NLE Renal & Urinary Nursing — Acute & Chronic Kidney DiseaseStudy Notes

Acute kidney injury is defined as a **sudden, potentially reversible decline in renal function** characterized by rising serum creatinine and blood urea nitrogen (BUN) with a corresponding decrease in glomerular filtration rate (GFR) and typically reduced urine output (oliguria or anuria). Unlike chronic kidney disease, AKI develops over hours to days and may be reversed if the underlying cause is promptly identified and treated. The key nursing priority is early recognition of AKI because the condition can rapidly progress to life-threatening electrolyte disturbances and fluid overload. **Classification by Pathophysiology (AKIN Staging and Clinical Correlation):** AKI is classified into three categories based on the anatomical location of the problem: **PRERENAL AKI (Most Common—60–70% of Cases):** Prerenal AKI results from **decreased renal PERFUSION** or inadequate blood flow to the kidneys, while the kidney tissue itself remains intact. If perfusion is restored promptly, renal function typically recovers completely. Common causes include: - **Hypovolemic states:** hemorrhage, severe dehydration, extensive burns, severe vomiting/diarrhea - **Distributive shock:** sepsis, anaphylaxis - **Cardiogenic shock:** acute myocardial infarction, heart failure, arrhythmias - **Hepatorenal syndrome:** end-stage liver disease with renal vasoconstriction Diagnostic clue: **BUN:creatinine ratio >20:1** (normal is 10–20:1) because the kidney reabsorbs urea but not creatinine, concentrating it in the tubular filtrate when flow is low. **INTRARENAL (INTRINSIC) AKI (20–50% of Cases):** Intrinsic renal AKI involves **direct damage to kidney tissue**—glomeruli, tubules, or interstitium. The most common form is acute tubular necrosis (ATN), which accounts for ~50% of all AKI cases in hospitalized patients. Causes include: - **Nephrotoxic medications:** aminoglycoside antibiotics (gentamicin, amikacin), NSAIDs (ibuprofen, naproxen), ACE inhibitors/ARBs in certain settings, amphotericin B, vancomycin - **Contrast-induced nephropathy:** radiocontrast dyes used in cardiac catheterization and CT imaging - **Endogenous toxins:** myoglobin (rhabdomyolysis from muscle crush injury), hemoglobin (massive hemolysis), light chains (multiple myeloma) - **Glomerulonephritis:** post-infectious, lupus, vasculitis - **Acute interstitial nephritis:** allergic reaction (beta-lactam antibiotics, NSAIDs, phenytoin), infection Intrinsic AKI carries a worse prognosis than prerenal AKI because the kidney tissue is damaged; recovery is slower and some baseline function may be permanently lost. **POSTRENAL AKI (10–15% of Cases):** Postrenal AKI results from **mechanical OBSTRUCTION** of urine flow anywhere from the kidney collecting system to the urethral meatus. The kidneys produce urine normally, but it cannot exit, causing backpressure. Early recognition is critical because prolonged obstruction can lead to permanent renal scarring and loss of function. Common causes include: - **Upper urinary tract:** kidney stones (nephrolithiasis), renal tumors, strictures - **Lower urinary tract:** **benign prostatic hyperplasia (BPH)** in older males, prostate cancer, bladder tumors, urethral strictures, blood clots obstructing the catheter Postrenal AKI is often **reversible if the obstruction is relieved within 1–2 weeks** of onset; prolonged obstruction (>4 weeks) risks permanent renal damage. **Distinguishing Features:** The clinical presentation and urinary findings help differentiate the three types. In **prerenal AKI**, urine is highly concentrated (specific gravity >1.030, osmolality >500 mOsm/L) because the tubules are trying to conserve water in response to hypoperfusion. In **intrarenal AKI**, particularly ATN, urine is dilute (specific gravity <1.020, osmolality <350 mOsm/L) because damaged tubules cannot concentrate urine. The **fractional excretion of sodium (FENa)** is another key discriminator: FENa <1% in prerenal states (tubules reabsorb sodium to conserve volume) versus FENa >2% in ATN (damaged tubules cannot reabsorb sodium).

AKI progresses through four distinct phases, each with characteristic changes in renal function, electrolyte balance, and fluid status. Understanding these phases is essential for anticipating complications and adjusting nursing interventions accordingly. **PHASE 1: ONSET (INITIATING PHASE)** The onset phase begins with the initial insult (e.g., hypotension, nephrotoxic drug exposure, obstruction) and extends until signs of renal dysfunction become clinically evident. This phase may last hours to days. Serum creatinine may not yet be markedly elevated, but urine output begins to decline. **Nursing priority:** Recognize early warning signs and intervene to prevent progression. Monitor for the causative event and correct it immediately—for example, restore blood pressure in hypovolemic shock, discontinue the nephrotoxic drug, or relieve the obstruction. Even during this phase, electrolyte shifts may begin, so check baseline potassium, calcium, and phosphate. **PHASE 2: OLIGURIC PHASE (Most Dangerous)** The oliguric phase is defined by **urine output <400 mL/day** (some sources use <0.5 mL/kg/day as the threshold) and typically lasts **1–3 weeks**, though it can extend longer in severe cases. This is the **most dangerous phase** because the kidneys cannot eliminate water, electrolytes, or waste products, leading to rapid accumulation of toxic substances. **Manifestations of the Oliguric Phase:** - **Oliguria/anuria:** urine output <400 mL/day or absent - **Fluid overload:** weight gain (1 kg = ~1 liter fluid), peripheral and pulmonary edema, hypertension, distended neck veins - **Hyperkalemia:** serum potassium >5.5 mEq/L; this is the **#1 life-threatening electrolyte disturbance** in AKI - **Metabolic acidosis:** pH <7.35, low bicarbonate due to lack of renal excretion of acid and loss of bicarbonate reabsorption - **Uremia:** elevated BUN (often >100 mg/dL), elevated creatinine (often >10 mg/dL), causing nausea, vomiting, anorexia, confusion, lethargy, pericarditis - **Hyperphosphatemia and hypocalcemia:** phosphate accumulates; kidneys cannot activate vitamin D to promote calcium absorption - **Anemia:** from shortened RBC lifespan in the uremic environment, bleeding from uremic platelet dysfunction, and decreased erythropoietin production **Nursing Priority in Oliguric Phase—HYPERKALEMIA Management:** Hyperkalemia is the **greatest immediate threat to life** because elevated potassium causes cardiac dysrhythmias that can lead to sudden asystole. The nurse must: 1. **Monitor serum potassium DAILY and ECG changes continuously** 2. **Recognize ECG changes of hyperkalemia:** peaked (tall) T waves → widened QRS complex → flattened P wave → sine-wave pattern (pre-arrest) 3. **Institute emergency interventions if K+ >6.0 mEq/L or ECG changes present:** - **IV calcium gluconate 10% (5–20 mL IV push over 2 minutes):** PROTECTS the myocardium from the effects of high potassium by stabilizing cell membranes; does NOT remove potassium, so it is given first while other measures take effect. Onset is within 1–3 minutes. - **Regular insulin 10 units IV + dextrose 25 g (D50W 50 mL IV push):** Insulin shifts potassium INTO cells by promoting glucose uptake; dextrose prevents hypoglycemia. Onset 10–20 minutes; lasts 4–6 hours. - **Sodium bicarbonate 50 mEq (44–88 mEq IV over 5–10 minutes):** Alkalinizes blood, driving potassium into cells. Onset 30 minutes; lasts 2–4 hours. - **Beta-2 agonist (nebulized albuterol 10–20 mg over 10 minutes):** Also shifts K+ into cells. Can be combined with other measures. - **Sodium polystyrene sulfonate (Kayexalate) 15–60 g PO or 30–50 g PR:** Resin binds potassium in the GI tract for fecal excretion. Onset 4–24 hours; removes 1 mEq K+ per gram of resin. Often used as a bridge therapy between dialysis sessions. - **Dialysis (most definitive):** Removes potassium from blood directly; reserved for refractory hyperkalemia or when other measures fail. **Fluid Management in Oliguric Phase:** The nurse implements **strict fluid restriction**—typically "previous day's urine output plus 500–700 mL for insensible loss" (perspiration, respiration). For example, if a patient's previous day output was 300 mL, today's fluid allowance (IV fluids, medications, food, beverages) is capped at 800–1000 mL total. Carefully **measure and record ALL intake and output**, including oral fluids, IV fluids and medications, nasogastric feedings, and any drainage. Daily weight is critical—a gain of >1 kg per day suggests fluid overload. Monitor for signs of volume overload: crackles on lung auscultation, orthopnea, elevated JVP, peripheral edema, hypertension. **Nutritional Management:** Protein is **restricted** during the oliguric phase (typically 0.5–1 g/kg/day) to minimize nitrogenous waste accumulation. However, adequate **calories from carbohydrates and fats** (35–40 kcal/kg/day) are provided to prevent catabolism and muscle wasting. **Potassium, sodium, and phosphate are strictly limited.** A dietitian consultation is essential. **Medication Management:** All medications must be **renally dosed** or held. Nephrotoxic drugs (NSAIDs, ACE inhibitors, aminoglycosides, contrast agents) are **absolutely contraindicated**. Diuretics are generally ineffective during oliguria and are not given unless there is evidence of volume overload with pulmonary edema (a rare situation—fluids are removed via dialysis instead). **Preparation for Dialysis:** During the oliguric phase, the nurse monitors for **indications for urgent dialysis initiation:** - **Refractory hyperkalemia** (K+ >6.5 despite maximal medical management) - **Severe fluid overload** with pulmonary edema or hypertensive crisis - **Severe metabolic acidosis** (pH <7.1) - **BUN >100 mg/dL with uremic symptoms** (altered mental status, pericarditis) - **Serum creatinine >10 mg/dL** The nurse ensures vascular access is placed (for hemodialysis) or peritoneal catheter is secured (for peritoneal dialysis), and coordinates timing with the dialysis team. **PHASE 3: DIURETIC PHASE (High-Risk for Fluid/Electrolyte Loss)** As tubular function begins to recover, the diuretic phase begins—urine output gradually increases, sometimes dramatically to **3–5 liters/day or more**. This phase lasts **1–3 weeks**. However, recovered tubules cannot yet **concentrate urine or reabsorb electrolytes efficiently**, so this is a phase of **fluid and electrolyte loss**, not retention. **Manifestations of Diuretic Phase:** - **Polyuria:** high urine output (up to 5–10 L/day in some cases) - **Risk of HYPOVOLEMIA:** despite high urine output, the patient may become depleted of fluid and electrolytes - **Risk of HYPOKALEMIA:** excessive renal potassium loss as dilute urine is produced in large volumes - **Risk of HYPONATREMIA:** sodium loss combined with continued fluid intake - **Risk of DEHYDRATION:** if fluid intake does not keep pace with output - **Persistent azotemia:** BUN and creatinine may still be elevated even as output increases, because tubular reabsorption is impaired **Nursing Priorities in Diuretic Phase:** 1. **Replace fluids carefully:** The strategy shifts from restriction to **replacement of output**. Monitor daily weights; stable or slowly decreasing weight is the goal (not rapid loss, which signals dehydration). 2. **Monitor electrolytes daily:** potassium, sodium, and bicarbonate are particularly vulnerable. 3. **Replace losses:** IV or oral potassium, sodium, and other electrolytes as needed based on serum levels. 4. **Assess volume status:** watch for signs of dehydration (orthostatic hypotension, tachycardia, dry mucous membranes, acute weight loss) versus continued overload (edema, crackles). The balance is delicate. 5. **Continue renal-protective diet:** protein gradually increases as renal function improves, but potassium and sodium remain controlled until urine output stabilizes. 6. **Monitor renal function:** BUN and creatinine should trend downward, though slowly. **Complications Specific to Diuretic Phase:** Hypokalemia during diuresis can cause muscle weakness, fatigue, cardiac dysrhythmias (prolonged QT interval, U waves), and constipation. Hyponatremia can cause confusion, seizures, or cerebral edema. If the patient is discharged or transferred during this phase before full recovery, careful follow-up is essential. **PHASE 4: RECOVERY (CONVALESCENT PHASE)** Over **weeks to months**, GFR and tubular function progressively normalize. Serum creatinine and BUN fall, urine becomes concentrated again, and electrolytes stabilize. Most patients regain full renal function; however, if the initial AKI was severe or the kidneys were compromised before the injury, some baseline impairment may persist, transitioning to chronic kidney disease. **Nursing Focus in Recovery Phase:** - Continue monitoring renal function (monthly or as ordered) until creatinine and electrolytes are stable. - Gradually liberalize diet as renal function permits. - Reinforce patient teaching about avoiding future nephrotoxic insults (NSAIDs, dehydration, contrast exposure without prophylaxis). - Arrange nephrology follow-up for those with persistent renal impairment.

Accurate assessment and early diagnostic work-up are essential for determining the **type** of AKI and guiding treatment. The nursing assessment integrates history, physical examination, and laboratory/imaging findings. **CLINICAL HISTORY AND RISK FACTORS:** The nurse asks focused questions: - **Recent hypotensive events:** hemorrhage, severe infection, dehydration, heart failure exacerbation, surgical blood loss? - **Nephrotoxic exposures:** recent medications (aminoglycosides, NSAIDs, ACE inhibitors, contrast dye), herbal supplements (licorice), or environmental toxins? - **Obstruction symptoms:** hesitancy, weak stream, incomplete emptying, large post-void residual (suggesting BPH or stones)? - **Constitutional symptoms:** fever (infection/sepsis), muscle pain (rhabdomyolysis), chest pain (pericarditis)? - **Baseline renal function:** previous serum creatinine and BUN to determine if this is truly acute or a new baseline in undiagnosed CKD? **PHYSICAL EXAMINATION:** - **Volume status:** assess perfusion by checking skin turgor, mucous membranes, capillary refill, orthostatic BP changes. Jugular venous pressure (JVP) indicates fluid overload (JVP >4 cm H₂O). Peripheral edema, sacral edema, and ascites suggest volume excess. - **Cardiovascular:** heart rate, blood pressure (hypertension in volume overload, hypotension in hypovolemia), heart sounds (muffled in pericarditis), presence of S3 gallop (heart failure). - **Respiratory:** breath sounds for crackles (pulmonary edema), respiratory rate, work of breathing. - **Abdominal:** palpate kidneys for tenderness (glomerulonephritis, pyelonephritis, renal infarction), check for bladder distension (suggesting obstruction), listen for bruits over renal arteries (renal artery stenosis). - **Neurologic:** altered mental status, lethargy, irritability, asterixis (flapping tremor of uremia), seizures. - **Skin:** uremic frost (fine urea crystals on skin in severe uremia), pallor (anemia), yellow tinge (urochrome pigment). **SERUM LABORATORY FINDINGS:** *Renal Function Markers:* - **Serum creatinine:** rises acutely (>0.3 mg/dL increase in 24 hours or 50% increase from baseline suggests AKI). Creatinine is produced by muscle at a roughly constant rate and is filtered by the kidneys; in AKI, it accumulates. Note: Serum creatinine may not rise for 24–48 hours after renal dysfunction begins, so it is not always an early marker. - **Blood urea nitrogen (BUN):** rises in AKI. BUN is filtered by the kidneys and reabsorbed in the proximal tubule; in AKI, it accumulates. BUN is less specific than creatinine (elevated by catabolism, high protein intake, GI bleeding) but reflects the severity of azotemia. - **Estimated GFR (eGFR):** calculated using creatinine, age, sex, and race (MDRD or CKD-EPI equations); rapid decline in eGFR confirms AKI. *Discriminating Prerenal from Intrarenal AKI:* - **BUN:creatinine ratio:** >20:1 suggests **prerenal** (kidneys are concentrating urine, reabsorbing both BUN and creatinine, but reabsorbing urea preferentially). <10:1 suggests **intrarenal** (tubules are damaged, cannot selectively reabsorb). - **Fractional excretion of sodium (FENa):** Calculated as (urine Na × serum creatinine) / (serum Na × urine creatinine) × 100. **FENa <1% suggests PRERENAL** (tubules are actively reabsorbing sodium to conserve volume). **FENa >2% suggests INTRARENAL, especially ATN** (damaged tubules cannot reabsorb sodium). FENa 1–2% is indeterminate. - **Urine osmolality:** **>500 mOsm/L** in prerenal (concentrated urine); **<350 mOsm/L** in ATN (dilute urine). - **Urine specific gravity:** **>1.030** in prerenal; **<1.020** in intrarenal. *Electrolytes and Acid-Base:* - **Potassium:** Elevated in AKI, especially oliguric phase (normal 3.5–5.0 mEq/L; >5.5 is hyperkalemic). - **Sodium:** Usually normal to low (dilutional hyponatremia from fluid overload). - **Calcium:** Low (hypocalcemia) due to impaired active vitamin D activation. - **Phosphate:** Elevated (hyperphosphatemia) because kidneys cannot excrete it. - **Bicarbonate and arterial pH:** Low (metabolic acidosis) from accumulation of organic acids and loss of renal acid excretion. - **Magnesium:** May be elevated (kidneys cannot excrete it). *Hematologic:* - **Hemoglobin/hematocrit:** Low (anemia) from shortened RBC lifespan, uremic platelet dysfunction with bleeding, and eventual decreased erythropoietin. - **Platelet count:** Normal to low; platelet dysfunction is more significant than count. - **WBC:** May be elevated if the AKI is from infection/sepsis. **URINALYSIS AND URINE MICROSCOPY:** The **type of cells and casts** in the urine helps identify the cause of AKI: - **Hyaline casts alone:** nonspecific; can be seen in prerenal states, dehydration, or normal subjects. - **Muddy brown (epithelial) casts:** pathognomonic for **ATN**; indicate sloughed tubular epithelial cells. - **RBC casts, WBC casts, dysmorphic RBCs:** suggest **glomerulonephritis** (intrarenal). - **WBC casts, bacteria:** suggest **acute interstitial nephritis** or pyelonephritis. - **Uric acid crystals or calcium oxalate crystals:** suggest **tumor lysis syndrome** or **rhabdomyolysis** (intrarenal causes). - **Crystals in a patient with postrenal obstruction:** may see calcium oxalate, uric acid, or struvite crystals suggesting stones. - **Specific gravity and osmolality:** as noted above, help differentiate prerenal from intrarenal. **RENAL IMAGING:** - **Renal ultrasound:** Gold standard for ruling out **postrenal AKI** (obstruction). Looks for hydronephrosis (dilation of collecting system and calyces indicating backup of urine above an obstruction). Also assesses kidney size and echogenicity. In prerenal and intrarenal AKI, kidneys are usually normal size with normal echogenicity. - **CT (non-contrast or with IV contrast if renal function permits):** Provides better detail for stones, tumors, or other obstructive lesions. **Iodinated contrast is avoided in AKI** because contrast-induced nephropathy worsens renal function. - **Renal artery Doppler ultrasound or CT angiography:** If renal artery stenosis or thrombosis is suspected. - **Chest X-ray:** Assess for pulmonary edema, pneumonia (if sepsis is the cause), or pericardial effusion (uremic pericarditis). **ECG:** - **Critical for assessing hyperkalemia.** Changes progress: peaked T waves → widened QRS → loss of P waves → sine-wave pattern (pre-arrest). Any peaked T waves or QRS widening in a patient with elevated K+ is a red flag warranting emergency intervention. **ADDITIONAL SPECIALIZED TESTS (As Indicated):** - **Urine myoglobin, serum myoglobin, creatine kinase:** If rhabdomyolysis is suspected. - **Urine light chains, serum light chains:** If multiple myeloma is suspected. - **Antinuclear antibodies (ANA), complement levels (C3, C4), ANCA, anti-GBM:** If glomerulonephritis is suspected. - **Blood cultures:** If sepsis/endocarditis is the trigger. **DISTINGUISHING AKI FROM CKD:** A critical question is whether the elevated creatinine is from **acute kidney injury** (reversible, days to weeks) or **chronic kidney disease** (irreversible, months to years). Clues: - **Ultrasound:** AKI kidneys are normal size; CKD kidneys are usually shrunken (<9 cm) with thinned cortices and increased echogenicity. - **Previous labs:** If a patient has a documented baseline creatinine of 1.0 one month ago and today's creatinine is 8.0, it is clearly AKI. If no previous baseline is available, assume the patient's baseline is the lowest creatinine recorded during the current hospitalization (unless it is obvious they were chronically ill). - **Anemia:** Severe anemia (Hgb <8 g/dL) suggests CKD (chronic lack of erythropoietin). In AKI, anemia develops more slowly (unless there was acute bleeding). - **Renal bone disease:** Presence of hyperphosphatemia, hypocalcemia, and elevated parathyroid hormone suggests CKD; these are not as pronounced in acute AKI.

Chronic kidney disease is defined as **progressive, IRREVERSIBLE loss of kidney function over months to years**, characterized by declining GFR and permanent changes in kidney structure. Unlike AKI, CKD cannot be reversed, though progression can sometimes be slowed with careful management. **Diabetes mellitus and hypertension are the two leading causes of CKD globally and in the Philippines**, accounting for ~60–70% of cases; other causes include chronic glomerulonephritis, autoimmune diseases, recurrent pyelonephritis, polycystic kidney disease, and hereditary nephritis. **PATHOPHYSIOLOGY: THE PROGRESSION OF CKD** CKD begins with **nephron loss** from whatever cause (diabetes destroying glomeruli, hypertension sclerosis of arterioles, chronic infection damaging tubules). As nephrons are destroyed, the remaining healthy nephrons attempt to compensate by **increasing their filtration rate and reabsorption capacity**—a process called **hyperfiltration**. This adaptive response helps maintain adequate GFR in the early stages, but over time, hyperfiltration itself damages the remaining nephrons, accelerating their loss. This creates a **vicious cycle of progressive nephron loss**, a phenomenon called the "chronic kidney disease progression pathway." As the GFR declines, the kidneys **lose their ability to excrete potassium, phosphate, and acid**, leading to **hyperkalemia, hyperphosphatemia, and metabolic acidosis**. The kidneys also **fail to produce active vitamin D (calcitriol)**, leading to **hypocalcemia and secondary hyperparathyroidism**. The kidney's production of **erythropoietin decreases**, causing **anemia**. These disturbances accumulate as the GFR falls further, creating the **uremic syndrome**—the constellation of systemic effects of retained uremic toxins. **STAGING OF CKD BY GFR (KDIGO Classification):** The severity of CKD is classified into five stages based on **estimated GFR (eGFR)**, which correlates with nephron mass and predicts outcomes: - **Stage 1: eGFR ≥90 mL/min/1.73 m² (Normal or High)** - Kidney function is normal; GFR may even be high due to hyperfiltration compensation. - Diagnosis is made by finding kidney damage (proteinuria, hematuria, or imaging abnormalities) despite normal GFR. - Examples: diabetes or hypertension with albuminuria but normal creatinine. - Nursing focus: Aggressive disease prevention; tight glucose and BP control. - **Stage 2: eGFR 60–89 mL/min/1.73 m² (Mildly Decreased)** - Mild decrease in GFR; kidneys still compensate well. - Most patients are asymptomatic; disease is detected on screening (urine protein or elevated creatinine on routine labs). - Nursing focus: Slow progression with lifestyle modification, BP control, ACE inhibitor or ARB therapy. - **Stage 3a: eGFR 45–59 mL/min/1.73 m² (Mildly to Moderately Decreased)** - GFR has declined further; some early uremic symptoms may appear (fatigue, mild anemia). - Medications need renal dosing; risk of complications increases. - Nursing focus: Monitor renal function every 3–6 months; introduce renal protective diet and medications. - **Stage 3b: eGFR 30–44 mL/min/1.73 m² (Moderately to Severely Decreased)** - Significant GFR loss; uremic symptoms become more evident (anemia, bone disease, electrolyte disturbances). - Preparation for renal replacement therapy (dialysis or transplant) should begin. - Nursing focus: Educate about dialysis options, vascular/peritoneal access placement, psychosocial support for major life change. - **Stage 4: eGFR 15–29 mL/min/1.73 m² (Severely Decreased)** - Marked renal insufficiency; multiple uremic complications are present. - Dialysis or transplantation will be needed very soon. - Nursing focus: Finalize dialysis modality choice, place access, adjust medications aggressively, provide intensive patient education. - **Stage 5: eGFR <15 mL/min/1.73 m² (End-Stage Renal Disease / ESRD)** - Kidney function is <15% of normal; kidneys can no longer sustain life without renal replacement therapy (dialysis or transplant). - At this stage, dialysis is initiated immediately (or transplantation if a donor kidney is available). - Nursing focus: Manage dialysis complications, optimize nutritional status, prevent cardiovascular events, psychosocial support. **GFR Classification Reminder for Filipino Students:** The eGFR is calculated using the **MDRD (Modification of Diet in Renal Disease)** or **CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration)** equation; these formulas use serum creatinine, age, sex, and race. Most modern laboratories in the Philippines report eGFR automatically. A patient's stage may change as GFR fluctuates with acute illness (superimposed AKI in a patient with CKD) or with response to therapy. **MANIFESTATIONS OF CKD / UREMIC SYNDROME** As CKD progresses, retained uremic toxins cause multisystem disease: **Fluid and Electrolyte Disturbances:** - **HYPERKALEMIA:** Potassium excretion fails as GFR drops; serum K+ rises to >5.5 mEq/L. Risk of fatal arrhythmias. - **Metabolic ACIDOSIS:** Kidneys fail to excrete hydrogen ions and cannot generate new bicarbonate; arterial pH falls, bicarbonate <15 mEq/L. Chronic acidosis worsens bone disease and protein catabolism. - **HYPERPHOSPHATEMIA:** Phosphate excretion fails; serum phosphate rises to >4.5 mg/dL. Phosphate binds calcium, precipitating in tissues. - **HYPOCALCEMIA:** Low serum calcium results from (1) hyperphosphatemia precipitating calcium phosphate in tissues, and (2) failure of kidneys to activate vitamin D (kidney 1-alpha-hydroxylase is reduced). Calcium <8.5 mg/dL. - **Fluid OVERLOAD:** Kidneys cannot excrete sodium and water adequately; fluid accumulates, causing edema, hypertension, and potentially acute heart failure and pulmonary edema. **Hematologic Manifestations:** - **ANEMIA:** Progressive; hemoglobin often <10 g/dL in Stage 4–5 CKD. Causes include (1) decreased erythropoietin production by the kidneys, (2) shortened RBC lifespan in the uremic environment, (3) blood loss from hemodialysis, (4) chronic GI bleeding (uremia damages the GI mucosa), and (5) occult hemorrhage from anticoagulation (dialysis, transplant). - **Bleeding tendency:** Uremia impairs platelet function; bleeding time is prolonged despite normal platelet count. Patients may have spontaneous bleeding (nosebleeds, GI bleeding, bruising), though this is less common since dialysis improved. **Bone and Mineral Metabolism (Renal Osteodystrophy):** - **Secondary hyperparathyroidism:** Low active vitamin D (calcitriol) → low serum calcium → stimulates PTH secretion. PTH remains elevated because the kidney is also resistant to PTH. Chronically elevated PTH causes bone demineralization (osteitis fibrosa) and increased fracture risk. - **Bone disease:** Osteomalacia (soft bones from vitamin D deficiency), osteosclerosis (excessive new bone formation), and adynamic bone disease (low bone turnover) all occur in CKD. Patients have bone pain, muscle weakness, and high fracture risk. - **Vascular calcification:** High phosphate and calcium-phosphate product cause calcification of blood vessels (increasing cardiovascular risk), cardiac valves, and soft tissues (calciphylaxis). **Cardiovascular Manifestations (Leading Cause of Death in CKD):** - **Hypertension:** From fluid overload and activation of the renin-angiotensin system. Present in ~80% of CKD patients; very difficult to control as GFR falls. - **Left ventricular hypertrophy (LVH):** Chronic hypertension and anemia cause the left ventricle to thicken; increases risk of heart failure and arrhythmias. - **Uremic pericarditis:** Accumulation of uremic toxins irritates the pericardium; presents with chest pain and pericardial friction rub. Can progress to pericardial effusion and tamponade. - **Atherosclerosis and coronary artery disease:** CKD is an independent risk factor for premature CAD; the combination of hypertension, anemia, dyskalemia, and abnormal lipid metabolism accelerates atherosclerosis. - **Heart failure:** From hypertension, LVH, anemia, and fluid overload; can be systolic or diastolic. **Neurologic Manifestations:** - **Uremic encephalopathy:** Chronic uremia causes altered mental status, difficulty concentrating, lethargy, and cognitive slowing. In severe cases, asterixis (flapping tremor), confusion, and seizures occur. - **Uremic neuropathy:** Peripheral neuropathy (restless legs, numbness), autonomic neuropathy (orthostasis, impotence). - **Muscle cramps:** Common, especially at night and during dialysis; from electrolyte shifts and uremia. **Gastrointestinal Manifestations:** - **Uremia causes GI toxicity:** Anorexia, nausea, vomiting, metallic taste (uremic fetor—ammonia-smelling breath), and abdominal pain. - **Peptic ulcer disease and GI bleeding:** More common in CKD; uremic toxins damage the mucosa. - **Constipation:** From restricted diet, medications (iron, phosphate binders), and reduced physical activity. **Dermatologic Manifestations:** - **Uremic pruritus:** Severe itching, sometimes intractable; from accumulation of uremic toxins and hyperphosphatemia. - **Uremic frost:** Fine white crystals of urea on skin; seen only in severe untreated uremia. - **Sallow or gray-yellow color:** From urochrome pigment and anemia. - **Ecchymosis:** From bleeding tendency. **Reproductive and Endocrine Effects:** - **Infertility:** Women may have irregular menses; both genders have reduced fertility. - **Sexual dysfunction:** Erectile dysfunction in men; reduced libido in both genders. - **Abnormal glucose metabolism:** Diabetes worsens; insulin resistance increases (in part due to uremia). **Immunologic Compromise:** - Uremia impairs cell-mediated immunity; patients on dialysis are at high risk for infections (catheter infections in PD, bloodstream infections in HD). - Vaccination response is poor; live vaccines are contraindicated. **THE CONCEPT OF "UREMIA":** **Uremia** is not simply elevated BUN; it is the **clinical syndrome of retained uremic toxins**—a complex mixture of substances that would normally be excreted by the kidneys. Uremic toxins include urea, creatinine, indoles, phenols, middle molecules, and advanced glycation end products (AGEs). These toxins have systemic toxic effects causing the constellation of symptoms described above. **The goal of dialysis and renal replacement therapy is to remove these toxins and control fluid balance to prevent uremic symptoms.**

The nursing management of CKD focuses on **slowing progression, managing complications, and preparing for renal replacement therapy**. This is a chronic disease requiring sustained patient education, medication adherence, and lifestyle modification. **MEDICATION MANAGEMENT IN CKD** **Renal-Protective Medications (Slow CKD Progression):** **ACE Inhibitors and ARBs:** - **Mechanism:** Block the renin-angiotensin-aldosterone system (RAAS), reducing intraglomerular pressure and preventing hyperfiltration. They also have anti-inflammatory and anti-fibrotic effects on the kidneys. - **Benefits:** In diabetic CKD, ACE-I/ARB therapy slows the decline in GFR and reduces proteinuria; in non-diabetic CKD, they reduce proteinuria and blood pressure. - **Examples:** Lisinopril (ACE-I), ramipril (ACE-I), losartan (ARB), irbesartan (ARB), telmisartan (ARB). - **Important cautions:** - **Do NOT combine ACE-I and ARB** (no additive benefit and increased risk of hyperkalemia, hypotension, and acute renal dysfunction). - **Monitor potassium closely**—these drugs reduce aldosterone, so potassium excretion falls; in CKD, hyperkalemia is a serious risk. Check K+ within 1–2 weeks of starting or increasing dose. - **Monitor creatinine**—a small rise in creatinine (10–20%) after starting ACE-I/ARB is expected and usually tolerated; larger increases warrant discontinuation. - **Contraindicated in pregnancy** (teratogenic) and in patients with **severe bilateral renal artery stenosis** (both kidneys depend on angiotensin II for perfusion). - In the Philippines, these drugs are first-line for CKD management, especially in diabetic CKD. **Other Antihypertensives:** - **Calcium channel blockers** (amlodipine, nifedipine) are safe and effective; non-dihydropyridines (diltiazem, verapamil) also reduce proteinuria. - **Beta-blockers** are useful in CKD with hypertension and heart disease; avoid in CKD with bronchospasm or severe bradycardia. - **Diuretics:** Used to manage volume overload and hypertension; loop diuretics (furosemide) are needed in advanced CKD because thiazides are less effective at low GFR. Avoid potassium-sparing diuretics (spironolactone) unless K+ is low—they exacerbate hyperkalemia. - **Avoid NSAIDs absolutely**—they reduce renal perfusion and accelerate CKD progression. NSAIDs are contraindicated in all stages of CKD. **Medications for Anemia:** **Erythropoietin-Stimulating Agents (ESAs):** - **Epoetin alfa (Eprex)** and **darbepoetin alfa (Aranesp)** replace the missing erythropoietin and stimulate RBC production. - **Dosing:** Started when Hgb falls to <10 g/dL or Hct <30%; titrated to target Hgb 10–12 g/dL (older targets of Hgb >13 were associated with increased thrombotic events). - **Monitoring:** Check Hgb/Hct every 1–2 weeks during titration, then monthly. A slow rise in Hgb is safer than rapid rise (risk of hypertensive crisis, seizures). - **Route:** Subcutaneous (preferred) or IV (during hemodialysis). - **Cautions:** - ESAs carry a **FDA black box warning** for thromboembolism, stroke, and MI, especially if Hgb is driven too high; use the lowest effective dose. - Patients on ESAs have higher hematocrit, which increases blood viscosity—monitor BP closely; may need more aggressive BP management. - **Iron must be repleted** before and during ESA therapy; without iron, ESA response is poor. Check serum iron, TIBC, and ferritin; give iron supplements or IV iron as needed. **Iron Supplements:** - **Oral iron:** Ferrous sulfate, ferrous gluconate; given between meals (better absorption on empty stomach) but often causes GI upset. Many CKD patients take iron with phosphate binders and antacids, which reduce iron absorption—separate dosing by 2 hours. - **IV iron:** Used in hemodialysis patients (iron sucrose given IV during dialysis, weekly or every other week); bypasses GI absorption issues. Preferred in advanced CKD. - **Iron monitoring:** Serum iron should be 60–170 mcg/dL; ferritin 100–500 ng/mL (higher targets in CKD). TSAT (transferrin saturation) 20–50%. - **Caution:** Excess iron causes oxidative stress and infection risk; avoid iron overload. **Other Agents for Anemia:** - **Vitamin B12 and folate:** Check levels; deficiency is common in CKD (especially in vegetarians or dialysis patients). Supplement if low. **Medications for Bone and Mineral Metabolism:** **Phosphate Binders:** - **Goal:** Maintain serum phosphate 3.5–5.5 mg/dL and calcium-phosphate product <55 (to prevent vascular calcification). - **Types:** - **Calcium-based:** Calcium carbonate (Caltrate, Os-Cal), calcium acetate (Phoslo). Bind phosphate in the gut; also provide calcium supplementation. **Given WITH meals** so they bind dietary phosphate before it is absorbed. Doses typically 2–4 g per meal. - **Non-calcium-based:** - **Sevelamer** (Renagel, Renvela)—does not contain calcium or metal; binds phosphate by ionic interaction. Given with meals. Used if serum calcium is already high or if there is concern about vascular calcification from calcium overload. - **Lanthanum carbonate** (Fosrenol)—lanthanide binds phosphate; given with meals. Used for phosphate-resistant hyperphosphatemia. - **Administration:** Phosphate binders MUST be taken WITH meals; taking them separate from food is ineffective. Counsel patients on proper timing. - **Side effects:** Constipation (especially calcium-based and sevelamer); GI upset. Ensure adequate fluid intake and fiber to manage constipation (unless fluid is restricted). **Active Vitamin D (Calcitriol):** - **Calcitriol (Rocaltrol)** is the active form of vitamin D, normally produced by kidneys. Given orally or IV (during dialysis in ESRD). - **Dosing:** Titrated to normalize serum calcium and suppress PTH. Usual dose 0.25–0.5 mcg twice daily initially, increasing by 0.25 mcg every 2–3 weeks based on serum calcium and PTH. - **Monitoring:** Check serum calcium and phosphate every 2–4 weeks during titration; target calcium 8.5–10 mg/dL. Monitor PTH (goal in Stage 3–5 CKD is 30–300 pg/mL; varies by stage and dialysis status). - **Caution:** Calcitriol increases both serum calcium AND phosphate (enhances GI absorption of both). If hyperphosphatemia is present, optimize phosphate binders BEFORE starting calcitriol. - **Hypercalcemia:** If serum calcium rises >10.5 mg/dL, hold calcitriol, increase phosphate binders, and check for vitamin D toxicity (from over-supplementation of native vitamin D). **Calcimimetic Agents (Secondary Hyperparathyroidism Resistant to Standard Therapy):** - **Cinacalcet (Sensipar):** A calcimimetic that increases the kidney's sensitivity to extracellular calcium, thereby suppressing PTH secretion. Used when PTH remains high despite calcium, phosphate binder, and calcitriol therapy. - **Dosing:** 30 mg PO daily initially; titrated to target PTH <300 pg/mL. - **Monitoring:** PTH, serum calcium, and phosphate every 2–4 weeks. Cinacalcet can lower serum calcium; monitor for hypocalcemia symptoms. **Potassium Binders (For Hyperkalemia in CKD):** - **Sodium polystyrene sulfonate (Kayexalate):** 15–60 g PO daily or 30–50 g PR (rectal). Resin exchanges sodium for potassium in the GI tract; potassium is excreted in feces. Onset is slow (4–24 hours); mainly used to maintain potassium between dialysis sessions in ESRD patients. - **Newer agents:** Patiromer (Veltassa) and sodium zirconium cyclosilicate (Lokelma) are newer, more effective potassium binders; less constipating than Kayexalate. - **Important:** Kayexalate is given as a suspension; if given as an enema, it is mixed with sorbitol or glucose to ensure potassium is not reabsorbed. Never mix Kayexalate with sorbitol if the patient is taking lactulose or mannitol (risk of colonic necrosis). **Metabolic Acidosis Management:** - **Sodium bicarbonate:** If serum bicarbonate <15 mEq/L and patient is symptomatic, sodium bicarbonate 650 mg PO 1–3 times daily is given. Goal is to raise bicarbonate to >15 mEq/L. Excess sodium should be monitored (may worsen hypertension); balance with dietary sodium restriction. - **Alternative:** In dialysate-based therapies, the dialysate bicarbonate concentration is increased. **DIET AND NUTRITION IN CKD** Dietary management is **critical to slowing progression and preventing uremic complications.** A renal dietitian should be consulted for all CKD patients at Stage 3 or beyond. **Protein Restriction:** - **Goal:** Reduce the protein load to minimize nitrogenous waste (BUN, creatinine, ammonia) while maintaining adequate nutrition and preventing protein malnutrition. - **Pre-dialysis CKD:** Protein is restricted to **0.6–0.8 g/kg/day** (approximately the minimum to prevent catabolism). A 70 kg patient would limit protein to ~42–56 g/day. - **Post-dialysis ESRD:** Protein is INCREASED to **1.0–1.2 g/kg/day** (~70–84 g/day for a 70 kg patient) because dialysis removes amino acids and proteins during treatment; underproviding protein leads to protein-energy malnutrition. - **Quality of protein:** Emphasize **high-biological-value proteins** (eggs, chicken, fish, lean meat) that are more efficiently used and produce less nitrogenous waste than plant proteins. Limit soy and legumes. - **Patient education:** Show examples: 3 oz chicken breast = 25 g protein; one egg = 6 g protein; 1 cup milk = 8 g protein. Help patients plan meals within their limit. **Potassium Restriction:** - **Goal:** Keep serum potassium 4.0–5.0 mEq/L to prevent hyperkalemia and fatal arrhythmias. - **Target intake:** <2000–3000 mg/day (normal intake is ~3000–4000 mg/day). - **High-potassium foods to LIMIT:** bananas, oranges, tomatoes, potatoes (especially baked), squash, spinach, dried fruits, nuts, chocolate, coffee, tea, salt substitutes (contain KCl). - **Preparation:** Soaking potatoes, carrots, and beets in water overnight reduces potassium content (the potassium leaches into water, which is discarded). - **Cooking:** Boiling vegetables in water (rather than steaming) reduces potassium. - **Careful monitoring:** As CKD progresses (especially Stage 4–5), potassium restriction becomes stricter. Some patients must count every milligram. **Phosphate Restriction:** - **Goal:** Keep serum phosphate 3.5–5.5 mg/dL. - **Target intake:** <800–1000 mg/day (normal is ~1200 mg/day). - **High-phosphate foods to LIMIT:** dairy products (milk, cheese, yogurt), processed meats, organ meats, chocolate, nuts, seeds, cola drinks (contain phosphoric acid additives), whole grains. - **Lower-phosphate alternatives:** white rice (lower than brown), refined white bread, egg whites (yolk is high in phosphate), lean meats in moderation. - **Medication interaction:** Phosphate binders taken with meals reduce dietary phosphate absorption; ensure proper timing and adherence. **Sodium Restriction:** - **Goal:** Control fluid overload and hypertension. - **Target intake:** <2000 mg/day (normal is ~3000–4000 mg/day). - **High-sodium foods to LIMIT:** processed foods, canned foods, deli meats, cheese, condiments (soy sauce, ketchup), restaurant foods. - **Seasoning alternatives:** Use herbs, spices, lemon juice, garlic instead of salt. - **Cooking:** Prepare meals at home using fresh ingredients (vs. processed/canned). **Fluid Restriction:** - **Goal:** Prevent fluid overload, maintain euvolemia between dialysis sessions. - **In pre-dialysis CKD with preserved urine output:** Fluid restriction is usually not necessary; thirst is the natural regulator. - **In advanced CKD (Stage 4–5) or ESRD with oliguria:** Fluid is restricted to **previous day's urine output plus 500–700 mL for insensible loss**. For example, if a patient produces 400 mL urine/day, fluid allowance (all intake: IV, oral, food, medications) is limited to ~900–1100 mL/day. - **Fluid sources:** Include not just beverages but also soups, jello, ice cream, fruits (watermelon, grapes), and liquid medications. Teaching patients to count all fluid sources is critical. - **Managing thirst:** Ice chips, hard candy, chewing gum (sugar-free), frequent mouth rinses with mouthwash, and careful lip care help manage thirst without consuming fluid. - **Monitoring:** Daily weight (same time each day, same clothing) is the best indicator of fluid status. A gain >1 kg/day suggests fluid excess. Between dialysis sessions, ESRD patients should aim for <1 kg/day weight gain. **Caloric Intake:** - **Goal:** Prevent protein-energy malnutrition, maintain lean body mass. - **Target:** 30–35 kcal/kg/day (higher in dialysis patients who lose calories during treatment). - **Sources:** Carbohydrates and fats; minimize protein to meet the protein targets listed above. Foods like pasta, rice, oils, and jam provide calories without excess protein, potassium, or phosphate. **Interdialytic Weight Gain (IDWG) in ESRD:** - Patients on hemodialysis (typically 3 times per week for 4 hours) gain fluid/weight between treatments. **Target IDWG is <1.0 kg/day or <5% body weight between sessions.** This is achieved by balancing fluid intake, urine output (if any), and dialysis fluid removal. Excessive IDWG (>5% body weight) leads to hypertensive crises during dialysis, disequilibrium syndrome, and increased cardiovascular complications. **COMPLICATIONS OF CKD REQUIRING NURSING INTERVENTION** **Hypertension:** - **Target BP:** <120/80 mmHg (or individualized based on age, comorbidities, and proteinuria). - **Management:** Sodium restriction, weight loss, regular exercise, adequate dialysis (removes sodium and fluid), and multi-drug antihypertensive regimens (ACE-I/ARB + calcium channel blocker + diuretic ± other agents). - **Hypertensive urgency/emergency:** If BP >180/120 with symptoms (headache, chest pain, dyspnea), treat cautiously—avoid rapid reduction (risk of stroke, MI, acute renal failure). IV labetalol or hydralazine titrated slowly. **Hyperkalemia (Covered Above):** - Dietary restriction, phosphate binders (which also reduce potassium intake), medications (ACE-I/ARB dose reduction if necessary), potassium binders, and dialysis. **Pericarditis:** - **Uremic pericarditis** presents with pleuritic chest pain, pericardial friction rub, and elevated WBC. ECG shows PR segment depression and diffuse ST elevation. - **Management:** Intensify dialysis (remove more uremic toxins), NSAIDs (cautious use), colchicine, or corticosteroids in resistant cases. - **Complication:** Pericardial effusion and tamponade (life-threatening). Pericardiocentesis may be needed. **Bone Disease (Renal Osteodystrophy):** - Managed with phosphate binders, active vitamin D, calcium supplementation, and careful monitoring of PTH, calcium, and phosphate (as detailed above). - **Complications:** Fractures, bone pain, muscle weakness. Physical therapy and pain management are important. **Infection:** - CKD patients have impaired immunity; dialysis patients are at especially high risk (catheter infections, bacteremia). - **Prevention:** Good hand hygiene, clean catheter care, vaccination (influenza, pneumococcal—live vaccines are avoided), prompt treatment of infections. **Cardiovascular Disease:** - **Management:** Aggressive BP control, lipid management (statin therapy), smoking cessation, diabetes management, regular exercise, and treatment of anemia (to reduce cardiac strain from low oxygen). **Adherence and Psychosocial Support:** - CKD is a chronic condition requiring lifelong medication adherence, dietary modification, fluid restriction, and frequent medical visits. Depression, anxiety, and non-adherence are common. - **Nursing role:** Regular assessment of psychosocial status, referral to mental health if needed, patient education (written materials, videos, support groups), and motivational interviewing to improve adherence.

**Hemodialysis (HD) is the most common renal replacement therapy**, accounting for ~85% of dialysis patients globally and in the Philippines. It is an **external mechanical filtration process** in which blood is pumped through an artificial kidney (dialyzer), where **diffusion and ultrafiltration** remove waste products and excess fluid, and cleaned blood is returned to the patient. **PRINCIPLES OF HEMODIALYSIS** **The Dialyzer (Artificial Kidney):** The dialyzer consists of thousands of **hollow fiber membranes** with a semipermeable membrane wall. Blood flows through the hollow fibers; dialysate flows counter-current around the fibers (outside the fibers). The membrane separates blood from dialysate, allowing: - **Diffusion:** Small solutes (K+, urea, creatinine, phosphate) move down their concentration gradient from blood (where they are high) into dialysate (where they are low). Diffusion is a **concentration-dependent process**; the larger the concentration gradient, the faster the removal. - **Ultrafiltration:** Hydrostatic pressure (generated by the dialysis machine's blood pump) pushes **fluid and small solutes** across the membrane from blood into dialysate. The amount of fluid removed can be precisely controlled—this is how excess fluid is eliminated. - **The membrane is NOT permeable to large proteins or cells,** so they remain in the blood—this is why dialysis doesn't remove all uremic substances (some large uremic toxins and proteins remain), but it removes the majority of small-to-medium-sized solutes and excess fluid. **Dialysis Modalities (By Frequency and Duration):** - **Conventional hemodialysis (CHD):** 3–5 hours, 3 times per week (Monday/Wednesday/Friday or Tuesday/Thursday/Saturday). Most common in the Philippines. - **Nocturnal hemodialysis:** 6–8 hours, 3–6 nights per week. More efficient removal; fewer dietary/fluid restrictions. - **Twice-weekly dialysis (short dialysis):** Reserved for patients with significant residual renal function; less adequate for most ESRD patients. **Adequacy of Dialysis:** The **Kt/V (dimensionless urea clearance)** measures dialysis adequacy: - **K** = dialyzer urea clearance (mL/min) - **t** = dialysis time (min) - **V** = urea distribution volume (approximately total body water, ~60% body weight in L) - **Kt/V = (clearance × time) / distribution volume** For conventional hemodialysis, **target Kt/V ≥1.2** (meaning the dialyzer removes urea equal to more than the total body urea pool per treatment). Higher Kt/V correlates with better outcomes and fewer uremic symptoms. The nurse monitors Kt/V monthly (calculated from pre- and post-dialysis BUN, dialysis duration, and patient weight). **VASCULAR ACCESS FOR HEMODIALYSIS** Successful hemodialysis requires **reliable, high-flow vascular access** to allow ~200–400 mL/min blood flow through the dialyzer. There are three types of vascular access: **1. ARTERIOVENOUS (AV) FISTULA (Preferred):** A **surgically created connection between an artery and vein** in the forearm (usually), wrist, or upper arm. The artery's high pressure and flow forces blood into the vein, which dilates and thickens, allowing it to accommodate large-bore needles and high flow rates. **Advantages:** - **Lowest infection and clotting risk** (native vessels, not foreign material). - **Longest longevity** (some fistulas last 20+ years). - **Best outcomes and survival** in long-term hemodialysis. **Disadvantages:** - **Requires 6–12 weeks to mature** before first use (vessel remodeling takes time). - **Not all patients have suitable anatomy** for fistula creation. **Fistula Maturation:** - **THRILL (palpable vibration/buzz):** Palpate over the fistula; a normal thrill indicates good patency and arterial-venous flow. Absence of thrill suggests stenosis or clotting. - **BRUIT (audible sound):** Auscultate with stethoscope over the fistula; a normal bruit is a whooshing sound from turbulent flow. A high-pitched bruit may indicate stenosis; absence suggests clotting. - **Visual inspection:** The vein should be visibly distended and pulsatile. - **Needle cannulation:** Once mature (usually 6–12 weeks post-creation), the vein can accommodate two large-bore (15–17 gauge) needles. **Maturation Failure:** - ~20–30% of newly created fistulas fail to mature adequately. Causes include inadequate vein size, poor arterial inflow, stenosis, or thrombosis. - **Assessment:** If thrill/bruit are absent or weak, or if the vein is not visibly distended after 4–6 weeks, imaging (ultrasound or fistulography) is performed to identify stenosis or thrombosis. - **Intervention:** Angioplasty (percutaneous transluminal angioplasty or PTA) can open stenotic lesions; if thrombosed, thrombolytic therapy or thrombectomy may be attempted. **AV Fistula Arm Care (Critical Nursing Responsibility):** The nurse provides detailed education on **protecting the fistula arm**: - **NO blood pressure measurement** on the fistula arm (cuff pressure can damage the vessel). - **NO venipuncture or IV insertion** on the fistula arm (risk of infection, clotting, or loss of access). - **NO tight clothing, jewelry, or watches** on the fistula arm (restrict blood flow). - **NO sleeping on or prolonged pressure on the fistula arm** (may occlude the access). - **Daily thrill/bruit checks** at home: Patient palpates for the buzz (thrill) and listens for the sound (bruit); teaches family members to do the same. Absence of thrill/bruit warrants immediate medical evaluation. - **NO forceful compression or milking** of the fistula (can cause aneurysm or vessel rupture). - **Keep the arm clean and dry;** report any redness, warmth, or drainage at the needle sites. - **Avoid heavy lifting or strenuous activity** with the fistula arm for the first few weeks post-surgery (allow healing and maturation). **2. ARTERIOVENOUS (AV) GRAFT:** A **prosthetic conduit** (made of polytetrafluoroethylene [PTFE], polyurethane, or other materials) surgically placed to connect an artery to a vein. Often used if the patient lacks suitable veins for a native fistula. **Advantages:** - **Faster maturation** than native fistula (~2–4 weeks). - **Can be created with smaller veins** (useful in obese or diabetic patients with difficult vasculature). **Disadvantages:** - **Higher infection and clotting rates** than native fistula (foreign material, thrombus risk). - **Shorter longevity** (average 3–5 years; requires frequent interventions and eventual replacement). - **Higher cost** than native fistula. **Care:** Similar to native fistula (thrill/bruit checks, no BP/IV on graft arm, protect from trauma). Grafts occlude more easily than native fistulas; if thrill/bruit are lost, emergency intervention (thrombectomy, angioplasty) is needed to preserve access. **3. CENTRAL VENOUS CATHETER (CVC) FOR TEMPORARY OR EMERGENCY ACCESS:** A **double-lumen catheter** placed percutaneously (usually in the internal jugular vein, sometimes femoral or subclavian, though subclavian is increasingly avoided due to stenosis risk). One lumen draws blood from the patient; the other returns cleaned blood. **Advantages:** - **Immediate availability** (can use within minutes; no waiting for maturation). - **Useful in acute kidney injury** when dialysis is needed urgently before a permanent access can be created. - **Useful as bridge access** while a fistula or graft matures. **Disadvantages:** - **Very HIGH infection risk** (catheter is a foreign body in a blood vessel; biofilm forms; bacteremia and sepsis are common). - **Higher clotting risk** than fistula/graft (especially with turbulent flow in the catheter). - **Very short lifespan** (weeks to a few months; not suitable for long-term use). - **Risk of central venous stenosis** if used long-term (stenosis reduces access to the heart). - **Cannot be used long-term** (high morbidity and mortality; reserved for emergencies or temporary bridge). **CVC Care (Critical Infection Prevention):** - **Sterile dressing** over the catheter insertion site; change dressing every 3 days or if soiled, using aseptic technique. - **Daily site inspection** for signs of infection: redness, drainage, warmth, tenderness. - **Blood cultures** immediately if the patient develops fever (CVC-associated bacteremia is common). - **Antibiotic lock solution** (heparin or gentamicin/heparin) may be instilled in the catheter lumens between dialysis sessions to reduce clotting and infection. - **Avoid submerging the catheter** (shower with catheter site covered; no swimming/bathing). - **Remove the catheter as soon as a permanent access matures** (fistula or graft). **DURING HEMODIALYSIS: NURSING ASSESSMENT AND MONITORING** **Pre-Dialysis Assessment:** - **Vital signs:** BP, HR, RR, temperature, orthostatic BP changes (check for hypovolemia). - **Axial weight:** Nude weight before dialysis; compared to dry weight (target post-dialysis weight). **Interdialytic weight gain (IDWG) = pre-dialysis weight − dry weight.** IDWG >1 kg/day indicates excessive fluid/sodium intake. - **Vascular access assessment:** Palpate for thrill, auscultate for bruit; inspect for signs of infection, clotting, or aneurysm. - **General assessment:** Fatigue, dyspnea, chest pain, orthostatic symptoms, nausea. - **Recent labs:** BUN, creatinine, potassium, phosphate, calcium, hemoglobin, and previous Kt/V (to assess adequacy). - **Fluid restrictions adherence:** Ask about fluid intake, thirst management, weight changes at home. - **Medications:** Review for renal dosing; some drugs (antihypertensives, phosphate binders) may need adjustment based on dialysis schedule. **During Dialysis:** - **Needle insertion:** Two 15–17 gauge needles are inserted into the fistula/graft (one for blood outflow to the dialyzer, one for return). Needle insertion may cause discomfort; local anesthesia (topical lidocaine cream) or subcutaneous injection is often used. Over time, repeated needle punctures cause **cannulation site stenosis** (vessel narrowing) and aneurysm formation (outpouching of vessel wall). - **Machine monitoring:** The dialysis technician monitors blood pump speed (mL/min), dialysate temperature (35.5°C, 96°F), dialysate conductivity (electrolyte concentration), and ultrafiltration rate (mL/min fluid removal). Any alarm indicates a problem (disconnection, low blood pressure, clotting). - **Vital signs during dialysis:** BP, HR, and symptoms are monitored every 30–60 minutes. Record all parameters in the dialysis flow sheet. - **Ongoing nursing assessment:** - **Hypotension:** Common during dialysis (especially in the first 1–2 hours when fluid is being removed and the patient's vascular space is contracting). Symptoms include dizziness, nausea, cramps, chest discomfort. **Management:** Slow the ultrafiltration rate, give an IV bolus (0.5–1 L normal saline or hypertonic saline), elevate legs, have patient lie flat, reduce dialysate temperature, or use sodium profiling (increase dialysate sodium early in treatment). If severe (SBP <80 mmHg with symptoms), consider stopping dialysis temporarily. - **Hypertension:** Less common but can occur if fluid removal is inadequate (IDWG was excessive). Treat by removing more fluid, counseling on dietary sodium/fluid restriction, or adjusting antihypertensives. - **Muscle cramps:** Painful involuntary muscle contractions, usually in legs or hands; from electrolyte shifts, ultrafiltration, or uremia. **Management:** Slow ultrafiltration, give IV bolus, or quinine sulfate (though evidence is mixed). Stretching and massage may provide relief. - **Disequilibrium syndrome (Dialysis Disequilibrium Syndrome or DDS):** A constellation of neuro symptoms from **osmotic shifts of fluid** during rapid solute removal. As blood urea falls rapidly, water shifts INTO the brain cells (osmotic gradient), causing cerebral edema. Symptoms: headache, nausea, vomiting, confusion, agitation, restlessness, muscle twitching, and in severe cases, seizures or coma. **Onset is usually in the last 1–2 hours of dialysis or immediately post-dialysis.** Risk factors: first dialysis session, severe uremia (high initial BUN), dialysis with high blood flow/ultrafiltration. **Prevention/management:** Use slower blood flow/ultrafiltration on initial dialyses, increase dialysate osmolality (add glucose), or use shorter, more frequent dialyses; if symptoms occur, stop dialysis immediately and give IV hypertonic saline or mannitol (shrink brain cells and reduce edema). Symptoms usually resolve within 6–12 hours but can be prevented with careful initial dialysis prescription. - **Bleeding:** Dialysis uses **heparin** (anticoagulant) to prevent clotting in the extracorporeal circuit; this increases bleeding risk. Occult blood loss (via heparin) contributes to anemia. Watch for blood in dialysate, bleeding at needle sites, hematuria, or epistaxis. At the end of dialysis, **needle sites are compressed for 5–10 minutes** to achieve hemostasis. - **Infection (line sepsis):** Fever, chills, rigors during or shortly after dialysis, especially with CVCs. Obtain blood cultures from both catheter lumens and peripheral blood before starting antibiotics. Empiric broad-spectrum antibiotics (vancomycin + ceftazidime or fluoroquinolone) are started; narrowed based on culture results. - **Disconnection:** If dialyzer or tubing disconnects, blood spills into the dialysate. Alarms sound; the technician immediately clamps blood lines and reconnects. Patient may lose 200–300 mL blood; monitor for signs of hypovolemia (dizziness, tachycardia). - **Clotting:** If the access clots during dialysis, blood flow through the fistula/graft stops; blood in the dialyzer and tubing clots as well. Clotting is indicated by **loss of thrill/bruit, absence of blood return on the venous (return) line, and alarm on the machine** (pressures change). **Do NOT squeeze or milk the fistula to try to dislodge clots** (risk of embolism or vessel rupture); instead, notify the technician and nephrologist. The access must be cleared of clots within a few hours or it is lost. Thrombolytic therapy (alteplase infused into the access) or mechanical thrombectomy may be performed to restore patency. - **Pericarditis or pulmonary edema:** Monitor for pleuritic chest pain (pericarditis) or dyspnea with crackles (pulmonary edema from fluid overload). Intensify dialysis or diuretics (if patient has residual urine output). **Post-Dialysis Assessment:** - **Axial weight:** Post-dialysis weight should equal or be close to dry weight (target). If weight loss >2.5 kg in one session, the patient had significant IDWG and likely experienced hypotension during treatment. - **Vital signs:** BP, HR, orthostatic vital signs (to assess for hypovolemia). - **Hemostasis:** Ensure needle site bleeding has stopped; apply additional pressure if needed. - **Vascular access:** Final inspection for swelling, hematoma, or infection. - **Symptom review:** Any residual headache, cramps, nausea, or dizziness? These may indicate disequilibrium syndrome or hypovolemia requiring intervention. - **Medications:** Administer any post-dialysis medications (e.g., antihypertensives held before dialysis, phosphate binders with food). - **Restrictions for the interdialytic period:** Remind patient of fluid (usually ~1000 mL/day including food), potassium, sodium, and protein limits. Education on managing thirst and avoiding weight gain >1 kg/day. - **Documentation:** Record IDWG, ultrafiltration, Kt/V, any complications, and patient tolerance in the dialysis flow sheet and medical record. **COMPLICATIONS OF HEMODIALYSIS** **Vascular Access Complications:** - **Stenosis:** Neointimal hyperplasia (abnormal smooth muscle cell proliferation) narrows the vessel. Presents as loss of thrill/bruit, inadequate blood flow, or difficulty achieving prescribed blood flow. Diagnosed by ultrasound or fistulography; treated with PTA (angioplasty) or surgical revision. Stenosis recurs in 50% of cases within 6 months; repeated interventions are common. - **Thrombosis:** Access clots; blood flow stops. Urgent intervention (thrombectomy or thrombolytic therapy) needed within hours or access is lost. Thrombosis risk is ~0.5–2 episodes per access-year. - **Infection (vascular access infection):** Cellulitis or abscess at needle sites (bacterial entry); presents as redness, warmth, drainage, pain. Treat with antibiotics; if severe or recurring, access removal may be needed. **CVC-associated infections are much more frequent than fistula/graft infections.** Bacteremia from access infection can lead to endocarditis or sepsis. - **Aneurysm:** Repeated needle punctures weaken the vessel wall; outpouching develops. Risk increases with time and frequency of cannulation. Ruptured aneurysm is a hemorrhagic emergency. - **Steal syndrome (vascular steal):** High flow through the fistula/graft diverts blood away from distal tissues, causing ischemia (pain, coolness, numbness, skin breakdown, gangrene in worst cases). Managed by reducing flow (access ligation) or revision surgery. - **Venous hypertension:** Stenosis downstream of the access causes pressure backup; leads to arm swelling and pain. Treated with PTA or revision. **Systemic Complications:** - **Hypotension and hypovolemia:** Managed as described above (slow ultrafiltration, IV fluids, elevate legs, reduce dialysate temperature). - **Disequilibrium syndrome:** Managed as described above (prevent with slow initial dialysis, manage with hypertonic saline/mannitol if occurs). - **Muscle cramps:** Managed with slower ultrafiltration, IV bolus, or quinine. - **Arrhythmias:** From electrolyte shifts (especially K+, Ca2+), ischemia, or pericarditis. Monitor ECG; treat underlying cause. - **Bacterial infection (bloodstream infection, endocarditis):** From contaminated dialysate, infected access, or line sepsis. Treat with antibiotics; remove infected CVC if source. - **Hepatitis B and C:** Transmitted via contaminated blood or dialysate (now rare with modern infection control); screen all dialysis patients and provide HBV vaccination (though response is poor in uremia). - **Anemia:** From chronic blood loss (dialysis removes ~1 mL blood per dialysis session), shortened RBC lifespan, and low erythropoietin. Managed with ESAs and iron supplementation. - **Chronic kidney disease-mineral bone disorder (CKD-MBD):** Hyperphosphatemia, hypocalcemia, secondary hyperparathyroidism, and vascular calcification. Managed with phosphate binders, vitamin D, and calcimimetics (as discussed in the CKD section). - **Encephalopathy (dialysis-related encephalopathy or DRE):** Now rare but was historically caused by accumulation of aluminum (from dialysate and phosphate binders) in the brain, causing dementia and seizures. Modern dialysate is aluminum-free and aluminum-containing binders have been phased out; patients on these older binders need monitoring. **Cardiovascular Complications in Dialysis Patients:** - Dialysis patients have very high rates of myocardial infarction, stroke, and sudden cardiac death (10–20× normal population). - Mechanisms: hypertension, LVH, coronary atherosclerosis, dysrhythmias (especially in hyperkalemic episodes), anemia (increased cardiac workload), chronic inflammation, and uremia. - **Prevention:** Strict BP control, treatment of anemia, lipid management, smoking cessation, and adequate dialysis (Kt/V >1.2).