Year : 2013  |  Volume : 16  |  Issue : 3  |  Page : 186--187

Oral pregabalin holds promise to reduce pain after cardiac surgery


PN Jain 
 Department of Anesthesiology, Critical Care & Pain, Head Division of Pain, Tata Memorial Hospital, Mumbai, Maharashtra, India

Correspondence Address:
P N Jain
Department of Anesthesiology, Critical Care & Pain, Head Division of Pain, Tata Memorial Hospital, Mumbai- 400 012, Maharashtra
India




How to cite this article:
Jain P N. Oral pregabalin holds promise to reduce pain after cardiac surgery.Ann Card Anaesth 2013;16:186-187


How to cite this URL:
Jain P N. Oral pregabalin holds promise to reduce pain after cardiac surgery. Ann Card Anaesth [serial online] 2013 [cited 2019 Dec 12 ];16:186-187
Available from: http://www.annals.in/text.asp?2013/16/3/186/114240


Full Text

Persistent post-surgical pain represents a major, largely unrecognized clinical problem, often difficult to treat. If left untreated, it may further transform into persistent post-operative chronic-pain leading to a disability. Acute post-operative pain may be prolonged by persistent neuropathic pain in 10-50% of individuals after common operations including cardiac surgery. A prospective cohort study (n = 203) of acute and chronic post-sternotomy reported severe pain (numeric rating scale score 7-10) in 49% at rest, in 78% during coughing and in 62% patients on movement. One year after the operation, 26 patients (14%) reported mild chronic post-sternotomy pain at rest. The persistent pain was even more common on movement: 45 patients (24%) had mild, 5 patients (3%) had moderate and 7 patients (4%) had severe pain. Patients who experienced moderate to severe acute post-operative pain also reported any chronic post-sternotomy pain (numeric rating scale score 1-10) more frequently. [1] Many patients develop chronic pain state, which can be severe in about 2-10% of patients. Iatrogenic neuropathic pain is probably the most important cause of long-term post-surgical pain. The effect of aggressive, early optimum therapy for post-operative pain should be fully investigated since the intensity of acute post-operative pain correlates with the risk of developing a persistent pain state. Multimodal analgesia is cornerstone for post-operative pain management. It is hypothesized to reduce persistent post-operative pain and also development of chronic pain states in certain patients.

Pregabalin, like gabapentin, is an amino derivative of gamma-amino-butyric acid. Its main action is on alpha-2 delta receptors and acts as anti-hyperalgesic agent. Pregabalin has been shown to delay or offset the sensitization of dorsal horn neurons, which may lead to augmentation of surgical stimulation that affect changes in the central and peripheral nervous system. Recently, there have been promising studies showing that pregabalin may not only reduce post-operative pain, but alter the neuropathic pain incidence also. A systematic review on pregabalin for post-operative pain has shown its efficacy. The optimal dose and duration of the treatment cannot be recommended because of the heterogeneity of the trials. Studies are needed to determine the long-term benefits, if any, of perioperative gabapentinoids. [2],[3] Pregabalin has a proven role in treating various neuropathic pains; however, evidence supporting the post-operative analgesic efficacy of pregabalin is still emerging. A meta-analysis on the role of pregabalin on acute post-operative pain reported that post-operative pain intensity was not reduced by pregabalin. [4] Out of 11 trials in metaanalysis, 7 trials were found to be fair-good quality including a total of 899 patients with 521 patients receiving pregabalin. Patients in two trials, Jakela et al., (n=56) and Chang et al., (n=39) received 300 mg or more pregabalin in preoperative and postoperative study design, but did not find any significant reduction in pain. However, the cumulative opioid consumption at 24 h was significantly decreased with pregabalin. The authors of this study, Joshi and Jagadeesh, [5] in this double-blind placebo control randomized study reported a reduction in pain scores up to 36 h at rest and on movement (P < 0.05) and a significant reduction in opioid consumption (P < 0.001) with no additional side- effects. They did not discuss the reasons of their superior results as compared to the findings of the metaanalyses. It is not surprising, that they did not find any difference in the incidence of chronic post-operative pain on telephonic interview. Many patients may not have significant pain at 1 month and 3 months at rest, which is worth reporting on follow-up to cardiac surgeons; however, they may exhibit neuropathic pain characteristics if measured by a neuropathic scale such as painDETECT or DN4. Neuropathic pain may be exacerbated by deep breathing, coughing or during movement or may spontaneously occur without any exciting incidents. Patients expect and often are prepared for suffering significant pain during the post-operative period, which may be quite extended to few months in some of them. However, they remain largely stoic and do not complain. Patients' need to be explained during the pre-operative check-up about pain, what to expect and their pain control plan using a printed brochure or a video and keeping a pain diary to record their pain. A current literature search on Pubmed on post-operative pain after cardiac surgery showed 3,265 results and that shows its global concern. A randomized double blind placebo control trial is undergoing in Aikaterini Bouzia, Larissa University Hospital, Greece accruing 80 patients until December 2013 using 75 mg and 150 mg pregabalin pre-operative dose studying pain scores for 48 h, at 1 month and also quality-of-life at 3 months. A final verdict about administering routinely pre-operative pregabalin for controlling acute post-operative pain and saving chronic pain state later is still not out.

References

1Lahtinen P, Kokki H, Hynynen M. Pain after cardiac surgery: A prospective cohort study of 1-year incidence and intensity. Anesthesiology 2006;105:794-800.
2Agarwal A, Gautam S, Gupta D, Agarwal S, Singh PK, Singh U. Evaluation of a single preoperative dose of pregabalin for attenuation of postoperative pain after laparoscopic cholecystectomy. Br J Anaesth 2008;101:700-4.
3Tiippana EM, Hamunen K, Kontinen VK, Kalso E. Do surgical patients benefit from perioperative gabapentin/pregabalin? A systematic review of efficacy and safety. Anesth Analg 2007;104:1545-56, table of contents.
4Zhang J, Ho KY, Wang Y. Efficacy of pregabalin in acute postoperative pain: A meta-analysis. Br J Anaesth 2011;106:454-62.
5Joshi SS, Jagadeesh AM. Efficacy of perioperative pre-gabalin in acute and chronic post-operative pain after off-pump coronary artery bypass surgery: A randomized, double-blind placebo controlled trial. Ann Card Anaesth 2013;16:180-5.