hypotension).

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)