Dialysis
DIALYSIS STUDY NOTES
RENAL SYSTEM AND RENAL FAILURE
Key Concepts Related to Renal Failure and Nursing Interventions:
Renal Diet: Essential dietary modifications are crucial for managing renal failure:
High Carbohydrates: Important for energy.
Low Potassium: Recommend 60-70 mEq/day to prevent hyperkalemia.
Low Phosphorus: Reduces risk of phosphorus retention.
Moderate Protein: Adequate but not excessive protein intake.
Sodium Restrictions: To manage blood pressure and fluid retention.
Vitamin Supplements: Required for those on restricted diets.
Fluid Restrictions: Consideration of approximately 3 days of fluid intake without dialysis.
VITAL SIGNS AND MONITORING
Key Interventions in Monitoring:
Vital Signs (V/S): Regular monitoring is necessary to detect any fluctuations.
Intake and Output (I&O):
Monitor hourly for patients in Acute Renal Failure (ARF).
Weight Monitoring: Track weight changes as indicators of fluid status.
Laboratory Assessments:
Blood Urea Nitrogen (BUN): Indicators of renal function.
Creatinine: Important for evaluating kidney function.
Electrolytes: Specifically potassium, sodium, phosphate.
Acidosis Monitoring: Possible metabolic acidosis; administer bicarbonate as needed.
URINALYSIS INSPECTIONS
Key Components to Observe in Urinalysis:
Presence or absence of urine: Some patients may still urinate despite renal failure.
Protein Levels: High protein can indicate kidney damage.
Casts & Hematuria: Assess for kidney injury.
Specific Gravity: Evaluates concentrating ability of the kidney.
Level of Consciousness (LOC): Changes could indicate systemic effects.
Check for Infection: Signs of urinary tract infection (UTI).
Assess for Dysrhythmias: Electrolyte imbalances can lead to cardiac issues.
Monitor for Fluid Overload: Symptoms include swelling, weight gain, dyspnea.
COMPLICATIONS OF RENAL FAILURE
Potential Complications Include:
Gastrointestinal Bleeding
Hypertension (HTN)
Hypervolemia and Hypovolemia
Infection Risks
Insomnia/Fatigue: Affects quality of life.
Decreased Calcium Levels: Can have systemic effects, including bone health.
Ocular Irritation
Phosphorus and Potassium Retention: Risks associated with anemia.
Pruritus: Commonly reported itching in renal failure.
Psychosocial Changes: Mental health may decline.
Metabolic Acidosis
Neurological Changes: Confusion or altered mental status.
DIALYSIS OVERVIEW
Definition and Function:
Dialysis is a treatment option for renal failure and certain other traumatic conditions.
Serves as an imperfect replacement for kidney function, required when 85% to 90% of kidney function is lost.
Operates on principles of Diffusion and the Convection of fluids through a semipermeable membrane.
INDICATIONS FOR DIALYSIS
Acute Indications Include:
Hyperkalemia: High potassium levels requiring urgent intervention.
Increasing Acidosis: Metabolic issues necessitate dialysis intervention.
Fluid Overload: Prevents pulmonary edema and further complications.
Uremic Serositis: Inflammation of lining tissue (heart, lungs, abdomen).
Uremic Pericarditis and Encephalopathy: Serious complications of uremia.
Acute Poisoning Cases: Certain toxins can be effectively removed.
Chronic Indications Include:
Symptomatic Renal Failure: Fluid volume overload, hyperkalemia, or anorexia/nausea that is unresponsive to diuretics.
Low Glomerular Filtration Rate (GFR): Less than 10-15 mL/min signifies need for dialysis.
Difficulties Managing Serum Phosphorus or Anemia: GFR extremely low complicates average management.
TYPES OF DIALYSIS
Types of Dialysis Modalities:
Hemodialysis (HD): Blood is pumped through a dialyzer, removing toxins through a semipermeable membrane. Ultrafiltration and negative pressure facilitate the process.
Peritoneal Dialysis (PD): Utilizes peritoneal cavity; sterile solution runs through a tube, allowing fluid to be drained and refreshed multiple times daily.
Hemofiltration or Continuous Renal Replacement Therapy (CRRT): Typically for critically ill patients, performed continuously over a day to several days.
HEMODIALYSIS PROCESS
Mechanics of Hemodialysis:
Blood is pumped into the dialyzer, exposing it to a semipermeable membrane where ultrafiltration occurs.
Toxins are removed as fluid flows from high to low concentration.
Several liters of fluid and waste can be effectively removed during a session.
PERITONEAL DIALYSIS PROCESS
Mechanics of Peritoneal Dialysis:
Sterile solution containing minerals and glucose infuses into the peritoneal cavity via a catheter.
Solution must dwell for a period before draining; frequent exchanges, typically 4-5 times a day or 8-10 hours overnight.
Utilizes diffusion and osmosis through the peritoneum to cleanse blood effectively.
HEMODIALYSIS AND PERITONEAL DIALYSIS COMPLICATIONS
Dialysis-Related Complications Include:
Hemodialysis Complications:
Disequilibrium Syndrome: Rapid changes in extracellular fluid composition.
Dialysis Encephalopathy: Aluminum toxicity affecting neurological function.
Infections, Hypotension, Shock, Sepsis: Monitor for these critical conditions.
Muscle Cramping
Peritoneal Dialysis Complications:
Peritonitis: Indicators include cloudy drainage fluid and abdominal pain.
Risks of Hypotension, bladder/bowel perforation, insufficient outflow, or leakage.
NURSING INTERVENTIONS FOR DIALYSIS
For Hemodialysis Interventions:
Monitor vital signs frequently; hypotension is a significant risk.
Conduct relevant lab tests before, during, and after treatments.
Assess potential fluid overload and ensure the patency of the access device.
Weigh the patient before and after each procedure to track fluid loss.
Hold medications that might affect blood pressure or are water soluble.
Educate patients and families regarding the process and any potential risks.
For Peritoneal Dialysis Interventions:
Monitor vital signs, particularly for signs of infection and fluid status.
Assess the catheter site for complications such as bleeding or infection.
Keep track of infusion outflow quality and quantity; ensure it is a continuous stream.
Monitor dwell times closely and avoid exceeding prescribed limits.
TYPES OF ACCESS FOR DIALYSIS
Access Types for Dialysis:
Subclavian Catheter:
Short-term use in acute kidney injury (AKI).
Should only be used for dialysis; filled with heparin.
Can remain for up to 6 weeks under strict observation.
Femoral Catheter:
Short-term use, must limit patient positioning to prevent complications.
Continuous assessment of circulation is necessary.
External AV Shunt:
Designed for immediate use; involves surgical placement in arteries and veins.
Requires careful maintenance to avoid complications such as infection.
Arteriovenous Fistula (AVF):
Surgical anastomosis of artery and vein; preferred method for long-term dialysis, requiring maturation time of 2-3 months before use.
Arteriovenous Graft (AVG):
Indicates use when venous access is inadequate; uses synthetic materials to connect artery and vein.
Requires careful monitoring for risks of infection, thrombosis, and stenosis.
NURSING INTERVENTIONS FOR ACCESS TYPES
For AV Graft and Shunt:
Avoid using the affected arm for blood pressure monitoring, blood draws, or IV insertions.
Palpate for a thrill or auscultate for bruit as indicators of patent access.
Regular assessments for infection signs, circulation, and potential ischemia.
WHO NEEDS DIALYSIS?
Diagnostic Indicators for Selecting Dialysis Patients:
Acid-Base Problems
Electrolyte Problems
Intoxications: Removed through dialysis.
Overload of Fluids: Complicated by renal failure.
Uremic Symptoms: Signifying end-stage renal disease or severe dysfunction.
References:
Mayo Foundation for Medical Education and Research. All rights reserved.
REG 02007 Nursing Education Consultants, Inc.
RENAL SYSTEM AND RENAL FAILURE
Key Concepts Related to Renal Failure and Nursing Interventions:
Renal Diet: Essential dietary modifications are crucial for managing renal failure, aiming to reduce the workload on the kidneys and prevent complications:
High Carbohydrates: Provide necessary energy to prevent muscle wasting (protein catabolism) as protein intake is often restricted.
Low Potassium: Typically recommended at 60-70 mEq/day to prevent hyperkalemia, which can lead to life-threatening cardiac arrhythmias. Foods high in potassium include bananas, oranges, potatoes, and tomatoes.
Low Phosphorus: Reduces the risk of hyperphosphatemia, which contributes to renal osteodystrophy (bone disease) and metastatic calcifications. Phosphate binders are often prescribed.
Moderate Protein: Adequate but not excessive protein intake is necessary for tissue repair and maintenance without increasing nitrogenous waste products (BUN, creatinine). The amount is carefully individualized based on the patient's remaining kidney function and dialysis status.
Sodium Restrictions: Essential to manage blood pressure and fluid retention, preventing hypertension, edema, and fluid overload.
Vitamin Supplements: Required due to dietary restrictions and the loss of water-soluble vitamins during dialysis. Specific supplements often include B vitamins, vitamin C, and folic acid.
Fluid Restrictions: Consideration of approximately 3 days of fluid intake without dialysis. The amount is precisely calculated based on urine output and insensible losses, to prevent fluid overload that can lead to pulmonary edema, hypertension, and heart failure.
VITAL SIGNS AND MONITORING
Key Interventions in Monitoring:
Vital Signs (V/S): Regular monitoring, including blood pressure, heart rate, respiratory rate, and temperature, is necessary to detect any fluctuations indicative of fluid imbalance, infection, or cardiac complications.
Intake and Output (I&O):
Monitor hourly for patients in Acute Renal Failure (ARF) to assess kidney function recovery, fluid balance, and response to treatment. This includes all oral and intravenous fluids, as well as urine, emesis, and drain output.
Weight Monitoring: Track daily weight changes accurately as the most reliable indicator of fluid status. A sudden weight gain can signify fluid overload, while rapid loss might indicate dehydration.
Laboratory Assessments:
Blood Urea Nitrogen (BUN): A primary indicator of renal function and protein metabolism. Elevated levels suggest impaired kidney function and accumulation of nitrogenous waste.
Creatinine: A more specific indicator of kidney function, as it is primarily excreted by the kidneys. Elevated levels correlate with decreased Glomerular Filtration Rate (GFR).
Electrolytes: Specifically potassium (to prevent hyperkalemia), sodium (for fluid balance), phosphate (for bone health), and calcium (often low in renal failure due to hyperphosphatemia and impaired vitamin D activation).
Acidosis Monitoring: Patients often develop metabolic acidosis due to the kidneys' inability to excrete acid effectively. Monitor arterial blood gases (ABGs) and administer bicarbonate or other alkalizing agents as needed to maintain acid-base balance.
URINALYSIS INSPECTIONS
Key Components to Observe in Urinalysis:
Presence or absence of urine: Some patients may still urinate despite significant renal failure (oliguria or anuria), while others may have non-oliguria with poor kidney function.
Protein Levels: High protein (proteinuria) can indicate various degrees of kidney damage, from mild glomerular injury (microalbuminuria) to severe damage (macroalbuminuria).
Casts & Hematuria: Assess for kidney injury. Red blood cell casts suggest glomerulonephritis; white blood cell casts indicate pyelonephritis or interstitial nephritis; waxy or broad casts are seen in chronic kidney disease; hematuria (blood in urine) signifies damage to the urinary tract or glomeruli.
Specific Gravity: Evaluates the concentrating ability of the kidney. A fixed specific gravity (around ) indicates impaired renal concentrating ability.
Level of Consciousness (LOC): Changes could indicate systemic effects of uremia, electrolyte imbalances (e.g., hypernatremia, hyponatremia), or severe acidosis affecting the brain.
Check for Infection: Signs of urinary tract infection (UTI), such as pyuria (white blood cells in urine), bacteriuria, and nitrites.
Assess for Dysrhythmias: Electrolyte imbalances, particularly hyperkalemia, can lead to serious cardiac issues and dysrhythmias. Monitor ECG changes.
Monitor for Fluid Overload: Symptoms include peripheral edema, sudden weight gain, dyspnea (shortness of breath), orthopnea, crackles in the lungs, and elevated jugular venous pressure.
COMPLICATIONS OF RENAL FAILURE
Potential Complications Include:
Gastrointestinal Bleeding: Caused by uremic gastritis, peptic ulcers, or impaired platelet function (uremic coagulopathy).
Hypertension (HTN): Often due to fluid overload, activation of the renin-angiotensin-aldosterone system, and increased sympathetic nervous system activity.
Hypervolemia and Hypovolemia: Hypervolemia (fluid overload) is common due to impaired excretion, leading to edema and HTN. Hypovolemia can occur from excessive diuresis or fluid restriction.
Infection Risks: Patients are immunocompromised due to uremia, and dialysis access sites provide entry points for pathogens.
Insomnia/Fatigue: Common due to accumulation of toxins, anemia, and psychological stress, significantly affecting quality of life.
Decreased Calcium Levels: Hypocalcemia often results from hyperphosphatemia (phosphate binds to calcium) and impaired activation of vitamin D by the kidneys, contributing to renal osteodystrophy.
Ocular Irritation: Can be caused by metastatic calcifications in the conjunctiva due to high calcium-phosphate product.
Phosphorus and Potassium Retention: Leads to hyperphosphatemia and hyperkalemia, with risks associated with bone disease, pruritus, and life-threatening cardiac dysrhythmias, respectively.
Pruritus: Commonly reported itching in renal failure, attributed to uremic toxins, hyperphosphatemia, and secondary hyperparathyroidism.
Psychosocial Changes: Mental health may decline, including depression, anxiety, and body image disturbance due to chronic illness and lifestyle changes.
Metabolic Acidosis: The kidneys' inability to excrete hydrogen ions and regenerate bicarbonate often leads to chronic metabolic acidosis.
Neurological Changes: Can range from mild confusion to uremic encephalopathy (lethargy, seizures, coma) due to accumulation of uremic toxins. Peripheral neuropathy is also common.
DIALYSIS OVERVIEW
Definition and Function:
Dialysis is a medical treatment option for end-stage renal disease (ESRD), severe acute kidney injury (AKI), and certain other traumatic conditions or intoxications.
It serves as an imperfect replacement for the kidneys' functions, required when approximately 85% to 90% of kidney function is lost, or GFR falls below 10-15 mL/min.
Operates on fundamental principles of Diffusion (movement of solutes from an area of higher concentration to lower concentration across a semipermeable membrane) and the Convection (movement of solutes with fluid across a semipermeable membrane due to pressure differences, also known as ultrafiltration) of fluids and solutes through a semipermeable membrane.
INDICATIONS FOR DIALYSIS
Acute Indications Include:
These conditions require urgent intervention to prevent life-threatening complications.
Hyperkalemia: High potassium levels (>6.5 ext{ mEq/L}) unresponsive to medical management, posing a significant risk for fatal cardiac arrhythmias.
Increasing Acidosis: Severe metabolic acidosis (pH <7.2) recalcitrant to bicarbonate therapy, which can impair cellular function across multiple organ systems.
Fluid Overload: Severe hypervolemia leading to pulmonary edema, hypertension, or heart failure that is unresponsive to diuretics.
Uremic Serositis: Inflammation of the lining tissues such as pericarditis (heart), pleuritis (lungs), or peritonitis (abdomen), indicating severe uremia.
Uremic Pericarditis and Encephalopathy: Serious, life-threatening complications of uremia signifying advanced kidney failure requiring immediate removal of toxins.
Acute Poisoning Cases: Dialysis can effectively remove certain dialyzable toxins (e.g., lithium, salicylates, ethylene glycol) from the blood that cannot be cleared by other means.
Chronic Indications Include:
These reflect long-term management needs for ESRD.
Symptomatic Renal Failure: Manifestations such as fluid volume overload, intractable hyperkalemia, severe nausea or anorexia, uremic pruritus, and neurological symptoms that are unresponsive to conventional medical therapies.
Low Glomerular Filtration Rate (GFR): A consistently low GFR, typically less than , regardless of symptoms, signifies that the kidneys are no longer able to adequately clear waste products.
Difficulties Managing Serum Phosphorus or Anemia: When the GFR is extremely low, average medical management (e.g., phosphate binders, erythropoiesis-stimulating agents) becomes insufficient to control hyperphosphatemia or severe anemia related to kidney disease.
TYPES OF DIALYSIS
Types of Dialysis Modalities:
Hemodialysis (HD): Blood is pumped from the patient's body through an artificial kidney (dialyzer) external to the body. Toxins, waste products, and excess fluid are removed by passing the blood across a semipermeable membrane, counter-current to a specially formulated dialysate solution. Ultrafiltration and negative pressure (suction) are used to precisely remove fluid.
Peritoneal Dialysis (PD): Utilizes the patient's own peritoneal cavity as the semipermeable membrane. A sterile solution (dialysate) containing minerals and glucose is introduced into the peritoneal cavity via a permanently implanted catheter. The solution dwells for a prescribed period, allowing waste products and excess fluid to diffuse and osmotically move from the blood in the abdominal capillaries into the dialysate. After dwelling, the fluid is drained and refreshed multiple times daily (e.g., Continuous Ambulatory Peritoneal Dialysis - CAPD) or overnight by a cycler (Automated Peritoneal Dialysis - APD).
Hemofiltration or Continuous Renal Replacement Therapy (CRRT): Typically used for critically ill patients with acute kidney injury who are hemodynamically unstable and cannot tolerate the rapid fluid and solute shifts of conventional intermittent hemodialysis. CRRT is performed continuously over 24 hours to several days, providing a slower, gentler removal of fluid and waste, leading to better hemodynamic stability.
HEMODIALYSIS PROCESS
Mechanics of Hemodialysis:
Blood is drawn from the patient's vascular access (e.g., AV fistula, graft, central catheter) and pumped into the dialyzer, an external filter often referred to as an artificial kidney.
Inside the dialyzer, the blood flows in very thin fibers or channels, exposing it to a large surface area of a semipermeable membrane.
A specially formulated dialysate solution flows in the opposite direction (counter-current) on the other side of the membrane. This counter-current flow maximizes the concentration gradient, enhancing toxin removal.
Toxins such as urea, creatinine, and excess electrolytes diffuse from the blood (high concentration) into the dialysate (low concentration). Excess fluid (ultrafiltration) is removed through convection by applying a negative pressure gradient across the membrane.
Several liters of fluid and various waste products can be effectively removed during a typical hour session, usually performed times a week.
PERITONEAL DIALYSIS PROCESS
Mechanics of Peritoneal Dialysis:
A sterile solution, called dialysate, containing minerals, electrolytes, and glucose (as an osmotic agent) is infused into the peritoneal cavity through a surgically implanted Tenckhoff catheter.
The solution must remain and