|- candidate number||22517|
|- NTR Number||NTR5336|
|- ISRCTN||ISRCTN no longer applicable|
|- Date ISRCTN created|
|- date ISRCTN requested|
|- Date Registered NTR||30-jul-2015|
|- Secondary IDs||P15-020 |
|- Public Title||The influence of pre-operative pain perception on the development on chronic pain after inguinal hernia repair surgery|
|- Scientific Title||The Influence of the Pre-operative Nociceptive Profile on the Development of Chronic Pain after Inguinal Hernia Repair Surgery|
|- hypothesis||In the current study we aim to pre-operatively test the effectiveness of the endogenous pain modulatory system. We hypothesize that patients with a pre-operative anti-nociceptive profile (measured by CPM) will have a lower risk to develop chronic pain after surgery compared to patients with a pro-nociceptive profile (measured by temporal summation). Furthermore, we will use questionnaires to evaluate the psychological state of the patients, as it is known that patients with catastrophizing, anxious or depressive thought have a higher probability to develop chronic pain. We aim to correlate psychological parameters to the chance of developing chronic pain and to treatment effects.
We hypothesize that:
1) Patients with a pro-nociceptive profile will experience more pain direct post-operative, have a higher consumption of analgesics and have a higher probability of developing chronic post-operative pain compared to patients with anti-nociceptive profile.
2) Patients with catastrophizing, anxious or depressive thoughts have a higher probability to develop chronic pain and are more likely to have a pro-nociceptive profile.
|- Healt Condition(s) or Problem(s) studied||Post-operative pain, Hernia inguinal|
|- Inclusion criteria||Inclusion criteria include:|
1) American Society of Anesthesiologists score 1, 2 or 3;
2) age 18 to 75 year;
3) planned for elective inguinal hernia repair surgery (either open or laparoscopy).
|- Exclusion criteria||Exclusion criteria include: |
(1) Pain scores > 3 (on a 11-point numerical rating scale, NRS) reported for most of the day during the past month;
(2) Regular use of analgesics for any purpose, including SNRIs, gabapentinoids, COX inhibitors or NSAIDs during the previous month;
(3) The presence of any chronic pain disorder;
(4) Inability to perform psychophysical testing (eg. in case of cognitive or psychiatric disorders);
(5) Inability to give informed consent;
(6) Inability to communicate with the investigators.
|- mec approval received||yes|
|- multicenter trial||yes|
|- Type||Single arm|
|- planned startdate ||1-jun-2015|
|- planned closingdate||1-jun-2017|
|- Target number of participants||500|
|- Interventions||This study has no intervention. It is an observational study assessing the pre-operative nociceptive profile to study whether this is a predictive factor for the development of post-operative chronic pain.|
|- Primary outcome||The primary outcome includes the development of chronic post-operative pain.|
|- Secondary outcome||Secondary outcomes include:|
1) Post-operative pain and analgesic consumption in the first 24 hours after surgery;
2) The effectiveness of the endogenous analgesic system (as measure for the nociceptive profile) in patients planned for elective inguinal hernia surgery.
|- Timepoints||1) The effectiveness of the endogenous analgesic system as measure for the nociceptive profile, will be tested 0-14 days prior to surgery.|
2) The postoperative pain scores and analgesic consumption will be measured in the recovery room.
3) The development of chronic pain will be evaluated at 1,2,3,6 and 12 months after surgery.
|- Trial web site||-|
|- status||open: patient inclusion|
|- CONTACT FOR PUBLIC QUERIES||Dr. M. Niesters|
|- CONTACT for SCIENTIFIC QUERIES||Dr. M. Niesters|
|- Sponsor/Initiator ||Leiden University Medical Center (LUMC)|
(Source(s) of Monetary or Material Support)
|Leiden University Medical Center (LUMC)|
|- Brief summary||Postoperative pain and the development of chronic pain is a serious complication of surgical interventions. While the treatment of acute postoperative pain is well organized in current medical practice, the development of chronic pain still has a relatively large incidence. The latter depends on many factors including the type of surgery (a high incidence of postoperative chronic pain is observed following thoracotomies, mastectomies and inguinal hernia repairs) and specific patient-related factors. These patient-related factors include the state of the endogenous analgesia system, a modulatory and highly plastic system that is involved in modulation of afferent nociceptive input to central sites using top-down inhibitory and facilitatory pathways that inhibit or facilitate pain perception. The preoperative balance between anti- and pronociception may play a crucial role in the development of postoperative chronic pain. We believe that a diminished pain inhibitory system or an enhanced pain facilitatory system may enhance the risk to develop chronic postoperative pain. Some evidence for this comes from Yarnitsky et al. who showed that the ability to engage endogenous inhibitory pathways (as tested by the experimental paradigm of Conditioned Pain Modulation (CPM)) was associated with a lower risk of development of chronic post-thoractomy pain (odd ratio 0.52).1 In the current study we aim to pre-operatively test the effectiveness of the endogenous pain modulatory system (by conditioned pain modulation and temporal summation) in a large group of patients planned for an elective inguinal hernia repair.|
|- Main changes (audit trail)||9-sept-2017 -IK|
'For the power analysis we presumed that patients with an anti-nociceptive profile had a 15% reduced risk (estimated standard deviation of 25%) for the development of chronic postoperative pain compared to patients with a pro-nociceptive profile. With a power of 90% and an alpha of 0.05 we need 60 patients with chronic postoperative pain in our study. Assuming 10% loss to follow-up we aim to have 75 patients with chronic postoperative pain at the end of the study period.
Initially we estimated that the incidence of chronic postoperative pain after inguinal hernia surgery was 15% (lower range reported in literature). If 75 patients need to develop chronic pain this means that we need to include 500 patients in our study. However, the incidence of chronic pain in the first 175 patients appears to be higher in our study population where we observe an incidence of 30% of chronic postoperative pain. This indicates that we only need to include 250 patients in our study to have 75 patient with chronic postoperative pain at the end of the study period. Therefore, we decided after consideration with our local ethics board to stop the study after inclusion of 250 patients.'
|- RECORD||30-jul-2015 - 9-sep-2017|