We read with interest the randomised clinical trial by Di Pietro et al. 1, comparing the pericapsular nerve group (PENG) block with infra-inguinal fascia iliaca block for acute hip fracture pain in the emergency department. We commend the authors for performing a technically demanding study in a challenging emergency medicine environment. The accompanying editorial by Barrett and Metcalfe 2 appropriately highlights that the central challenge in this field is not only which block is superior, but whether we are measuring what matters to patients with hip fracture. This perspective is highly relevant when interpreting the apparent divergence between the present trial and our previously published randomised study conducted in the same clinical setting 3. Di Pietro et al. contrast their findings with our previous trial, suggesting that methodological differences explain the divergent results. Our study was conceived in 2019 as a pragmatic emergency department trial. We agree that outcome selection is pivotal and we selected a clinically intuitive and patient-centred endpoint: achievement of dynamic numeric rating pain scale score ≤ 4 during mobilisation, which reflects the analgesia required for positioning, imaging and anaesthesia. Dynamic assessments, although imperfect, better reflect clinical reality. This aspect was acknowledged in our discussion as a pragmatic choice. The 30-min assessment window in our study was not arbitrary. In emergency hip fracture care, the clinical need is for rapid analgesia that allows early mobilisation and procedural readiness. While Di Pietro et al. used the proportion of summed pain intensity difference over 60 min, this longer composite outcome may reflect evolving pharmacodynamics rather than the immediate clinical utility that is often decisive in the emergency department. Both trials also introduce some pharmacological asymmetry. In Di Pietro et al., PENG (20 ml 0.375% levobupivacaine) and fascia iliaca block (30 ml 0.25% levobupivacaine) were delivered with different volumes and local anaesthetic concentration. Moreover, perineural dexamethasone was added without clear justification, introducing another uncontrolled modifier of block performance. The choice of visual analogue scale instead of numeric rating scale deserves some consideration. These are two of the most used tools for measuring pain intensity. They are both validated for use in a general population, and acute and chronic pain. Their usability and individual preference in older adults have suggested the use of the numeric rating scale rather than the visual analogue scale 4, 5. In older patients with a hip fracture, the numeric rating scale is potentially regarded as more reliable, easier to administer or less cognitively demanding than the visual analogue scale. While Di Pietro et al. appropriately did not include patients with delirium, the visual analogue scale may remain more vulnerable to measurement error in frail older adults, particularly when repeated measurements are required and the two instruments may not be used interchangeably when assessing pain in older adults 6. Finally, with respect to cognitive screening, although Di Pietro et al. used a formal tool, our protocol did not include patients unable to provide informed consent or report pain reliably, which similarly avoids inclusion of patients with clinically significant cognitive impairment. This reflects a pragmatic emergency department trial design rather than a methodological weakness. Taken together, both studies show that PENG and fascia iliaca blocks provide analgesia, but the apparent superiority of one technique over the other may be sensitive to endpoint selection, timing, injectate composition and measurement tools. As Barrett and Metcalfe argue, the field needs a consensus-driven, patient-centred core outcome set that captures not only early pain reduction but also functional analgesia and duration in different contexts. Until such a framework exists, caution is warranted before declaring which block is categorically superior.
Marrone et al. (Thu,) studied this question.