In a retrospective analysis of a small sample that only included 28 kidney transplant recipients, Sharipova and colleagues1 assessed postoperative analgesic efficacy of continuous erector spinae plane block (CESPB) by comparison with a conventional analgesia modality using non-opioid drugs. They showed that CESPB provided adequate pain control and significantly decreased postoperative opioid consumption. Considering the fact that use of a multimodal analgesia protocol including a nerve block to improve postoperative analgesia and decrease opioid consumption is an important component of Enhanced Recovery After Surgery protocols,2 the study by Sharipova and colleagues has potentially important implications. Other than the limitations described by the authors in the discussion, however, there were several issues in methodology and results in this study that we feel require further clarification.
First, the CESPB was performed before anesthesia, and 20 mL of 0.25% bupivacaine was first adminis-tered. However, the authors did not provide the details of anesthetic management and intraoperative opioid consumption, unlike performed in previously similar works that assessed perioperative benefits of erector spinae plane block.3,4 Because of this design limitation, a question that this study cannot answer is whether the CESPB can also produce an intraope-rative opioid-sparing effect in patients undergoing kidney transplant.
Second, in the Materials and Methods section, the authors described that pain intensity was evaluated using a numerical rating scale (NRS) of 0 to10 points at 6, 12, 18, and 24 hours postoperatively. However, in Table 1 of the article by Sharipova and colleagues,1 the authors only provided the NRS pain scores for a single time point. Thus, it was unclear whether the NRS rest and movement pain scores at all time points within 24 hours postoperatively were significantly different between the 2 groups.
Third, the NRS pain scores at rest and movement states after surgery were significantly different between the 2 groups. We note that the net between-group differences in mean NRS rest and movement pain scores were 1.2 and 1.4, respectively. We would like to remind readers that the recommended minimal clinically important differences of posto-perative pain scores in the available literature is 1.5 at resting state and 1.8 at movement state, when pain is assessed by the NRS score from 0 to 10.5 That is, the improvement of postoperative pain control by the CESPB compared with conventional analgesia modality did achieve statistical significance, but its clinical significance is debatable.
Finally, in their study, Sharipova and colleagues1 observed the incidence of nausea and vomiting during the first postoperative day, but they did not assess the effects of the CESPB on the quality of early postoperative recovery and the patients’ satisfaction with pain management, unlike performed in other studies.3,4 In fact, these variables are very important to determine efficacy and clinical availability of a postoperative pain intervention and are very easily measured with a 5-point Likert scale (5 = completely satisfied, 4 = quite satisfied, 3 = slightly dissatisfied, 2 = dissatisfied, and 1 = very dissatisfied) and a Quality of Recovery-15 score. We believe that this study would have provided more useful data about clinical values of the CESPB for pain control after kidney transplant if the design had included the assessment of these postoperative outcomes.
Volume : 21
Issue : 2
Pages : 194 - 195
DOI : 10.6002/ect.2022.0143
From the Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, People’s Republic of China
Acknowledgements: The authors have not received any funding or grants in support of the presented research or for the preparation of this work and have no declarations of potential conflicts of interest.
Author contributions: All authors have carefully read the manuscript of Sharipova and colleagues and analyzed the methods and data therein. XTL suggested comment points and drafted this letter. FSX critically revised the comment points and this letter and is the author responsible for this manuscript. TT revised the comment points and letter. All authors have seen and approved the final manuscript.
Corresponding author: Fu-Shan Xue, Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, NO. 95 Yong-An Road, Xi-Cheng District, Beijing100050, People’s Republic of China
Phone: +86 139 1117 7655
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