Acute Renal Failure Flashcards
Differentiate between 3 types of Acute Renal Failure (ARF) based on H+P, labs, and diagnostic tests. Compare and contrast assessment findings for each phase of Acute Renal Failure Explain rationale of therapeutic management for a client in Acute Renal Failure Describe priorities of nursing care for a client in each phase of Acute Tubular Necrosis (ARF) Develop nursing strategies to minimize complications of Acute Renal Failure Develop an individualized plan of care for a client in acute ren
Renal Anatomy and Function
- Renal perfusion – 1200ml/min. Kidneys receive 20-25% of CO @ rest
- Regulate filtrate – tubular reabsorption, and tubular secretion
Sudden deterioration in renal function characterized by:
Change in urine output - oliguria, anuria, normal urine volume Increased serum creatinine and BUN Fluid Overload Electrolyte imbalance Acid-base imbalance
Types of Acute Renal Failure
Prerenal (55 % of all ARF)
Intrarenal/Intrinsic (40% of all ARF)
Postrenal (5% of all ARF)
Prerenal cause:
hypoperfusion / diminished renal perfusion
Prenrenal
Hypovolemia -Burns –> fluid loss -Dehydration -Gastrointestinal losses (N/V/D) Impaired cardiac output - pump not working -Myocardial Infarct -Heart Failure -Cardiogenic shock Vasodilation - distributive shock -Sepsis -Anaphylaxis -Medications
Prerenal Labs
BUN inc – normal 10-20 mg/dl Creatinine inc – normal 0.5 – 1.2 mg/dl Urine sodium decreased to < 20 mEq/L Normal sediment, few casts Urine specific gravity - Increased
Intrarenal Cause
damage to the kidney parenchyma
Intrarenal
Myoglobinurea (released into blood stream) -Burns – tissue damage -Trauma, crush injuries -Rhabdomyolysis (muscle breakdown) Hemoglobinurea -Transfusion reaction -Hemolytic anemia Nephrotoxic agents -Medications -Solvents and chemicals Infectious processes -Acute pylonephritis, glomerulonephritis
Acute Tubular Necrosis (ATN)
Most common type of intrarenal failure
ATN and ARF are not the same because ARF can occur without ATN
ATN is generally described as postischemic or nephrotoxic
Intrarenal Labs
inc BUN – normal 10-20 mg/dl
inc Creatinine – normal 0.5 – 1.2 mg/dl
Urine sodium - > 40 mEq/L
Abnormal casts, debris (kidneys are being damaged)
Urine specific gravity = low normal 1.010
Postrenal cause
obstruction, dysfunction in post renal structures
Postrenal
Mechanical – urine cannot drain -Calculi -Tumors Benign prostatic hyperplasia -Strictures -Blood clots
Postrenal Labs
Inc BUN – normal 10-20 mg/dl Inc Creatinine – normal 0.5 – 1.2 mg/dl Urine sodium varies – often decreased Abnormal casts, debris - varies Urine specific gravity - varies
Diagnostic Tests
Kidney Ultrasound, EKG, Urinalysis, Blood gases – metabolic acidosis, BUN and Creatinine (Azotemia)
Diagnostic Evaluation
KUB – X-ray of kidneys/ ureters/ bladder
Bladder Catheterization – Used to rule out obstruction/ infection
Renal Ultrasound – Often used 1st-line/ identifies obstructive causes of renal failure
CT scan – Provides information regarding the size and shape of kidneys and the presence of lesions, cysts, calculi
IVP – Shows outline of the kidneys with dye
Renal Biopsy – differentiate between acute and chronic renal failure
Renal arteriogram – measures blood flow
Bladder US – noninvasive measure of bladder volume
Urodynamic studies – for evaluation of voiding problems like retention or incontinence
Stages of ARF
initiation, maintenance, recovery
Initiation Phase
Initial insult to when oliguria develops Usually recognized in retrospect BUN and creatinine begin to elevate Lasts – hours to days -might barely be at the 30mL/hr UO
Maintenance Phase
Lasts 1 – 2 weeks
Increase (in the serum) of substances normally excreted by kidney: urea, creatinine, uric acid, K+
Urine output decreases to < 400 mL/day
Recovery Phase
Gradual increase in urine output (may start looking like water)
Fluid loss as GFR recovers
Electrolyte imbalances
Renal function returns to normal rapidly first 5 – 25 days lasts up to 1 year
-Electrolytes return to normal
Clin Man- Nervous System
Accumulation of nitrogenous waste products from impaired renal functioning and metabolic acidosis
-Uremic encephalopathy
-Cerebral edema
Signs and Symptoms: Lethargy, confusion, disorientation. Asterixis, myoclonic muscle twitching, possible seizures
Clin Man - Cardiovascular
Tachycardia, Hypertension, CHF, Periorbital and Peripheral edema, Cardiac dysrhythmias
Clin Man - Pulmonary
Adventitious breath sounds Decreased cough reflex (fluid retention) Kussmaul breathing Infiltrates on CXR -Pneumonia -Pulmonary edema
Clin Man - GI
Urea decomposition in the gut results in ammonia release causing capillary fragility and GI mucosal irritation
Signs and Symptoms: N/V, GI Bleed, Impaired glucose use, Impaired protein synthesis
Clin Man - Hematopoietic
Impaired renal function
Decreased erythropoietin production = decreased RBC production and impaired platelet function
Signs and Symptoms: Anemia -> Treatment = Epogen
Clin Man - Integumentary
Dry, pruritic skin
Petechiae
Ecchymoses
Uremic frost - rare (looks like frost, salt coming up to skin)
Therapeutic Management - Fluid Overload
Nursing diagnosis – Excess fluid volume
Interventions:Fluid Restrictions: intake = output
Diuretic Therapy = Lasix, Mannitol, Bumex
Dialysis
Therapeutic Management - Electrolyte Imbalances
Collaborative diagnosis:PC Hyperkalemia – Most life threatening / GFR decreases / patient unable to excrete potassium
Nursing Interventions: Monitor K levels, Administer Meds as ordered: Kaexalate, Glucose and Insulin - Insulin given in glucose solution - facilitates movement of K from serum back into cells - until they can get pt to dialysis! Calcium gluconate
Therapeutic Management - Diet Considerations
Goal: limit accumulation of nitrogenous wastes
Decrease -> Potassium, Protein – Only high biologic should be allowed (no processed meats). Sodium, Phosphorus intake
Diet should be high in: Carbohydrates, Fats, Essential amino acids
Dialysis Issues
Reasons for Initiation: Volume overload, Uncontrolled hyperkalemia, Uncontrolled acidosis, Symptomatic uremia, Pericarditis
Types of Dialysis
hemodialysis, peritoneal dialysis, CRRT
Pediatric
ARF uncommon in children
could be initiated by: dehydration, glomerulernephritis
Older Patient
more prone to dehydration (prerenal), comordities of diabetes, hypertension (intrarenal) BPH obstruction (postrenal)