Comment on: “Continuous Analgesia with Intercostal Catheterization under the Thoracoscopy”

Continuous Analgesia with Intercostal Catheterization after Thoracoscopy

By a randomized controlled trial of 80 patients undergoing single-hole thoracoscopic surgery, Yang et al[1] evaluated postoperative analgesic efficacy of continuous intercostal nerve block (CINB) and showed that addition of a CINB to the basic intravenous analgesia significantly improved postoperative pain control, with a decreased opioid consumption. However, we noted several issues in this study that were not well addressed.

First, as a randomized controlled trial, this study did not include a flowchart for eligibility of the study objects. Thus, it was unclear how many patients were screened based on their criteria of inclusion and exclusion to obtain 80 eligible patients. As there was the lack of sample size evaluation in this study design, moreover, the authors did not provide the effect size of primary endpoint, that is., the expected minimal clinically important difference of postoperative pain visual analog scale (VAS) score. This can result in a possibility of inappropriate interpretation for their findings about between-group comparisons of pain VAS scores that are only based on statistically significant differences rather than clinically significant differences.[2] For example, the pain VAS scores at 12, 24, 36, and 48 hours postoperatively were significantly lower in the patients receiving the CINB than in the control patients. However, the net between-group differences in the mean pain VAS scores at all time points postoperatively were 1.4 or less, which do not exceed the recommended minimal clinically important difference of 1.5 on a 0 to 10 point VAS.[3] Thus, we believe that clarifying these issues will improve the transparency of this research design and the interpretation of results.

Second, the readers were not provided with the patient' status when postoperative pain intensity was evaluated using a VAS. The available evidence indicates that pain intensity following thoracoscopic surgery is less at rest than during movement or coughing.[4] We are concerned that using an inconsistent patient status for postoperative pain evaluation would have confused the findings of primary endpoint in this study.

Third, basic analgesia regimen of all patients was an opioid-based intravenous analgesia, with mean sufentanil consumption of up to 98.6 to 106 μg within 48 hours postoperatively. This does not meet the requirements of an opioid-sparing multimodal strategy in the best practices of enhanced recovery after surgery practices for thoracoscopic surgery, which includes a serial of nonopioid basic analgesics with different mechanisms, such as acetaminophen, nonsteroidal anti-inflammatory drugs, N-methyl-D-aspartic acid (NMDA) receptor antagonists, steroids, and others.[5] Most important, it is required that nonopioid basic analgesics are started to be given before or during operation and regularly be repeated after surgery, and opioids are only administered as rescue analgesia when nonopioid basic analgesics are ineffective or contraindicated. We believe that different results about postoperative analgesic efficacy of the CINB would have been obtained, if a standard opioid-sparing multimodal analgesic strategy was included in this study design.

Fourth, sufentanil consumption within 48 hours postoperatively was significantly decreased in the patients receiving the CINB, but the mean between-group difference was 7.4 μg, which is only equivalent to 7.4 mg intravenous morphine and is smaller than the recommended minimal clinically important difference of opioid consumption for postoperative pain control, that is, 10 mg intravenous morphine in 24 hours.[3] Thus, we question the opioid-sparing effect with addition of the CINB in this study.

Finally, this study observed the postoperative chest complications and side effects of sufentanil, but did not assess and compare any outcomes of enhanced recovery after surgery practices for thoracoscopic surgery, such as the time to first ambulation, preservation of lung function, quality of postoperative recovery, length of hospital stay, readmission rate, and others.[5] Due to the lack of these data, it was unclear whether addition of a CINB to the basic intravenous analgesia after thoracoscopic surgery may really benefit patients by improving clinical outcomes and postoperative experience.

Authors' Contribution

All authors had carefully read the manuscript of Wang et al. and analyzed their methods and data. W.H.Y. suggested comment points and drafted this manuscript, and is the author responsible for this manuscript. F.S.X critically revised comment points and this manuscript, and is the author responsible for this manuscript. X.T.L and N.H. revised comment points and this manuscript. All authors had seen and approved the final manuscript.

Publication History

Received: 28 September 2023

Accepted: 13 October 2023

Accepted Manuscript online:
16 October 2023

Article published online:
12 February 2024

• References

• 1 Yang WH, Li XT, Xue FS, He N. Comment on: “Continuous analgesia with intercostal catheterization under the thoracoscopy”. Thorac Cardiovasc Surg 2023; (e-pub ahead of print). DOI: 10.1055/a-2168-9081.
• 2 Abdulatif M, Mukhtar A, Obayah G. Pitfalls in reporting sample size calculation in randomized controlled trials published in leading anaesthesia journals: a systematic review. Br J Anaesth 2015; 115 (05) 699-707
• 3 Doleman B, Leonardi-Bee J, Heinink TP. et al. Pre-emptive and preventive NSAIDs for postoperative pain in adults undergoing all types of surgery. Cochrane Database Syst Rev 2021; 6 (06) CD012978
• 4 Zengin EN, Zengin M, Yiğit H, Sazak H, Şekerci S, Alagöz A. Comparison of the effects of one-level and bi-level pre-incisional erector spinae plane block on postoperative acute pain in video-assisted thoracoscopic surgery; a prospective, randomized, double-blind trial. BMC Anesthesiol 2023; 23 (01) 270
• 5 Semenkovich TR, Hudson JL, Subramanian M, Kozower BD. Enhanced recovery after surgery (ERAS) in thoracic surgery. Semin Thorac Cardiovasc Surg 2018; 30 (03) 342-349