Kidney Function and Disorders Study Guide

• Quiz 2 study guide on kidney function, kidney disorders, and related conditions.

Glomerular Filtration Rate (GFR)

• Measures the rate of blood flow through the kidneys.
• Expected range: 90-120 mL/min.
• Possible causes of decreased GFR: Kidney dysfunction (CKD).
• Possible causes of increased GFR: Pregnancy.

Creatinine

• Indicates kidney function.
• An end product of muscle metabolism removed from the blood by the glomerulus.
• Expected range: 0.5-1.2 mg/dL.
• Possible causes of elevated levels: Low muscle mass, hyperthyroidism, starvation, or liver disease.
• Possible causes of decreased levels: Acute or chronic kidney disease, CHF, or dehydration.

Blood Urea Nitrogen (BUN)

• Normal waste product of protein breakdown.
• Expected range: 8-21 mg/dL.
• Possible causes of elevated levels: Liver damage, malabsorption, poor diet, or low nitrogen diet.
• Possible causes of decreased levels: Prerenal failure, postrenal failure, or intrarenal failure.

Urine Specific Gravity

• Measures the kidney's ability to excrete or conserve water (H2O).
• Expected range: 1.005-1.03.
• Possible causes of elevated levels: Too much fluid intake or diabetes insipidus.
• Possible causes of decreased levels: Dehydration or SIADH.

Urine Output

• Amount of urine excreted from the bladder.
• Expected output: At least 30 mL/hr; Average = 1500 mL/day.
• Possible causes of decreased output: Shock, hypotension, trauma, or infection.
• Possible causes of increased output: Diabetes Mellitus (DM) or Diabetes insipidus (DI), or too many diuretics.

Normal Urine Findings

• Free from glucose, ketones, blood, protein, bilirubin, nitrates, or leukocyte esterase.

24-Hour Creatinine Clearance

• Used to measure hormones and metabolites.
• Evaluates kidney disease progression.
• Measures volume of blood cleared of creatinine per minute.
• Discard the first void of the day; begin collecting specimens after, refrigerate/keep on ice.
• Creatinine clearance typically decreases by about 1 mL/year.
• Age ranges for creatinine clearance:
• Under 30: Male 88-146, Female 81-134
• 30-40: Male 82-140, Female 75-128
• 40-50: Male 75-133, Female 69-122
• 50-60: Male 68-126, Female 64-116
• 60-70: Male 61-120, Female 58-110
• 70-80: Male 55-113, Female 52-105

Urodynamic Testing

• Pre-procedure: In-depth interview about signs, symptoms, and voiding habits.
• Intra-procedure: Position changes (supine/sitting/standing) or coughing/bearing down might be requested.
• Multiple catheters may be required to measure bladder pressure and filling.
• Catheters might be inserted into the rectum/vagina to measure vaginal pressure.
• Electrodes in the perianal area for electromyography may cause discomfort.
• The bladder will be filled through the catheter one or more times.
• Post-procedure: May experience urinary frequency, urgency, dysuria, or hematuria immediately after.
• Drink fluids, warm sitz bath for meatal irritation, watch for signs/symptoms of UTI.

Kidney Function

• G - Glomerular filtration: First step of making urine.
• A - Acid-base balance: Kidneys excrete or retain acids and bases to maintain pH between 7.35-7.45.
• W - Water balance: Kidneys excrete more urine when you drink a lot, less when you are dehydrated.
• E - Electrolyte balance: Kidneys filter electrolytes and return them or excrete them.
• T - Toxin removal: Kidneys filter out toxins and water-soluble waste products.
• B - Blood pressure: Regulations of fluid volume; Excrete renin (renin converts angiotensin I to angiotensin II, and increased BP).
• E - Erythropoietin: Produced by kidneys used to create RBC.
• D - Metabolism (Vit D): Kidneys transform calcifediol into calcitriol, the active form of vitamin D.

RAAS Simplification

• Sympathetic Nervous System senses low BP or low blood volume, which then stimulates the kidneys to produce renin.
• Renin converts angiotensin I to angiotensin II, which is a vasoconstrictor that then increases BP.
• Angiotensin II stimulates increased aldosterone, which causes the reabsorption of sodium and H₂O.
• The end results increase BP.

Common Fluid and Electrolyte Imbalances in Kidney Disorders

• Fluid volume deficit:
• Signs and Symptoms: Weight loss, poor skin turgor, oliguria, increased hematocrit, increased BUN:creatinine, and hypothermia.
• Management: Fluid challenge; give fluids (IV or oral).
• Fluid volume excess:
• Signs and Symptoms: Weight gain, edema, crackles, SOB, decreased hematocrit, decreased BUN, and JVD.
• Management: Fluid and sodium restriction, diuretics, dialysis.
• Hyponatremia:
• Signs and Symptoms: N/V, fatigue/lethargy, headache, abdominal cramps, anxiety, and seizures.
• Management: Increase sodium in diet, administer NS IV.
• Hypernatremia:
• Signs and Symptoms: Dry sticky membranes and tongue, thirst, fever, restlessness, weakness, and disorientation.
• Management: Dietary restrictions and diuretics.
• Hypokalemia:
• Signs and Symptoms: Anorexia, abdominal distention, muscle weakness, paralytic ileus, arrhythmias, and EKG changes.
• Management: Diet, oral, or IV potassium replacement.
• Hyperkalemia:
• Signs and Symptoms: Diarrhea, N/V, irritability, muscle weakness, and EKG changes.
• Management: Diet restrictions, diuretics, IV glucose or calcium gluconate, and dialysis.
• Hypocalcemia:
• Signs and Symptoms: Tetany, Trousseau/Chvostek sign, muscle cramps, stridor, tingling of fingers and around mouth, and EKG changes.
• Management: Diet, oral, or IV calcium replacement.
• Hypercalcemia:
• Signs and Symptoms: Bone pain, muscle weakness, decreased DTR, N/V, constipation, confusion, polyuria, polydipsia, and EKG changes.
• Management: Fluids, etidronate, mithramycin, calcitonin, corticosteroids, and phosphate salts.
• Hypomagnesemia:
• Signs and Symptoms: Tetany, Trousseau/Chvostek, dysphagia, muscle weakness, increased DTR, tingling, and arrhythmias.
• Management: Diet, oral, or IV magnesium replacement.
• Hypermagnesemia:
• Signs and Symptoms: Facial flushing, N/V, warmth, drowsiness, decreased DTR, muscle weakness, respiratory depression, and cardiac arrest.
• Management: Calcium gluconate, mechanical ventilation, and dialysis.
• Hypophosphatemia:
• Signs and Symptoms: Bone pain, flank pain, muscle weakness, tingling, confusion, and seizures.
• Management: Diet, oral, or IV phosphate replacement.
• Hypoalbuminemia:
• Signs and Symptoms: Chronic weight loss, depression, pallor, fatigue, and soft flabby muscles.
• Management: Diet/supplements, albumin, and hyperalimentation.
• Metabolic Acidosis (low bicarbonate):
• Signs and Symptoms: Headache, confusion, drowsiness, increased RR and depth (hyperventilating), N/V, and warm flushed skin.
• Management: Bicarbonate replacement and dialysis.
• Metabolic Alkalosis (high bicarbonate):
• Signs and Symptoms: Respiratory depression, increased DTR, dizziness, tingling of fingers and toes.
• Management: Fluid replacement if indicated, ensure adequate chloride.

Gerontological Considerations for Kidney Dysfunction

• Increased risk of kidney dysfunction and disease due to structural and functional changes.
• Declining number of nephrons and GFR.
• Diminished thirst sensation leads to dehydration and hypernatremia.
• Incomplete emptying of the bladder (BPH).
• Increased risk of urinary incontinence and UTIs.
• Increased likelihood of comorbidities like atherosclerosis, HTN, diabetes, and heart failure.
• Alterations in renal blood flow, GFR, and renal clearance can lead to a risk of medication/drug toxicity and adverse effects.

Acute Kidney Injury (AKI) / Acute Renal Failure

• Rapid loss of renal function due to kidney damage, requiring emergent treatment.
• Criteria: 50% or greater increase in creatinine from baseline.
• Complications: Metabolic acidosis, fluid and electrolyte imbalances.

AKI Causes:

• Prerenal:
• Causes decreased kidney perfusion.
• Hypovolemia (burns, GI loss, bleeding).
• Hypotension (sepsis, shock).
• Vasodilation (anaphylaxis, anti-HTN meds).
• MI or HF.
• Intrarenal:
• Damage within the kidneys, often from prolonged ischemia.
• Hemoglobinuria (transfusion reaction, hemolytic anemia).
• Rhabdo/myoglobinuria (trauma, crush injuries, burns).
• Nephrotoxic drugs (ACE inhibitors, NSAIDs, contrast, heavy metals).
• Infections (acute glomerulonephritis/pyelonephritis).
• Postrenal:
• Damage after the kidneys due to obstruction.
• Kidney stones.
• Blood clots.
• Tumors.
• BPH.
• Neuro damage (strokes).
• Pregnancy.

AKI Stages:

• Initiation:
• Begins with the insult or injury and ends when oliguria develops.
• Oliguric:
• Urine output is under 400 mL/day.
• Metabolic acidosis, increased BUN and creatinine, decreased GFR, increased potassium, and decreased sodium.
• Treatment: Low protein diet, limit fluids, monitor I+O, monitor EKG and labs (esp. potassium), and may require dialysis.
• Diuretic:
• Gradual increase in urine output as GFR starts to recover.
• BUN and creatinine begin to normalize but dehydration may increase levels.
• Monitor for hypovolemia, dehydration, and decreased potassium levels.
• Recovery:
• Values return to normal, may take 3-12 months.
• A permanent decrease in GFR by 1-3% may be evident.

AKI Signs, Symptoms, Diagnosis and Management:

• Signs and Symptoms: Whole body affected by renal deficiency.
• Increased BUN/creatinine, declining GFR, inability to concentrate urine, plus oliguria, hematuria, and anemia.
• Hyperkalemia (arrhythmias, cardiac arrest), hyperphosphatemia, and hypocalcemia.
• Metabolic acidosis or alkalosis and drowsiness, headache, lethargy, and seizures.
• Diagnosis: Creatinine clearance, ultrasound, labs, and urinalysis.
• Management: Restore chemical balance and avoid fluid overload.
• Implement renal replacement therapy (RRT)
• Daily weights, I+O monitoring, BP, fluid and electrolyte monitoring, and EKG monitoring. Administer cation-exchange resins and EKG changes.
• Use reduced medication dosages for patients with AKI.
• Diet: High carbohydrate meals, and restricted sodium, potassium, and phosphate.
• Treat fever, prevent infection and encourage cough, deep breathing, and incentive spirometry.

Categories on Kidney Disorders by Characteristics

• Prerenal:
• Etiology in Hypoperfusion due to shock and hypovolemia.
• Increased Blood urea nitrogen value (out of normal 20:1 proportion to creatinine).
• Increased Creatinine.
• Decreased Urine output.
• <20 mEq/L Urine sodium.
• Normal, few hyaline casts Urinary sediment.
• Increased to > 500 mOsm Urine osmolality.
• Increased Urine specific gravity.
• Intrarenal:
• Etiology in Parenchymal damage.
• Increased Blood urea nitrogen value.
• Increased Creatinine.
• Varies decreases Urine output.
• Increased to > 40 mEq/L Urine sodium.
• Abnormal casts and debris Urinary sediment.
• ~350 mOsm, similar to serum Urine osmolality.
• Low normal Urine specific gravity.
• Postrenal:
• Etiology in Obstruction.
• Increased Blood urea nitrogen value.
• Increased Creatinine.
• Varies increases ,may be, or sudden anuria Urine output.
• Varies, often to ≤20 mEq/L Urine sodium.
• Usually normal Urinary sediment.
• Varies increases↑ or equal to serum Urine osmolality.
• Varies Urine specific gravity.

Chronic Kidney Disease (CKD) / End-Stage Kidney Disease (ESKD)

• Normal GFR is 125; Stage 5 CKD is under 15, indicating ESKD.
• Increased risk of cardiovascular disease, the leading cause of death in ESKD.
• When a patient requires RRT on a permanent basis.
• Risk factors: Cardiovascular disease, diabetes, HTN, obesity.

CKD / ESKD Signs and Symptoms:

• Decreased GFR and creatinine clearance; Increased BUN and creatinine
• Neurological: Weakness, fatigue, confusion, headaches, seizures.
• Cardiovascular: HTN, edema, high CVP, pericarditis, pericardial effusion.
• Respiratory: SOB, increased RR, Kussmaul respirations, thick sputum.
• Gastrointestinal: Ammonia breath, metallic taste, mouth ulcerations, anorexia, nausea, vomiting. -Hematological: Metabolic acidosis, anemia, bleeding, hyperlipidemia, hyperkalemia, calcification of the blood vessels, paradoxically high phosphate/ low calcium.
• Skin: Dry skin, brittle nails, itching, bruising, yellow-gray color.
• Musculoskeletal: Cramps, bone pain, renal osteodystrophy (brittle bones). Psychological: Behavior changes, depression, withdrawal.

CKD / ESKD Management:

• Dialysis
• Medications: Calcium with phosphate binders, anti-HTN, erythropoietin.
• Diet:
• Fluid restriction (1000 mL/day), diet low in sodium, potassium, and phosphate; restrict alcohol.
• Careful regulation of protein.
• ESKD without dialysis: low protein diet
• ESKD with dialysis: High protein diet; 1.2 g/kg/day from high-value sources.

Hemodialysis (HD)

• For patients with AKI, advanced CKD, or ESKD.
• Indicated in: Uremic symptoms, hyperkalemia, fluid overload not responsive to diuretics.
• Urgent indication: Pericardial friction rub (uremic preicarditis).
• Typically received 3 times a week, takes 3-4 hours each.
• Prolongs life, does not cure or alter course CKD

HD Objectives:

• Remove nitrogenous waste and excess fluid, balance electrolytes, and manage acidosis.
• Uses dialyzer / "artificial kidney" that the patient's blood is passed through.
• Toxins are removed by diffusion, and excess fluids are removed by osmosis.

Hemodialysis

• Heparin given to prevent blood clotting

HD Vascular Access

• Vascular Access Methods:
• Vascular Access Device (VAD):
• Double lumen, large-bore catheter inserted into jugular or femoral vein.
• Risks: infection, bleeding, hematoma, pneumothorax, thrombosis.
• AV Fistulas:
• Preferred method, done by anastomosis of an artery to a vein, in lower forearm.
• Needs 3 months, minimum to use.
• AV Graft:
• Used if AVF is not an option.
• Biologic, synthetic, or semi synthetic graft that is usually placed in the arm, can be in thigh/chest wall.
• Risks: stenosis, infection, thrombosis.

HD Complications for Vascular Access:

• Accelerated lipid metabolism results in cardiovascular complications (CAD, angina, stroke, PVD).
• Anemia is worsened due to blood loss during hemodialysis.
• Malnutrition, Calcification of vessels can occur.
• Sleep disturbances, Bleeding, air embolism.

Hemodialysis During

• Hypotension, SOB, muscle cramps, arrhythmias, N/V due to fluid shifts

HD Nursing Management:

• If patient is on Medication: -Medications are removed in dialysis, time administrations.
• Diet: Low protein, restriction of fluids, sodium, potassium, and phosphate.
• Site: -Protect site during dialysis.
• Assess site for patency.
• Never take blood pressure / draw blood from extremity.
• Assess for bruit and thrill every 8-12 hours.
• Observe for signs / symptoms of infection, change dressing as needed.
• If pt requires fluids, admin at slowest rate possible.
• Assess: Monitor F+E and accurate I+O.
• Assess for signs and symptoms of uremia.
• Assess for cardiac and respiratory complications (fluid overload, pericarditis).
• Provide psychological support and assess for signs , symptoms of isolation and/or depression.

UTI

• Infection of the urinary tract (most common = bladder).
• Common in females or those who are sexually active.

UTI Signs and Symptoms:

• Fever/chills, nausea/vomiting, flank pain.
• Hematuria and dysuria and foul smelling urine.
• Poor feeding , lethargy, urgency/incontinence.
• Older adults may show signs of AMS

UTI Diagnosis and Management:

• Diagnosis : Urinalysis + urine culture.
• Management : Antibiotics (ampicillin, Bactrim, gentamicin, Rocephin).
• Take adequate fluid and pain management with Antipyretics, heating pad for flank pain .
• Prevention : Cotton underwear, H2O, hygiene.

Nephrotic Syndrome:

• Abnormal loss of protein through kidneys causes Extreme Proteinuria and Low Albumin: This can lead to hypercoagulable state.
• Hallmark: Massive proteinuria which is over 3.5 g/day.
• Signs and Symptoms include massive proteinuria, hypoalbuminemia, hyperlipidemia, hypercoagulability, periorbital edema, ascites, oliguria and headaches.

Nephrotic Syndrome Dx, Complications, & Management:

• Dx involves protein& WBC in the urine , low levels of albumin, high cholesterol and 24 hr urine.
• Diagnosis:
• Involves protein and WBC in urine, low levels of albumin, high levels of cholesterol, and 24-hr urine.
• Diagnosis is confirmed with needle biopsy of a kidney.
• Complications: Infections, Thromboembolism (DVT + PE), Accelerated Atherosclerosis and AKI.
• Management: Promote diuresis and prevent infection.
• Diuretics (edema), ACE Inhibitors (HTN), Statins (hyperlipidemia), and sodium restriction are implemented.
• Same Treatment with Acute Glomerulonephritis in Early Stages.
• Progressions lead to needing Dialysis or kidney transplant, and more similar treatment with eskd

Acute Glomerulonephritis:

• Inflammation of the glomerular capillaries, often seen following a Strep A or viral infection.
• Can result in CKD or ESKD.

Acute Glomerulonephritis Signs and Symptoms:

• Hematuria, Proteinuria, Azotemia, HTN, edema.
• Hypoalbuminemia and Hyperlipidemia and atypical symptoms like confusion or seizures.
• Fatty, Edema, High dose, Protein

Glomerulonephritis Diagnosis and Management:

• Diagnosis involves elevated IGA, Hematocrit,Proteinuria.
• Requires Azotemia and Fatty Caused kidneys tests in urine .
• May require kidney biopsy.

Managing signs and symptoms:

-Plasma exchanges .

• High Dose can use Corticosteroids to decrease inflammatory: therapeutic.

If caused can treat :

-Antibiotics can to treat by with PCN (Penicillin), or with sodium and protein restriction.

• Careful hydration, strict I+O and follow-up care , assess HTN.

Chronic Glomerulonephritis:

• Kidneys are reduced to 1\5: largely of fibrous scar tissue. -Can follow hypertensive: repeated issues with Acute with Hyperlipidemia or secondary.
• It’s caused with SLE or Good Pasture: syndrome.

Chronic Glomerulonephritis Signs and Symptoms and management

• Signs an symptom: may not be present for years.
• With elevated BUN & creatinine .
• May cause: CKD, Edema and Skin yellow.
• Also might cause High BP/HTN.
• Weakness an Weight.

Late Chronic Glomerulonephritis:

• It could potentially indicate Neuropathy: cause decreased confusion.
• It needs: fixed gravity can’t urinate .

Chronic Glomerulonephritis Testing in kidneys:

• Urinalysis = Specific gravity
• Requires protein and can’t urinate . Low: High albumin, high CA.
• Needs cardiac enlargement.

BPH- Benign Prostatic Hyperplasia:

• Enlarged prostate, that is one of the diseases in males.
• Most men can have it, affects or approximate to 90% (age: 85+) .
• Can result in ureters kidneys (hydronephrosis) caused by an abundance of ureters.

Benign Prostatic Hyperplasia Risk Factors, Signs and Symptoms and Diagnosis:

• Risk Factors: Caused by smoking along with heavy ALC and diet choices.
• Symptoms: Cause Urinary problems, such as frequency, urgency, also with nocturne.
• Diagnosis: levels and urethrocytoscopy, used with a check for UL to test retention.
• Alpha-adrenergic block: can relax which can help with the bladder muscles.
• It’s caused by sinus medications.

TURP:

• Gold standard treatment for BPH
• Surgery to inside of which is inserted into the Urethra.
• May require external incision or less Risk.

TURP (Gold Standard Treatment for BPH):

• Requires surgical removals of the prostate: can be made by the ueretha through and insert 6-8 inch needle.
• Minimal Cut to do.
• Pros: Less risks, better and shorter recoveries.
• Cons: Reoccurring.

Management for TURP

• Monitor: Fluids or any balance, can also take Strict meds and follow drainage with irrigations.

Complications and Management

• Comps: TURS and bleeding caused by TURS
• Mgm: monitor the fluids, and make or add saline solution.