Acute Renal Failure Flashcards
Functional unit of the kidney
Nephron
Percentage C.O
up to 20%
Renal structure
1- outer layer
2- inner layer
- cortex
- medulla
how many liters of filtrate per day
180 L
how much concentrated urine
1-2 L
GFR
125 ml/min
Acute Kidney Injury
- decline of GFR in 48 hrs or less
- fluid retention
- Retention of waste products normally filtered out
- can turn into acute renal failure
why is UO not always a reliable indicator of GFR
because of diuretic treatment
what is not excreted by injured kidneys
Creatinine
Other S/S of injured kidneys
- unbalanced I/O
- weight gain
- crackles in lungs
- edema
RIFLE Criteria
R-risk I-Injury F-Failure L-Loss E-End-stage kidney dz
AKIN Criteria for renal failure
- Serum Cr increased by 0.3 mg/dl
- more than 50% incr. creatinine level
- UO 6hr
Lab draws how many times
2 x in 48 hrs
Factors on the prognosis
- depends on cause
- depends how quickly treatment is started
- how sick pt is
- length of stay
- mortality 15-60%
- can lead to permanent dialysis
Pre-Renal Causes
- hypoperfusion
* blood loss and dehydration
Pre-Renal S/S
- GFR decreases
- UO decreases
- AZOTEMIA: build up of protein
- can be fixed quickly if caught early
Intra-Renal Causes
Acute Kidney tissue is damaged
Intra-Renal S/S
- harder to treat than pre-renal
- ATN- acute tubular necrosis
- Infection
- antibiotics
- kidney failure
- contrast
Post-Renal Causes
OBSTRUCTION
- tumor
- ureter
- bladder
- abdominal
Post-Renal Causes
urine cant leave the ureters
Functions of the Kidney
- Waste Removal
- BP regulation
- RBC production (erythropoietin)
- Vitamin D activation
- Prostaglandin synthesis
- Acid base balance (buffer system)
- Fluid balance
- Electrolyte imbalance
Systemic Effects of Renal Failure:
-CARDIOVASCULAR
- excess fluid
- edema and HTN
- BP regulation: renin: HTN , stroke, organ damage
- Arrythmias-solutes in blood (K+) irritate the heart
Systemic Effects of Renal Failure:
-HEMATOPOIETIC
no erythropoietin –> anemia
Systemic Effects of Renal Failure:
-RESPIRATORY
fluid overload–>crackles, dyspnea
Rapid Respirations-> acid/base imbalance
Systemic Effects of Renal Failure:
-GASTROINTESTINAL
-can alter GI motility d/t electrolyte imbalance (nausea/vomiting)
Systemic Effects of Renal Failure:
-NEUROMUSCLULAR
- electrolyte imbalances
Systemic Effects of Renal Failure:
-INTEGUMENTARY
- edema –> stretched, weak tissue
- uremic crystals
Systemic Effects of Renal Failure:
-ENDOCRINE
Renin (RAAS) erythropoietin- kidney damage = no secretion
-no prostaglandin release to regulate renal blood flow: vascular permeability
Systemic Effects of Renal Failure:
-SKELETAL
- impaired Ca++ absorption
- weak bones, impaired blood clotting
Values that DECREASE
Albumin- moves extracellular
Na- dilutional hyponatremia
Ca- d/t phosphorus increasing
Hct- d/t fluid retention and anemia of kidney disease
what to be aware of when taking labs
Be aware of meds pt is taking
Medical Management:
-FLUIDS
- replacement for early pre-renal AKI treatment
- Restriction -prevent complications
- Removal-dialysis if kidneys not functioning
Medical Management:
-medications
d/c or reorder with renal dosing
- diuretics
- phosphorus binders
- electrolyte replacement/ removal
Renal Failure Nutrition:
- low K diet
- low phos diet
- fluid restrictions
Renal Failure medication education
- tell them about the mechanism of action
- EX) phosiov binds with phosphorus in food so eat with meds
Hemodialysis:
-tonocity
Osmolality- measures the number of particles in a solution
Hemodialysis:
-hydrostatic pressure
movement from an area of high pressure to low pressure
Hemodialysis:
-Osmotic pressure
movement of fluid from an area of low particle concentration to high concentration
-or fluid staying in high concentration
Hemodialysis:
-blood pushed in one direction
+ hydrostatic pressure
Hemodialysis:
-dialysate pushed in opposite direction
- hydrostatic pressure
Hemodyalisis Access:
-Temporary
- IJ
- subclavian
- femoral
- emergency HD
- failed access or ARF
Hemodialysis Access:
-tunneled catheter
- not permanent but long term
- internal jugular but looks subclavian
Hemodialysis Access:
-AV fistula
- artery and vein connected
- needs time to ripen
- bruit and thrill
- NO BP or blood draws
Hemodialysis Access:
-AV GRAFT
-synthetic material between vein and artery
_NO BP OR LABS
Continuous Renal Replacement CRRT
continuous hemodialysis
removes large amounts of fluids
** removed in 24 hrs rather than 4 which is better for patients hemodynamically
Slow continuous Ultrafiltration SCUF
FLUID REMOVAL ONLY
-used in fluid overlaod pts , HF, not responding to diuretics
Continuous Venous hemofiltration CVVH
REMOVES FLUID BUT NO COUNTER CURRENT
- takes out LARGER MOLECULAR WEIGHTS
- CONVECTION
CVVH
how many liters removed
5-20 ml/min (7-30 L/24 hrs)
Continuous Venovenous Hemodialysis CVVHD
REMOVES FLUIDS & COUNTERCURRENT
- takes out LOW MOLEC. WEIGHT (urea, cr, K)
- DIFFUSION
CVVHD
-how long
24 hr (2-10 days) hemodynamically safer to use
Continuous Venous Hemodiafiltration CVVHDF
COMBO
*CONVECTION AND DIFFUSION
maximal fluid and solute removal
CVVHDF
pre-filter
countercurrent
- increases + hydrostatic pressure
- neg hydrostatic pressure
Problems with dialysis
-infection
-clots
-acid base imbalance
-blood loss: dislodge catheter
-air embli
cardiac arrest d/t E/I imbalance
PERITONEAL dialysis
- who uses it
- location
- how does it drain
- chronic KF
- abdomen and dwell time
- drains by gravity
PERITONEAL high risk
peritonitits incr temp abdominal tender cloudy fluid in drain site red and oozing
