28 Acute Kidney Injury and Chronic Kidney Disease Flashcards
Acute Kidney Injury fka…
Acute Kidney Failure
Acute Kidney Injury
sudden reduction of kidney function
- causes DECREASED GFR
- reults in characteristic alterations in laboratory blood + urine tests
Decreased Glomerular Filtration Rate [GFR]
- urine output
- retention of nitrogenous waste
- incr serum creatinine
- disrupt in fluid, electrolyte, + acid=base balance
renal function is monitored by ___
calculated by SERUM CREATININE + calculated GFR
retention of AZOTEMIA/UREMIA (metab waste) is monitored by
BUN
-produces widespread systemic effects- [UREMIC SYNDROME]
3 sites of disruption
1 PRERENAL
2 POSTRENAL
3 INTRINSIC/INTRARENAL
-distinction bw sites of disruption helps determine appropriate therapy
PRERENAL disruption
renal perfusion
POSTRENAL disruption
urine flow distal to the kidney
INTRINSIC/INTRARENAL disruption
circumstances w/in kidney blood vessels, tubules, glomeruli, or interstitium
Prerenal Kidney Injury
due to conditions that diminish perfusion of kidney
-prolonged prerenal ARF leads to acute tubular necrosis (intrinsic)
Prerenal Kidney Injury
causes
- hypovolemia, hypotension, HF
- renal artery obstruction
- fever, vomit, diarrhea
- burns
- overuse of diuretics
- edema, ascites
- drugs ACE inhibitors, angiotensin II blockers, NSAIDs
Prerenal Kidney Injury
s/s
- low GFR
- oliguria
- high urine specific gravity
- high osmolarity
- low urine sodium
prolonged PRERENAL ARF leads to…
Acute Tubular Necrosis [ATN]
—-intrinsic
Post Renal Kidney Injury
due to OBSTRUCTOIN w/in urinary collecting system DISTAL to the kidney
-clinical findings are based on duration of obstruction
Post Renal Kidney Injury
effects
- elevated prssure in Bowman capsule
- impedes flomerular filtration
Intrinsic/Intrarenal Kidney Injury
due to DYSFUNCTION OF THE NEPHRONS + kidney itself
- most common problem w/in renal tubules
- —-results in [ATN]
- —-may also occur w glomerular, vascular, or interstitial etiologies
Acute Tubular Necrosis [ATN]
causes
1 nephrotoxic insult (contrast media)
2 ischemic insult (sepsis)
Intrinsic/Intrarenal Kidney Injury
2 pathophysiological processes
1 Vascular process
2 Tubular process
Vascular pathophysiological processes
DECREASE in renal blood flow
-hypoxia, vasoconstriction
1 of 2 intrinsic/intrarenal kidney injury
Tubular pathophysiological processes
INFLAMMATION + reperfusion injury
-casts, obstructs urine flow, tubular backleak
1 of 2 intrinsic/intrarenal kidney injury
Intrinsic/Intrarenal Kidney Injury
self-limiting
can repair itself (self-limiting)
or if injury is sustained, leads to end-stage renal disease
Acute Tubular Necrosis [ATN]
3 phases
1 Prodromal
2 Oliguric
3 Post-Oliguric
Acute Tubular Necrosis [ATN]
clinical presentations
varies by each phase (3)
-lab findings can help differentiate prerenal from intrinsic/intrarenal kidney injury
Prodromal Phase of ATN
- injury has occured
- normal or decr UO
- incr BUN + Cr
-usually asymptomatic bc normal UO + normal GFR
Oliguric Phase of ATN
- oliguria/anuria
- Vol overload
- hyPERkalemia>metab acidosis
- azotemia/uremia
- hypervolemia>edema
- uremic syndrome
Post-Oliguric Phase of ATN
- fluid vol deficit
- labs begin to normalize
Renal Function Recovery
- incr DIURESIS
- tubular function impaired (GFR + urine quality)
- azotemia continues