The relationship between the level of μ-opioid receptor (μORs) and postoperative analgesic use in patients undergoing septoplasty: a prospective randomized controlled trial

Comparison of Acute Pain Syndrome after Surgical Interventions in the Nasal Cavity and Rhinoplasty

Comparison of acute pain syndrome after septoplasty, rhinoplasty, and rhinoseptoplasty was carried out. It is shown that the intensity of acute pain is higher in patients after rhinoseptoplasty in the first 3-6 h after surgery.

Serum levels of mu-opioid receptor according to menstrual cycle phases are associated with postoperative pain and opioid consumption in laparoscopic gynecological surgeries: a prospective observational study

AIMS

In this prospective observational clinical study, we aimed to evaluate the relationship between serum mu-opioid receptor (MOR) levels according to menstrual cycle phases on postoperative pain scores and analgesic requirements.

METHODS

A total of 80 female patients undergoing laparoscopic surgery were divided into two groups according to the phases of the menstrual cycle as follicular and luteal. Postoperative pain scores, total tramadol consumptions, and numbers of demands on patient-controlled analgesia (PCA) of the patients were recorded at 5 time points (T0: in the recovery room, T1: 1st hour in the ward, T2: 6th hour in the ward, T3: 12th hour in the ward, T4: 24th hour in the ward). Serum MOR concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

The mean serum MOR levels were significantly higher in the follicular group (275 ± 32 pg/ml) compared to the luteal group (254 ± 28 pg/ml) (p = 0.003). Total tramadol consumption (T0, T2, and T3) was significantly higher in the luteal group (p = 0.031, p = 0.012, p = 0.017, respectively). Postoperative pain scores did not differ significantly between the groups. With the exception of T4 (p = 0.057), the number of demands on PCA was significantly higher in the luteal group. However, multivariate logistic regression analysis showed that serum MOR levels were affected by the menstrual cycle phase (follicular) (β = 0.361) (p = 0.001).

CONCLUSIONS

Our study revealed that patients during the follicular phase with higher serum MOR levels consumed less opioid analgesic postoperatively. More comprehensive studies are needed to determine the relationship between serum MOR levels and menstrual cycle phases as well as postoperative pain. (Trial registration number: NCT04690491 www.

CLINICALTRIALS

gov ).

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).