Treatment of ipsilateral shoulder pain after thoracic surgery—time for comparative studies?

Ipsilateral shoulder pain (ISP) is a common complication to thoracic surgery with an incidence between 37–97% depending on the study population and type of thoracic surgery (1-4). In many cases, the pain resolves or minimizes after the first few days, but has been reported to last up to 4 days and becomes chronic in a subset of patients (5,6). The cause of ISP is multifactorial and involves a visceral component originating from irritation of the diaphragm and mediastinal pleura, mediated via the phrenic nerve, and a somatic component originating from the shoulder, caused by strain during surgery and positioning (7-10). Historically ISP has been difficult to treat because it is relatively resistant to pharmacological agents. Also common types of regional anesthesia used to treat the incisional pain such as epidural, paravertebral or intercostal blocks are ineffective because these blocks don’t cover the area relevant to ISP which is the ipsilateral shoulder and the phrenic nerve (1,2,11,12). Several studies, however, have demonstrated significant effect of regional anesthesia of the shoulder area such as the interscalene (13) and suprascapular (14,15) blocks and significant effect of phrenic nerve blocks at the supraclavicular (16) or diaphragmatic level (17-19).

In the study by Woo et al. (20) it was demonstrated that the incidence of ISP could be effectively reduced by performing a preoperative, ipsilateral, interscalene block. Although the result should be interpreted with caution since the patients were not blinded to the intervention and the sample size was relatively small, the result is comparable to a previous study of interscalene block for ISP (13). Interestingly, dexamethasone was used as an adjuvant to prolong the effect of the block. This is particularly relevant regarding ISP as the pain intensity usually decreases considerably after 1–2 days (6) and prolonging the effect of the block to last during this period could potentially prevent repeated nerve blocks or additional pharmacological treatment. Unfortunately the study design did not allow any conclusions about the effect of the additional dexamethasone even though the authors argue that they previously demonstrated that dexamethasone can prolong the median time of sensory blockade by the interscalene block during shoulder surgery for up to 24 hours (21). Another interesting finding was that the postoperative pulmonary function did not differ between the intervention group and the control group meaning that the concomitant phrenic nerve block which usually is the consequence of an interscalene block did not compromise the postoperative pulmonary function beyond what was already caused by the operation, chest tube and anesthesia. Although the sample size was too small to make any final conclusions about the safety of the block, the result is similar to the findings in a recent study where a phrenic nerve block was performed to prevent ISP in patients for major thoracic surgery (16). In both cases all patients suffered from reduced pulmonary function after lobectomy regardless of whether they had an intervention directed at blocking the phrenic nerve or not, suggesting that the combined effect of surgery, chest tube and anesthesia is compromising the immediate pulmonary function of the operated lung to an extent that an additional phrenic nerve block doesn’t change the pulmonary function significantly. It is however important to note that both studies involved patients who had preoperatively been considered eligible to one-lung ventilation during major pulmonary surgery, which excludes a group of patients with very compromised preoperative pulmonary function. In this group of patients, blocking the phrenic nerve might have more deleterious effects on the pulmonary function.

Where ISP historically has been considered difficult to treat, we now have evidence for several effective options for treatment via regional anesthesia of the relevant body region, including interscalene, suprascapular and phrenic nerve blocks. The 2 first options primarily address the musculoskeletal component of ISP but most often also results in a phrenic nerve block. A major side effect to these methods is the full motor block of the ipsilateral arm. The phrenic nerve block primarily addresses the visceral component of ISP but will, if performed at the supraclavicular level, regularly also result in some, at least sensory, block of the shoulder but will less often result in motor block of the ipsilateral arm. Comparative studies between these three different possible approaches are warranted. Future studies should not only compare the effects but also focus on possibilities to extent the effect beyond the first 48 hours and minimizing side effects such as irrelevant motor blockade.

Acknowledgements

None.

Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

References

1. Burgess FW, Anderson DM, Colonna D, et al. Ipsilateral shoulder pain following thoracic surgery. Anesthesiology 1993;78:365-8. [Crossref] [PubMed]
2. Barak M, Ziser A, Katz Y. Thoracic epidural local anesthetics are ineffective in alleviating post-thoracotomy ipsilateral shoulder pain. J Cardiothorac Vasc Anesth 2004;18:458-60. [Crossref] [PubMed]
3. Mac TB, Girard F, Chouinard P, et al. Acetaminophen decreases early post-thoracotomy ipsilateral shoulder pain in patients with thoracic epidural analgesia: a double-blind placebo-controlled study. J Cardiothorac Vasc Anesth 2005;19:475-8. [Crossref] [PubMed]
4. Pennefather SH, Akrofi ME, Kendall JB, et al. Double-blind comparison of intrapleural saline and 0.25% bupivacaine for ipsilateral shoulder pain after thoracotomy in patients receiving thoracic epidural analgesia. Br J Anaesth 2005;94:234-8. [Crossref] [PubMed]
5. MacDougall P, Slinger P. Post-thoracotomy shoulder pain and gabapentin: a tale of two enigmas. Can J Anaesth 2008;55:323-7. [Crossref] [PubMed]
6. Blichfeldt-Eckhardt MR, Andersen C, Ording H, et al. Shoulder Pain After Thoracic Surgery: Type and Time Course, a Prospective Cohort Study. J Cardiothorac Vasc Anesth 2017;31:147-51. [Crossref] [PubMed]
7. MacDougall P. Postthoracotomy shoulder pain: diagnosis and management. Curr Opin Anaesthesiol 2008;21:12-5. [Crossref] [PubMed]
8. Holt M. Ipsilateral shoulder pain following thoracic operations. Anesthesiology 1993;79:192-author reply 3. [Crossref] [PubMed]
9. Mark JB, Brodsky JB. Ipsilateral shoulder pain following thoracic operations. Anesthesiology 1993;79:192-author reply 3. [Crossref] [PubMed]
10. Bamgbade OA, Dorje P, Adhikary GS. The dual etiology of ipsilateral shoulder pain after thoracic surgery. J Clin Anesth 2007;19:296-8. [Crossref] [PubMed]
11. Huot MP, Chouinard P, Girard F, et al. Gabapentin does not reduce post-thoracotomy shoulder pain: a randomized, double-blind placebo-controlled study. Can J Anaesth 2008;55:337-43. [Crossref] [PubMed]
12. Imai Y, Imai K, Kimura T, et al. Evaluation of postoperative pregabalin for attenuation of postoperative shoulder pain after thoracotomy in patients with lung cancer, a preliminary result. Gen Thorac Cardiovasc Surg 2015;63:99-104. [Crossref] [PubMed]
13. Barak M, Iaroshevski D, Poppa E, et al. Low-volume interscalene brachial plexus block for post-thoracotomy shoulder pain. J Cardiothorac Vasc Anesth 2007;21:554-7. [Crossref] [PubMed]
14. Ozyuvaci E, Akyol O, Sitilci T, et al. Preoperative ultrasound-guided suprascapular nerve block for postthoracotomy shoulder pain. Curr Ther Res Clin Exp 2013;74:44-8. [Crossref] [PubMed]
15. Saha S, Brish EL, Lowry AM, et al. In select patients, ipsilateral post-thoracotomy shoulder pain relieved by suprascapular nerve block. Am J Ther 2011;18:309-12. [Crossref] [PubMed]
16. Blichfeldt-Eckhardt MR, Laursen CB, Berg H, et al. A randomised, controlled, double-blind trial of ultrasound-guided phrenic nerve block to prevent shoulder pain after thoracic surgery. Anaesthesia 2016;71:1441-8. [Crossref] [PubMed]
17. Scawn ND, Pennefather SH, Soorae A, et al. Ipsilateral shoulder pain after thoracotomy with epidural analgesia: the influence of phrenic nerve infiltration with lidocaine. Anesth Analg 2001;93:260-4, 1st contents page.
18. Danelli G, Berti M, Casati A, et al. Ipsilateral shoulder pain after thoracotomy surgery: a prospective, randomized, double-blind, placebo-controlled evaluation of the efficacy of infiltrating the phrenic nerve with 0.2%wt/vol ropivacaine. Eur J Anaesthesiol 2007;24:596-601. [Crossref] [PubMed]
19. Martinez-Barenys C, Busquets J, de Castro PE, et al. Randomized double-blind comparison of phrenic nerve infiltration and suprascapular nerve block for ipsilateral shoulder pain after thoracic surgery. Eur J Cardiothorac Surg 2011;40:106-12. [Crossref] [PubMed]
20. Woo JH, Kim YJ, Kim KC, et al. The effect of interscalene block on ipsilateral shoulder pain and pulmonary function in patients undergoing lung lobectomy: A randomized controlled trial. Medicine (Baltimore) 2018;97:e11034. [Crossref] [PubMed]
21. Woo JH, Kim YJ, Kim DY, et al. Dose-dependency of dexamethasone on the analgesic effect of interscalene block for arthroscopic shoulder surgery using ropivacaine 0.5%: A randomised controlled trial. Eur J Anaesthesiol 2015;32:650-5. [Crossref] [PubMed]