Background

Hemodialysis is a procedure used to manage severe kidney failure. It employs a machine to sift out waste, salts, and excess fluid from the bloodstream. This treatment demands adherence to a strict regimen, including regular medication intake and dietary adjustments. Patients collaborate closely with a healthcare team and may opt for home-based hemodialysis. 

Dialysis is a temporary solution for individuals experiencing acute kidney injury (AKI), chronic kidney disease (CKD), or those ineligible for transplantation ensuring kidney function homeostasis. 

Renal replacement therapy frequency depends on conditions leading to ESRD, timely detection of chronic kidney disease, and strategies to delay progression. Identifying individuals with declining eGFR, proteinuria, and acute kidney injury episodes helps to initiate planned RRT. Proper preparation and education about treatment choices are essential for patients at risk of ESRD and their caregivers. 

Around 2.5 million individuals worldwide underwent chronic Renal Replacement Therapy in 2010, with high rates in North America and Taiwan and Japan. Regional and national dialysis registries monitor RRT populations providing hospital-specific data and clinical research resources. Sociocultural and socioeconomic factors influence decision-making, with ESRD more prevalent among African Americans and CKD more common among Whites. ESRD is linked to conditions like diabetes mellitus and hypertension, while rarer causes include polycystic kidney disease, obstructive nephropathy, and glomerulonephritis. 

The Study of Heart and Renal Protection (SHARP) found that simvastatin-ezetimibe treatment can reduce cardiovascular mortality and major incidents in patients with chronic kidney disease (CKD). Recommended cardioprotective measures include beta-blockers, aspirin, and renin angiotensin-aldosterone system inhibitors. Hypertension is linked to end-stage renal disease (ESRD) risk, with high mortality rates in the first three months post-dialysis commencement especially among elderly patients. 

Indications

Hemodialysis is necessary for acute diseases like renal injury, pericarditis, uremic encephalopathy, and hyperkalemia that impair clearance and cytokine control, leading to pulmonary edema and failure to thrive. Renal replacement therapy (RRT) can eliminate cytokines but can cause electrolyte imbalances and catheter issues.  

The Kidney Disease Outcomes Quality Initiative recommends counseling stage 4 CKD patients about treatment options, including kidney transplantation, hemodialysis, peritoneal dialysis, and conservative management. 

Contraindications

Hemodialysis may not be suitable for patients with uncontrolled bleeding disorders, severe hemodynamic instability, untreated septicemia, advanced age, limited vascular access, poor prognosis, or intractable psychiatric illness. These conditions can lead to complications during the procedure, including access site bleeding, anticoagulation, fluid shifts, and increased risk of complications.  

Patients in shock or severe hypotension may not tolerate the fluid shifts and hemodynamic changes during hemodialysis, and stabilization of their condition is prioritized. Hemodialysis may exacerbate hemodynamic instability and increase the risk of complications in patients with untreated septicemia, so antibiotic therapy and source control should be initiated.  

Age alone is not a contraindication to hemodialysis, but advanced age may be considered a relative contraindication if the patient’s overall prognosis, comorbidities, or quality of life considerations outweigh the potential benefits.  

Patients with limited vascular access, poor prognosis, or intractable psychiatric illness may struggle with the complex treatment regimen and lifestyle changes required for hemodialysis, and alternative renal replacement therapies or palliative care options may be considered. 

Outcomes

Hemodialysis is a treatment that significantly improves survival rates in end-stage renal disease (ESRD) patients compared to untreated kidney failure. It helps manage symptoms such as fluid overload, electrolyte imbalances, and uremic symptoms, ensuring a better quality of life for many patients.  

Maintaining fluid and electrolyte balance is crucial for preventing complications like heart failure and hypertension. It also provides nutritional support by removing waste products and excess fluids while controlling blood pressure. 

Hemodialysis maintains acid-base balance by removing excess acids from the blood by promoting overall health and organ function. It reduces uremic complications by removing waste products. Despite regular treatments many patients report improved quality of life. 

Equipment

The dialyzer also known as the artificial kidney is the central part of a hemodialysis machine containing a semipermeable membrane that allows small molecules to pass while retaining larger ones. Blood tubing connects the patient’s vascular access to the dialyzer for filtration and return. 

The dialysate delivery system is a system that mixes and heats a solution to remove waste products from blood. It measures the composition of the dialysate, including electrolyte concentrations and pH to ensure its balanced for the patient’s needs. The blood pump regulates the flow rate of blood through the dialyzer for effective filtration without damaging blood cells. 

Hemodialysis machines have a pressure monitoring system to ensure safe blood tubing and dialyzer use. A water treatment system purifies water used to make dialysate by removing impurities and bacteria.  

The solution delivery system delivers dialysate at the appropriate rate and temperature for treatment duration. A control panel allows healthcare providers to program the machine with patient parameters. Safety alarms alert healthcare providers to issues like low blood pressure, air bubbles, or equipment malfunctions that require immediate attention. 

Hemodialysis machine 

Patient preparation

The hemodialysis process involves several steps including a vascular access assessment, weight measurement, blood pressure measurement, temperature check, and medication review.

The access site is assessed for patency and infection, the site is cleaned and prepared for cannulation. Patients are weighed before and after each session to monitor fluid removal and prevent complications.

Blood pressure is monitored before, during, and after hemodialysis and medications may be adjusted or withheld as needed. The patient undergoes an access cannulation procedure to connect blood tubing to an arteriovenous fistula or graft and a central venous catheter is checked for proper placement.

The patient’s dialysis prescription is reviewed and programmed into the machine. Patient education is provided about the procedure, vascular access care, and potential complications. Comfort measures are made to ensure patient comfort during the procedure.

Monitoring and Follow-up

The patient’s health is monitored through vital signs, fluid status, and biochemical tests.

These measures assess the patient hemodynamic status and prevent fluid overload and assess symptoms like edema, shortness of breath, and hypertension.

Regular blood tests are conducted to assess the adequacy of dialysis and monitor for complications and adjust treatment as needed.

Dialysis adequacy is assessed using parameters like Kt/V and URR to remove waste products from blood. Access site monitoring is crucial for infection, thrombosis, and other complications. Regular maintenance prevents complications.

Regular nutritional and medication management ensure patients receive adequate nutrition and manage dietary restrictions effectively while reviewing medications to avoid adverse interactions with dialysis treatment.

Symptom Management:

The patient’s quality of life is enhanced through monitoring and management of symptoms like fatigue, muscle cramps, and insomnia.

Psychosocial Support:

Hemodialysis patients may experience psychosocial issues like depression and anxiety, which can be effectively managed through a multidisciplinary team of social workers and psychologists.

Technique

Hemodialysis

Step:1 – Preparation of the Hemodialysis Machine:

Technicians prepare hemodialysis machines, dialyzers, blood tubing, and dialysate solutions before treatment. They ensure cleanliness, calibration, and proper functioning ensuring patient-prescribed electrolyte concentration and pH level.

Step:2 – Patient Preparation:

When patient is undergoing hemodialysis preparation, undergoes checkups for patency and infection, medical history evaluation, and cleaning and cannulation preparation of the vascular access site possibly involving antiseptic skin sterilization and local anesthetic numbing.

Step:3 – Vascular Access Cannulation:

Blood tubing is sterilely attached to the vascular access site using needles in arteriovenous fistulas, grafts, or central catheters for security and used for pre-dialysis tests.

Vascular access

Step:4 – Initiation of Hemodialysis Treatment:

Connect patient to hemodialysis machine then start blood pump and dialysate delivery system by monitoring vital signs, fluid status, and dialysis parameters for safety and efficacy.

Step:5 – Monitoring and Adjustment of Treatment Parameters:

Hemodialysis patient vital signs are closely monitored and dialysis prescriptions are adjusted based on their clinical state and response to the treatment.

Step:6 – Completion of Hemodialysis Treatment:

After treatment the hemodialysis machine is turned off where blood tubing is removed and vital signs assessed where post-dialysis treatments provided. Patient is monitored for bleeding, infection, and drug-drug reactions.

Step:7 – Documentation and Follow-Up:

Healthcare providers monitor patients post-hemodialysis by recording vital signs and treatment parameters or any complications. Regular follow-up visits progress to adjust treatments and address issues.

Complications

Hypotension during hemodialysis can cause symptoms like dizziness, lightheadedness, and cramping. Management involves adjusting ultrafiltration rate by increasing dialysate sodium concentration or using intravenous fluids.

Muscle cramps is a common hemodialysis complication which are temporary and can be alleviated through gentle stretching, dialysis prescription adjustments, or medication use like quinine or gabapentin.

Hemodialysis patients are at higher risk of infection especially at the vascular access site which can lead to complications like sepsis or endocarditis.

Hemodialysis can lead to bleeding at the vascular access site particularly in patients with fragile blood vessels or clotting disorders which can be minimized through proper cannulation technique.

Hematomas or blood collection outside the blood vessels can occur during cannulation due to trauma. Most resolve on their own but large hematomas may require drainage or intervention.

Thrombosis is a blood clot formation that can cause reduced blood flow and inadequate dialysis in hemodialysis patients and anticoagulation therapy can prevent or treat it.

Dialyzer reactions is rare but rare can cause allergic reactions or anaphylaxis in patients causing symptoms like itching, rash, shortness of breath, and hypotension.

Hemodialysis can cause electrolyte imbalances such as hyperkalemia, hypokalemia, hypercalcemia, and hypocalcemia which can be prevented by regular monitoring and prescription adjustments.

Dialysis Disequilibrium Syndrome is a rare neurological complication caused by rapid changes in serum osmolality during hemodialysis which can be managed by slowing ultrafiltration and dialysis rate.

References

Epidemiology of haemodialysis outcomes – PMC

Hemodialysis – StatPearls

References

Epidemiology of haemodialysis outcomes – PMC

Hemodialysis – StatPearls