AKI Flashcards
1
Q
what is AKI?
A
term used to encompass the entire scope of the syndrome.
ranging from a slight deterioration in kidney function to severe impairment
2
Q
what is AKI characterized by?
A
a rapid loss of kidney function
3
Q
the loss of kidney function is accompanied by what?
A
a rise in serum creatinine and/or a reduction in urine output
4
Q
AKI can develop over how long? with progressive elevations of what?
A
- hours or days
- blood urea nitrogen (BUN), creatinine, and potassium with or without a reduction in urine output
5
Q
what is azotemia?
A
accumulation of nitrogenous waste products (urea nitrogen, creatinine) in the blood
6
Q
compare/contrast: onset of AKI vs CKD
A
AKI: sudden
CKD: gradual, often over many years
7
Q
compare/contrast: most common cause of AKI vs CKD
A
AKI: acute tubular necrosis (ATN)
CKD: diabetic nephropathy
8
Q
compare/contrast diagnostic criteria AKI vs CKD
A
AKI: acute reduction in urine output AND/OR elevation in serum creatinine
CKD: GFR <60mL/min for >3 months AND/OR kidney damage >3 months
9
Q
compare/contrast reversibility AKI vs CKD
A
AKI: potentially reversible
CKD: progressive and irreversible
10
Q
compare/contrast: primary cause of death AKI vs CKD
A
AKI: infection
CKD: CVD
11
Q
what are causes of PRERENAL AKI?
A
factors that reduce systemic circulation, causing a reduction in renal blood flow
12
Q
prerenal: the decrease in blood flow leads to decreased what?
A
glomerular perfusion and filtration of the kidneys
13
Q
in prerenal oliguria, there is no damage to what?
A
no damage to the kidney tissue (parenchyma).
14
Q
what is prerenal oliguria caused by? what are some examples?
A
a decrease in circulating blood volume (e.g., severe dehydration, HF, decreased CO)
15
Q
T/F: prerenal oligura is reversible
A
TRUE :) with appropriate treatment!
16
Q
prerenal: with a decrease in circulating blood volume, what tries to preserve blood flow to essential organs? (4 things)
A
autoregulatory mechanisms that increase angiotensin II, aldosterone, norepinephrine, and antidiuretic hormone
17
Q
what does prerenal azotemia result in?
A
a reduction in sodium excretion (less than 20mEq/L), increased sodium and water retention, and decreased urine output
18
Q
what do prerenal conditions contribute to?
A
intrarenal AKI. if decreased perfusion persists for an extended time, the kidneys lose their ability to compensate and damage to kidney parenchyma occurs
19
Q
what causes INTRARENAL AKI?
A
conditions that cause direct damage to the kidney tissue, resulting in impaired nephron function
20
Q
what does the damage from intrarenal causes result from?
A
prolonged ischemia, nephrotoxins (e.g., aminoglycoside antibiotics, contrast media), hemoglobin released from hemolyzed RBCs, or myoglobin released from necrotic muscle cells.
21
Q
nephrotoxins cause ___ of intrarenal structures by crystallizing or causing damage to the epithelial cells of the tubules?
A
obstruction
22
Q
intrarenal: hemoglobin and myoglobin can block the tubules and cause ___ ___
A
renal vasoconstriction
23
Q
intrarenal: what kidney diseases cause AKI?
A
acute gomerulonephritis and systemic lupus erythematosus (SLE)
24
Q
what is the most common intrarenal cause of AKI in hospitalized pts?
A
acute tubular necrosis (ATN)
25
Acute tubular necrosis is primarily the result of what?
ischemia, nephrotoxin, or sepsis
26
what % if intrarenal AKI cases are ischemic and nephrotoxic ATN responsible for?
90%
27
what causes a disruption in the basement membrane and patchy destruction of the tubular epithelium?
severe kidney ischemia
28
what do nephrotoxic agents cause in tubular epithelial cells?
necrosis of tubular epithelial cells, which slough off and plug the tubules
29
what happens with the flow of urine being obstructed?
urine refluxes into the renal pelvis, impairing kidney function
29
what are risks associated with developing ATN while in the hospital? (5 answers)
major surgery, shock, blood transfusion reaction, muscle injury from trauma, and prolonged hypotension
29
is ATN reversible?
ATN is potentially reversible if the basement membrane is not destroyed and the tubular epithelium regenerates
30
what are the most common postrenal causes of AKI? (5 answers)
benign prostatic hyperplasia (BPH), prostate cancer, stones/calculi, trauma, and external tumors
30
what is the main/broad cause of postrenal AKI?
mechanical obstruction in the outflow of urine
31
what does bilateral ureteral obstruction lead to? resulting in what?
hydronephrosis (kidney dilation, increase in hydrostatic pressure, and tubular blockage. resulting in a progressive decline in kidney function
32
what develops if a pt does not recover from AKI?
CKD
33
what is the most common initial manifestation of AKI? when does it usually occur?
oliguria = urine output <400mL/day, occurs within 1-7 days of injury to kidneys
34
RIFLE classification: GFR criteria and urine output criteria for RISK
GFR: Serum creatinine increased × 1.5 OR GFR decreased by 25%
Urine: Urine output <0.5mL/kg/hr for 6hr
35
RIFLE classification: GFR and Urine criteria for INJURY
GFR: Serum creatinine increased × 2 OR GFR decreased by 50%
Urine: Urine output <0.5mL/kg/hr for 12hr
36
RIFLE classification: GFR and Urine criteria for FAILURE
GFR: Serum creatinine increased × 3
OR GFR decreased by 75%
OR Serum creatinine >4 mg/dL with acute rise ≥0.5 mg/dL
Urine: Urine output <0.3mL/kg/hr for 24hr (oliguria) OR Anuria for 12 hr
37
RIFLE classification: GFR and Urine criteria for LOSS
GFR: Persistent acute kidney failure. Complete loss of kidney function >4wk
Urine: ---
38
RIFLE classification: GFR and Urine criteria for End-stage renal disease
GFR: Complete loss of kidney function >3mo
Urine: ---
39
what makes the initial diagnosis of AKI more difficult?
nonoliguric patients
40
what may be present if AKI is related to glomerular membrane dysfunction?
proteinuria
41
describe the features and duration of the onset phase of AKI
- common triggering events: significant blood loss, burns, fluid loss, diabetes insipidus
- renal blood flow 25% of normal
- tissue oxygenation 25% of normal
- urine output below 0.5mL/kg/hr
- duration: hrs to days
42
describe the features and duration of the oliguric (anuric) phase of AKI
- urine output below 400 mL/day, possibly as low as 100 mL/day
- increases in blood urea nitrogen (BUN) and creatinine levels
- electrolyte disturbances, acidosis, and fluid overload (from kidneys inability to excrete water)
- duration: 8 to 14 days (10-14) or longer, depending on the nature of AKI and dialysis initiation
43
describe the features and duration of the diuretic phase of AKI
- occurs when cause of AKI is corrected
- renal tubule scarring and edema
- increased GFR
- daily urine output above 400 mL (usually around 1-3L/day but may reach 5L)
- possible electrolyte depletion from excretion of more water and osmotic effects of high BUN
- duration: 7 to 14 days
44
describe the features and duration of the recovery phase of AKI
- decreased edema
- normalization of fluid and electrolyte balance
- return of GFR to 70% or 80% of normal
- duration: several months to 1 yr
45
What should pt be monitored for during the diuresis phase due to large losses of fluid and electrlyes?
MONITOR PT FOR HYPONATREMIA, HYPOKALEMIA AND DEHYDRATION
46
consider prerenal causes of AKI when pt has a history of what 3 things?
dehydration, hypotension, or blood loss
47
suspect intrarenal causes of AKI if the pt has been exposed to what?
potentially nephrotoxic drugs or contrast media used in radiologic study
48
a history of changes in what would suggest postrenal causes?
changes in urinary stream, stones, BPH, or bladder or prostate cancer
49
what is one important diagnostic test for AKI?
urinalysis
50
urine sediment containing what 3 things suggests intrarenal disorders?
abundant cells, casts or proteins
51
what are the 7 diagnostic studies for AKI?
1. obtain a thorough hx
2. serum creatinine
3. urinalysis
4. kidney ultrasonography
5. renal scan
6. CT scan
7. renal biopsy
52
what is often the first diagnostic test done for AKI? why?
kidney ultrasound, provides imaging without exposure to potentially nephrotoxic contrast agents. it is useful for evaluating for kidney disease and obstruction of the urinary collection system
53
a renal scan can assess what?
abnormalities in kidney blood flow, tubular function and collecting system
54
what can a CT scan identify in the kidneys?
lesions, masses, obstructions and vascular anomalies
55
what is the BEST method for confirming intrarenal causes of AKI?
renal biopsy
56
what diagnostic test is not advised/contraindicated in patients with kidney failure? why?
MRI or magnetic resonance angiography (MRA with the contrast media gadolinium because it can be potentially fatal
57
in pts with normal kidney function, contrast media poses minimal risk. but in pts with kidney disease, _______ can occur when contrast media for diagnostic studies causes nephrotoxocity injury
contrast-induced nephropathy (CIN)
58
in AKI, the ___ ___ level increases because the kidney's normal ability to excrete it is impaired
serum potassium
59
the risk for ___ increases if AKI is caused by massive tissue trauma bc the damaged cells release ___ into the ECF
hyperkalemia, potassium
60
___ and ___ ____ may cause cellular destruction, releasing more potassium into the ECF
bleeding, blood transfusions
61
what signs/changes would be apparent on an ECG from hyperkalemia?
peaked T waves, widening of QRS complex, ST segment depression
62
tx for hyperkalemia: this medication is generally used in advanced cardiac toxicity (evidence of hyperkalemic ECG changes) and raises the threshold for excitation, resulting in dysrhythmias.
calcium gluconate IV
63
what dietary restriction would be on a pt with hyperkalemia? why?
potassium intake is limited to 40mEq/day
primarily used to prevent recurrent elevation, not for acute elevation
64
what is the most effective therapy to remove potassium?
hemodialysis, works within a short time
65
oral suspension that binds potassium in GI tract
patirometer (Veltassa)
- used to treat pts with CKD
- do not use as emergency drug for life-threatening hyperkalemia!!!!
- has a delayed onset of action
- do not give to a pt with paralytic ileus as bowel necrosis can occur
66
potassium moves into the cells when ___ is given
insulin, when effects decrease, potassium moves back out of cells
67
IV ___ given concurrently with regular insulin IV in pt with hyperkalemia to prevent hypoglycemia
glucose
68
this can correct acidosis and cause a shift of potassium into cells
sodium bicarbonate
69
given by muth or retention enema, produces osmotic diarrhea, allowing for evacuation of potassium-rich stool
sodium polystyrene sulfonate (kayexalate)
- when resin is in the bowel, potassium is exchanged for sodium
- remove 1mEq of potassium per 1g of drug
- do not give to pts with a paralytic ileus as bowel necrosis can occur!!
70
bc AKI is potentially reversible, what are the primary goals of tx?
- eliminate cause
- manage s/s
- prevent complications while the kidneys recover
71
what is the first step in interprofessional care of AKI?
determine if there is adequate intravascular volume and cardiac output to ensure adequate perfusion of the kidneys
72
diuretic therapy may be given and usually includes loop diuretics such as ___ and ___ or an osmotic diuretic such as ___
furosemide (Lasix), bumetanide (Bumex), mannitol
73
closely monitor ___ ___ during the oliguric phase of AKI
fluid intake
73
if AKI is already established forcing ___ and ___ will not be effective and may be harmful
fluids, diuretics
74
if conservative therapy is not effective in treating AKI, then ___ ____ ___ is used
renal replacement therapy (RRT)
75
____ is one of the most serious complications in AKI bc it can cause dysrhythmias
hyperkalemia
75
what is the general rule for calculating the fluid restriction?
add all losses for the previous 24 hrs (e.g., urine, diarrhea, emesis, blood) plus 600 mL for insensible losses (e.g., respiration, diaphoresis)
ex. pt excreted 300 mL of urine on Tuesday with no other losses, the fluid allocation on Wednesday would be 900mL
76
what are the 6 most common indications for RRT?
1. volume overload, resulting in compromised cardiac and/or pulmonary status
2. high serum K level
3. metabolic acidosis (serum HCO3 level <15 mEq/L (12 mmol/L)
4. BUN level >120mg/dL (43mmol/L)
5. significant change in mental status
6. pericarditis, pericardial effusion, or cardiac tamponade
77
intermittent __ and continuous ___ ___ ___ have both been used effectively for AKI
hemodialysis (HD), renal replacement therapy (CRRT)
78
_ _ _ _ is provided continuously over 24 hrs through cannulation of a vein or catheter placement, and has much slower blood flow rates compares with intermittent HD
CRRT
79
_ _ is the method of choice for conservative therapy when changes are needed emergently
HD
80
the goal of nutritional management in AKI is to provide adequate ___ to prevent catabolism despite restrictions that prevent electrolyte and fluid problems and azotemia
calories
81
nutritional intake must maintain adequate caloric intake, providing _____ of protein per kg of desired body weight to prevent the breakdown of body protein
30 to 35 kcal/kg and 0.8 to 1.0 g of protein per kg
82
adequate energy should primarily be from ___ and ___ sources to prevent ketosis from endogenous fat breakdown and gluconeogenesis from muscle protein breakdown
carbohydrate, fat
83
sodium is restricted as needed to prevent ___, ___, and __
edema, hypertension, HF
84
Dietary fat intake is increased so that the patient receives at least __% to __% of total calories from fat
30%-40%
85
If a patient cannot maintain adequate oral intake, ___ ___ is the preferred route for nutritional support
enteral nutrition
86
___, ___, ___ are key in essential assessments for developing an interprofessional plan of care
daily weights, strict I&O's, vital signs
87
daily monitoring of a pt's __ ___ has prognostic implications and is crucial for determining therapy and daily fluid volume replacement
urine output
88
examine pt's urine for what 6 characteristics?
color
specific gravity
glucose
protein
blood
sediment
89
assess pt's general appearance including what? (4 things)
skin color
edema
neck vein distention
bruises
90
If a patient is receiving dialysis, observe the access site for ____ and ____
inflammation, exudate
91
nursing management: evaluate the pt's ___ ___ and __
mental status, LOC
92
nursing mgmt: assess pt oral mucosa for ___ and ___
dryness, inflammation
93
nursing mgmt: auscultate the lungs for ___ and ___ or __ ___ __
crackles, wheezes, decreased breath sounds
94
nursing mgmt: monitor the heart for an _ __, ___, or a ___ ___ ___
S3 gallop, murmurs, pericardial friction rub
95
the overall goals for pt with AKI are (4)
1. completely recover w/o any loss of kidney function
2. maintain normal fluid and electrolyte balance
3. have decreased anxiety
4. adhere to and understand the need for careful follow up
96
nursing interventions: what are 3 health promotion tactics?
1. identify and monitor high risk populations
2. control exposure to nephrotoxic drugs and industrial chemicals
3. preventing prolonged episodes of hypotension and hypovolemia
97
nursing mgmt: carefully monitor pt's ___, ___'s, and ___ and ___ balance
weight, i&o's, fluid, electrolye
98
nursing mgmt: replace significant ___ losses, provide aggressive __ ___ for fluid overload, and use _____ drugs sparingly
fluid, diuretic therapy, nephrotoxic
99
nursing mgmt: regulate __ and ___ intake, follow up care, teaching, and appropriate referrals
protein, potassium
100
evaluation: expected outcomes for pt with AKI
1. regain and maintain normal fluid and electrolyte balance
2. adhere to tx regimen
3. have no complications
4. have a complete recovery
101
gerontologic considerations (8)
1. more susceptible to AKI
2. dehydration: can occur from polypharmacy - diuretics, laxatives, OTC AND acute febrile illness and immobility
3. hypotension
4. diuretic therapy
5. aminoglycoside therapy
6. obstructive disorders
7. surgery
8. infection
