Acute renal failure / Repetitorium

Acute renal failure
Glomerular filtration is the process in which it occurs filtration plasma through the capillary wall of the glomeruli and the visceral leaf of the Bowman housing, which surrounds the capillary wall through its protrusions ( = podocyte pedicals ). The other two processes involved in the formation of definitive urine are tubular reabsorption and tubular secretion. Through tubular secretion H+ ions regulate the kidneys' blood pH.

Causes

 * prerenal
 * Decreased renal blood flow, eg due to systemic hypovolemia, reduced minute cardiac output or reduced effective arterial volume (ascites, sepsis, hepatorenal syndrome), leads to potentially reversible armor of functional renal circulation, while the nutritious circulation may not be significantly affected unless normal flow is restored early.
 * renal
 * Renal parenchyma is damaged mainly due to ischemic ( prolonged restriction of functional and numbing circulation ), nephrotoxic ( ATB therapy - especially aminoglycosides, chemotherapy, radiocontrast agents, nonsteroidal anti-inflammatory drugs - NSAIDs ); also due to acute haemolysis or urate toxicity (tumor lysis syndrome).
 * postrenal
 * Prevention of urine runoff leads to vesico-ureteral reflux and subsequent pressure atrophy renal parenchyma.

ASL phase

 * Oliguric ( anuric )


 * retention H+, K+: hyperkalaemia - > heart rhythm disorders ( leading to AV block, ventricular fibrillation, asystole ) manifested on ECG recording as fenced P-waves, pointed T-waves, QRS complex extension under severe hyperkalaemia ( over 6.5 mmol / l ). Therapeutic solution is given insulin ( increases potassium input to cells ), pH adjustment ( hyperkalaemia may be accompanied acidosis - tubular cells tend to "replace" potassium with hydrogen ) and administration of β-adrenergic.
 * retention of water and other ions: hypervolemia
 * retention of organic substances


 * Polyuric


 * Increase GFR ( glomerular filtration rate ) and excretion of retained substances. With the GFR elevated polyuria manifestation of failure of the concentration function of the tubules.

In reversible phases and also in the "end-stage renal disease" stage, the patient is often the only hope for improvement hemodialysis.

Source

 * VÍZEK, Martin. Repetitorium [ online ]. [ cit. 2012-01-08 ].
 * VÍZEK, Martin. Repetitorium [ online ]. [ cit. 2012-01-08 ].

Literature used

 * ČEŠKA, Richard, et al. Intern. 1st edition. Prague: Triton, 2010. 855 p. ISBN 978-80-7387-423-0.
 * GUYTON, Arthur C and John E HALL. Textbook of Medical Physiology. 11th edition. Elsevier, 2006. 0 p. 11; ISBN 978-0-7216-0240-0.
 * GUYTON, Arthur C and John E HALL. Textbook of Medical Physiology. 11th edition. Elsevier, 2006. 0 p. 11; ISBN 978-0-7216-0240-0.