Erector spinae plane vs. paravertebral blockade for rib fracture analgesia

Wewould like to commendAdhikary et al. for their continued efforts to show benefit from novel regional techniques for chest trauma [1] and agree that patients with rib fracture(s) have significantly improved pain scores after regional analgesia. We would like to invite the authors to reply to a numberof comments thatwehave about their work. Firstly, the authors make several comments about the technically challenging nature of paravertebral blockade. In our institution, ultrasound-guided thoracic paravertebral blockade is the regional technique of choice in unilateral chest trauma. Data from our experiences reveal an extremely low complication rate, with no significant complications from 314 paravertebral catheters over a 4-year period [1], inserted by consultant and registrar anaesthetists. This is consistent with our experience of thousands of single-shot blocks performed for breast surgery, and with similar experiences in other centres worldwide [2]. We recognise that there is, undoubtedly, a learning curve associated with the paravertebral technique, but we believe this is similar in appearance to learning curves for any other new regional anaesthetic technique. Secondly, we note that only 79 patients were administered an erector spinae plane (ESP) block over 19 months. Can we ask whether there were other patients in the authors’ institution that received epidural or paravertebral blockade during this time, and whether comparative analysis has been possible? We are not aware of any published evidence that the ESP block is technically easier, and the results of any such analysis would be useful to know when organising training. Are there novices or nonanaesthetists performing the ESP block at the authors’ institution? Thirdly, the authors question the feasibility of paravertebral blockade in coagulopathy and haemodynamic instability. In our opinion, neither coagulopathy nor anticoagulation is a contra-indication to paravertebral techniques, necessarily. We assess each case individually, in line with the collaborative guideline from on regional anaesthesia techniques in patients with abnormalities of coagulation [3]. This guideline classifies paravertebral block as ‘higher risk’ compared with more peripheral or superficial techniques, but provides no quantification of this risk, and does not reference any evidence documenting complications in patients with disorders of coagulation. Furthermore, we can find no case reports of spinal or epidural haematomas following ultrasound-guided paravertebral block performance. The practice of using curled catheters rather than straight in the paravertebral space further reduces the risk of accidental epidural placement. Our experience also reveals no associated haemodynamic instability following paravertebral blockade. Their analysis revealed a statistically significant increase in spirometry values, but such improvement would be expected normally over time, with or without regional anaesthesia. Are the authors confident about ascribing causality between the block and the spirometry improvement, given the 24-h gap between insertion and measurement? In our experience, spirometry improves very soon (within 30 min) after block insertion, and often improves further by the following day. We suggest that paravertebral block overcomes the variability in analgesia observed in the authors’ study, because it places local anaesthetic in close proximity to the target nerves, can be performed by a range of anaesthetist grades, is associated with minimal complications and sideeffects, and performance of which is contra-indicated in very few patients. Regardless of the block choice however, we agree with the authors that good analgesia (under the aegis of a comprehensive pain service) remains critical in the successful management of rib fractures.