Inhibition of colon C5a/C5a receptor signalling pathway confers protection against LPS-induced acute kidney injury via gut microbiota-kidney axis

Acute kidney injury (AKI) is a critical condition often associated with systemic inflammation and dysregulated gut microbiota. This study aimed to investigate the effects of the C5a receptor antagonist W54011 on lipopolysaccharide (LPS)-induced AKI, focusing on the colon's C5a/C5a receptor pathway, intestinal barrier integrity, and gut microbiota. Our findings demonstrate that W54011 effectively ameliorated kidney injury in the LPS-induced AKI model by selectively inhibiting the colon's C5a/C5a receptor signalling pathway. Additionally, C5a receptor blockade resulted in the inhibition of colonic inflammation and the reconstruction of the intestinal mucosal barrier. Furthermore, W54011 administration significantly impacted the composition and stability of the gut microbiota, restoring the abundance of dominant bacteria to levels observed in the normal state of the intestinal flora and reducing the abundance of potentially harmful bacterial groups. In conclusion, W54011 alleviates LPS-induced AKI by modulating the interplay between the colon, gut microbiota, and kidneys. It preserves the integrity of the intestinal barrier and reinstates gut microbiota, thereby mitigating AKI symptoms. These findings suggest that targeting the colon and gut microbiota could be a promising therapeutic strategy for AKI treatment.

Development and validation of a clinical prediction model for early ventilator weaning in post-cardiac surgery

Background

Weaning patients from mechanical ventilation is a critical clinical challenge post cardiac surgery. The effective liberation of patients from the ventilator significantly improves their recovery and survival rates. This study aimed to develop and validate a clinical prediction model to evaluate the likelihood of successful extubation in post-cardiac surgery patients.

Method

A predictive nomogram was constructed for extubation success in individual patients, and receiver operating characteristic (ROC) and calibration curves were generated to assess its predictive capability. The superior performance of the model was confirmed using Delong's test in the ROC analysis. A decision curve analysis (DCA) was conducted to evaluate the clinical utility of the nomogram.

Results

Among 270 adults included in our study, 107 (28.84%) experienced delayed extubation. A predictive nomogram system was derived based on five identified risk factors, including the proportion of male patients, EuroSCORE II, operation time, pump time, bleeding during operation, and brain natriuretic peptide (BNP) level. Based on the predictive system, five independent predictors were used to construct a full nomogram. The area under the curve values of the nomogram were 0.880 and 0.753 for the training and validation cohorts, respectively. The DCA and clinical impact curves showed good clinical utility of this model.

Conclusion

Delayed extubation and weaning failure, common and potentially hazardous complications following cardiac surgery, vary in timing based on factors such as sex, EuroSCORE II, pump duration, bleeding, and postoperative BNP reduction. The nomogram developed and validated in this study can accurately predict when extubation should occur in these patients. This tool is vital for assessing risks on an individual basis and making well-informed clinical decisions.