Topic 5 Chapter 16 Flashcards
1
Q
Kidneys
• Location
• Structure
A
- Location • Retroperitoneal area - Structure • Cortex • Medulla • Nephron - Receives 20% to 25% of cardiac output - Performs numerous functions
2
Q
Fluids and electrolytes; waste
• Glomerular filtration rate (GFR)
• Hormonal control
A
- Glomerular filtration rate (GFR) • Result of pressure gradient • 80 to 125 mL/min • Reabsorption • Secretion - Hormonal control • Aldosterone • Antidiuretichormone
3
Q
Acid Base Balance
A
- Reabsorption of filtered bicarbonate
- Production of new bicarbonate
- Excretion of small amounts of hydrogen ions
4
Q
Kidney blood pressure regulation
A
- Juxtaglomerular apparatus
* Renin-angiotensin-aldosterone
5
Q
The term used to describe accumulation of nitrogenous wastes is: A. Anuria B. Azotemia C. Oliguria D. Uremic syndrome
A
B. Azotemia
6
Q
Acute kidney injury
A
- Sudden deterioration of renal function
- Oliguria: low urine output
- Azotemia: accumulation of nitrogenous wastes
- Acid-base disturbances
7
Q
AKI Causes
A
- Prerenal
- Renal: intrinsic; parenchymal
- Postrenal
8
Q
Prerenal Etiology
A
- Diminished blood flow; hypoperfusion of the kidney • Volume depletion • Vasodilation • Decreased cardiac output - Can progress to intrarenal damage
9
Q
Intrarenal Etiology
A
• Kidney tissue affected directly
• Glomerular, vascular, and/or hematological
problem
10
Q
Intrarenal Etiology
-Acute tubular necrosis (ATN)
A
• Ischemia • Nephro toxic agents - Antibiotics - Nonsteroidal antiinflammatory drugs (NSAIDs) • Contrast-induced • Rhabdomyolysis
11
Q
Postrenal Etiology
A
- Obstruction of flow
- Increased intratubular pressure leads to decreased GFR
- Reverses when obstruction is removed
12
Q
Pathophysiology Summary
• Prerenal:
• Renal:
• Postrenal:
A
- Prerenal: decreased blood supply
- Renal: failure of nephrons
- Postrenal: obstruction of outflow
13
Q
A treatment for postrenal etiology of AKI is: A. Diuretic administration B. Fluid administration C. Nephrectomy D. Ureteral stent placement
A
D. Ureteral stent placement
14
Q
Course of AKI
-Initiation Phase
A
- Initiation phase
• Time from event to signs of decreased renal perfusion
• Several hours to 2 days
• Potentially reversible
15
Q
Course of AKI
- Maintenance phase (oliguric/anuric)
A
- Maintenance phase (oliguric/anuric) • BUN and creatinine increase daily • Oliguria is common • Urine output less than 400 mL/day • Fluidoverload,electrolyte imbalances, and acidosis • Renal replacement therapy required
16
Q
Course of AKI
-Recovery phase
A
- Recovery phase
• Return of tubular function
• 4 to 6 months for BUN and creatinine to return to normal
• Residual impairment of GFR
• Early dialysis may prevent the traditional “diuretic” phase of AKI
17
Q
Assessment Patient History
- Predisposing factors
A
- Disease states • Hypertension • Diabetes • Immunological disease • Hereditary disorders - Hypotensive episodes - Exposure to nephrotoxic agents
18
Q
Clinical Presentation of AKI
A
- Vital signs may be altered
• Blood pressure changes, depending on etiology
• Hyperventilation to compensate for metabolic acidosis
• Body temperature may be altered - Assess for volume depletion and volume overload
19
Q
Physical findings of AKI
- The patient’s general appearance is assessed for:
A
• Signs of uremia (malaise, fatigue, disorientation, and
drowsiness)
• Color and texture of skin
• Bruising, petechiae, and edema
• Current and admission body weight and intake and output
• Dehydration/fluid overload
20
Q
Laboratory tests for AKI
A
• Serum creatinine
• Serum BUN
- Affected by catabolism, bleeding, and dehydration
• BUN:creatinine ratio
- Normal 10:1 to 20:1
- More than 20:1, suspect nonrenal causes of Laboratory abnormalities
- Urine creatinine clearance
• Estimate of GFR
• 24-hour urine; specific collection protocol
• Normal 84 to 138 mL/min
• Can calculate an estimated value with serum lab values (Cockcroft and Gault formula)
21
Q
Laboratory Findings
A
- Specific gravity
- Urine osmolality
- Urine sodium
- Microscopic examination
- BUN/Creatinine ratio
- FENa (the factional excretion of sodium)
22
Q
Urine tests for AKI
A
- Urine electrolytes
- Urine specific gravity
- Urine osmolality
23
Q
Diagnostic studies for AKI
- Noninvasive tests
A
- Noninvasive tests • X-ray of kidneys, ureter, and bladder (KUB) - Size, shape, and position of kidneys - Calculi, cysts, and tumors • Renal ultrasound - Size of kidneys - Obstruction • MRI
24
Q
Diagnostic Studies
- Invasive tests (5)
A
- IV pyelogram
- Computed tomography
• Structures,accumulationoffluid - Renal angiography
• Abnormalities in blood flow; infarction; masses - Renal scan
• Renal uptake of isotopes - Renal biopsy
• Histological changes
25
Which intervention is most important in assessing fluid balance in the patient with AKI?
A. Daily weight
B. Intake and output
C. Serumcreatinine D. Estimated GFR
A. Daily weight
26
Nursing Diagnosis
| - Assessment of overload or deficit
```
- Excess fluid volume
• Daily weight
- 1 kg approximately 1000 mL fluid
- 1 pound approximately 500 mL fluid
• Intake and output (I&O)
```
27
Nursing Diagnosis
• Imbalance fluid volume
• Electrolyte imbalance
• Risk for infection
- Strict aseptic care with IV lines
- Not all patients need urinary catheters; avoid use if not required
- Prevent progression of AKI with antibiotics
• Monitor peak and trough drug levels
28
Nursing Diagnosis
| - Imbalanced nutrition
```
- Imbalanced nutrition
• Small feedings
• Oral hygiene
• Intake in collaboration with dietitian
• Avoid fluid overload and electrolyte imbalance
- Anxiety
- Deficient knowledge
```
29
Fluid and Electrolyte Imbalances
```
- Hyperkalemia
• Low excretion
- Hyponatremia
• Fluid retention
- Hypocalcemia
• Low excretion of phosphorus
• Decreased level of vitamin D
- Hyperphosphatemia
• Low excretion
- Hypermagnesemia
•Low excretion
```
30
Medical Management-Prerenal
- Early recognition
- Fluid or volume replacement
- Caution in patients with underlying cardiac disease
• May require inotropes, antidysrhythmic agents, preload/afterload reducers, intraaortic balloon pump
• May require hemodynamic monitoring to guide treatment
31
Medical Management for Postrenal
* Alleviate obstruction
| * May need stent
32
Medical Management for ATN
- Medications
- Dietary control
• Protein and electrolyte restrictions
- Management of fluid and electrolyte imbalances
- Dialysis or CRRT
33
Diuretic Therapy
- Controversial
• Convert oliguria to nonoliguric state
• Hypovolemia corrected first • Loop (furosemide)
• Osmotic (mannitol)
34
Diuretic Therapy
```
- Controversial
• Convert oliguria to nonoliguric state
- Hypovolemia corrected first
- Loop (furosemide)
- Osmotic (mannitol)
```
35
Drug Therapy
1) Dopamine
• May increase renal blood flow
• Efficacy questioned in current research
2) Acetylcysteine, fenoldopam, theophylline
• Prevent contrast-induced AKI
3) Epoetin alfa
• Treat anemia
- Must adjust dosages and timing of medication if patient is on dialysis
36
Dietary Management
- Higher-than-normal basal requirement
- Provide adequate energy, protein, and micronutrients
- 25 to 35 kcal/kg of ideal body weight per day
- Restricted
• Protein
• Sodium
• Potassium
• Fluid intake (output + 600-1000 mL)
37
Hyperkalemia
- Due to decreased GFR
- Reduced content
• Kayexalate
• Mineralocorticoids
• Diuretics
- Shift intracellularly
• Glucose and insulin
• Alkali (sodium bicarbonate)
- Antagonize cellular membrane effect
• Calcium gluconate
38
Hyponatremia
* R/t fluid overload
* Salt wasting can occur as nephrons damaged
* Treated with fluid restriction
39
Acid Base Imbalance
| - Metabolic acidosis
• Treatment based on severity of imbalance
• May need IV bicarbonate
• Monitor ionized calcium as hypocalcemia can occur
as pH is corrected
40
Renal Replacement Therapy
- Lifesaving treatment
- Classification
• Hemodialysis
• Continuous renal replacement therapy (CRRT)
• Peritoneal dialysis
41
Dialysis
| - Two physical principles
* Diffusion
| * Ultrafiltration
42
Dialysis Indications
* Fluid overload
* Electrolyte imbalances
* Acid-base disturbances
43
Vascular Access
* Percutaneous catheters
* Arteriovenous fistulas
* Grafts
* External shunts
44
Hemodialysis
- Usually done at the bedside in the ICU
- Pre- and postdialysis labs and weight
- Monitor for complications
• Volume depletion
• Dysrhythmias
• Hypoxemia
• Disequilibrium syndrome
• Vascular access infections
45
Continuous Renal Replacement Therapy (CRRT)
- Used with patients too unstable for hemodialysis
- Advantages
• More gradual solute removal
• Flexible fluid administration
• Minimal heparin
• Can be done by staff nurses at the bedside
- Disadvantages
• Bed rest
• One-to-one nursing care
46
CRRT Types
* CAVH—continuous arteriovenous hemofiltration
* CVVH—continuous venovenous hemofiltration
* CAVHD—continuous arteriovenous hemodialysis
* CVVHD—continuous venovenous hemodialysis
47
Peritoneal Dialysis
* Removal of solutes and fluids using the peritoneal membrane as a filter
* Rarely used in the critical care setting because it is less efficient
* High risk of peritonitis
48
Geriatric Considerations
* Normal decline owing to aging
* Comorbidities
* Diabetes
* Hypertension
* Prescribed medications
