iPACK block with adductor canal block vs. lumbar erector spinae plane block (L-ESPB) in total knee arthroplasty: a randomized, double-blinded, controlled trial

Introduction Total knee arthroplasty (TKA) is associated with severe pain. We examined whether an ultrasound-guided, single-injection L2 erector spinae plane block could improve analgesia compared to an ultrasound-guided iPACK (infiltration between the popliteal artery and capsule of the knee) block with adductor canal block (ACB) in patients undergoing TKA under spinal anesthesia. Material and methods Ninety patients aged 65–89 years of both sexes (ASA I–III) scheduled for TKA were randomly allocated to receive iPACK block (ropivacaine 0.2%, 20 mL) with ACB (ropivacaine 0.2%, 10 mL), lumbar erector spinae plane block (L-ESPB) (ropivacaine 0.2%, 20 mL on each side), or to the control group. The primary outcome was total opioid consumption. The secondary outcomes included pain scores, time to first rescue opioid analgesia, quadriceps muscle strength, neutrophil-to-lymphocyte ratio (NLR), and platelet- to-lymphocyte ratio (PLR). Results The total opioid consumption in 48 h was significantly lower in the iPACK+ACB group (mean ± SD) (3.0 ± 3.3) compared to L-ESPB (6.8 ± 3.8, P = 0.0442) and the control group (18.2 ± 4.0, P < 0.001). The time to first rescue opioid analgesia was longer in the iPACK+ACB (12.0 ± 1.9) compared to the L-ESPB (9.2 ± 1.9, P < 0.001) group and the control group (4.3 ± 1.1, P < 0.001). The pain scores, NLR, and PLR levels were significantly lower in the iPACK+ACB and L-ESPB groups than at all time points in the control group. Conclusions The iPACK+ACB is more effective than L-ESPB in pain management following TKA. iPACK+ACB and the L-ESPB lowered total opioid consumption and prolonged time to first opioid analgesia. NLR and PLR levels did not differ between the groups.