Correspondence
Comparing Postoperative Pain After Laparoscopic Cholecystectomy Jian-Hua Liu, Fu‑Shan Xue, Chao Sun, Gao‑Pu Liu Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100144, China
To the Editor: In a recent article published by Guo et al.[1] who compared postoperative pain after traditional and single‑incision laparoscopic cholecystectomy (SILC), it was showed that SILC resulted in a slightly less immediate postoperative pain, but pain scores at 24 hours, 7 days, and 1–6 months after surgery were not different between the two operations. Many things of this study were well done. The authors used a double‑blinded, randomized, and controlled design. They chose a well‑validated endpoint of postoperative pain assessment: Visual analog scale (VAS). They had a large number of patients with a consistent operation and attempted to control most of the known factors affecting postoperative pain following cholecystectomy, such as age, gender, body mass index, type of surgery, and surgical complications. Furthermore, they openly discussed the limitations of their work. All of these are strengths in the study design. We can learn from their example. In our view, however, there were several important issues in this study that were not well addressed. First, the study subjects were patients with symptomatic gallstones or polyps documented by imaging. Actually, chronic abdominal pain is highly prevalent among these patients and can often cause psychological disorders, such as neuroticism, depression, and anxiety. It was unclear whether preoperative pain intensity, duration of pain, and pain‑related psychological morbidities were comparable between groups. It has been shown that a high preoperative gastrointestinal quality of life index score, episodic pain, and duration of pain of 1 year or less are associated with the postoperative absence of pain in patients undergoing cholecystectomy for uncomplicated symptomatic cholecystolithiasis.[2] Furthermore, preoperative neuroticism, depression, and anxiety can significantly affect the postoperative pain severity determined by VAS.[2,3] Second, the readers were not provided with detail of anesthesia and perioperative managements. The available literature indicates that preoperative single‑dose dexamethasone, wound infiltration of local anesthetic, subhepatic infiltration of local anesthetic, and combined wound and intraperitoneal use of local anesthetic can significantly reduce pain scores after laparoscopic cholecystectomy.[4,5] For laparoscopic cholecystectomy, spinal anesthesia is associated with less early postoperative pain and lower incidence of postoperative complications than general anesthesia.[6] Moreover, we were very interested in knowing whether dose of opioid and analgesic drugs used during anesthesia were comparable between groups. Access this article online Quick Response Code:
Website: www.cmj.org
DOI: 10.4103/0366-6999.177006
628
When early postoperative pain between groups is compared, standardization of intraoperative use of opioid and analgesic drugs should be a crucial component of study design. For example, in patients scheduled for cholecystectomy under general anesthesia, intraoperative low‑dose ketamine infusion provides good postoperative analgesia and reduces the need of opioid analgesics.[7] Therefore, in the absence of comparisons of opioid and analgesic drug dosages during anesthesia, the primary findings about early postoperative pain and their subsequent conclusions must be interpreted with caution, as they may have been obtained using incomplete methodology. Third, the authors did not specify what VAS was used in this study. In clinical practice, VASs at rest and during movement were often used for pain assessment after chest and abdominal operations, and they can provide different information for postoperative pain management. To ensure a good quality of postoperative recovery, a fast recovery of normal activity and a high patient satisfaction, it is recommended that postoperative VAS during movement should be maintained at 3 or less. Finally, a number of patients requiring nonnarcotic analgesic loxoprofen sodium for postoperative analgesia was not significantly different between groups, but the readers were not provided with the aim of postoperative analgesia. Thus, it was unclear how investigators determined postoperative analgesic requirements of a patient. Moreover, the authors calculated the sample size only based on mean VASs obtained in their initial study but did not take other variables of interest into account. Thus, we cannot exclude the possibility that this study is not powered to show a difference in postoperative analgesic requirement between groups. We argue that addressing the above factors would further clarify the transparency of this study and improve interpretation of their findings. Address for correspondence: Prof. Fu‑Shan Xue, Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100144, China E‑Mail: [email protected]
This is an open access article distributed under the terms of the Creative Commons Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited and the new creations are licensed under the identical terms. © 2016 Chinese Medical Journal ¦ Produced by Wolters Kluwer ‑ Medknow
Received: 22‑12‑2015 Edited by: Qiang Shi How to cite this article: Liu JH, Xue FS, Sun C, Liu GP. Comparing Postoperative Pain After Laparoscopic Cholecystectomy. Chin Med J 2016;129:628-9. Chinese Medical Journal ¦ March 5, 2016 ¦ Volume 129 ¦ Issue 5
Financial support and sponsorship Nil.
Conflicts of interest
4.
There are no conflicts of interest.
References 1. Guo W, Liu Y, Han W, Liu J, Jin L, Li JS, et al. Randomized trial of immediate postoperative pain following single‑incision versus traditional laparoscopic cholecystectomy. Chin Med J 2015;128:3310‑6. doi: 10.4103/0366‑6999.171422. 2. Lamberts MP, Den Oudsten BL, Gerritsen JJ, Roukema JA, Westert GP, Drenth JP, et al. Prospective multicentre cohort study of patient‑reported outcomes after cholecystectomy for uncomplicated symptomatic cholecystolithiasis. Br J Surg 2015;102:1402‑9. doi: 10.1002/bjs.9887. 3. De Cosmo G, Congedo E, Lai C, Primieri P, Dottarelli A, Aceto P. Preoperative psychologic and demographic predictors
5.
6.
7.
of pain perception and tramadol consumption using intravenous patient‑controlled analgesia. Clin J Pain 2008;24:399‑405. doi: 10.1097/AJP.0b013e3181671a08. Sistla S, Rajesh R, Sadasivan J, Kundra P, Sistla S. Does single‑dose preoperative dexamethasone minimize stress response and improve recovery after laparoscopic cholecystectomy? Surg Laparosc Endosc Percutan Tech 2009;19:506‑10. doi: 10.1097/ SLE.0b013e3181bd9149. Yeh CN, Tsai CY, Cheng CT, Wang SY, Liu YY, Chiang KC, et al. Pain relief from combined wound and intraperitoneal local anesthesia for patients who undergo laparoscopic cholecystectomy. BMC Surg 2014;14:28. doi: 10.1186/1471‑2482‑14‑28. Yu G, Wen Q, Qiu L, Bo L, Yu J. Laparoscopic cholecystectomy under spinal anaesthesia vs. general anaesthesia: A meta‑analysis of randomized controlled trials. BMC Anesthesiol 2015;15:176. doi: 10.1186/s12871‑015‑0158‑x. Kaur S, Saroa R, Aggarwal S. Effect of intraoperative infusion of low‑dose ketamine on management of postoperative analgesia. J Nat Sci Biol Med 2015;6:378‑82. doi: 10.4103/0976‑9668.160012.
Author’s Reply
Study on the Postoperative Pain Calls for More Methods to Control Potential Bias Wei Guo1,2, Yang Liu1,2, Wei Han3, Jun Liu1,2, Lan Jin1,2, Jian‑She Li1,2, Zhong‑Tao Zhang1,2 1
Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China 2 National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Beijing 100050, China 3 Department of General Surgery, Beijing Luhe Hospital, Capital Medical University, Beijing 101100, China
DOI: 10.4103/0366-6999.177007
We thank Dr. Liu et al. very much for their attention on our recent article. In that paper, we reported a prospective randomized clinical trial comparing outcomes between traditional laparoscopic cholecystectomy and single‑incision laparoscopic cholecystectomy (SILC). It revealed that the SILC‑treated patients had a significantly lower pain score only at postoperative 6 hours, but at 24 hours and longer after surgery pain scores were not different between the two groups. In the earlier reports of clinical trials of SILC from 2007 to 2011, the safety and feasibility of the SILC have been confirmed by many studies.[1‑3] However, besides the obvious better cosmesis, whether the SILC had more benefits, such as less postoperative pain, shorter hospital stays, faster return to work, and routine activity, was unknown.[4,5] Therefore, we set the postoperative pain as the primary outcome in this randomized controlled trial. The visual analog scale (VAS) is a psychometric response scale which lacks objectivity, but at present, it is regarded as the most common measurement instrument to evaluate the postoperative pain. Hence, it was used in the clear majority of the clinical trial of single‑incision laparoscopic surgery. We totally agree with Dr. Liu et al. that the preoperative psychological disorders would affect postoperative pain score. However, unfortunately, we did not find a well‑designed trial as a satisfactory reference before the date of recruitment, November 1, 2011. Moreover, we were afraid that paying too much attention to the psychological factors would Chinese Medical Journal ¦ March 5, 2016 ¦ Volume 129 ¦ Issue 5
bring more bias to the study when lacking a better measurement instrument than VAS. All the patients underwent general anesthesia without any special medication such as dexamethasone. Actually, we had noticed that single‑dose preoperative dexamethasone would decrease VAS.[6] Hence, all the anesthetists were told not to use dexamethasone when the patient was recruited. Furthermore, to exclude all potential affecting factors and control the potential confounding bias, we did not use any local anesthetic, such as wound infiltration, subhepatic infiltration, or the combined. In the present clinical trial, the sample size was calculated based on mean VASs obtained in our initial study. The reason has been mentioned that the pain scores were quite different from those in papers published earlier than October 2011 in PubMed. As regarding the analgesic requirement, we did not set it as the primary outcome in this study. Therefore, we would look specifically at the analgesic requirement in a future study if it is really an interesting issue. In conclusion, the postoperative pain is one of the most important outcomes of a surgical procedure. By far, the VAS is the most common instrument to evaluate the pain, although Address for correspondence: Dr. Zhong‑Tao Zhang, Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China E‑Mail: [email protected] 629
Comparing Postoperative Pain After Laparoscopic Cholecystectomy Jian-Hua Liu, Fu‑Shan Xue, Chao Sun, Gao‑Pu Liu Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100144, China
To the Editor: In a recent article published by Guo et al.[1] who compared postoperative pain after traditional and single‑incision laparoscopic cholecystectomy (SILC), it was showed that SILC resulted in a slightly less immediate postoperative pain, but pain scores at 24 hours, 7 days, and 1–6 months after surgery were not different between the two operations. Many things of this study were well done. The authors used a double‑blinded, randomized, and controlled design. They chose a well‑validated endpoint of postoperative pain assessment: Visual analog scale (VAS). They had a large number of patients with a consistent operation and attempted to control most of the known factors affecting postoperative pain following cholecystectomy, such as age, gender, body mass index, type of surgery, and surgical complications. Furthermore, they openly discussed the limitations of their work. All of these are strengths in the study design. We can learn from their example. In our view, however, there were several important issues in this study that were not well addressed. First, the study subjects were patients with symptomatic gallstones or polyps documented by imaging. Actually, chronic abdominal pain is highly prevalent among these patients and can often cause psychological disorders, such as neuroticism, depression, and anxiety. It was unclear whether preoperative pain intensity, duration of pain, and pain‑related psychological morbidities were comparable between groups. It has been shown that a high preoperative gastrointestinal quality of life index score, episodic pain, and duration of pain of 1 year or less are associated with the postoperative absence of pain in patients undergoing cholecystectomy for uncomplicated symptomatic cholecystolithiasis.[2] Furthermore, preoperative neuroticism, depression, and anxiety can significantly affect the postoperative pain severity determined by VAS.[2,3] Second, the readers were not provided with detail of anesthesia and perioperative managements. The available literature indicates that preoperative single‑dose dexamethasone, wound infiltration of local anesthetic, subhepatic infiltration of local anesthetic, and combined wound and intraperitoneal use of local anesthetic can significantly reduce pain scores after laparoscopic cholecystectomy.[4,5] For laparoscopic cholecystectomy, spinal anesthesia is associated with less early postoperative pain and lower incidence of postoperative complications than general anesthesia.[6] Moreover, we were very interested in knowing whether dose of opioid and analgesic drugs used during anesthesia were comparable between groups. Access this article online Quick Response Code:
Website: www.cmj.org
DOI: 10.4103/0366-6999.177006
628
When early postoperative pain between groups is compared, standardization of intraoperative use of opioid and analgesic drugs should be a crucial component of study design. For example, in patients scheduled for cholecystectomy under general anesthesia, intraoperative low‑dose ketamine infusion provides good postoperative analgesia and reduces the need of opioid analgesics.[7] Therefore, in the absence of comparisons of opioid and analgesic drug dosages during anesthesia, the primary findings about early postoperative pain and their subsequent conclusions must be interpreted with caution, as they may have been obtained using incomplete methodology. Third, the authors did not specify what VAS was used in this study. In clinical practice, VASs at rest and during movement were often used for pain assessment after chest and abdominal operations, and they can provide different information for postoperative pain management. To ensure a good quality of postoperative recovery, a fast recovery of normal activity and a high patient satisfaction, it is recommended that postoperative VAS during movement should be maintained at 3 or less. Finally, a number of patients requiring nonnarcotic analgesic loxoprofen sodium for postoperative analgesia was not significantly different between groups, but the readers were not provided with the aim of postoperative analgesia. Thus, it was unclear how investigators determined postoperative analgesic requirements of a patient. Moreover, the authors calculated the sample size only based on mean VASs obtained in their initial study but did not take other variables of interest into account. Thus, we cannot exclude the possibility that this study is not powered to show a difference in postoperative analgesic requirement between groups. We argue that addressing the above factors would further clarify the transparency of this study and improve interpretation of their findings. Address for correspondence: Prof. Fu‑Shan Xue, Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100144, China E‑Mail: [email protected]
This is an open access article distributed under the terms of the Creative Commons Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited and the new creations are licensed under the identical terms. © 2016 Chinese Medical Journal ¦ Produced by Wolters Kluwer ‑ Medknow
Received: 22‑12‑2015 Edited by: Qiang Shi How to cite this article: Liu JH, Xue FS, Sun C, Liu GP. Comparing Postoperative Pain After Laparoscopic Cholecystectomy. Chin Med J 2016;129:628-9. Chinese Medical Journal ¦ March 5, 2016 ¦ Volume 129 ¦ Issue 5
Financial support and sponsorship Nil.
Conflicts of interest
4.
There are no conflicts of interest.
References 1. Guo W, Liu Y, Han W, Liu J, Jin L, Li JS, et al. Randomized trial of immediate postoperative pain following single‑incision versus traditional laparoscopic cholecystectomy. Chin Med J 2015;128:3310‑6. doi: 10.4103/0366‑6999.171422. 2. Lamberts MP, Den Oudsten BL, Gerritsen JJ, Roukema JA, Westert GP, Drenth JP, et al. Prospective multicentre cohort study of patient‑reported outcomes after cholecystectomy for uncomplicated symptomatic cholecystolithiasis. Br J Surg 2015;102:1402‑9. doi: 10.1002/bjs.9887. 3. De Cosmo G, Congedo E, Lai C, Primieri P, Dottarelli A, Aceto P. Preoperative psychologic and demographic predictors
5.
6.
7.
of pain perception and tramadol consumption using intravenous patient‑controlled analgesia. Clin J Pain 2008;24:399‑405. doi: 10.1097/AJP.0b013e3181671a08. Sistla S, Rajesh R, Sadasivan J, Kundra P, Sistla S. Does single‑dose preoperative dexamethasone minimize stress response and improve recovery after laparoscopic cholecystectomy? Surg Laparosc Endosc Percutan Tech 2009;19:506‑10. doi: 10.1097/ SLE.0b013e3181bd9149. Yeh CN, Tsai CY, Cheng CT, Wang SY, Liu YY, Chiang KC, et al. Pain relief from combined wound and intraperitoneal local anesthesia for patients who undergo laparoscopic cholecystectomy. BMC Surg 2014;14:28. doi: 10.1186/1471‑2482‑14‑28. Yu G, Wen Q, Qiu L, Bo L, Yu J. Laparoscopic cholecystectomy under spinal anaesthesia vs. general anaesthesia: A meta‑analysis of randomized controlled trials. BMC Anesthesiol 2015;15:176. doi: 10.1186/s12871‑015‑0158‑x. Kaur S, Saroa R, Aggarwal S. Effect of intraoperative infusion of low‑dose ketamine on management of postoperative analgesia. J Nat Sci Biol Med 2015;6:378‑82. doi: 10.4103/0976‑9668.160012.
Author’s Reply
Study on the Postoperative Pain Calls for More Methods to Control Potential Bias Wei Guo1,2, Yang Liu1,2, Wei Han3, Jun Liu1,2, Lan Jin1,2, Jian‑She Li1,2, Zhong‑Tao Zhang1,2 1
Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China 2 National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Beijing 100050, China 3 Department of General Surgery, Beijing Luhe Hospital, Capital Medical University, Beijing 101100, China
DOI: 10.4103/0366-6999.177007
We thank Dr. Liu et al. very much for their attention on our recent article. In that paper, we reported a prospective randomized clinical trial comparing outcomes between traditional laparoscopic cholecystectomy and single‑incision laparoscopic cholecystectomy (SILC). It revealed that the SILC‑treated patients had a significantly lower pain score only at postoperative 6 hours, but at 24 hours and longer after surgery pain scores were not different between the two groups. In the earlier reports of clinical trials of SILC from 2007 to 2011, the safety and feasibility of the SILC have been confirmed by many studies.[1‑3] However, besides the obvious better cosmesis, whether the SILC had more benefits, such as less postoperative pain, shorter hospital stays, faster return to work, and routine activity, was unknown.[4,5] Therefore, we set the postoperative pain as the primary outcome in this randomized controlled trial. The visual analog scale (VAS) is a psychometric response scale which lacks objectivity, but at present, it is regarded as the most common measurement instrument to evaluate the postoperative pain. Hence, it was used in the clear majority of the clinical trial of single‑incision laparoscopic surgery. We totally agree with Dr. Liu et al. that the preoperative psychological disorders would affect postoperative pain score. However, unfortunately, we did not find a well‑designed trial as a satisfactory reference before the date of recruitment, November 1, 2011. Moreover, we were afraid that paying too much attention to the psychological factors would Chinese Medical Journal ¦ March 5, 2016 ¦ Volume 129 ¦ Issue 5
bring more bias to the study when lacking a better measurement instrument than VAS. All the patients underwent general anesthesia without any special medication such as dexamethasone. Actually, we had noticed that single‑dose preoperative dexamethasone would decrease VAS.[6] Hence, all the anesthetists were told not to use dexamethasone when the patient was recruited. Furthermore, to exclude all potential affecting factors and control the potential confounding bias, we did not use any local anesthetic, such as wound infiltration, subhepatic infiltration, or the combined. In the present clinical trial, the sample size was calculated based on mean VASs obtained in our initial study. The reason has been mentioned that the pain scores were quite different from those in papers published earlier than October 2011 in PubMed. As regarding the analgesic requirement, we did not set it as the primary outcome in this study. Therefore, we would look specifically at the analgesic requirement in a future study if it is really an interesting issue. In conclusion, the postoperative pain is one of the most important outcomes of a surgical procedure. By far, the VAS is the most common instrument to evaluate the pain, although Address for correspondence: Dr. Zhong‑Tao Zhang, Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China E‑Mail: [email protected] 629
