Bilevel positive airway pressure ventilation in patients susceptible to hypoxemia during procedural sedation for colonoscopy: a prospective randomized controlled study.

BACKGROUND AND AIMS: Hypoxemia is one of the most common adverse events during colonoscopy, particularly among patients who are diagnosed with obstructive sleep apnea (OSA) or are overweight. Consequently, the objective of this study was to evaluate the effectiveness of bilevel positive airway pressure (BPAP) ventilation for patients with high-risk hypoxemia during colonoscopy with sedation. METHODS: In this trial, 127 patients who met the eligibility criteria were randomly assigned to the BPAP oxygen group and nasal cannula (NC) group. The primary endpoint was the incidence of hypoxemia. RESULTS: Compared with the use of NC, BPAP ventilation exhibited a significant reduction in the incidence of hypoxemia, decreasing it from 23.8% to 6.3% (absolute risk difference, 17.5%; 95% confidence interval, 5.4-29.6; P = .006). Importantly, BPAP ventilation prevented the occurrence of severe hypoxemia (9.5% vs 0%; absolute risk difference, 9.5%; 95% confidence interval, 2.3-16.7; P = .035). In addition, the BPAP group required fewer airway interventions (P < .05). CONCLUSIONS: In individuals with OSA or overweight status, the use of BPAP ventilation during colonoscopy significantly reduced the incidence of hypoxemia. (Clinical trial registration number: ChiCTR2300073193.).

Overview of the molecular mechanisms contributing to the formation of cancer­associated adipocytes (Review).

Adipocytes are the main stromal cells in the tumor microenvironment. In addition to serving as energy stores for triglycerides, adipocytes may function as an active endocrine organ. The crosstalk between adipocytes and cancer cells was shown to promote the migration, invasion and proliferation of cancer cells and to cause phenotypic and functional changes in adipocytes. Tumor­derived soluble factors, such as TNF­α, plasminogen activator inhibitor 1, Wnt3a, IL­6, and exosomal microRNAs (miRNA/miRs), including miR­144, miR­126, miR­155, as well as other miRNAs, have been shown to act on adipocytes at the tumor invasion front, resulting in the formation of cancer­associated adipocytes (CAAs) with diminished reduced terminal differentiation markers and a dedifferentiated phenotype. In addition, the number and size of CAA lipid droplets have been found to be significantly reduced compared with those of mature adipocytes, whereas inflammatory cytokines and proteases are overexpressed. The aim of the present review was to summarize the latest findings on the biological changes of CAAs and the potential role of tumor­adipocyte crosstalk in the formation of CAAs, in the hope of providing novel perspectives for breast cancer treatment.