Analgesia for Total Hip Arthroplasty With PENG Block (ATHAPENG)

Total hip arthroplasty (THA) for osteoarthritis is a commonly performed surgery worldwide. It is associated with significant pain, with median pain scores in the first 24 hours postoperatively exceeding 3 on the standardized numeric rating scale (NRS). Multimodal analgesia, including infusion of systemic analgesics and regional anesthesia through the Pericapsular Nerve Group Block (PENG block), has demonstrated efficacy in literature, when compared to other commonly used techniques such as the iliofascial block or surgical infiltration. However, analgesia provided by the PENG block appears to be incomplete, with a significant consumption of opioids in the postoperative period. The investigators hypothesis is that PENG block does not cover every hip sensitive territory involved during the surgical procedure.

The investigators conducted a single-center, observational, prospective study evaluating the antinociceptive effect of a PENG block performed preoperatively, at various surgical time points (incision, dislocation, femoral osteotomy, acetabular reaming, femoral reaming, femoral stem impaction, reduction, closure) by monitoring the Nociception Level Index (NOL index) during general anesthesia.

NOL index values (0 to 100) between 10 and 25 reflect nociception control, NOL index values exceeding 25 reflect excess of nociception, NOL index < 10 reflects a potential excess of opioids infusion.

After surgery, pain scores (NRS), opioid consumption, and the presence of motor blockade within the first 48 hours postoperatively were also assessed.

The aim of the study is to determine the efficacy of PENG block combined to multimodal analgesia on intraoperative nociception and postoperative pain in patients undergoing total hip arthroplasty under general anaesthesia.

Inclusion criteria

• Adult patients (> 18 years old)
• Undergoing primary hip arthroplasty for osteoarthritis
• Under general aneasthesia
• With PENG block

Exclusion criteria

• Patient under 18 years old
• Severe cognitive impairment or patient under guardianship
• Pregnancy
• Allergy to local anaesthetics
• Chronic pain with daily opioid consumption
• Non sinusal cardiac rhythm