Renal Flashcards
Danger Signals
Rh_______
Acute P________
Acute _____ Injury/Failure
B____ Cancer
Rhabdomyolysis
Acute Pyelonephritis
Acute Kidney Injury (Acute Renal Failure)
Bladder Cancer
Rhabdomyolysis
Patient complains of an acute onset of _____ pain (not related to physical exertion), muscle ____ness, and _____ urine (myoglobinuria). Muscle tenderness and swelling may be seen, which rules out compartment syndrome.
M______ released from damaged muscle result in r____-br____ or t___-colored urine. They damage the ______ and can result in acute kidney failure, a common complication of rhabdomyolysis.
Serum (1) levels are markedly elevated (____ times normal value or higher). Blood chemistry abnormalities, elevated aldolase, _____ dehydrogenase, electrolyte abnormalities, and disseminated (1) can complicate the condition. Ask patient if he or she has a history of severe exercise, cr_____ injury, high fever, or high-dose ____ use. Refer to ED.
Patient complains of an acute onset of muscle pain (not related to physical exertion), muscle weakness, and dark urine (myoglobinuria). Muscle tenderness and swelling may be seen, which rules out compartment syndrome.
Myoglobins released from damaged muscle result in reddish-brown or tea-colored urine. They damage the kidneys and can result in acute kidney failure, a common complication of rhabdomyolysis.
Serum creatine kinase levels are markedly elevated (five times normal value or higher). Blood chemistry abnormalities, elevated aldolase, lactate dehydrogenase, electrolyte abnormalities, and disseminated intravascular coagulation (DIC) can complicate the condition. Ask patient if he or she has a history of severe exercise, crush injury, high fever, or high-dose statin use. Refer to ED.
Acute Pyelonephritis
Patient presents with acute onset of high ____, chills, nausea/vomiting, dys____, fr_____ urination, and ___lateral f____ pain. The flank pain is described as a deep ____. May complain of nausea (with/without vomiting) and may have a recent history of (1).
Indications for hospitalization include inability to maintain oral h_____, per_____ high fever (>101.0°F/>38.4°C), toxic appearance, immune compromise, or suspicion of s_____ or noncompliance to treatment.
Patient presents with acute onset of high fever, chills, nausea/vomiting, dysuria, frequent urination, and unilateral flank pain. The flank pain is described as a deep ache. May complain of nausea (with/without vomiting) and may have a recent history of urinary tract infection (UTI).
Indications for hospitalization include inability to maintain oral hydration, persistently high fever (>101.0°F/>38.4°C), toxic appearance, immune compromise, or suspicion of sepsis or noncompliance to treatment.
Acute Kidney Injury (Acute Renal Failure)
Patient presents with abrupt onset of ____uria, ed____, and weight gain (fluid _____) and complains of lethargy, nausea, and loss of appetite.
The condition is characterized by rapid decrease in renal _____ and elevated serum ______. During early stages, serum creatinine and the estimated glomerular filtration rate (eGFR) may not accurately reflect true renal function. Most cases of acute kidney injury (AKI; acute decline of GFR) are usually _______ when the offending substance is stopped.
Some of the most common causes of drug-induced AKI are amino_____, con_____ agents, N____s, A_ _ inhibitors, and pro_____ inhibitors.
Patient presents with abrupt onset of oliguria, edema, and weight gain (fluid retention) and complains of lethargy, nausea, and loss of appetite. The condition is characterized by rapid decrease in renal function and elevated serum creatinine. During early stages, serum creatinine and the estimated glomerular filtration rate (eGFR) may not accurately reflect true renal function. Most cases of acute kidney injury (AKI; acute decline of GFR) are usually reversible when the offending substance is stopped. Some of the most common causes of drug-induced AKI are aminoglycosides, contrast agents, nonsteroidal anti-inflammatory drugs (NSAIDs), angiotensin-converting enzyme (ACE) inhibitors, and protease inhibitors.
Bladder Cancer
(1) aged (1) gender patient (median age at diagnosis: 73 years) who sm_____ presents with pain____ ____turia.
The hematuria can be ____scopic or g____ (pink- to reddish-color urine). Some patients only notice this problem after they see a blood-tinged stain on underwear (males, menopausal females). The hematuria may only appear at the ___ of voiding.
May have irr_____ voiding symptoms (dysuria, frequent urination, nocturia) that are not related to a UTI. Order a (3) labs. Patients who have advanced disease with metastases may complain of lower ab____ or p____ pain, perineal pain, low-b____ pain, or b___ pain.
Elderly male patient (median age at diagnosis: 73 years) who smokes presents with painless hematuria.
The hematuria can be microscopic or gross (pink- to reddish-color urine). Some patients only notice this problem after they see a blood-tinged stain on underwear (males, menopausal females). The hematuria may only appear at the end of voiding. May have irritative voiding symptoms (dysuria, frequent urination, nocturia) that are not related to a UTI. Order a urinalysis (UA), urine culture and sensitivity (C&S), and urine for cytology. Patients who have advanced disease with metastases may complain of lower abdominal or pelvic pain, perineal pain, low-back pain, or bone pain.
Kidneys Normal Findings
Kidneys location =
Which kidney is lower than the other? why?
The basic functional units of the kidney are the _____, which contain the _____.
The kidneys are located in the retroperitoneal area.
The right kidney is lower than the left kidney because of displacement by the liver.
The basic functional units of the kidney are the nephrons, which contain the glomeruli.
Normal Kidney Function
The kidneys regulate the body’s el_____ and fl____, which affects blood _____.
Water is reabsorbed back into the body by the action of (2)
The kidneys excrete ____-soluble waste products of metabolism (e.g., cr_____, urea, uric acid) into the urine.
They secrete several hormones such as ______ (red blood cell [RBC] production), r____ and br______ (blood pressure), pr______ (renal perfusion), and cal____/vitamin __ (bone).
The average daily urine output is _____ mL.
Oliguria is defined as a urinary output of
The kidneys regulate the body’s electrolytes and fluids, which affects blood pressure.
Water is reabsorbed back into the body by the action of antidiuretic hormone and aldosterone.
The kidneys excrete water-soluble waste products of metabolism (e.g., creatinine, urea, uric acid) into the urine.
They secrete several hormones such as erythropoietin (red blood cell [RBC] production), renin and bradykinin (blood pressure), prostaglandins (renal perfusion), and calcitriol/vitamin D3 (bone).
The average daily urine output is 1,500 mL.
Oliguria is defined as a urinary output of <400 mL/day (adults).
Serum Creatinine
- Male:* ___ to ___ mg/dL
- Female:* ___ to ___ mg/dL
Factors that affect creatinine (3)
- Male:* 0.7 to 1.3 mg/dL
- Female:* 0.6 to 1.1 mg/dL
Factors that affect creatinine Gender, Race, Muscle Mass
(males > females, greater in African Americans, greater with larger muscle mass (low in elderly))
Creatinine Clearance (24-hour Urine)
This test is used to assess what?
24 Cr Clearance vs. Serum Creatinine?
24 hr Creatinine Clearance is _____ for every 50% reduction in GFR
Ideally, exercise should be avoided immediately prior to and during the period of specimen collection.
Evaluates proteinuria, albuminuria, microalbuminuria
24CrCl is a more sensitive test than serum creatinine alone because it reflects the renal function within a 24-hour period. Creatinine clearance is relatively constant and is not affected by fluid status, diet, or exercise.
Creatinine clearance is doubled for every 50% reduction of the GFR.
Ideally, exercise should not exercise immediately prior to and during period of specimen collection
Estimated Glomerular Filtration Rate
Normal =
Chronic kidney disease =
- eGFR is the best test to measure kidney ____ and is used to determine stages of?
- The eGFR is calculated by using (3) (with adjustment for those of African American descent).
- The estimation equations (3) are used to calculate the eGFR, which one is the most accurate?
Normal: eGFR >90 mL/min
Chronic kidney disease: eGFR <60 mL/min for at least 3 months (or longer)
- The eGFR is the best test to measure kidney function. It is used to determine chronic kidney disease stages
- The eGFR is calculated by using serum creatinine, age, and gender (with adjustment for those of African American descent).
- The estimation equations (i.e., Modification of Diet in Renal Disease [MDRD], Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI], Cockcroft–Gault equation) are used to calculate the eGFR. - CKD-EPI most accurate (from columbia lecture)
Estimated Glomerular Filtration Rate
GFR definition =
The more damaged the kidneys, the ____ the eGFR. The GFR is affected by ___ (decreases), ___ (males have more muscle mass), and body ____.
(1) race eGFR values are higher than values for other races.
Some patients with underlying kidney disease may have a _____ eGFR.
eGFR is _____ reliable in these cases: Pregnancy, muscle wasting, elderly, and lower-extremity amputees.
The GFR is the amount of fluid filtered by the glomerulus within a certain unit of time. The more damaged the kidneys, the lower the eGFR. The GFR is affected by age (it decreases with age), sex (males have more muscle mass), and body size.
African Americans’ eGFR values are higher than values for other races.
Some patients with underlying kidney disease may have a normal eGFR. (compensating)
eGFR is less reliable in these cases: Pregnancy, muscle wasting, elderly, and lower-extremity amputees.
CKD Stages
Blood Urea Nitrogen
The ____ breaks down (1) → into (1) and then converts it into (1)
Blood urea nitrogen (BUN) =
- If the kidneys are damaged or the renal blood flow is decreased, the urea level becomes ______.
- BUN vs. SrCr or eGFR?
The liver breaks down amino acids into ammonia and then converts it into urea.
Blood urea nitrogen (BUN) = measure of the kidneys’ ability to excrete urea (waste product of protein metabolism).
- If the kidneys are damaged or the renal blood flow is decreased, the urea level becomes elevated.
- BUN is not as sensitive as serum creatinine or the eGFR.
Blood Urea Nitrogen
A high BUN may be caused by
- acute kidney ____ (lowers GFR)
- high-____ diet
- ____lysis
- c____ h____ failure
- dr___
Among patients with heart failure, lower GFR with higher BUN is associated with higher mortality.
Among critically ill patients in the ICU, elevation of BUN is independently associated with mortality.
Low BUN can be caused by liver damage or liver disease. If a patient has an abnormal BUN level, check the eGFR. If the eGFR is normal, the renal function is probably normal.
A high BUN may be caused by
- acute kidney failure (lowers GFR)
- high-protein diet
- hemolysis
- congestive heart failure
- drugs.
Among patients with heart failure, ____ GFR with ____ BUN is associated with higher mortality.
Among critically ill patients in the ICU, elevation of BUN is ind_____ associated with mortality.
Low BUN can be caused by ____ damage or disease. If a patient has an abnormal BUN level, check the eGFR. If the eGFR is normal, the renal function is probably normal.
Bun-to-Creatinine Ratio
A decrease in the blood flow of the kidneys will _____ the BUN-to-creatinine (BUN:Cr) ratio. It is used to help evaluate dehydration, hypovolemia, and acute kidney failure. This ratio is useful for classifying the ____ of failure (renal, infrarenal, or postrenal).
A decrease in the blood flow of the kidneys will increase the BUN-to-creatinine (BUN:Cr) ratio. It is used to help evaluate dehydration, hypovolemia, and acute kidney failure. This ratio is useful for classifying the type of failure (renal, infrarenal, or postrenal).
Urinalysis
(with Microscopic Exam)
A complete UA consists of (3) components
A complete UA consists of three components
- gross evaluation
- dipstick analysis,
- microscopic exam of urine sediment
Urinalysis Components
(7)
Epithelial Cells
Leukocytes
RBCs
Protein
Nitrates
Casts
pH
- Urine for culture and sensitivity
Epithelial Cells
What does it mean if you see large amounts of squamous epithelial cells in the urine sample?
Contamination
A few epithelial cells are considered normal. (Squamous epithelial cells are associated with the external urethra and transitional epithelial cells with the bladder.)
Leukocytes
Normal white blood cells (WBCs) in urine: ≤__ to __ WBCs/hpf (high-power field)
Called leukocyte _____ test with urine dipstick strips
Presence of leukocytes in urine (pyuria) is always abnormal in _____ (infection)
UA is a more sensitive test for infection in males than females
Normal white blood cells (WBCs) in urine: ≤2 to 5 WBCs/hpf (high-power field)
Called leukocyte esterase test with urine dipstick strips
Presence of leukocytes in urine (pyuria) is always abnormal in males (infection)
UA is a more sensitive test for infection in males than females
Urine for Culture and Sensitivity
≥___5 colony-forming units (CFU)/mL of one dominant bacteria (usually (1)).
E. coli belongs in the gram-_____ Enterobacteriaceae family.
What does multiple types of bacteria in the culture show?
_____ values are indicative of bacteriuria.
≥105 colony-forming units (CFU)/mL of one dominant bacteria (usually Escherichia coli).
E. coli belongs in the gram-negative Enterobacteriaceae family.
If multiple bacteria are present, it is considered a contaminated sample.
Lower values are indicative of bacteriuria.
Red Blood Cells
Few RBCs
Microscopic hematuria =
Gross hematuria =
Can be contaminated by m____, vaginal dis____, s____, hem____, r____ bleeding.
Few RBCs <3 cells is considered normal
Microscopic hematuria = refers to RBCs that are visible only by microscopy.
Gross hematuria = means you can see blood in the urine.
(The color ranges from pink, red, to cola or brown. The source of the bleeding may come from the urethra (urethritis), bladder (cystitis, bladder cancer), or the kidneys (kidney stones, pyelonephritis, polycystic kidneys, cancer)
Can be contaminated by menses, vaginal discharge, semen, hemorrhoids, rectal bleeding.
Protein
What does it mean when you see protein in the urine?
- The next step is to order the (2) and send ___stream urine for microscopic exam.
- If the patient has normal microscopic exam for urine sediment and normal kidney function, it is called ______ proteinuria.
Indicates kidney damage if it is persistent (chronic kidney disease).
- The next step is to order the serum creatinine and eGFR, and send midstream urine for microscopic exam.
- If the patient has normal microscopic exam for urine sediment and normal kidney function, it is called isolated proteinuria.
Proteinuria
Transient Proteinuria =
Benign causes of proteinuria =
Proteinuria during acute pyelonephritis =
Urine dipsticks detect only _____.
Transient proteinuria = is common, especially in patients age 18 years or younger (8% to 12%) and among young adults (4%).
Benign causes of proteinuria = include fever, intense physical activity, acute illness, dehydration, and emotional stress.
May be present in acute pyelonephritis (resolves after treatment), recheck urine after treatment.
Urine dipsticks detect only albumin.
Proteinuria
In what situations can you see false positive proteinuria with urinary dipstick?
What test quantifies proteinuria? order 24-hour urine for protein-to-creatinine ratio (UPr/Cr).
False-positive results with urinary dipstick testing may be seen with alkaline urine (pH >7.5), if dipstick is immersed too long, highly concentrated urine, gross hematuria, presence of semen, or vaginal secretions.
24hr urine/Cr ratio = To quantify proteinuria
Nitrates
Positive result is highly indicative of what?
What produces nitrates?
Positive result is highly indicative of UTI
Nitrates result from when bacteria breakdown urea into nitrite
Casts
- WBC casts:* May be seen with infections (1) or inflammation (1)
- RBC casts:* Caused by microscopic bleeding in the glomeruli; suspect (1) (accompanied by edema, weight gain, dark cola-colored urine, or hypertension)
- Casts are shaped like ______ because they are formed in the renal tubules.
- _____ casts are nonspecific; it can be seen in small volumes in concentrated urine or with diuretic therapy.
- WBC casts:* May be seen with infections (pyelonephritis) or inflammation (interstitial nephritis)
- RBC casts:* Caused by microscopic bleeding in the glomeruli; suspect glomerulonephritis (accompanied by edema, weight gain, dark cola-colored urine, or hypertension)
- Casts are shaped like cylinders because they are formed in the renal tubules.
- Hyaline casts are nonspecific; it can be seen in small volumes in concentrated urine or with diuretic therapy.
pH
___–___ reference range
Useful in the evaluation of kidney _____ and in______.
Citrus and low-carbohydrate diet are associated with low or high acidity?
High-protein diet are associated with low or high acidity?
4.6–8.0 reference range
Useful in the evaluation of kidney stones and infections.
Lower acidity (high pH) = Citrus and low-carbohydrate diet
Higher acidity (low pH) = high-protein diet
Hematuria
(2) Types of Hematuria
Can be either tr_____ or per______
The blood may come from the
- urethra (1)
- bladder (2)
- prostate (1)
- kidneys (3)
Test for microscopic hematuria (1) (presence of ≥__ RBCs/hpf).
2 Types = Microscopic or Gross hematuria
Transient or Persistent
The blood may come from the
- urethra (urethritis)
- bladder (cystitis, bladder cancer)
- prostate (prostatitis)
- kidneys (pyelonephritis, polycystic kidneys, cancer).
Microscopic hematuria is revealed by a microscopic UA (presence of ≥3 RBCs/hpf).
Hematuria Cases
What should you do if you find hematuria in a
- female with a history of vigorous sexual activity or exercise?
- female with menses?
- Stop exercise and repeat 4–6 weeks
- menses = repeat UA with microscopic exam about 1 week after last day of menses
Hematuria Cases
If infection (e.g., urethritis, cystitis, pyelonephritis) is suspected, the UA will show ____ blood cells (with or without nitrites).
It is accompanied by symptoms (4).
Order UA with urine for (1). Persistent unexplained microscopic hematuria that does not resolve, what should you do?
If infection (e.g., urethritis, cystitis, pyelonephritis) is suspected, the UA will show white blood cells (with or without nitrites).
It is accompanied by symptoms (dysuria, frequency, urgency, nocturia).
Order UA with urine for C&S. Persistent unexplained microscopic hematuria that does not resolve; refer to nephrologist.
Hematuria Cases
Suspect ____ (or visible) hematuria if color of urine is pink, red, or brown or blood clots are present.
The next step is to look for the _____ of the blood.
- If dipstick is heme positive, next step is to order a _____ UA.
- If infection is suspected, order urine for (1).
- New onset of dark reddish-brown urine, edema, proteinuria, fatigue, and decreased urine output after a recent strep throat, scarlet fever, or impetigo infection raises the possibility of (1), an immune reaction from the infection. It can occur 10 days following the infection and up to 3 weeks after. It is a rare complication that is more common in (1).
Suspect gross (or visible) hematuria if color of urine is pink, red, or brown or blood clots are present.
The next step is to look for the source of the blood.
- If dipstick is heme positive, next step is to order a microscopic UA.
- If infection is suspected, order urine for C&S.
- New onset of dark reddish-brown urine, edema, proteinuria, fatigue, and decreased urine output after a recent strep throat, scarlet fever, or impetigo infection raises the possibility of poststreptococcal glomerulonephritis, an immune reaction from the infection. It can occur 10 days following the infection and up to 3 weeks after. It is a rare complication that is more common in children.
Hematuria Cases
- If malignancy is suspected, send urine for ______ , and refer to specialist.
- Risk factors for urothelial or renal malignancy are age older than ___ years, (1) gender, s_____ , and gross hematuria.
- Red urine not due to bleeding can be caused by some
- medications (e.g., r_____, ph_____) and ingestion of certain
- foods (e.g., b____, rh____, senna, food d____).
- If malignancy is suspected, send urine for cytology, and refer to specialist.
- Risk factors for urothelial or renal malignancy are age older than 50 years, male, smoker, and gross hematuria.
- Red urine not due to bleeding can be caused by some
- medications (e.g., rifampin, phenytoin) and ingestion of certain
- foods (e.g., beets, rhubarb, senna, food dyes).
Proteinuria
>____ mg/day or protein
Gold Standard Test =
(4) Types
>150 mg/day of protein
24-hour urine for protein
Glomerular, Tubular, Overflow, Postrenal
Albuminuria
(previously known as microalbuminuria)
What urine test cannot detect low levels of albumin or moderately increased albuminuria unless concentrated?
Urine Dipstick Test cannot detect albumininuria