Can a pericapsular nerve group (PENG) block be performed on a patient with an intertrochanteric femoral neck fracture who took Eliquis (apixaban) the night before?

PENG Block After Recent Eliquis: Proceed with Caution Based on Timing and Apixaban Levels

A PENG block can be performed on a patient who took Eliquis the night before an intertrochanteric fracture, but only if the apixaban concentration is measured and confirmed to be below 30 ng/mL, or if at least 24 hours have elapsed since the last dose—otherwise, the procedure should be delayed or apixaban levels checked before proceeding. 1

Risk Classification and Decision Framework

The PENG block is classified as a neuraxial-adjacent procedure with high bleeding risk due to its proximity to neurovascular structures and the potential for uncontrollable bleeding in a deep fascial plane. The 2025 French guidelines explicitly address this scenario:

Timing-Based Approach

If the patient took Eliquis (apixaban) "the night before":

• Minimum safe interval: The FDA label recommends discontinuing Eliquis at least 24 hours prior to procedures with low bleeding risk 2
• For neuraxial procedures: The 2025 guidelines specify a 30 ng/mL threshold for neuraxial and intracranial procedures (stricter than the 50 ng/mL for other high-risk procedures) 1
• Peak effect consideration: Apixaban peaks 3-4 hours post-dose, so "night before" likely means 8-16 hours elapsed—potentially insufficient clearance 1

Recommended Algorithm

Step 1: Measure apixaban anti-Xa concentration immediately 1

• If < 30 ng/mL: Proceed with PENG block safely 1
• If 30-50 ng/mL: High risk—delay if possible or consider alternative analgesia
• If > 50 ng/mL: Do NOT perform the block 1

Step 2: If measurement unavailable, use time-based estimation:

• < 24 hours since last dose: Delay the block if clinically feasible
• ≥ 24 hours since last dose: Reasonable to proceed, but measure levels if available
• Consider renal function: Check creatinine clearance—impaired renal function prolongs apixaban half-life and increases risk 1

Step 3: If the procedure cannot be delayed and levels exceed threshold:

• The 2025 guidelines strongly recommend against neuraxial procedures even with PCC reversal due to spinal hematoma risk 1
• Consider alternative analgesia: IV opioids, fascia iliaca block (more superficial, potentially lower risk), or general anesthesia for surgery 3

Critical Safety Considerations

Why PENG Blocks Are High-Risk on Anticoagulation

• Anatomical location: The PENG block targets the space between the psoas tendon and pubic ramus, near the femoral neurovascular bundle 4, 5
• Compressibility: Unlike peripheral nerve blocks in compressible sites, bleeding in this deep fascial plane is difficult to detect and control
• Neuraxial proximity: While not technically neuraxial, the consequences of hematoma formation could be catastrophic

The 24-Hour Rule Is Insufficient Alone

The FDA label states 24 hours for "low bleeding risk" procedures 2, but:

• PENG blocks carry higher bleeding risk than typical peripheral blocks
• The 2025 guidelines emphasize that time alone is inadequate—concentration measurement is essential for high-risk procedures 1
• Individual pharmacokinetics vary significantly, especially in elderly patients with hip fractures who often have renal impairment

Practical Implementation

For your specific patient with an intertrochanteric fracture:

1. Obtain anti-Xa apixaban level stat (if available at your institution)
2. Check renal function (CrCl via Cockcroft-Gault formula) 1
3. Calculate time since last dose precisely (not just "night before")
4. If < 30 ng/mL or > 24 hours with normal renal function: Proceed with PENG block 1
5. If levels unavailable and < 24 hours: Use IV morphine or fascia iliaca block as bridge analgesia 3

Alternative Analgesic Strategy

Recent evidence shows PENG blocks provide superior analgesia to IV opioids 3, but if unsafe to perform:

• IV morphine 0.1 mg/kg provides adequate pain control (though inferior to PENG) 3
• Fascia iliaca block may be considered as a more superficial alternative, though less effective for intertrochanteric fractures
• Multimodal analgesia: Acetaminophen, IV lidocaine infusion, ketamine as adjuncts

Common Pitfalls to Avoid

• Assuming "night before" equals safe timing: Always calculate exact hours and measure levels when possible
• Ignoring renal function: Elderly hip fracture patients frequently have CrCl < 50 mL/min, prolonging apixaban half-life significantly 1
• Proceeding without measurement in high-risk patients: The 2025 guidelines represent the most current evidence and explicitly require concentration measurement for neuraxial-adjacent procedures 1
• Using PCC as a safety net: The guidelines state PCC does not make neuraxial procedures safe and should not be relied upon 1

The evidence strongly supports measuring apixaban levels before proceeding with PENG blocks in patients with recent Eliquis exposure, particularly given the catastrophic consequences of spinal/epidural hematoma in this vulnerable elderly population. 1