Lumbar Plexus and Suprainguinal Fascia Iliaca Blocks For Total Hip Replacement

A Randomized Comparison Between Ultrasound Guided Lumbar Plexus and Suprainguinal Fascia Iliaca Blocks For Total Hip Replacement Analgesia

The nerves from lumbar plexus (LP) are the current target to achieve analgesia after a total hip arthroplasty (THA). Lumbar plexus block (LPB) is an alternative that provides optimal postoperative analgesia. However, many adverse effects and complications have been reported due to its proximity to vital structures. Because of these shortcomings, an alternative to block the LP nerves is required.

In a recent trial suprainguinal Fascia Iliaca Block (SFIB) was reported to provide reliable analgesia in THA. SFIB may carry a lower risk profile, however, no study has compared the efficacy of LPB and SFIB in this setting.

Thus, this randomized trial is set out to compare US guided LPB and SFIB for analgesia after THA. The hypothesis is that both blocks would result in similar postoperative opioid (morphine) consumption at 24 hours and, therefore, designed the study as an equivalence trial.

Inclusion Criteria:

• Age between 18 and 80 years
• American Society of Anesthesiologists classification 1-3
• Body mass index between 20 and 35 (kg/m2)

Exclusion Criteria:

• Adults who are unable to give their own consent
• Pre-existing neuropathy (assessed by history and physical examination)
• Coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or prothrombin time ≥ 50)
• Renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. creatinine ≥ 100)
• Hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. transaminases ≥ 100)
• Allergy to local anesthetics (LAs) or morphine
• Pregnancy
• Prior surgery in the corresponding side of the lumbar o suprainguinal area
• Chronic pain syndromes requiring opioid intake at home