Chapter 68: Assessment Of The Renal/urinary System

Question 0

Renin

Answer 0

Special cells in the juxtaglomerular complex produce and store renin. It is a hormone that helps regulate blood flow, glomerular filtration rate, and blood pressure. It is secreted when cells sense changes in blood volume and pressure. It is also produced when sodium levels are low. It converts into angiotensin one. It leads to a series of reactions that cause the secretion of aldosterone.

Angiotensin II increases systemic blood pressure through vessels constricting effects. And the release of aldosterone.

Question 1

Nephrons

Answer 1

The work horse or the functional unit of the kidney. Urine is formed from the blood here. 20% are juxtamedullary nephrons and their purpose is to concentrate urine during difficult times of low fluid intake.

The other nephrons are called cortical nephrons that are located in the adrenal cortex

Question 2

Aldosterone

Answer 2

Increases kidney reabsorption of sodium and water, restoring blood pressure, blood volume, and sodium levels. It promotes potassium excretion. Water and chloride follow sodium

Question 3

Regulatory functions

Answer 3

They control fluid, electrolytes, and acid-base balance.

Question 4

Hormonal functions

Answer 4

Control red blood cell formation, blood pressure, and vitamin D activation

They produce renin, prostaglandins, bradykinin, EPO, and activated vitamin D. They help break down and secrete insulin.

Question 5

Glomerular Filtration

Answer 5

Is the first process in your information. They are filtered into the Bowmans capsule. Large cells such as blood, albumin, in proteins should not fit through. It is controlled by blood pressure and blood flow. Kidneys can self-regulating renal blood pressure to keep glomerular filtration rate constant. When afferent arterial is constricted or the efferent arterial dilates the pressure falls and the filtration decreases. If the afferent arterial is dilated or the efferent arterial is constricted, pressure in the capillaries rises and filtration increases. When systolic blood pressure drops below 70 mmHg they cannot compensate and filtration stops.

After the Bowman capsule It is filtered through the tubules which return 99% of water back the body. ADH INCREASES TUBULAR PERMEABILITY TO WATER, ALLOWING IT TO BE REABSORBED INTO THE CAPILLARIES. ALDOSTERONE PROMOTES THE REABSORPTION OF SODIUM IN THE DISTAL CONVOLUTED TUBULE. WATER ABSORPTION FOLLOWS THE SODIUM.

Tubular secretion allows movement of K and H to maintain electrolytes and pH.

Question 6

Renal threshold

Answer 6

The kidney reabsorbs some of the glucose filtered from the blood, but there is a limit to how much it can reabsorb. The usual renal threshold for glucose is about 220 mg/dL. If your blood glucose level is below 220, then all of it is reabsorbed and returned to blood. No glucose should be seen in the urine.

Question 7

Erythropoietin

Answer 7

Triggers red blood cell production in the bone marrow. When kidney tissue is nonfunctional, the person becomes anemic

Question 8

Vitamin D

Answer 8

Processing occurs from sun light and the liver but then it is activated in the kidney. It is needed to absorb calcium in the intestinal track and to regulate calcium balance

Question 9

Changes with aging

Answer 9

Decreased glomerular filtration rate which leads to dehydration.
Nocturia from decreased renal concentrating ability.
Decreased bladder capacity
Weakened urinary sphincter muscles and shortened urethra i. women which can lead to incontinence and infections
Tendency to retain urine

Blood flow to the kidney decreases about 10% per decade. Glomerular filtration rate decreases with age especially after 45 years. The regulation of sodium, acids, and bicarbonate is less efficient. There is a risk for dehydration and hypernatremia. Hormonal changes including decreased renin secretion, aldosterone levels, and activation of vitamin D

Question 10

Anuria

Answer 10

Total output of less than 100 mL in 24 hours

Question 11

Azotemia

Answer 11

Increase blood urea nitrogen and serum creatinine levels suggestive of renal impairment but without outword symptoms of renal failure

Question 12

Micturition

Answer 12

The act of voiding

Question 13

Oliguria

Answer 13

Decreased urine output. Between 100 and 400 mL in 24 hours

Question 14

Polyuria

Answer 14

Greater than 2000 mL in 24 hours

Question 15

Uremia

Answer 15

Full-blown manifestations of renal failure. Sometimes referred to as uremic syndrome, especially if the cause of renal failure is unknown

The build up of nitrogenous waste products in the blood as a result of failure. Manifestations include anorexia, nausea and vomiting, muscle cramps, pruritus, fatigue, and lethargy

Question 16

Common medication that impair renal function

Answer 16

Gentamicin

High dose or long-term use of NSAID’s or acetaminophen

Question 17

Average urine output for adults

Answer 17

Between 1500 to 2000 mL per day or within 500 mL of the volume intake in a day.

Question 18

Creatinine

Answer 18

Creatinine. Males .6-1.2mg/dL
Females .5-1.1

Increased level indicates renal impairment. A decreased level can be caused by decreased muscle mass

Is produced when protein or muscle breaks down. It does not increase until at least 50% of renal function is lost. Any elevation is important

Question 19

Blood urea nitrogen BUN

Answer 19

10-20 mg/dL

Older 8-23

Increased level may indicate hepatic or renal disease, dehydration or decrease renal perfusion, high-protein diet, infection, stress, steroid use, G.I. bleed. A decreased level may indicate malnutrition, fluid volume excess, or severe hepatic damage

It is the measurement of urea nitrogen which is a byproduct of protein breakdown in the liver. The kidneys filter it and excrete it.

Question 20

BUN to creatinine ratio

Answer 20

12:1 to 20:1
Mole ratio 48.5:1 to 80.8:1

An increased ratio may indicate fluid volume deficit, obstructive uropathy, catabolic state, or a high-protein diet. A decreased ratio may indicate fluid volume excess or acute renal tubular acidosis. No change in the ratio with increases in both the BUN and creatinine indicate renal impairment

Helps to determine whether nonrenal factors are causing elevated the BUN level.

Question 21

Urinalysis. Color odor and turbidity

Answer 21

Pale yellow is the normal.
Dark amber indicates concentrated urine.
Very pale yellow indicates dilute urine.
Dark red or brown indicates blood in the urine brown may indicate increased urinary bilirubin level. Red may indicate the presence of myoglobin.

Foul smell may indicate infection, dehydration, or certain food or drugs ingested

Turbidity should be clear. Cloudy urine indicate infection, sediment, or high levels of protein

Question 22

Specific gravity

Answer 22

1.005-1.030
After 24 hr fluid restriction >1.025
Decreased with age.
Increased is seen in dehydration, decreased renal perfusion, inappropriate antidiuretic hormone secretion, or congestive heart failure, and times of stress.
Decrease is in chronic renal insufficiency, diabetes insipidus, malignant hypertension, diuretic administration, and lithium toxicity

Question 23

Other labs

Answer 23

pH usually around 6. 4.6-8. Must refrigerate to not change this.
Glucose. <1000 colonies/mL
Nitrites and leukoesterace Indicate a UTI

Question 24

Creatinine clearance

Answer 24

Men 90-139
Woman 80-125

Is a measure of glomerular filtration rate and is the best indicator of overall kidney function. A 24 hour collection is needed but it could possibly be collected for shorter periods. It compares urine creatinine level with blood creatinine level

Question 25

Intravenous urography

Preparation

Answer 25

Aka excretory urography or pyelography IVP

REPORT CONTRAST ALLERGY INFORMATION. Report asthma. PATIENT WILL NEED TO BE NPO AFTER MIDNIGHT WITH POSSIBLE CLEAR LIQUIDS ALLOWED. TRY TO SCHEDULE OLDER ADULTS IN THE MORNING TO REDUCE THE RISK OF DEHYDRATION.

Bowel preparation with a laxative or enema is prescribed to remove fecal contents, fluid, and air which could obscure the kidneys, ureter’s, and bladder.

Make sure creatinine level is no greater than 1.5. Metformin is contraindicated and should be discontinued for at least 48 hours before and after. Patients at risk for contrast induced nephrotoxicty should be hydrated before the procedure. Diuretics after may help secrete it.

Question 26

Intravenous urography procedure

Answer 26

Dye is injected into the IV while laying supine. The series of x-rays are taken at various times. Your then empty your bladder and return for more x-rays. It provides information about the number, size, shape, and location of kidneys. The adequacy of filling and the rate of excretion of contrast medium. The number, size, location, appearance, and patency of the calyces, pelves, and ureters. Size, location, and nature of the urinary bladder.

Monitoring the patient for altered renal function and effects from the die. Ensure adequate hydration. Monitor blood creatinine levels. Resume normal activities

Question 27

CT

Answer 27

Three-dimensional information about the kidneys, ureter’s, bladder, and surrounding tissues. You could measure kidney size and evaluate for masses or obstruction. Contrast may be used. Possibly NPO status. Dye is given orally or injected. No follow up care except for dye.

Question 28

Cystography

Answer 28

Use catheter installed contrast dye. Xrays taken from the front, back, and side positions. The patient may be requested to void and x-rays taken during the voiding. This is to determine whether the urine reflexes into the ureter. Often used in cases of trauma. Monitor for infection. Encourage fluid intake. Contrast does not cause a reaction because it does not enter the blood

Question 29

Renography

Answer 29

Kidney scan

Question 30

Cystoscopy and cystourethroscopy

Answer 30

It is used to diagnose or treat. Examines the bladder for trauma in the urethral for trauma. It identifies causes of urinary tract obstruction. It may be used to remove bladder tumors or an enlarged prostate gland. Patient can have general or local anesthesia. NPO. Bowel prep. Lithotomy position.

Post op normal care. Monitor output, bleeding, infection. Urinary frequency is normal cuz of irritation. Possible catheter. Pink tinge normal but not gross bleeding. Notify doc of blood clots in urine or decreased urine. Increase fluids.

Question 31

Renal biopsy

Answer 31

Most are performed percutaneously through the skin and tissues using ultrasound or CT guidance. Informed consent is needed, NPO for 4 to 6 hours before. There’s a risk for bleeding afterwards so coagulation studies such as platelet count, PTT, and PT are taken before. Blood transfusion used if needed. Hypertension and uremia increase the risk for bleeding and antihypertensive drugs or dialysis maybe prescribed before the biopsy. Patient is placed prone, site selected after images, local anesthetic injected, biopsy device inserted. The needle placement is confirmed by ultrasound. While the patient holds his or her breath, needle is advanced into the renal cortex. Samples are taken with a coring needle.

Afterwords bleeding is a major risk for 24 hours. Monitor the dressing site, vitals, urine output, H&H levels. An internal bleeding is not visible but the signs include the flank pain, decreasing blood pressure, decreasing urine output, or other signs of hypovolemia shock.

The patient maintain strict bedrest Wyman is supine position with the back row for 2 to 6 hours afterwards. Head ofbed maybe elevated and the patient may resume oral intake. After that timeframe they will have limited bathroom privileges if there’s no evidence of bleeding. Monitor for hematuria which usually resolves in 48-72 hrs can be up to 3 weeks. No clots should be seen in the urine.

Hematoma formation may begin as flank pain that radiates around to the front of the abdomen. If bleeding occurs IV fluids, packed red blood cells, or both maybe needed to prevent shock. In rare instances surgery or even a nephrectomy may be needed. Hematomas can become infected. If no bleeding the patient can resume normal activities after 24 hours. Avoid lifting heavy objects, exercising, and strenuous activities for 1 to 2 weeks.

Question 32

Retrograde procedures

Answer 32

˜Retrograde procedures means going against the normal flow of urine. A retrograde examination of the ureters and pelves (pyelogram), the bladder (cystogram), and the urethra (urethrogram) involves instilling dye directly into the lower urinary tract. Because the dye is instilled directly to obtain an outline of the structures desired, the dye does not enter the blood stream. Therefore the patient is not at risk for dye-induced acute kidney injury or a systemic allergic response.
˜Preparation the same as cystoscopy

Question 33

Summarized care of Pts.

Answer 33

Safety risks
ØUse sterile technique when inserting a catheter or any other instrument into the urinary system
ØUse Contact Precautions with any patient who has drainage from the genitourinary tract
ØEvaluate risk for kidney injury from diagnostic testing by asking about allergy to radiopaque contrast dye, shellfish, or iodine or adverse reactions following the use or diagnostic agents such as gadolinium in MRI.
ØAssess urine output closely after any procedure in which contrast dye is used IV.
ØAssess the patient for bleeding or manifestations of infection after any invasive test of kidney/urinary function.
ØIdentify prescribed , OTC and illicit drugs that increase risk for kidney dysfunction and nephrotoxicity

˜Patient teaching
ØTeach patients to clean the perineal area after voiding, after having a bowel movement, and after sexual intercourse.
ØUrge all patients to maintain an adequate fluid intake (sufficient t dilute urine to a light yellow color). A minimum of 2 L /day may be recommended unless another health problem requires fluid restriction.
ØContrast media procedures be sure to drink at least 3 L of fluids after procedure to help eliminate the dye faster if no fluid restrictions.
ØTeach patients who come into contact with chemicals in their workplaces or for leisure time activities to avoid direct skin or mucous membrane contact with these chemicals.
˜Family teaching
ØExplain all diagnostic procedures, restrictions, and follow-up care to the patient and family scheduled for tests
ØUse language and terminology that the patient and family can understand during discussion of kidney/urinary assessment and follow up care.
ØAsk the patient about kidney problems in any other members of the family, because some problems have a genetic component.