Characterization of Rebound Pain Following Peripheral Nerve Block and Its Association With Gut Microbiome Diversity
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT02998177|
Recruitment Status : Completed
First Posted : December 20, 2016
Last Update Posted : August 22, 2017
|Condition or disease|
|Pain, Postoperative Gastrointestinal Microbiome|
Based on an emerging understanding of the importance of the gut microbiome in the human and animal responses to stress, it is clear that gut microbiota influence bidirectional signaling between the central nervous system (CNS) and gut (microbiota-gut-brain axis). One element of this influence is the role of gut microbiota in visceral hypersensitivity and pain. Important clinical implications of this understanding have begun to emerge: for instance irritable bowel syndrome (IBS) patient cohorts demonstrate distinct gut microbiome characteristics and, in pre-clinical models, manipulation of the gut microbiome lessens visceral hypersensitivity. To date, attempts to improve pain symptoms in IBS using probiotics have been modestly and variably successful.
One research area which offers potential to the discovery of novel analgesic therapies is the activation of endogenous opiate pain processing including augmentation of descending inhibition. (Broadly, identification of new targets/alkaloid modification/ proteomics efforts have been unsuccessful). Manipulation of microbiota-gut-brain axis by administering probiotics offers one potential route for such activation. There are many of examples of such manipulation altering animal behavior and physiology. In theory, opportunities for such manipulation might exist during or close to early life stress or before noxious stimuli such as elective surgery.
The relationship between the gut microbiome and somatic or neuropathic pain has not been studied. Certain of the pathways and regulators of visceral pain and hypersensitivity are also critical in somatic pain handling. These include peripheral sensitization of primary sensory afferents, central sensitization in particular of spinal ascending neurons and alteration of descending inhibitory pathways. These neuroplastic changes have been well documented in the surgical setting in the examination of persistent post-surgical pain.
"Rebound pain" is a quantifiable difference in pain scores when the block is working, versus the increase in acute pain that is encountered during the first few hours after the effects of perineural single-injection or continuous infusion local anesthetics resolve. Rebound pain may represent a manifestation of hypersensitivity and offer an accessible clinical model suitable for examining the association between gut microbiome diversity and perioperative neuroplastic changes.
|Study Type :||Observational|
|Actual Enrollment :||20 participants|
|Official Title:||Characterization of Rebound Pain Following Peripheral Nerve Block and Its Association With Gut Microbiome Diversity|
|Study Start Date :||November 2016|
|Actual Primary Completion Date :||June 16, 2017|
|Actual Study Completion Date :||June 16, 2017|
- Association between gut microbiome α diversity and the magnitude of rebound pain (Numerical Rating Scale) [ Time Frame: Perioperative period ]
- Association between gut microbiome α diversity and magnitude of postoperative pain (Numerical Rating Scale). [ Time Frame: Perioperative period ]
- Association between gut microbiome α diversity and analgesic consumption (mg/24 hours). [ Time Frame: Perioperative period ]
- Association between gut microbiome α diversity and salivary cortisol concentration (ng/ml). [ Time Frame: Perioperative period ]
- Association between gut microbiome α diversity and Pain Perception Threshold (PPT, mAmp). [ Time Frame: Perioperative period ]
- Association between gut microbiome constitution (α diversity) and incidence of persistent post-surgical pain. [ Time Frame: Up to 4 weeks postoperatively ]
- Pearson's correlation coefficient for i. Maximum Numerical Rating Scale (NRS) score for rebound pain vs. ii. Pain Perception Threshold (PPT, mAmp) and Pain Tolerance Threshold (PTT, mAmp) based on Quantitative Sensory Testing. [ Time Frame: Up to 48 hours postoperatively ]
Biospecimen Retention: Samples Without DNA
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02998177
|Department of Anaesthesiology, South Infirmary-Victoria University Hospital|
|Cork, Co. Cork, Ireland|
|Division of Anaesthesia and Intensive Care, Cork University Hospital|
|Cork, Co. Cork, Ireland|
|Study Chair:||George Shorten, Professor||Professor of Anaesthesia and Intensive Care Medicine, Consultant Anaesthetist, University College Cork / Cork University Hospital|