Journal article
Chronic postsurgical pain in the Evaluation of Nitrous Oxide in the Gas Mixture for Anaesthesia (ENIGMA)-II trial
British journal of anaesthesia : BJA, Vol.117(6), pp.801-811
12/01/2016
DOI: 10.1093/bja/aew338
PMID: 27956679
Abstract
Background. Previous animal and clinical studies showed that nitrous oxide may produce long-term analgesia. The aim of this study was to evaluate the effect of nitrous oxide in preventing chronic postsurgical pain. We also explored whether methylenetetrahydrofolate reductase gene polymorphisms (1298A>C, 667C >T) would enhance nitrous oxide analgesia.
Methods. We conducted a telephone interview at 12 months after surgery on 2924 (41.1%) patients enrolled in the Evaluation of Nitrous Oxide in the Gas Mixture for Anaesthesia-II trial. Pain at the wound site was recorded using the modified brief pain inventory and the neuropathic pain questionnaire. General health status was measured using the EQ-5D questionnaire. Genotyping was performed in a subset of 674 Asian patients in Hong Kong.
Results, At 12 months after surgery, 356 (12.2%) patients reported chronic postsurgical pain at the wound site and 112 (3.8%) patients had severe pain and required regular analgesic interventions. Nitrous oxide did not affect the rate of chronic postsurgical pain (11.8% nitrous oxide group; 12.5% no nitrous oxide group), relative risk (95% confidence intervals): 0.94 (0.751.17), P-0.57. However, in a planned subgroup analysis, nitrous oxide reduced the risk of chronic postsurgical pain in Asian patients, relative risk (95% confidence intervals): 0.70 (0.50-0.98), P_0.031. Patients who were homozygous for either gene polymorphism and who received nitrous oxide during surgery were less likely to report chronic postsurgical pain.
Conclusions. Nitrous oxide administration had no impact on chronic postsurgical pain, but benefits may still be possible in Asian patients and patients with variants in methylenetetrahydrofolate reductase gene. Clinical trial registration. NCT00430989.
Details
- Title: Subtitle
- Chronic postsurgical pain in the Evaluation of Nitrous Oxide in the Gas Mixture for Anaesthesia (ENIGMA)-II trial
- Creators
- M. T. V. Chan - Chinese University of Hong KongP. J. Peyton - Austin HospitalP. S. Myles - The Alfred HospitalK. Leslie - Monash UniversityN. Buckley - McMaster UniversityJ. Kasza - Monash UniversityM. J. Paech - Royal Perth HospitalW. S. Beattie - Toronto General HospitalD. I. Sessler - Cleveland ClinicA. Forbes - Monash UniversityS. Wallace - The Alfred HospitalY. Chen - Chinese University of Hong KongY. Tian - Chinese University of Hong KongW. K. K. Wu - Chinese University of Hong KongAustralian and New Zealand College of Anaesthetists Clinical Trials Network for the ENIGMA-II investigatorsDetlef Obal - Anesthesia
- Resource Type
- Journal article
- Publication Details
- British journal of anaesthesia : BJA, Vol.117(6), pp.801-811
- Publisher
- Elsevier
- DOI
- 10.1093/bja/aew338
- PMID
- 27956679
- ISSN
- 0007-0912
- eISSN
- 1471-6771
- Number of pages
- 11
- Grant note
- 10/014; 12/ 008 / Anaesthesia and Pain Medicine Foundation, Australian and New Zealand College of Anaesthetists 11121051 / Health and Medical Research Fund, Hong Kong Special Administrative Region, China 461409 / General Research Fund, Research Grants Council, Hong Kong Special Administrative Region, China National Health and Medical Research Council; National Health & Medical Research Council (NHMRC) of Australia 435015 / Australian Government National Health and Medical Research Council; National Health & Medical Research Council (NHMRC) of Australia
- Language
- English
- Date published
- 12/01/2016
- Academic Unit
- Anesthesia
- Record Identifier
- 9984696723402771
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