This study aims to evaluate the effect of the dexamethasone administration route (intravenous vs. perineural) on postoperative pain, inflammatory response, and clinical outcomes in patients undergoing total hip arthroplasty (THA) with a pericapsular nerve group (PENG) block. The primary outcome is the intensity of postoperative pain measured using the numerical rating scale (NRS) at rest and during movement. Secondary outcomes include the inflammatory response assessed by neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), opioid consumption, and patient satisfaction. The findings from this study may contribute to optimizing anesthesia protocols and improving postoperative recovery in patients undergoing THA.

Total hip arthroplasty (THA) is a common orthopedic procedure associated with significant postoperative pain and inflammation, which can impact recovery and long-term outcomes. Regional anesthesia techniques, such as the pericapsular nerve group (PENG) block, have become increasingly popular for pain management in THA due to their ability to provide effective analgesia while preserving motor function.

Dexamethasone is frequently used as an adjuvant in regional anesthesia to prolong the duration of analgesia and reduce inflammation. However, there is limited evidence comparing the efficacy of different administration routes of dexamethasone (intravenous vs. perineural) in the context of PENG block. Additionally, understanding the impact of dexamethasone on postoperative pain, inflammatory markers, and overall patient recovery is crucial for optimizing clinical protocols.

This study is a prospective, randomized, double-blinded trial involving patients undergoing elective THA. Participants will be randomly assigned to two groups: the IV dexamethasone group or the perineural dexamethasone group. Both groups will receive standardized general anesthesia and PENG block with local anesthetic. Postoperative pain will be assessed using the NRS at various time intervals (e.g., 6, 12, 24, and 48 hours postoperatively) at rest and during movement. NLR and PLR will measure the inflammatory response from blood samples taken preoperatively and 24 hours postoperatively.

The primary outcome is time first to request rescue analgesia. Secondary outcomes include cumulative opioid consumption, length of hospital stay, and patient satisfaction. Safety and potential complications, such as local anesthetic systemic toxicity (LAST), will be closely monitored.

The results of this study may provide valuable insights into the optimal use of dexamethasone as an adjuvant in regional anesthesia for THA, potentially improving pain management, reducing opioid use, and enhancing postoperative recovery.

Inclusion Criteria:

• patients scheduled for total hip arthroplasty
• patients aged >65 and <100 years
• patients able to provide informed consent
• patients able to reliably report symptoms to the research team

Exclusion Criteria:

• inability to provide first-party consent due to cognitive impairment or a language barrier
• infection at the site of the regional block,
• coagulation disorders,
• immunodeficiency,
• American Society of Anesthesiologists (ASA) physical status of IV or higher,
• history of regular steroid medication.