2/10. The kidney is a remarkable vascular organ. Renal blood flow = 1000 ml/min, renal plasma flow = 600 ml/min.
3/10. Elevated central venous pressure affects renal function significantly more than reduced cardiac output in heart failure. jacc.org/doi/10.1016/j.…
4/10. Selective abdominal venous congestion leads to morphological glomerular changes already within weeks in animal models. The glomerular surface area ↑ and Bowman’s width↑.www.nature.com/articles/s41598-018-36189-3
6/10. Maintaining adequate mean arterial perfusion pressure (MAP) of 60-70 mmHg is sufficient. However, a too drastic reduction in MAP increases likelihood of worsening renal function. onlinelibrary.wiley.com/doi/full/10.10…
7/10. However, RV dysfunction (leading to increased CVP) does impair renal function, as shown by #JeffTestani.
9/10. Another under-recognized hemodynamic driver of impaired renal function in 60% of AHF is elevated intra-abdominal pressure, easily measured through a Foley catheter. jacc.org/doi/abs/10.101…
10/10. Differences in RBF are overcome by changes in tonus of glomerular arterioles affecting FF which determines renal sodium reabsorption. jacc.org/doi/10.1016/j.…
Glomerulus: renal blood flow ↓ in HF, but the kidney tries to maintain GFR by afferent arteriolar vasodilation and efferent arteriolar vasoconstriction. This leads to single-nephron hyperfiltration initially preserving total GFR, but further damaging the glomerulus. (2/6)
Proximal tubules: hyperfiltration leads to ↑ water and solutes filtered, but ↓ remaining in the peritubular capillaries. Due to ↑ peritubular capillary oncotic pressure + ↑ renal lymph flow -> ↑ water and Na+ reabsorption in the proximal tubules (3/6)