Exam 2- Renal Flashcards
Azotemia
Retention of metabolic waste (BUN/CREATININE)
May be reversible
Uremia
TOXIC accumulation of metabolic wastes leading to multi-system alterations
-urea, creatinine, uric acid, and other wastes
Acute Renal Failure
rapid decline in renal function resulting in accumulation of BUN, Creatinine, fluid & electrolyte imbalances and acid-base disturbances.
-may rapidly present as a life-threatening situation but is potentially reversible
Oliguria
Urinary output < 400-500ml/24hrs
Anuria
Urinary output <100mL/24hrs
GFR
Normal = 80-125mL/min
Producing 180L of filtrate/day when map >80-90
Prostaglandins - Blood pressure regulation
Cause:
- vasodilation
- Increase renal blood flow
- Promote Na+ excretion
- Decrease BP by decreasing SVR (dilate)
ADH - Blood pressure regulation
required for water reabsorption.
-stimulated by elevated serum osmolarity and decreased blood volume
Aldosterone
.
Renin
Released in response to decreased arterial pressure, renal ischemia, low serum Na+
Prerenal azotemia
- RENAL HYPOPERFUSION, usually with ATN
- fluid volume losses, SHOCK/hemorrhage, 3rd spacing from burns, diuretics
- systemic vasodialtion, SEPSIS
- Decrease CO
- Renal vascular disorders
BUN/Creatine ratio > 20:1
Urine Na+ < 20mEq/L
Elevated Specific gravity, normal sediment or hyaline/granular casts
Intrinsic (Intrarenal) Renal Disease
-Usually GLOMERULAR DISEASE
-Direct damage to the kidneys by:
Reduced blood supply/ischemic injury;
**ACUTE TUBULAR NECROSIS (ATN)- MOST COMMON
Inflammation, glomerulonephritis
Toxins
Drugs
Infection (pancreatitis, peritonitis, gram (-) sepsis)
Rhabdomyolysis
BUN/Creatinine ration 10:1
Urinary Na+ > 20mEq/L
Low specific gravity, RBC casts & cellular debris in urine
Drugs that cause Nephrotoxic Injury
- Antibiotics (Gentamycin)
- Antineoplastics
- Diuretics
- NSAIDS
- Contrast Agents/dyes
- Heavy metals
- Organic Solvents (carbon tetrachloride)
Postrenal azotemia
-OBSTRUCTION
Sudden obstruction of urine flow d/t:
enlarged prostate, kidney stones, bladder tumor, or injury
Rhabdomyolysis (myoglobin)
Is the breakdown of muscle fibers resulting in the release of muscle fiber contents (myoglobin) into the bloodstream and the kidneys filter it out of the body. The myoglobin breaks down into potentially harmful compounds that may block the structures of the kidney causing damage such as ATN or Kidney failure. Caused by: -Trauma -Seizures -Exertion (marathon running) -"Long lie down"
*INTRARENAL
Acute Tubular Necrosis
.
ATN - Initial/Onset Phase
- From insult to cell injury
- Lasts hours to 2 days
- May be reversed w/aggressive care: prevent hypotension, keep hydrated
ATN- Oliguric/Anuric Phase
Decreased U/O <400mL/day leads to FVE
- Lasts 1-2 weeks
- Decreased GFR:
- Hyperkalemia
- Hypocalcemia & Hyperphosphatemia
- Metabolic acidosis
- Accumulation of BUN, Creatinine
- Infection Risk
ATN - Diuretic Phase
Lasts 1-3 weeks
- Gradual increase in U/O, up to 5L/day
- Hyponatremia, Hypovolemia
- Hypokalemia
- Osmotic diuresis from high urea
- Tubules lack ability to concentrate urine
- Begin to excrete wastes; BUN & Cr
ATN - Recovery Phase
Lasts 6 months to a year
- Slow return of renal function
- Chronic renal insufficiency may remain
What to watch for with Dialysis
Hypovolemia and hypotension
Assessment of ARF - ONSET
- Oliguria
- Aztoemia
- HyperKalemia
- Metabolic Acidosis
Assessment of ARF - CARDIAC
- Fluid overload (CHF)
- HTN w/FVE
- Hypotension w/diuresis
- Peripheral, periorbital and sacral edema
- Pericarditis
- Arrhythmias
Assessment of ARF - HEMATOLOGIC
- Anemia
- Bleeding disorders (bruise easily)
Assessment of ARF - Respiratory
- Pulmonary edema
- Pleural effusions
- Kussmaul’s respirations
- Respiratory Alkalosis
Assessment of ARF - GI
- N/V/A
- Diarrhea, constipation
- Stomatitis
- Uremic halitosis
- Gastritis
- GI bleeds
Assessment of ARF - Neuromuscular
- Lethargy
- Asterixis (flapping hands, Inc.’d ammonia)
- Chvosteks sign = +
- Trousseau’s sign = +
- Tremors, twitching, parasthesias
- Confusion, memory deficits
- Watch for seizures
Chvostek’s Sign
Tap on cheek and observe for facial twitch, twitch = (+) sign, indicating the pt has hypocalcemia
Trousseau’s Sign
Inflate BP cuff and watch for carpal spasm, spasm = (+) sign, indicating hypocalcemia
Assessment of ARF - SKIN
- Pallor
- Jaundice
- Dry, itchy skin
- Bruising
Best measure of renal function
Creatinine Clearance: estimates GFR