Endometriosis is a chronic disease in which the endometrium cells are located outside the uterine cavity. The aim of this study was to evaluate circulating 20S proteasome and 20S immunoproteasome levels in plasma and peritoneal fluid in women with and without endometriosis in order to assess their usefulness as biomarkers of disease. Concentrations were measured using surface plasmon resonance imaging biosensors. Patients with suspected endometriosis were included in the study—plasma was collected in 112 cases and peritoneal fluid in 75. Based on the presence of endometriosis lesions detected during laparoscopy, patients were divided into a study group (confirmed endometriosis) and a control group (patients without endometriosis). Proteasome and immunoproteasome levels in both the plasma (p = 0.174; p = 0.696, respectively) and the peritoneal fluid (p = 0.909; p = 0.284, respectively) did not differ between those groups. There was a statistically significant difference in the plasma proteasome levels between patients in the control group and those with mild (Stage I and II) endometriosis (p = 0.047) and in the plasma immunoproteasome levels in patients with ovarian cysts compared to those without (p = 0.017). The results of our study do not support the relevance of proteasome and immunoproteasome determination as biomarkers of the disease but suggest a potentially active role in the pathogenesis of endometriosis.

Background: Opioids remain the most effective component of systemic analgesia and are considered safe and beneficial when administered at the lowest effective dose. Nevertheless, their potential adverse effects may diminish the quality of the postoperative period or, in some cases, lead to life-threatening complications. This analysis examines whether the mandatory implementation of a standardised protocol offers opioid-sparing potential. Methods: In this single-centre retrospective cohort study, intraoperative opioid consumption during laparoscopic appendectomy was compared between patients anaesthetised according to a standardised protocol (n₁ = 132) and those managed at clinicians’ discretion in line with good medical practice (n₂ = 212). Length of hospital stay and use of intraoperative non-opioid analgesics were also assessed. Results: The total fentanyl dose administered during anaesthesia was significantly lower in the standardised protocol cohort compared to the cohort without a protocol: 3.13 μg·kg⁻¹ (IQR: 2.98–4.08) vs. 5.19 μg·kg⁻¹ (IQR: 3.89–6.67), p < 0.001. In the protocol cohort, the percentage of patients who received acetaminophen and metamizole was significantly higher—increasing by 57% and 23%, respectively (p < 0.001). No significant inter-cohort difference was observed in terms of length of hospital stay. Conclusions: The use of a mandatory anaesthetic protocol based on a multimodal approach had an opioid-sparing effect in children undergoing laparoscopic appendectomy. This retrospective analysis was approved by the Ethics Committee of the Medical University of Warsaw (identifier: AKBE/118/2025; date of acceptance: 12 May 2025), and the primary trial was registered in the U.S. National Library of Medicine Clinical Trials Registry (registration number: NCT05238506; date of first registration: 14 February 2022).