Renal and Urinary System Disorders: Assessment, Pathophysiology, and Nursing Management

Comprehensive review flashcards for nursing management of patients with renal and urinary disorders, covering assessment, diagnostic tests, fluid and electrolyte imbalances, acute kidney injury, chronic kidney disease, dialysis modalities, transplantation, trauma, infections, urinary incontinence, renal calculi, urinary diversions, and bladder cancer.

What is acute kidney injury (AKI)?

A rapid loss of renal function due to damage to the kidneys, formerly referred to as acute renal failure.

How is acute nephritic syndrome defined?

A type of kidney disease characterized by glomerular inflammation.

What is acute tubular necrosis (ATN)?

A type of acute kidney injury characterized by damage to the kidney tubules.

What clinical threshold defines anuria?

A total urine output of less than $50\text{ mL}$ in $24\text{ hours}$.

What is an arteriovenous fistula (AVF)?

A type of vascular access for hemodialysis created by surgically connecting an artery directly to a vein.

What is an arteriovenous graft (AVG)?

A surgically created vascular access for hemodialysis where a piece of biologic, semibiologic, or synthetic graft material connects an artery to a vein.

How is azotemia defined?

An abnormal concentration of nitrogenous waste products in the blood.

What diagnostic timeframe defines chronic kidney disease (CKD)?

Kidney damage or a decrease in the glomerular filtration rate (GFR) lasting for $3$ or more months.

What is continuous ambulatory peritoneal dialysis (CAPD)?

A manual method of peritoneal dialysis whereby the patient performs a prescribed number of exchanges or cycles throughout the day.

What is continuous cyclic peritoneal dialysis (CCPD)?

A method of peritoneal dialysis in which a machine called a cycler automatically performs exchanges, typically while the patient sleeps at night.

What is continuous renal replacement therapy (CRRT)?

A method used to replace normal kidney function in hemodynamically unstable patients by circulating blood through a hemofilter and returning it to the patient.

What is dialysate?

The electrolyte solution that circulates through the dialyzer in hemodialysis and through the peritoneal cavity in peritoneal dialysis.

What is a dialyzer?

An artificial kidney containing a synthetic semipermeable membrane through which blood is filtered to remove uremic toxins and fluid.

How does the principle of diffusion function during hemodialysis?

Solutes and waste products move across a semipermeable membrane from an area of higher concentration in the blood to an area of lower concentration in the dialysate.

What is effluent in peritoneal dialysis?

The drained fluid recovered from the peritoneal cavity following an exchange cycle.

What is end-stage kidney disease (ESKD)?

The final stage of chronic kidney disease resulting in retention of uremic waste products and necessitating renal replacement therapy.

What three phases comprise an exchange in peritoneal dialysis?

The complete cycle consisting of the fill (instillation), dwell, and drain phases.

How is glomerulonephritis defined?

Inflammation of the glomerular capillaries.

What is hemodialysis (HD)?

A procedure during which a patient's blood is circulated through an artificial kidney (dialyzer) to remove waste products and excess fluid.

What is interstitial nephritis?

Inflammation occurring within the renal tissue.

What is nephrosclerosis?

Hardening of the renal arteries, most often due to prolonged hypertension and diabetes.

What clinical features characterize nephrotic syndrome?

A kidney disorder with increased glomerular permeability manifested by massive proteinuria, hypoalbuminemia, diffuse edema, and hyperlipidemia.

How is the term nephrotoxic defined?

Any substance, medication, or action that is directly toxic or damaging to kidney tissue.

What quantitative criteria define oliguria?

A urine output of less than $400\text{ mL}$ in $24\text{ hours}$ or less than $0.5\text{ mL/kg/h}$ over $6\text{ hours}$.

How does the principle of osmosis operate in peritoneal dialysis?

Water moves through a semipermeable membrane from an area of lower solute concentration (the blood) to an area of higher solute concentration (the hypertonic dialysate).

What is peritoneal dialysis (PD)?

A procedure that utilizes the patient's peritoneal membrane as the semipermeable membrane for the exchange of fluid and solutes.

What is peritonitis?

Inflammation of the peritoneal membrane.

What is polyuria?

Excessive or abnormally large production and excretion of urine.

What is ultrafiltration in renal replacement therapy?

The removal of water from blood via a pressure gradient created by applying negative suction pressure across a dialyzer membrane or an osmotic gradient in PD.

How is uremia defined?

An excess of urea and other nitrogenous waste products in the circulating blood accompanied by systemic manifestations.

What are urinary casts?

Proteins and cellular debris secreted and molded within damaged kidney tubules.

What is the most accurate indicator of fluid loss or gain in acutely ill renal patients?

Daily body weight measurements, where a $1\text{ kg}$ weight gain equals $1\text{ L}$ ($1000\text{ mL}$) of retained fluid.

What are the classic clinical manifestations of fluid volume deficit in kidney disorders?

Acute weight loss $\ge 5\%$, decreased skin turgor, dry mucous membranes, oliguria/anuria, increased hematocrit, hypothermia, and BUN elevated out of proportion to creatinine.

What are the manifestations and general management strategies for fluid volume excess?

Manifestations: acute weight gain $\ge 5\%$, edema, crackles, shortness of breath, decreased hematocrit, distended neck veins. Management: fluid/sodium restrictions, diuretics, dialysis.

What are the common clinical signs of hyperkalemia and its primary ECG changes?

Diarrhea, colic, nausea, irritability, muscle weakness, and ECG changes including tall, tented (peaked) T waves and widened QRS complexes.

What are the physical examination signs that confirm hypocalcemia?

Positive Chvostek sign (facial twitching) and positive Trousseau sign (carpopedal spasm), hyperactive reflexes, muscle tetany, and paresthesias.

What proportion of US adults are estimated by the CDC to have chronic kidney disease?

$15\%$ of the adult US population ($37\text{ million}$ people or $1$ in $7$ individuals), with $9$ out of $10$ affected individuals unaware of their condition.

What two underlying diseases account for approximately $70\%$ of all cases of CKD?

Diabetes and hypertension.

What is the leading cause of death in patients diagnosed with CKD prior to reaching ESKD?

A cardiovascular event (myocardial infarction or stroke).

What is the GFR criterion for Stage 1 Chronic Kidney Disease?

$\text{GFR} \ge 90\text{ mL/min/1.73 m}^2$ with evidence of kidney damage.

What is the GFR range defining Stage 2 Chronic Kidney Disease?

$\text{GFR} = 60\text{ to }89\text{ mL/min/1.73 m}^2$ (mild decrease in GFR).

What is the GFR range defining Stage 3 Chronic Kidney Disease?

$\text{GFR} = 30\text{ to }59\text{ mL/min/1.73 m}^2$ (moderate decrease in GFR).

What is the GFR range defining Stage 4 Chronic Kidney Disease?

$\text{GFR} = 15\text{ to }29\text{ mL/min/1.73 m}^2$ (severe decrease in GFR).

What is the GFR threshold defining Stage 5 Chronic Kidney Disease (ESKD)?

$\text{GFR} < 15\text{ mL/min/1.73 m}^2$, requiring renal replacement therapy to sustain life.

What target blood pressure is recommended to slow the progression of CKD?

Maintaining blood pressure below $125\text{ to }130/80\text{ mm Hg}$.

What population group has an eightfold elevation in the risk of hypertension-induced ESKD?

African Americans.

What is the medical management of choice for nephrosclerosis?

Aggressive antihypertensive therapy, especially with an angiotensin-converting enzyme (ACE) inhibitor alone or combined with other agents.

What preceding infection is classically linked to acute nephritic syndrome?

Group A beta-hemolytic streptococcal infection of the throat (or impetigo) that precedes the renal onset by $2\text{ to }3\text{ weeks}$.

What primary presenting symptoms characterize acute nephritic syndrome?

Hematuria (cola-colored urine with RBC casts), edema, azotemia, and proteinuria.

What histologic feature seen in Bowman space characterizes rapidly progressive glomerulonephritis?

Crescent-shaped cells accumulating in Bowman space that disrupt the filtering surface.

What diagnostic 24-hour urine excretion threshold defines nephrotic syndrome?

Proteinuria (predominantly albumin) exceeding $3.5\text{ g/day}$.

What are the genetic chromosome differences between PKD1 and PKD2 in polycystic kidney disease?

PKD1 involves a mutation on chromosome $16$ ($78\%$ of patients, ESKD by age $54.3$), whereas PKD2 involves chromosome $4$ (slower progression, ESKD by age $74.0$).

What pharmacologic agent slows the decrease in kidney function in polycystic kidney disease?

Tolvaptan (with common side effects of polyuria and rare, reversible liver injury).

What cell type accounts for $70\%$ to $80\%$ of all renal cell carcinomas?

Clear cell carcinoma (conventional/nonpapillary) arising from the proximal renal tubule.

What is the classic clinical triad of symptoms in renal cancer?

Painless hematuria, dull flank/back pain, and a palpable flank or abdominal mass (occurring together in only $10\%$ of patients).

What is postinfarction syndrome following renal artery embolization?

A symptom complex lasting $2\text{ to }3\text{ days}$ featuring flank/abdominal pain, elevated temperature, and gastrointestinal symptoms.

What serum creatinine increase defines acute kidney injury (AKI)?

A $50\%$ or greater increase in serum creatinine concentration above the patient's baseline.

What five stages constitute the RIFLE classification for acute kidney injury?

Risk, Injury, Failure, Loss, and ESKD.

What are the GFR and urinary output criteria for the 'Risk' category of RIFLE?

Serum creatinine increased $1.5 \times$ baseline OR GFR decreased $\ge 25\%$, with urine output $<0.5\text{ mL/kg/h}$ for $6\text{ hours}$.

What are the three physiologic categories of acute kidney injury?

Prerenal (hypoperfusion, $60\%\text{ to }70\%$ of cases), Intrarenal/intrinsic (parenchymal damage), and Postrenal (obstruction distal to kidney).

What four clinical phases comprise the course of acute kidney injury?

Initiation, oliguria, diuresis, and recovery.

How do urine sodium levels differentiate prerenal from intrarenal AKI?

Prerenal AKI demonstrates urine sodium $<20\text{ mEq/L}$; intrarenal AKI demonstrates urine sodium $>40\text{ mEq/L}$.

What intervention is considered the most effective method to prevent contrast-induced AKI?

Prehydration with intravenous normal saline ($0.9\%\text{ NaCl}$) prior to the procedure.

How is sodium polystyrene sulfonate utilized in hyperkalemia?

Administered orally or as a retention enema to exchange sodium ions for potassium ions in the colon (onset $>6\text{ hours}$).

What emergent IV medications are administered to rapidly shift potassium into the cells?

IV dextrose $50\%$, regular insulin, and calcium replacement (such as calcium gluconate).

What daily weight loss indicates a negative nitrogen balance in an AKI patient?

A loss of $0.2\text{ to }0.5\text{ kg}$ ($0.5\text{ to }1\text{ lb}$) per day.

What is the target hemoglobin range when administering erythrocyte-stimulating agents in ESKD?

$10\text{ to }11\text{ g/dL}$.

What are the daily dietary protein recommendations for patients on hemodialysis versus peritoneal dialysis?

Hemodialysis: $1.2\text{ g/kg/day}$; Peritoneal dialysis: $1.2\text{ to }1.3\text{ g/kg/day}$ of high-biologic value protein.

What is the maximum recommended interdialytic weight gain for patients on hemodialysis?

Less than $4\%$ of the patient's estimated dry weight.

How long must an arteriovenous fistula (AVF) mature before cannulation?

At least $3\text{ months}$.

Why is the subclavian vein avoided for acute double-lumen hemodialysis catheters?

Due to a significantly increased risk of developing central vein stenosis.

What causes dialysis disequilibrium syndrome and how is it managed?

Rapid cerebral fluid shifts occurring when BUN exceeds $150\text{ mg/dL}$; managed by prescribing short treatments with low blood and dialysate flow rates.

What laboratory criteria in peritoneal effluent confirm peritonitis in a PD patient?

Effluent WBC count $>100/\mu\text{L}$ after a dwell time of at least $2\text{ hours}$, with greater than $50\%$ polymorphonuclear cells.

What methods are explicitly prohibited when warming peritoneal dialysate bags?

Soaking bags in warm water (introduces bacteria) and using a microwave oven (danger of burning the peritoneum).

Where is a transplanted kidney surgically placed in the recipient?

In the iliac fossa anterior to the iliac crest.

What are the onset timeframes for hyperacute, acute, and chronic kidney transplant rejection?

Hyperacute: within $24\text{ hours}$; Acute: within $3\text{ to }14\text{ days}$ (or up to weeks); Chronic: after many years.

What are the common nursing implications and adverse effects of tacrolimus and cyclosporine?

Monitor for nephrotoxicity, hypertension, hyperkalemia, hirsutism, tremors, and gingival hyperplasia; administer consistently relative to meals.

What dietary fruit product interacts with immunosuppressants like cyclosporine and must be avoided?

Grapefruit and grapefruit juice.

What are the four classifications of blunt renal trauma?

Contusion, minor laceration, major laceration, and vascular injury.

What is the best clinical indicator of urinary system injury following trauma?

Gross and microscopic hematuria.

What are the dimensions and weight of a normal adult kidney?

Weighs $113\text{ to }170\text{ g}$ ($4.5\text{ oz}$), measures $10\text{ to }12\text{ cm}$ long, $6\text{ cm}$ wide, and $2.5\text{ cm}$ thick.

At what anatomical vertebral levels are the retroperitoneal kidneys situated?

From the $12\text{th}$ thoracic vertebra ($\text{T12}$) to the $3\text{rd}$ lumbar vertebra ($\text{L3}$).

Why is the right kidney positioned slightly lower than the left kidney?

Due to the anatomical space occupied by the liver.

What percentage of total resting cardiac output is received by the kidneys?

$20\%\text{ to }25\%$ of total cardiac output ($1000\text{ to }1300\text{ mL/min}$), circulating the body's blood approximately $12$ times per hour.

What are the two types of nephrons and their relative percentages?

Cortical nephrons ($80\%\text{ to }85\%$) and juxtamedullary nephrons ($15\%\text{ to }20\%$).

What structural feature enables juxtamedullary nephrons to concentrate urine effectively?

Long loops of Henle surrounded by specialized capillary loops called vasa recta that dip deep into the renal medulla.

What cellular structure within the juxtaglomerular apparatus synthesizes and secretes renin?

Juxtaglomerular cells functioning alongside the macula densa of the distal tubule.

What three distinct filtering layers comprise the glomerular membrane?

The capillary endothelium, the basement membrane, and the epithelium.

What are the three anatomical sites along the ureters prone to calculus obstruction?

The ureteropelvic junction, the ureteral segment near the sacroiliac junction, and the ureterovesical junction.

What is the normal physiologic bladder capacity of a healthy adult?

$400\text{ to }500\text{ mL}$.

What anatomical feature of the ureterovesical junction prevents vesicoureteral reflux?

The oblique angling of the ureter as it tunnels through the muscular bladder wall, which compresses the ureter during voiding.

What are the three fundamental steps of urine formation in the nephron?

Glomerular filtration, tubular reabsorption, and tubular secretion.

How much filtrate do the glomeruli produce daily, and what volume is excreted as urine?

Approximately $180\text{ L/day}$ of filtrate is produced, of which $99\%$ is reabsorbed, yielding $1\text{ to }2\text{ L}$ of excreted urine daily.

What is renal glycosuria?

The excretion of glucose in the urine, occurring when blood glucose concentrations exceed the renal tubule's reabsorption threshold.

Where is antidiuretic hormone (ADH) synthesized and released, and what stimulates it?

Synthesized in the hypothalamus, released by the posterior pituitary in response to increased blood osmolality.

What is the normal reference range for serum osmolality?

$275\text{ to }290\text{ mOsm/kg}$.

What volume of fluid is lost daily through insensible losses via the skin, lungs, and feces?

Approximately $800\text{ mL}$ through skin and lungs, and $200\text{ mL}$ through feces ($1000\text{ mL}$ total).

What volume of fluid gain or loss is represented by a $1\text{ lb}$ change in body weight?

Approximately $500\text{ mL}$ of fluid.

How does aldosterone regulate electrolyte excretion in the distal tubule?

It stimulates the kidneys to reabsorb sodium while promoting potassium excretion.

What is the normal serum pH range maintained by renal acid-base mechanisms?

$7.35\text{ to }7.45$.