Acute Renal Failure
Dr.Nariman FahmiClinical Scenario
History: A five years old male presents to emergency with a 5 day history of diarrhoea and vomiting. he has been unable to keep anything down including water and now lethargic and the mother noticed no urine output for the last 12 hours . O/E: he has dyspnea and has reduced skin turgor. BP is 70/50 and HR 95. Examination is otherwise unremarkable Ix: normal FBC, Na 149meq/l, K 6.7meq/l, Urea 17.0 mmol/l and Creatinine 258mmol/lAcute kidney injury
By the end of the lecture the student can -Describe the etiology &categories of AKI -Understand principles of management of AKI -Identification of appropriate investigations - Knowledge of indications for dialysis -Awareness of complications and management of hyperkalemia (common complication)Renal system
2 Kidneys 2 Ureters Bladder UrethraKidney Function
Detoxify blood Regulate blood pressure , electrolyte and fluid balance Increase calcium absorption calcitriol Stimulate RBC production erythropoietin
To function properly kidneys require:
Normal renal blood flow Functioning glomeruli and tubules Clear urinary outflow tract for drainage and elimination of formed urine from the body.Acute renal failure
Acute sudden onset rapid reduction in urine output Usually reversibleClassifications
Pre-renal (55%) renal(40%) post-renal(5-15%)Causes of ARF
Pre-renal = vomiting, diarrhea, cardiac failure, septic shock ,others Intrinsic Interstitial nephritis, acute glomerulonephritis, tubular necrosis, toxins Post-renal -prostatic hypertrophy, bilateral renal calculi, bladder carcinomaGeneralized or localized reduction in RBF
Hypovolaemia Haemorrhage Volume depletion ( vomiting, diarrhoea, burns)Hypotension Cardiogenicshock (sepsis, anaphylaxis)
Oedema states Cardiac failure Hepatic cirrhosis Nephrotic syndrome
Renal Hypoperfusion NSAIDs ACEI / ARBs RAS /occlusion Hepatorenal syndrome
Reduced GFR
PRE-RENAL (Hemodynamic) AKI
PRERENAL AKI
Symptoms of ARF
Decrease urine output (70%) Edema, esp. lower extremity Mental changes Nausea, vomiting TachypeniaManagement
Think about the diagnosis Maintenance of -volume homeostasis (Assess fluid status, Fluid resuscitation) -Stop Nephrotoxic drugs -correction of biochemical abnormalities Treat reversible elements Hydrate -Relieve obstructionManagement
Treat the Treat reversible causesInfection – give antibiotics, renal dosesIntrinsic renal disease – R/v medicationObstructionExample (calculus obstruction either surgical removal or nephrectomy)Hyperkalemia Symptoms
Weakness Lethargy DysrhythmiasHyperkalaemia
Potassium range is 3.5 – 5mmol/LRise in serum K+ >5mmol/lSigns/symptoms: muscle weaknessECG changes:Flattened P wavesBroad QRS complexSlurring of ST segmentTall tented T waves http://www.aafp.org/afp/2006/0115/p283.htmlHyperkalemia
Potassium >6.0 mmol/LCalcium resonium 15g QDS POIf septic or rising quickly treat as though K+ 6.5Potassium >6.5 mmol/LDextrose-insulin (50ml 50% Dextrose with 10units Actrapid insulin, IV over 5mins) –Calcium resonium 15g QDS PO
Hyperkalemia
Potassium >7 mmol/L Calcium gluconate (10ml of 10% solution into central vein or diluted into 40ml 0.9% saline into peripheral vein over 10mins, with cardiac monitor) Dextrose insulin Nebulised salbutamol 5mg IV sodium bicarbonate (50ml 8.4% over 5mins centrally or 500mls 1.26% over 30mins peripherally Calcium resoniumDialysis
DialysisDiffuse harmful waste out of body Control BP Keep safe level of electrolytes and acid base level in body 2 types Hemodialysis Peritoneal dialysis
Peritoneal Dialysis
Abdominal lining filters bloodINDICATIONS FOR DIALYSIS IN ACUTE RENAL FAILURE
PERICARDITIS MENTAL STATUS CHANGE SEIZURES Uncontrollable hypertension , hyperkalemia or acidosis Toxinssummary
Acute renal failure is defined as an abrupt or rapid decline in renal filtration function. It is the clinical manifestation of several disorders that affect the kidney acutely treatment is supportiveReferences
http://www.umm.edu/ency/article/000471.htm http://www.fpnotebook.com/REN38.htm http://www.paems.org/eWebquiz/renal%20failure/Dialysis%20CEU.pdf http://www.loyolaems.com/sop/4med.htm#med8 http://www.chpnet.org/BIEM_Res/lectures.aspDavidson's Principles and Practice of Medicine Edited by Brian R. Walker, BSc MD FRCPE FRSE, Nicki R Colledge, BSc (Hons) FRCPE, Stuart H. Ralston, MD FRCP FMedSci FRSE and Ian Penman, BSc MD FRCPE Harrisons Principles of Internal Medicine,
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