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?