study to evaluate the efficacy of a polyamine-deficient diet for treating postoperative pain after abdominal surgery

Conditions: Digestive System Surgical Procedures

Summary: the aim of this study is to evaluate if a polyamine deficient diet started 7 days prior to a major abdominal surgery (eventration cure and digestive continuity) and followed 7 days post-surgery reduces the area under the curve of the numerical pain rating scale in the 72 hours post-surgery.

morphine derivatives are known to be a major cause of postoperative ileus and also operative hyperalgesia. operative hyperalgesia corresponds to an increase in morphine needs postoperatively which is proportional to the morphine dose necessary during the surgery. this effect is due to two mechanisms: opioids tolerance and induced hypersensitivity. n-methyl-d-aspartate receptors (r-nmda) play a key role in this induced hypersensitivity. polyamines, organic compounds with several amines functions, are known r-nmda agonists. they increase the phosphorylation of the tyrosine group within the nr2b subunit responsible for the inflammatory hyperalgesia. limiting the binding of polyamines to the r-nmda seems an easy, safe and efficient way to limit the hypersensitivity induced post-operatively. most of the polyamines in the human body come from food. one study listed food regarding their polyamines content and allowed to check the safety of a polyamine deficient diet. such a well-followed diet would allow to reduce by 20 the polyamines quantity present in the body. the aim of this study is to evaluate whether a deficient polyamine diet introduced 7 days before and continued up to 7 days after an abdominal surgery requiring the use of morphine post-operatively reduces the post-operative pain, the consumption of analgesics (morphine) post-operatively and improve the recovery ability. abdominals surgeries concerned will be the eventration cure and digestive continuity. the medico-economic impact will be observed during this study.

Eligibility criteria:
inclusion criteria: * adult (\>18 years) * indication for a " major " abdominal surgery as second surgical procedure : cure of eventration and restoration of digestive continuity * intended use of a patient controlled morphine pump (pca) postoperatively or taking oral opioids * possible follow-up during 7 months (post-operative consultation at 1 month and 6 months only if postoperative pain or complications) * written informed consent form obtained from the patient * affiliated to the social security exclusion criteria: * pregnant women * minor, adult under guardianship or benefiting from a legal protection * oncological surgery * surgery not painful (cholecystectomy, hernia, thyroidectomy, bariatric surgery) * drug addicts patients, or under opiate dependency * chronic pain patients (pain over 3 months) * patients in nursing home or convalescence home (diet non possible in institution) * planned hospitalisation before the intervention (during the 7 days before the surgery) * severe undernutrition defined by the has criteria (weight loss \> 10% in 1 month and/or \> 15% in 6 months, albumin at inclusion \<15g/l) * patient refusing the possibility to change his eating habits * oral feeding impossible preoperatively * patient not able to express himself on their pain (silent, ...) * decompensated psychiatric pathologies (severe depression syndrome,...) * patient unable to understand the protocol and/or to give his informed consent

Keywords: abdominal surgery polyamine postoperative pain morphine hypersensitivity