List kidney functions:
2 primary fxns
Then list the other pertinent kidney functions (4)
Primary:
1. regulate the volume and composition of extracellular fluid
2. excrete waste products from the body
Others:
1. Control BP through renin production
2. activate Vitamin D
3. Regulate acid-base balance
4. produce Erythropoietin
How is erythropoietin production activated in the kidneys?
It is produced and secreted in response to hypoxia and decreased blood flow.
What are the three parts the nephrons are composed of?
Bowman's Capsule
Glomerulus
Tubular system (located in the cortex of the kidney)
Match: Urine formation begins here, where blood is filtered
A. bowman's: it is a semipermeable membrane that allows filtration
What is the definition of the GFR?
What value is normal GFR?
Glomerular Filtration Rate: the amount of blood filtered each minute by the glomeruli (the beginning of urine formation)
Normal GFR approx.: 125ml/min
1. This part of the nephron is where about 80% of the electrolytes are reabsorbed.
2. What are the 3 solutes that are normally all reabsorbed?
C. Tubular system
2. glucose, amino acids, and small proteins
Fill in: Usually AKI (acute kidney injury) follows severe prolonged ___a__ / __b__ or exposure to a nephrotoxic agent.
a. hypotension
b. hypovolemia
What is Azotemia?
What is the most common cause of death in acute kidney injury?
Azotomia: an accumulation of nitrogenous waste products (Urea nitrogen, Creatinine) in the blood
Most common cause of death in AKI is infection in the urinary and respiratory systems.
When assessing for acute renal failure or injury, list some questions you would ask the patient for possible causes
Where you in a MVC?
Are you or have you been on an antibiotic lately
Have you had a contrast dye recently?
Do you have trouble voiding?
Do you have prostate cancer?
List probable causes of each phase of acute renal failure:
1. Prerenal
2. Intrarenal
3. Postrenal
1. Prerenal: sudden and sever drop in BP (shock) or interruption of blood flow to kidneys from injury or illness
2. Intrarenal: direct damage to the kidneys by inflammation, toxins, drugs, infection, or reduced blood supply
3. Postrenal: sudden obstruction of urine flow due to enlarged prostate, kidney stones, bladder tumor, or injury
T or F: Prerenal Oliguria will show symptoms of damage to the kidneys
False: there is no dmg to kidney tissue
What is azotemia?
What can prerenal azotemia result in?
When there is a decrease in circulatory blood flow or volume, nitrogen compounds build up which can become toxic. If left untreated, it can lead to acute renal failure.
Prerenal azotomia results in a reduction in the excretion of sodium (<20 mEq/L), which means retention of sodium and water, as well as decreased urine output.
What is the most common cause of Intrarenal AKI?
Is the cause reversible?
Acute Tubular Necrosis (ATN): ATN is primarily result of ischemia, neprhotoxins, or sepsis. It is also responsible for 90% of intrarenal AKI cases.
It is potentially reversible if the basement membranes is not destroyed and the tubular epithelium regenerates
What are postrenal causes of AKI?
What are the most common causes?
Causes: mechanical obstruction in the outflow of urine, which impairs kidney fxn.
Most common: benign prostatic hyperplasia, prostate cancer, calculi, trauma, and extrarenal tumors.
Fill in: during a postrenal bilateral ureteral obstruction, if it is relieved within __a__ of onset, complete recovery is likely. However, after __b__, recovery is unlikely. Postrenal causes of AKI account for __c__ of AKI cases.
What can prolonged obstruction lead to?
a. 48 hours
b. 12 weeks
c. <10%
Prolonged obstruction can lead to tubular atrophy and irreversible kidney fibrosis.
List the 3 AKI phases
1. Oliguric
2. Diuretic
3. Recovery
During the Oliguric Phase, when does oliguria usually occur after injury to the kidneys?
What is the onset if ischemia is the cause of injury?
Nephrotoxic drugs?
How long does the oliguric phase last on average?
Oliguria: <400mL/day
It can occur 1-7 days after injury to the kidneys
24 hours if cause is ischemia
Delay may be for as long as 1 week if nephrotoxic drugs.
On average, this phase lasts 10-14 days, but can last months in some cases.
True or false: 50% of patients will NOT be oliguric
True: this makes the initial diagnosis more difficult.
List the clinical concerns of the Oliguric Phase
Urinary output: strict I/O
Fluid volume excess: monitor fluid overload
Metabolic acidosis: monitor LOC and resp; ABG
Sodium balance: monitor labs and LOC
Hyperkalemia: monitor lytes, rhythm changes
Calcium deficit: rarely symptomatic
Phosphate excess: diet
Elevated BUN and Cr: labs
Neurologic disorders: LOC and mood changes
Hematologic disorders: CBC, anemia, bleeding
How can the oliguric phase affect these:
Potassium
Calcium
BUN and Cr
pH
Fluid Volume
Phosphate
Hematology
Potassium: Hyperkalemia
Calcium imbalance: kidneys activate vitamin D -> calcitriol, which help maintain blood calcium levels.
BUN and Cr: elevated
pH: Metabolic acidosis
Fluid volume: excess, put pt. on strict I/O, monitor UA
Phosphate: excess
Hematology: monitor CBC, anemia, bleeding
Describe the Diuretic Phase.
What is the main concern?
What will you monitor for?
How long does it last?
Daily urine output is usually around 1-3L, but may reach 5L or more. Note that increased urine output doesn't mean a fully functional renal system.
This high output is caused from high urea concentration and the inability of the tubules to concentrate urine.
Main concern: hypovolemia and hypotension from the massive fluid losses.
Monitor: electrolytes including hyponatremia, hypokalemia, and dehydration.
Duration: may last 1-3 weeks
Describe the recovery phase
How long may it last?
Begins when GFR increase as kidney function returns
May last up to 12 months, but major improvements occur in the first 1 to 2 weeks.
What is the first and second leading cause of ESRD in the US?
1st: diabetes
2nd: HTN
What is Creatnine Clearance and list its values for men and women?
What is Cr values for men and women
CrCl is used to measure the GFR of the kidney.
Male: 107-139 mL/min
Female: 87-107 mL/min
CR values:
Male: 0.6-1.3 mg/dL
Female: 0.5-1.2 mg/dL
Men have a higher Cr because amount excreted depends on the muscle mass
What are normal BUN levels?
List the things that can raise it
Normal: 10-20 mg/dL
Azotemia is an elevated BUN
Prerenal azotemia:
- shock
- dehydration
- CHF
- excess of protein catabolism
- GI bleed
What is normal CO2 levels and what is it used to measure in the kidney?
How will HCO3 and the acids be affected in a failing kidney?
Normal: 23-30 mEq/L
It is used to evaluate the pH status, and as a rough guide to estimate acid-base balance.
A failing kidney cannot reabsorb HCO3, which is needed for the body to back into the blood stream to make it less acidic.
Furthermore, a failing kidney cannot excrete hydrogen ions or the acid products of metabolism.
In a urinalysis, what three things will you look at that can indicate intrarenal problems? intrarenal disorders?
Problems:
- Hematuria
- Pyuria (pus)
- Crystals
Disorders:
- abundant cells
- casts
- proteins
T or F: an MRI is not advised for patients with kidney failure
True: unless ultrasound or CT is not enough, administration of gadolinium has been associated with development of a devastating and potentially lethal disorder (nephrogenic systemic fibrosis)
List diagnostic tests typically used for kidney problems (4)
Renal ultrasound: usually first test used that doesn't include exposure to contrast media
Renal scans: evaluates abnormalities in kidney blood flow, tubular fxn, and collecting system
CT scan: identifies lesions, mases, obstructions, stones, and vascular anomalies
Renal biopsy: considered best method for confirming intrarenal causes of AKI
During a renal diet, you may want to restrict... (select all that apply)
C. Protein
c. Sodium
d. Potassium
e. Phosphate
When is protein not routinely restricted with a kidney compromised patient? Why?
One who is undergoing dialysis. Peritoneal dialysis requires a bit higher protein intake due to the protein loss through the semipermeable membrane to maintain a nitrogen balance
Fill in: Patients receiving hemodialysis must restrict dietary potassium to __a__ per day. If a patient is going through peritoneal dialysis, their daily intake of potassium is __b__.
a. 2-3g / day
b. not restricted - peritoneal dialysis do not accumulate K d/t dialysis exchange, and are often prescribed oral K supplements.
How much phosphate is a pt. with ESRD limited to per day? How is it managed?
Limited to 1 gm/day.
Most foods are high in phosphate and protein, so a patient is usually prescribed phosphate binders.
List nursing interventions for kidney dysfunction (8)
1. strict I/O
2. daily weight
3. VS and cardiac monitor
4. Monitor labs (lytes, BUN, Cr, CBC, UA)
5. Meds as needed (avoiding nephrotoxic drugs)
6. Skin/mouth care to prevent stomatitis
7. Prevent infection
8. education
List possible clinical manifestations of CKD (psychological)
Psychological:
- anxiety and depression
- mood swings
- chronic fatigue
- body image disturbance
- significant lifestyle changes
List possible clinical manifestations of CKD (endocrine / reproductive)
Amenorrhea
ED
thyroid abnormalities
hyperparathyroidism
List possible clinical manifestations of CKD (cardio)
HTN
HF
CAD
Pericarditis
PAD
most patients with CKD die from cardiovascular disease
List possible clinical manifestations of CKD (gastrointestinal)
anorexia
N/V
GI bleed
gastritis
List possible clinical manifestations of CKD
Metabolic
Hematologic
Neurologic
Ocular
Metabolic: carbohydrate intolerance and hyperlipidemia
Hematologic: anemia, bleeding, infection
Neurologic: fatigue, HA, sleep disturbance, encephalopathy (brain dz or ALOC)
Ocular: hypertensive retinopathy
List possible clinical manifestations of CKD
Pulmonary
Integumentary
Musculoskeletal
Peripheral neuropathy
Pulmonary: pulmonary edema, uremic pleuritis, PNA
Integumentary: pruritus, ecchymosis, and dry, scaly skin
Musculoskeletal: vascular and soft tissue calcifications, osteomalacia, and osteitis fibrosa (bones become weak and deformed)
Periphral neuropathy: paresthesias and restless leg syndrome
Describe Uremia
What will GFR look like?
List the s/s of Uremic syndrome
Uremia: when kidney fxn can decline so much that s/s develop in multiple body systems. This happens because urea and other nitrogenous waste that the kidneys eliminate build up in the blood.
In CKD, there is a decreased production of erythropoietin
List management of Hyperkalemia in CKD patients (7)
Put on monitor
Regular insulin (with glucose) to temporarily drive K back into cells
Sodium bicarb to correct acidosis and shift K into cells
Kayexalate to produce osmotic diarrhea to remove K
Possible dialysis for rapid correction
Restrict K in diet
Calcium Gluconate IV to raise threshold of cardiac excitation
Which of these interventions can shift K+ back into cells to manage hyperkalemia in CKD: (select all that apply)
A. regular insulin (temporary)
e. Sodium bicarb - corrects acidosis and shifts K into cells
Which of these interventions raises threshold of cardiac excitation to manage hyperkalemia:
D.
List normal and critical mag levels
Normal: 1.3-2.1
Critical: <1.0 or >9
How can bone deterioration occur in CKD? How does PTH play a role?
What will calcium and phosphate levels look like?
Known as CKD Mineral and Bone disorder: this is when kidneys aren't able to activate Vitamin D with calcitriol, leading to hypocalcemia.
During hypocalcemia, PTH is secreted, which stimulates bone demineralization to release calcium from bones.
Phosphate is also released, leading to hyperphosphatemia, which also further reduces serum calcium levels.
What do red eyes indicate in CKD?
This is known as Uremic red eye, caused by irritation from calcium deposits in the eye. The kidneys aren't able to regulate calcium in the serum effectively.
Fill in normal lab values
Ca
Cl
Mg
Phosphorus
K
Na
What are critical values for Ca and Phosphorus?
Ca: 8.5-10.9
Cl: 98-107
Mg: 1.6-2.6
Phosphorus: 2.5-4.5
K: 3.5-5.1
Na: 135-145
Critical
Ca: <6 or >13
Phosphorus: <1 mg/dL
Define:
Osteomalacia
Osteitis Fibrosa
Osteomalacia: a rare condition of adult bones associated with vit. D deficiency, resulting in decalcification and softening of bones
Osteitis fibrosa: bone decalcification and replacement of bone tissue with fibrous tissue
What is the acronym: AEIOU
Acidosis
Electrolytes
Ingestion/toxins (lithium, methanol, death caps)
Overload of fluid
Uremia - no longer manageable w/ conservative tx.
Match:
1. Peritoneal membrane acts as a semipermeable membrane
2. An artificial membrane is used as the semipermeable membrane and is in contact with the patient's blood
a. Hemodialysis
b. Peritoneal dialysis
1. b
2. a
Before hemodialysis can occur, what must be created first in the forearm or upper arm?
How long does maturation usually take before it can be accessed?
Which patients may have a difficult time with this procedure?
What is the alternative?
Arteriovenous fistula (AVF): anastomosis between an artery and a vein, to allow arterial blood to flow through the vein.
AVFs may take up to 3 months before access with HD
Patients with a hx of severe vascular dz, diabetes, hx of IVDA, or obese women.
A synthetic graft maybe required for these patients.
How do you assess a AVF (arteriovenous fistula)
What are nursing precautions with these?
Palpating a thrill (buzzing sensation) and auscultation of a bruit (rushing sound) with a stethoscope.
NEVER perform a BP, draw blood or start an IV on the arm that has a AVF.
List post-op procedures for a kidney transplant
Usually first 2-3 days in ICU
Strict monitoring of fluids and lytes
CVP and continuous cardiac monitoring
Pain management
Post-op education, including about organ rejection
Psychological support
T or F: With hyperkalemia, you'll see peak T waves leading to potential V-tach
True
What is Calcium Acetate an indication for?
Do you take it with or without food?
Indication: Hyperphosphatemia (Brand name is Phos-lo)
Taken with meals: combines with phosphate in food, and excreted in stool.
Why is Sevelamer used in conjunction with Dialysis?
It lowers high blood phosphate.
While dialysis removes some phosphate, it is used SEvelamer to remove excess.
