Hypertonic sodium lactate improves microcirculation, cardiac function, and inflammation in a rat model of sepsis

BACKGROUND: Hypertonic sodium lactate (HSL) may be of interest during inflammation. We aimed to evaluate its effects during experimental sepsis in rats (cecal ligation and puncture (CLP)). METHODS: Three groups were analyzed (n = 10/group): sham, CLP-NaCl 0.9%, and CLP-HSL (2.5 mL/kg/h of fluids for 18 h after CLP). Mesenteric microcirculation, echocardiography, cytokines, and biochemical parameters were evaluated. Two additional experiments were performed for capillary leakage (Evans blue, n = 5/group) and cardiac hemodynamics (n = 7/group). RESULTS: HSL improved mesenteric microcirculation (CLP-HSL 736 [407–879] vs. CLP-NaCl 241 [209–391] UI/pixel, p = 0.0006), cardiac output (0.34 [0.28–0.43] vs. 0.14 [0.10–0.18] mL/min/g, p < 0.0001), and left ventricular fractional shortening (55 [46–73] vs. 39 [33–52] %, p = 0.009). HSL also raised dP/dt(max) slope (6.3 [3.3–12.1] vs. 2.7 [2.0–3.9] 10(3) mmHg/s, p = 0.04), lowered left ventricular end-diastolic pressure-volume relation (1.9 [1.1–2.3] vs. 3.0 [2.2–3.7] RVU/mmHg, p = 0.005), and reduced Evans blue diffusion in the gut (37 [31–43] vs. 113 [63–142], p = 0.03), the lung (108 [82–174] vs. 273 [222–445], p = 0.006), and the liver (24 [14–37] vs. 70 [50–89] ng EB/mg, p = 0.04). Lactate and 3-hydroxybutyrate were higher in CLP-HSL (6.03 [3.08–10.30] vs. 3.19 [2.42–5.11] mmol/L, p = 0.04; 400 [174–626] vs. 189 [130–301] μmol/L, p = 0.03). Plasma cytokines were reduced in HSL (IL-1β, 172 [119–446] vs. 928 [245–1470] pg/mL, p = 0.004; TNFα, 17.9 [12.5–50.3] vs. 53.9 [30.8–85.6] pg/mL, p = 0.005; IL-10, 352 [267–912] vs. 905 [723–1243] pg/mL) as well as plasma VEGF-A (198 [185–250] vs. 261 [250–269] pg/mL, p = 0.009). CONCLUSIONS: Hypertonic sodium lactate fluid protects against cardiac dysfunction, mesenteric microcirculation alteration, and capillary leakage during sepsis and simultaneously reduces inflammation and enhances ketone bodies.