Acute Kidney Injury // Acute Renal Failure
B. Ibuprofen
Which of the following is most likely to be nephrotoxic? A. Potassium Chloride B. Ibuprofen C. Acetaminophen D. A beta blocker
C. Proteins
Which one of the following nutrients is limited in patients with acute renal disease in order to decrease metabolic waste products? A. Carbohydrates B. Fats C. Proteins D. Vitamins and Minerals
Diagnostics - BUN, Creatinine - Sonogram or CT Management - Urinary Catheterization - Surgery - Stone Removal - Stenting
Diagnosis and Management of Postrenal AKI
Monitor urine output and BUN & creatinine UA may be + for protein, casts Remove Nephrotoxins Monitor and manage fluid & electrolyte issues Ensure adequate renal perfusion Dialysis may be necessary
Diagnosis and Treatment of Intrarenal AKI
Excretion of waste products Regulation of fluid & electrolyte balance Regulation of blood pressure Production of erythropoietin Regulation of acid-base balance Activation of vitamin D
Functions of the Kidney
C. Postrenal
A neurogenic bladder from spinal cord trauma may cause which type of acute renal failure? A. Prerenal B. Intrarenal C. Postrenal
A. Prerenal
A patient is being treated with high doses of diuretics. Which type of acute renal failure does this place the patient at risk for? A. Prerenal B. Intrarenal C. Postrenal
C. 1000 mL
A patient is in oliguric acute renal failure. In the past 24 hours the patient's output includes 400 mL of urine and 100 mL of emesis. How much fluid should be allocated for the fluid restriction for the next day? A. 500 mL B. 900 mL C. 1000 mL D. 1500 mL
Aldosterone
Acts specifically on the tubules; mainly proximal tubule; Na reabsorption in distal tubule highly variable and dependent on presence of aldosterone
Acute Kidney Injury (AKI)
Acute and rapid decline in renal function Potentially reversible if precipitating factor can be corrected
Prerenal
Acute kidney injury affecting perfusion
Intrarenal
Acute kidney injury resulting from direct damage to glomerulus or tubules
Postrenal
Acute kidney injury resulting from obstruction
Renal Failure
Condition in which the kidney fails to maintain homeostasis: Build up of nitrogenous wastes - Increase in BUN & creatinine (Azotemia) - Normal BUN is 10-20 mg/dL - Normal creatinine is 0.5-1.2 mg/dL - Decrease in glomerular filtration Inability to regulate fluid & electrolyte balance Inability to maintain acid-base balance
Fluid Overload Hyperkalemia Uremia Blood infections from contamination through IV lines most common cause leading to death Recovery of Renal Function Dependent On: - Underlying cause - Overall health and condition of the client - The careful supportive management during the period of shutdown
Complications of Acute Renal Failure
Decreased urine output BUN will begin to rise when patient is "dry" Increase in BUN & creatinine
Early Signs of Prerenal AKI
Glomerulonephritis Acute Tubular Necrosis (ATN) - Ischemia from severe Prerenal causes Nephrotoxins - Drugs (Aminoglycosides, NSAIDS) - IV contrast Tubular Obstruction - Rhabdomyolysis - Hemolysis
Etiology of Intrarenal AKI
BPH Stones Tumors
Etiology of Postrenal AKI
Hypovolemia Shock/Sepsis Dehydration Excessive Diuresis Heart Failure Treatment is to restore perfusion
Etiology of Prerenal AKI
BUN > 100, creatinine > 10 Pulmonary edema Hyperkalemia Uncompensated metabolic acidosis Fluid excess not responsive to diuretics Uremia Uremic pericarditis Uremic encephalopathy
Indications for Dialysis
Cardiac monitoring Sodium polystyrene (Kayexalate®) Insulin with dextrose Sodium Bicarbonate Calcium gluconate Dialysis
Management of Acute Hyperkalemia
Restrict Sodium Fluid Restriction (output + Insensible losses (500 mL)) Monitor weight, I+Os, BP, Edema, Lung Sounds Possible try Furosemide if still making urine May require dialysis for pulmonary edema
Management of Fluid Overload
Limit Protein Intake - Majority of calories from carbohydrates Monitor BUN, creatinine Dialysis if severe
Management of Uremia
Initiation - Time from onset of initiating event until injury occurs Maintenance - Urine output drops and BUN/creatinine rise - Oliguric Phase (UO drops) Recovery - Urine output begins to increase (Diuretic phase) - Then BUN & creatinine begins to fall
Phases of Intrarenal AKI
ADH
Stimulates reabsorption of water from distal tubule and collecting duct
Key point
The frequent monitoring of urine output (UO) and the detection of excessive losses of body fluid will help identify instances of inadequate renal perfusion prior to the development of actual renal failure
Renal Blood Flow
The kidneys receive 20% - 25% of the cardiac output: - Approximately 600 ml/min Glomerulus = filtration - 180 liters are filtered each day Peritubular capillary = reabsorption; - 99% is reabsorbed: - Normal urine output = 1 - 2 liters/day (1500 ml)
Prerenal Intrarenal Postrenal
Types of Acute Kidney Injury
Aldosterone ADH
What two hormones affect urine formation?