The cardiovascular system at high altitude: A bibliometric and visualization analysis.

BACKGROUND: When exposed to high-altitude environments, the cardiovascular system undergoes various changes, the performance and mechanisms of which remain controversial. AIM: To summarize the latest research advancements and hot research points in the cardiovascular system at high altitude by conducting a bibliometric and visualization analysis. METHODS: The literature was systematically retrieved and filtered using the Web of Science Core Collection of Science Citation Index Expanded. A visualization analysis of the identified publications was conducted employing CiteSpace and VOSviewer. RESULTS: A total of 1674 publications were included in the study, with an observed annual increase in the number of publications spanning from 1990 to 2022. The United States of America emerged as the predominant contributor, while Universidad Peruana Cayetano Heredia stood out as the institution with the highest publication output. Notably, Jean-Paul Richalet demonstrated the highest productivity among researchers focusing on the cardiovascular system at high altitude. Furthermore, Peter Bärtsch emerged as the author with the highest number of cited articles. Keyword analysis identified hypoxia, exercise, acclimatization, acute and chronic mountain sickness, pulmonary hypertension, metabolism, and echocardiography as the primary research hot research points and emerging directions in the study of the cardiovascular system at high altitude. CONCLUSION: Over the past 32 years, research on the cardiovascular system in high-altitude regions has been steadily increasing. Future research in this field may focus on areas such as hypoxia adaptation, metabolism, and cardiopulmonary exercise. Strengthening interdisciplinary and multi-team collaborations will facilitate further exploration of the pathophysiological mechanisms underlying cardiovascular changes in high-altitude environments and provide a theoretical basis for standardized disease diagnosis and treatment.

Early Enteral Nutrition and Sepsis-Associated Acute Kidney Injury: A Propensity Score Matched Cohort Study Based on the MIMIC-III Database.

PURPOSE: We aimed to analyze the optimal timing of enteral nutrition (EN) in the treatment of sepsis and its effect on sepsis-associated acute kidney injury (SA-AKI.). MATERIALS AND METHODS: The MIMIC-III database was employed to identify patients with sepsis who had received EN. With AKI as the primary outcome variable, receiver operating characteristic (ROC) curves were utilized to calculate the optimal cut-off time of early EN (EEN). Propensity score matching (PSM) was employed to control confounding effects. Logistic regressions and propensity score-based inverse probability of treatment weighting were utilized to assess the robustness of our findings. Comparisons within the EEN group were performed. RESULTS: 2364 patients were included in our study. With 53 hours after intensive care units (ICU) admission as the cut-off time of EEN according to the ROC curve, 1212 patients were assigned to the EEN group and the other 1152 to the delayed EN group. The risk of SA-AKI was reduced in the EEN group (odds ratio 0.319, 95% confidence interval 0.245-0.413, p<0.001). The EEN patients received fewer volumes (mL) of intravenous fluid (IVF) during their ICU stay (3750 mL vs. 5513.23 mL, p<0.001). The mediating effect of IVF was significant (p<0.001 for the average causal mediation effect). No significant differences were found within the EEN group (0-48 hours vs. 48-53 hours), except that patients initiating EN within 48 hours spent fewer days in ICU and hospital. CONCLUSION: EEN is associated with decreased risk of SA-AKI, and this beneficial effect may be proportionally mediated by IVF volume.

Distance-saturation product of the 6-minute walk test predicts mortality of patients with non-cystic fibrosis bronchiectasis.

BACKGROUND: Previous surveillance methods to monitor the prognoses of patients with bronchiectasis are too complex for use in daily practice. The 6-minute walk test (6MWT) is a simple exercise test to predict the prognosis of chronic obstructive airway disease and numerous chronic lung diseases, including idiopathic pulmonary fibrosis. No studies have investigated exercise-induced oxygen desaturation (EID) and distance-saturation product (DSP) of 6MWT to predict the prognoses of patients with bronchiectasis. METHODS: This was a prospective study to identify correlations between variables of 6MWT and mortality in patients with bronchiectasis over a 6-year period. The study cohort included 69 patients with stable non-cystic fibrosis (non-CF) bronchiectasis who were regularly evaluated for functional status via 6-minute walk distance (6MWD), spirometry, BODE index, EID, and DSP. RESULTS: Of the 69 patients, 9 (13%) died and 60 (87%) survived during the 6-year follow-up period. The percentage of EID was higher [7 of 9 patients (78%) vs. 22 of 60 patients (27%), P=0.003] in the non-survivors group. The 6MWD (467.9±77.1 vs. 363.7±126.7 m, P=0.001) was higher in the survivors group. DSP was significantly lower in the non-survivors group (411.0±78.4 vs. 283.9±90.0 m%, P<0.001). Multivariate analysis showed that DSP (OR =0.983; 95% CI: 0.974-0.993, P=0.001) was the best parameter of 6MWT to predict mortality. Patients with a lower DSP of <280 m% were at a 66.5-fold greater risk (OR =66.5; 95% CI: 9.4-469.2) of 6-year mortality compared with those with DSP >280 m% (P<0.001). CONCLUSIONS: DSP is a simple parameter to predict 6-year mortality in patients with non-CF bronchiectasis.