Euvolemia-A critical target in the management of acute kidney injury

VExUS Score in the Management of Patients With Acute Kidney Injury in the Intensive Care Unit: AKIVEX Study

OBJECTIVES

Venous congestion is a potential cause of acute kidney injury (AKI) and venous excess ultrasound (VExUS) score is a potentially useful tool in this scenario. The aim of this study is to verify whether the VExUS score can serve as a guide to decongestion in patients with severe AKI and whether the modification of the score can be associated with an increase in the number of renal replacement therapy (RRT)-free days in 28 days.

METHODS

This quasi-experimental study was conducted in patients admitted to the intensive care unit who developed severe AKI. The intervention was to suggest to the attending physician the use of diuretic in patients with VExUS >1. After 48 hours, a new VExUS assessment was performed. Primary outcome was RRT-free days at Day 28.

RESULTS

Ninety patients were included. Patients with a VExUS score >1 (n = 36) at enrollment had a greater use of diuretics in the following 48 hours (75.0%, n = 27) than patients with a VExUS ≤1 (n = 54) at enrollment (38.9%, n = 21), P = .001. Patients who reduced the VExUS score had a significantly greater number of RRT-free days at Day 28 (28.0; 8.0-28.0) when compared with those who did not reduce (15.0; 3.0-27.5), P = .012.

CONCLUSIONS

We found a higher diuretic use in patients with a higher VExUS score, and patients who reduced the VExUS in 48 hours had significantly more RRT-free days in 28 days.

Caloric restriction reduces the pro-inflammatory eicosanoid 20- hydroxyeicosatetraenoic acid to protect from acute kidney injury

Acute kidney injury is a frequent complication in the clinical setting and associated with significant morbidity and mortality. Preconditioning with short-term caloric restriction is highly protective against kidney injury in rodent ischemia reperfusion injury models. However, the underlying mechanisms are unknown hampering clinical translation. Here, we examined the molecular basis of caloric restriction-mediated protection to elucidate the principles of kidney stress resistance. Analysis of an RNAseq dataset after caloric restriction identified Cyp4a12a, a cytochrome exclusively expressed in male mice, to be strongly downregulated after caloric restriction. Kidney ischemia reperfusion injury robustly induced acute kidney injury in male mice and this damage could be markedly attenuated by pretreatment with caloric restriction. In females, damage was significantly less pronounced and preconditioning with caloric restriction had only little effect. Tissue concentrations of the metabolic product of Cyp4a12a, 20-hydroxyeicosatetraenoic acid (20-HETE), were found to be significantly reduced by caloric restriction. Conversely, intraperitoneal supplementation of 20-HETE in preconditioned males partly abrogated the protective potential of caloric restriction. Interestingly, this effect was accompanied by a partial reversal of caloric restriction-induced changes in protein but not RNA expression pointing towards inflammation, endoplasmic reticulum stress and lipid metabolism. Thus, our findings provide an insight into the mechanisms underlying kidney protection by caloric restriction. Hence, understanding the mediators of preconditioning is an important pre-requisite for moving towards translation to the clinical setting.