Orthopedics · Medical Literature
Erector spinae plane block for postoperative analgesia in total hip arthroplasty: A randomized-controlled trial.
Abstract
This study aims to assess the efficacy of erector spinae plane block (ESPB) for postoperative analgesia in patients undergoing total hip arthroplasty (THA) under spinal anesthesia. In this randomized-controlled trial, a total of 30 patients (American Society of Anesthesiologists Class I-III, 20 to 65 years) who underwent elective unilateral THA under spinal anesthesia were included between January 2023 and December 2023. The patients were randomized either to Group E (n = 15) to receive ultrasound-guided lumbar ESPB with 40 mL of 0.25% bupivacaine in addition to spinal anesthesia (2.5 mL of 0.5% hyperbaric bupivacaine with 10 µg of fentanyl), or Group C (n = 15) who received spinal anesthesia alone. Primary outcomes were duration of analgesia and Visual Analog Scale (VAS) scores at 6 h. Secondary outcomes included VAS scores at 0, 0.5, 2, 4, 12, 24 h and total additional analgesic requirement in the first 24 h. Of a total of 30 patients included in the study, 22 were male and 8 were female with a mean age of 36.86 ± 13.24 (range, 18 to 65) years. The duration of analgesia was significantly longer in group E (10.76 ± 1.96 h vs. 4.18 ± 1.36 h; p < 0.01). The VAS scores were lower in group E at 0.5 h (p = 0.009), 2 h (p < 0.001), 4 h (p < 0.001), 6 h (p < 0.001), and 12 h (p = 0.02). Additional analgesic requirement during the first 24 h was higher in Group C. Surgeon and patient satisfaction scores significantly improved in Group E. No hemodynamic instability or motor weakness was observed. Lumbar ESPB with 40 mL of 0.25% bupivacaine significantly prolongs postoperative analgesia and reduces pain scores and analgesic consumption in patients undergoing THA under spinal anesthesia. Based on these findings, lumbar ESPB may provide effective and safe adjunctive analgesia in this patient population.
Clinical relevance
Does ultrasound-guided lumbar erector spinae plane block (ESPB) added to spinal anesthesia improve postoperative analgesia—as measured by duration of analgesia and VAS scores at 6 hours—compared with spinal anesthesia alone in patients undergoing elective total hip arthroplasty? __SNAPSHOT__ {"studyDesign":"Randomized controlled trial (parallel-group, two-arm)","setting":"Not reported (single-center; enrollment January–December 2023)","sampleSize":"n = 30 (Group E [ESPB + spinal]: n = 15; Group C [spinal alone]: n = 15)","population":"Adults aged 20–65 years (mean age 36.86 ± 13.24 years; range 18–65; 22 male, 8 female), ASA Physical Status Class I–III, undergoing elective unilateral total hip arthroplasty under spinal anesthesia","intervention":"Ultrasound-guided lumbar ESPB with 40 mL of 0.25% bupivacaine, administered in addition to spinal anesthesia (2.5 mL of 0.5% hyperbaric bupivacaine + 10 µg fentanyl intrathecally)","comparator":"Spinal anesthesia alone (2.5 mL of 0.5% hyperbaric bupivacaine + 10 µg fentanyl intrathecally), without any regional nerve block","primaryOutcome":"Duration of analgesia (time to first rescue analgesic request) and VAS pain score at 6 hours postoperatively","followUp":"24 hours postoperatively","fundingSource":"Not reported"}
Key findings
The primary outcome favored the ESPB group on both co-primary endpoints. Duration of analgesia was significantly longer in Group E compared with Group C (10.76 ± 1.96 h vs. 4.18 ± 1.36 h; p < 0.01); the absolute difference was 6.58 hours (calculated), representing a 2.57-fold prolongation of analgesia (calculated). VAS scores at 6 hours were reported as statistically significantly lower in Group E (p < 0.01; exact values at 6 h are truncated in the available abstract text). Secondary outcomes—VAS scores at 0, 0.5, 2, 4, 12, and 24 hours, and total rescue analgesic consumption over 24 hours—were assessed; specific numerical values for these time points and total analgesic amounts are not fully reported in the available abstract excerpt. Confidence intervals and relative effect sizes (e.g., risk ratio, mean difference with CI) for secondary outcomes are not reported. No NNT or NNH can be calculated from the available data. Adverse event data are not reported in the available abstract.
Practice implications
This small, single-year RCT suggests that adding a lumbar ESPB to spinal anesthesia may meaningfully prolong the duration of postoperative analgesia (by approximately 6.6 hours, calculated) and reduce early pain scores following THA. If replicated, this magnitude of analgesic extension could be clinically important by reducing early opioid rescue requirements and facilitating more comfortable initial mobilization. However, several critical limitations substantially constrain the interpretive confidence: only the abstract was available for review, which prevents assessment of randomization fidelity, allocation concealment, blinding status, missing data handling, and baseline comparability. The study population was notably young (mean age ~37 years) with a wide age range extending as low as 18 years, which is atypical for elective THA, limiting generalizability to the usual older THA patient population (typically ≥55–65 years). The comparator arm lacks periarticular infiltration or other multimodal analgesia elements reflective of contemporary enhanced recovery protocols for THA, which may have inflated the apparent benefit of ESPB. Whether these findings apply to elderly patients, those with significant comorbidities, or those receiving modern multimodal perioperative analgesia (including NSAIDs, acetaminophen, and periarticular injections) is not established. The broader ESPB-THA literature has yielded mixed results, with at least two prior RCTs demonstrating no significant analgesic benefit of ESPB at the lumbar level for THA, particularly when comprehensive multimodal analgesia is already employed. Practice should not change based on this study alone. __LIMITATIONS__ Critically small sample size (n = 15 per arm): profoundly underpowered to detect rare adverse events, support subgroup analyses, or provide precise effect estimates; results are highly susceptible to random error and type I error inflation.,Only the abstract was available for review: randomization sequence generation, allocation concealment, blinding procedures (or lack thereof), fidelity of protocol adherence, and handling of missing data cannot be assessed.,Atypical population demographics: mean patient age of ~37 years is inconsistent with the epidemiological profile of elective THA (predominantly ≥55–65 years), severely limiting generalizability to the typical arthroplasty patient.,Comparator arm does not reflect current standard of care: modern enhanced recovery after surgery (ERAS) protocols for THA routinely include periarticular infiltration, scheduled acetaminophen and NSAIDs, and other multimodal analgesic elements, none of which appear to have been used; this control arm design may artificially amplify apparent ESPB benefit.,Surrogate/intermediate outcomes only: duration of analgesia and VAS scores are patient-reported surrogate measures; clinically important outcomes such as opioid consumption (in morphine milligram equivalents), time to first unassisted ambulation, length of hospital stay, and patient-reported functional recovery are not fully reported in the abstract.,24-hour follow-up is insufficient: it does not capture medium- or long-term analgesic trajectories, functional recovery, or return to baseline activity.,No reported confidence intervals for any outcome: the precision of the effect estimates cannot be evaluated.,Funding source is not reported: potential conflicts of interest cannot be excluded.,The broader ESPB-THA RCT literature is inconsistent, with negative trials (including a single-shot L1 ESPB RCT and a placebo-controlled ESPB + local infiltration analgesia RCT), generating uncertainty about the clinical utility of this block specifically in the THA context. __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This small (n = 30) RCT found that lumbar ESPB added to spinal anesthesia extended analgesia duration by approximately 6.6 hours and reduced early VAS scores in THA patients, but the atypically young study population, absent multimodal analgesia comparator, and critically limited sample size substantially restrict generalizability and certainty. In the context of a broader, inconsistent ESPB-THA literature, these findings are hypothesis-generating rather than practice-changing; confirmation in larger, adequately powered trials using contemporary ERAS protocols and a representative older THA population is required before routine adoption can be recommended.