This randomized controlled trial investigates the impact of local anesthetic volume and perineural dexamethasone on the analgesic and anti-inflammatory effectiveness of the pericapsular nerve group (PENG) block in patients undergoing total hip arthroplasty (THA). Patients were randomized to receive one of four PENG block variants differing in ropivacaine volume (10 mL or 20 mL of 0.2%) and the addition of 4 mg of perineural dexamethasone. The study evaluates postoperative pain, opioid requirements, systemic inflammatory markers, and quadriceps motor preservation.
The pericapsular nerve group (PENG) block has become a widely used motor-sparing component of multimodal analgesia for total hip arthroplasty (THA). However, its optimal formulation-particularly the volume of local anesthetic and the role of adjuvants-remains undetermined. This prospective, double-blind, randomized controlled trial evaluates the influence of ropivacaine volume (10 mL vs. 20 mL of 0.2%) and the addition of perineural dexamethasone (4 mg) on analgesic efficacy, opioid consumption, systemic inflammation, and quadriceps strength preservation. A total of 120 adult patients undergoing unilateral THA under spinal anesthesia were randomized to one of four PENG block groups: Group 1: 20 mL of 0.2% ropivacaine (standard-volume PENG) Group 2: 20 mL of 0.2% ropivacaine + 4 mg perineural dexamethasone Group 3: 10 mL of 0.2% ropivacaine (low-volume PENG) Group 4: 10 mL of 0.2% ropivacaine + 4 mg perineural dexamethasone The primary outcome was the time to first rescue opioid analgesia. Secondary outcomes included total 48-hour opioid consumption (expressed in oral morphine equivalents), numeric rating scale (NRS) pain scores, quadriceps muscle strength, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) at 12, 24, and 48 hours postoperatively. Results demonstrated that the addition of dexamethasone, regardless of volume, significantly prolonged the duration of analgesia and reduced opioid consumption compared to non-adjuvanted PENG blocks. The low-volume + dexamethasone group achieved comparable analgesia to high-volume protocols with better inflammatory profiles. Quadriceps strength was preserved in all groups. These findings support the use of perineural dexamethasone as an effective enhancer of PENG block analgesia while enabling lower local anesthetic volume, potentially improving safety and recovery outcomes in THA patients.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
120
20ml 0.2% Ropivacaine
perineural 4mg Dexamethasone
10ml 0.2% Ropivacaine
Poznan University of Medical Sciences
Poznan, Poland
Time to first rescue opioid
Time after surgery when the patient needs opiate for the first time
Time frame: 24 hours after surgery
Total 48h opioid consumption
Total opiate consumption after surgery
Time frame: 48 hours after surgery
Numerical Rating Scale [range 0:10]
Postoperative pain assessment will be performed using the NRS score (0 = no pain, 10 = the most severe pain felt)
Time frame: 4 hours after surgery
Numerical Rating Scale [range 0:10]
Postoperative pain assessment will be performed using the NRS score (0 = no pain, 10 = the most severe pain felt)
Time frame: 8 hours after surgery
Numerical Rating Scale [range 0:10]
Postoperative pain assessment will be performed using the NRS score (0 = no pain, 10 = the most severe pain felt)
Time frame: 12 hours after surgery
Numerical Rating Scale [range 0:10]
Postoperative pain assessment will be performed using the NRS score (0 = no pain, 10 = the most severe pain felt)
Time frame: 24 hours after surgery
Numerical Rating Scale [range 0:10]
Postoperative pain assessment will be performed using the NRS score (0 = no pain, 10 = the most severe pain felt)
Time frame: 48 hours after surgery
NLR
neutrophile-to-lymphocyte ratio
Time frame: 12 hours after surgery
NLR
neutrophile-to-lymphocyte ratio
Time frame: 24 hours after surgery
NLR
neutrophile-to-lymphocyte ratio
Time frame: 48 hours after surgery
PLR
platelet-to-lymphocyte ratio
Time frame: 12 hours after surgery
PLR
platelet-to-lymphocyte ratio
Time frame: 24 hours after surgery
PLR
platelet-to-lymphocyte ratio
Time frame: 48 hours after surgery
Quadriceps strength
Quadriceps muscle strength (knee extension and hip adduction) will be evaluated according to the medical research council muscle strength rating
Time frame: 4 hours after surgery
Quadriceps strength
Quadriceps muscle strength (knee extension and hip adduction) will be evaluated according to the medical research council muscle strength rating
Time frame: 8 hours after surgery
Quadriceps strength
Quadriceps muscle strength (knee extension and hip adduction) will be evaluated according to the medical research council muscle strength rating
Time frame: 12 hours after surgery
Quadriceps strength
Quadriceps muscle strength (knee extension and hip adduction) will be evaluated according to the medical research council muscle strength rating
Time frame: 24 hours after surgery
Quadriceps strength
Quadriceps muscle strength (knee extension and hip adduction) will be evaluated according to the medical research council muscle strength rating
Time frame: 48 hours after surgery
blood glucose
blood glucose level
Time frame: 12 hours after surgery
blood glucose
blood glucose level
Time frame: 24 hours after surgery
blood glucose
blood glucose level
Time frame: 48 hours after surgery
Nerve damage
Nerve damage assesment will be performed using the nerve damage score (N0- no nerve damage; N1- minor - sensory paresthesia; N2- major -complete sensory anesthesia; N3- Complete- complete motor defect with or without paraesthesia; N4-CRPS- Complex Regional Pain Syndrome)
Time frame: 12 hours after surgery
Nerve damage
Nerve damage assesment will be performed using the nerve damage score (N0- no nerve damage; N1- minor - sensory paresthesia; N2- major -complete sensory anesthesia; N3- Complete- complete motor defect with or without paraesthesia; N4-CRPS- Complex Regional Pain Syndrome)
Time frame: 24 hours after surgery
Nerve damage
Nerve damage assesment will be performed using the nerve damage score (N0- no nerve damage; N1- minor - sensory paresthesia; N2- major -complete sensory anesthesia; N3- Complete- complete motor defect with or without paraesthesia; N4-CRPS- Complex Regional Pain Syndrome)
Time frame: 48 hours after surgery
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