Radford University NURS 448: Critical Care: Study Guide Test #3 | Complete Updated A+ Study guide.

Critical Care: Study Guide Test #3

Chapter 48: Acute Kidney Failure and Chronic Kidney Disease

Acute Kidney Injury
- Rapid reduction in kidney function occurring over a few hours or days.
- Creatinine increases by 0.3 mg/dL withing 48hrs or urine volume <0.5ml/kg/hr for 6 hrs
- Can be temporary or progress to CKD
- Results in a failure of kidneys to eliminate waste, balance fluid and electrolytes, and
excrete hydrogen ions
- Causes:
 Low perfusion to kidneys
 Damage to kidney
 Obstruction of urine outflow
Pre-Renal AKI
- Kidney compensates by constricting kidney blood vessels, activating the renin angiotensin-
aldosterone pathway, and releasing ADH
- Causes:
 Shock
 Dehydration
 Burns
- Oliguria: urine output <400ml/day (<16ml/hr)
- Azotemia: retention and buildup of nitrogenous wastes in blood, accumulation of
nitrogenous waste products (BUN/creatinine) in the blood due to decreased
kidney function
- Anuria: <100mL/day

Nursing Priorities
- Prevent volume depletion
- Assess continually for signs and symptoms of volume depletion

Intrinsic Renal Failure
- Causes:
 Embolism of renal vessels
 Nephrotoxic agents
 Antibiotics: Rifampin, Vancomycin
 Chemotherapy agents
 NSAIDs
 Acetaminophen- OD can affect both liver and kidneys
 Radiographic Contrast
 Metformin- patient with DM on this drug CANNOT have contrast
 Allergic disorders
 Glomerunephritis

Post-Renal Failure (Urine Flow Obstruction)
- Causes:
 Cancers
 Clots
 Kidney Stones
- Induces similar response as prerenal renal failure

,Cues
- UOP < 0.5 ml/kg/hr for 2 or more hours
- Pulmonary crackles (posterior bases, back)
- Edema
- Drop O2
- Increase BUN & Creatinine
- Increase Potassium

Diagnosis Studies
- Renal US: shows kidneys size and patency of ureters
 Keep the patient’s bladder full for test.
- CT scan w/o contrast: determines adequacy of kidney perfusion and identify any
obstruction
 Usually avoided, if necessary pre-hydrate 500-1000mL an hour before the scan

Nursing Interventions
- Goal: avoid hypo/hypertension & maintain normal fluid balance
- Keep MAP closer to 70mmhg
- Strict I&O, daily weights
- Monitor electrolytes, edema and pulmonary crackles
- Monitor therapeutic vs toxic drug levels
- Give IV fluid or diuretics depending on UOP

Nutrition Therapy
- If patient NOT in HD, 40grams protein/day
- AKI patients have high catabolism or protein breakdown leading to the breakdown of
muscle tissue

Kidney Replacement Therapy
- When to start:
 Decline in LOC
 Persistently high potassium
 Severe metabolic acidosis
 Fluid overload that inhibits tissue perfusion
- Types:
 Intermittent or continuous hemodialysis
 Peritoneal dialysis
- Life expectancy: 3-5yrs

Hemodialysis
- Blood dialysate flow in opposite directions across semipermeable membrane.
 Dialysate: resembles human plasma
- Removes unwanted molecules from blood by diffusion
- HD occurs 3-4x wk, delivered 3-6hrs
- Anticoagulant used
- Symptoms during:
 Fatigued
 Hypotensive (do not give BP meds prior to dialysis)

AV Fistula & Graft

, - Fistula surgically connects artery and vein. Must mature prior to use
- Graft is used when fistula does not develop or complication
- Care:
 Cap refill and pulse in distal extremity
 Fill for thrill
 Listen for bruit
- Don’t do:
 Don’t check BP affected extremity
 Don’t start IV or do venipuncture unrelated to HD on affected arm
 Don’t compress extremity while sleeping or carrying a heavy bag

Complications During HD
- Hypotension
- Dialysis disequilibrium syndrome
 Mild: N/V, HA, fatigue, restlessness
 Severe: Mental status changes, seizures, coma
- Cardiac events
- Reaction to dialyzers:
 Allergic reaction
 Stop HD and do not return blood
- 200mL is lost when the blood is NOT returned to the patient

Continuous Renal Replacement Therapy
- Start flow rate at 50
- Removes 2-3L fluid in 2-3 hours
- Restores acid-base balance and fluid and electrolyte balance in patients that cannot
tolerate HD
- Continuous process so there is not as much drop in BP due to more subtle fluid shifts

Chronic Kidney Disease
- Chronic, irreversible disorder lasting LONGER than 3 months
- Stage 1
 eGFR: 90 or >
 Level of kidney damage: mild kidney damage
- Stage 2
 eGFR: 60-89
 Level of kidney damage: mild kidney damage
- Stage 3A
 eGFR: 45-59
 Level of kidney damage: Mild to moderate kidney damage
- Stage 3B
 eGFR: 30-44
 Level of kidney damage: Mild to moderate kidney damage
- Stage 4
 eGFR: 15-29
 Level of kidney damage: Moderate to severe kidney damage
- Stage 5
 eGFR: < 15
 Level of kidney damage: End-sate kidney disease. Kidneys are close to failure or
have completely failure or have failed. Will need start dialysis or kidney transplant.