Hip surgery accounts for a high percentage of both emergency and elective surgical procedures in hospitals. Regardless of surgery being prescribed to treat a fracture or coxarthrosis, patients are usually elderly with multiple associated comorbidities. When faced with this patient profile, there is a tendency to undertreat pain for fear of the side effects and pharmacological interactions of conventional analgesic drugs.

Ultrasound-guided regional anesthesia applied in orthopedic and trauma surgery has been shown to reduce the doses of opioids and conventional analgesics, to ease deambulation and early recovery, to improve respiratory dynamics and to reduce vein thrombosis and pneumonias. Our study aims to verify whether L-ESP block is effective in the hip and proximal femur surgeries and allows to lower the dosage of opioids in these patients.

Inclusion Criteria:

• Both sexes over 18 years of age having undergone hip surgery
• ASA I-III (classification system used by the American Society of Anesthesiologists where I is low anesthetic risk and IV is high risk)
• Capacity to comprehend the principles of pain assessment using the VAS visual analogue scale
• Previously signed an informed consent.

Exclusion Criteria:

• Contraindications for the technique and/or the drugs used in this context
• Technical inability to perform the block
• Severe cognitive impairment or prior mental disabilities described in their medical records
• Patients already included in other clinical trials.

Pragmatic randomized low interventional single-centre parallel non blinded design with blinded assessment of the objectives.