Hemodialysis - Preparing Patient Article
Hemodialysis Overview
Definition: Hemodialysis is a life-sustaining treatment required when kidneys fail to function properly, involving the removal of blood from the body, cleaning it of toxins, excess water, and electrolytes using a dialyzer, and returning the clean blood back to the patient.
Statistics: Approximately 300,000 people receive hemodialysis three times a week.
Significance: Nurses must prepare patients for hemodialysis to ensure safety and effectiveness of treatment.
Access Devices for Hemodialysis
Types of Access Devices
Arteriovenous Fistula (AVF)
Creation: Surgically made by connecting an artery to a vein.
Function: Increased blood flow stimulates growth of the AVF; typically ready for use in 6 to 12 weeks.
Arteriovenous Graft (AVG)
Creation: Uses synthetic materials to connect an artery to a vein when blood vessels are inadequate for AVF placement.
Maturation Time: Usually takes about 3 weeks.
Temporary Hemodialysis Catheter
Placement Sites: Subclavian, femoral, or internal jugular vein.
Usage: Used for immediate hemodialysis access while AVF or AVG matures.
Lumens: Two lumens - one for blood removal and one for returning cleaned blood.
Pre-Dialysis Patient Preparation
Weight Measurement
Action Required: Obtain an accurate weight before treatment.
Expected Change: Patients are usually heavier due to fluid buildup.
Importance: This weight helps to determine fluid to be removed during dialysis to achieve "dry weight" (goal weight without excess fluid).
Vital Signs Assessment
Blood Pressure (BP)
Considerations: Assess BP, avoiding the arm with the AVF or AVG.
Conditions to Monitor: Hypertension or hypotension.
Temperature
Significance: Check for fever indicating possible infection.
Respiratory Rate and Quality
Observation: Monitor for dysrhythmias; note heart rate and rhythm during assessment.
Overall Patient Condition
Assessment Areas: Skin condition, mental status, complaints (pain, nausea).
Access Site Examination
Checking for:
Bleeding, oozing, drainage, or signs of infection (redness, warmth).
Assessment of distal pulses, thrill, and bruit (vibration and sound at the site) for circulation adequacy.
Action if Absent: Notify healthcare provider if thrill or bruit is not detectable.
Lab Results Review
Essential Labs: Check levels of sodium, potassium, phosphorus, blood urea nitrogen, and creatinine.
Anticipated: Levels should be elevated pre-dialysis compared to post-dialysis.
Complete Blood Cell Count (CBC)
Particular Focus: Look at RBC count, hemoglobin, and hematocrit levels, anticipating low levels post-dialysis.
Drug Considerations:
Do not administer antihypertensive drugs before dialysis.
Review scheduled medications and hold those that may pass through the dialysis machine (water-soluble vitamins).
Post-Dialysis Nursing Interventions
Immediate Actions: Obtain set of vital signs and weight immediately after treatment.
Access Site Monitoring: Check for bleeding and signs of infection, similarly to pre-dialysis.
Observing for Complications:
Monitor for neurologic changes (confusion, decreased consciousness, sudden headaches) indicating possible disequilibrium syndrome.
Lab Collection Review: Ensure familiarity with when post-dialysis labs are due and track results closely.
Medication Administration: Resume medications held before treatment only after patient stability is verified, generally 2 to 4 hours after treatment.
Conclusion
Professional Responsibility: Nurses play a crucial role in the care and preparation of patients undergoing hemodialysis and must understand the necessary protocols, interventions, and the importance of monitoring to ensure patient safety and treatment efficacy.
References
Ignatavicius DD, Workman ML. Medical-Surgical Nursing: Patient-Centered Collaborative Care. 6th ed. St. Louis, MO: Saunders; 2010.
National Kidney and Urologic Diseases Information Clearinghouse. Treatment methods for kidney failure: hemodialysis. http://kidney.niddk.nih.gov/Kudiseases/pubs/hemodialysis/.
National Kidney Foundation. Dialysis. http://www.kidney.org/atoz/atozTopic_Dialysis.cfm.
Hemodialysis Overview
Definition: Hemodialysis is a life-sustaining renal replacement therapy primarily indicated for End-Stage Renal Disease (ESRD) when the kidneys can no longer effectively filter waste products from the blood. It is an extracorporeal process involving the continuous circulation of the patient's blood through a specialized synthetic, semi-permeable filter called a dialyzer (often referred to as an artificial kidney). Within the dialyzer, the semi-permeable membrane facilitates the efficient removal of metabolic waste products, such as urea and creatinine, as well as excess water and electrolytes (e.g., potassium, phosphorus) from the blood, primarily relying on the principles of diffusion (movement of solutes), osmosis (movement of water across a semi-permeable membrane), and ultrafiltration (removal of water by convection under hydrostatic pressure). The cleaned blood is then warmed and returned to the patient's body.
Statistics: Approximately 300,000 individuals in the United States undergo hemodialysis, with typical treatment regimens consisting of three sessions per week, each lasting about 3 to 5 hours, depending on individual patient needs, comorbidities, and prescribed dialysis parameters.
Significance: Nurses are indispensable in the comprehensive care of hemodialysis patients. Their responsibilities encompass meticulous patient assessment, detailed preparation for each treatment session, continuous monitoring during dialysis, proactive prevention and expert management of potential acute and chronic complications, providing critical patient education regarding self-care and adherence, and offering essential emotional support to enhance patient safety, optimize treatment efficacy, and improve overall quality of life.
Access Devices for Hemodialysis
Types of Access Devices
Arteriovenous Fistula (AVF)
Creation: This is the preferred long-term vascular access, surgically created by directly connecting an artery (e.g., radial or brachial artery) to a vein (e.g., cephalic or basilic vein), typically in the forearm or upper arm of the non-dominant arm. This surgical anastomosis allows high-pressure arterial blood flow to be shunted into a lower-pressure vein.
Function: The increased arterial blood flow and pressure cause the vein to gradually enlarge, thicken, and develop stronger, more resilient walls over time—a vital process known as "arterialization" or maturation. This matured vein, with its increased diameter and robust walls, becomes suitable for robust, repeated cannulation with large-bore needles () required for hemodialysis blood flow. It typically takes 6 to 12 weeks, and sometimes longer (up to several months), for an AVF to mature sufficiently for safe and effective use.
Advantages: AVFs boast the lowest rates of infection and thrombosis (clotting), have the longest functional lifespan, provide superior blood flow for highly efficient dialysis, and generally result in fewer complications and better patient outcomes compared to other access types.
Disadvantages: Requires significant maturation time, and there's a possibility of maturation failure (up to 20-50% in some populations) requiring re-intervention or alternative access. They can also be cosmetically noticeable due to vein enlargement and may cause some discomfort during needle insertion.
Care: Strict protection of the access arm (often referred to as an "arm alert" or "limb alert" for staff training) is crucial. This includes meticulously avoiding blood pressure measurements, venipuncture, intravenous lines, or tight clothing/jewelry on the access arm to prevent injury, compression, and potential thrombosis. Regular assessment for signs of infection (redness, warmth, swelling) and checking for the presence of thrill/bruit are also vital.
Arteriovenous Graft (AVG)
Creation: An AVG is typically used when a patient's native blood vessels are deemed inadequate or unsuitable for AVF creation. It involves surgically implanting a synthetic tube (commonly made of polytetrafluoroethylene or PTFE) to connect an artery to a vein. The graft is typically placed subcutaneously, forming a bridge between the artery and vein, often in a loop or straight configuration in the forearm or upper arm.
Maturation Time: AVGs generally require less maturation time than AVFs, usually becoming ready for cannulation within 2 to 4 weeks after implantation, once the surrounding tissue has healed and integrated with the graft material.
Advantages: Provides quicker access than an AVF and serves as a viable alternative when native veins are unsuitable or when AVF maturation fails. They are also easier to cannulate than immature fistulas.
Disadvantages: AVGs are associated with higher risks of infection (due to the foreign material), stenosis (narrowing, often at the venous anastomosis), thrombosis (clotting), and potential aneurysm or pseudoaneurysm formation. They generally have a shorter lifespan and require more frequent interventions compared to AVFs.
Care: Similar protective measures as for an AVF's access arm are necessary, with heightened vigilance for infection given the foreign material, and careful monitoring for signs of thrombosis (loss of thrill/bruit) or bleeding.
Temporary Hemodialysis Catheter
Placement Sites: These are central venous catheters (CVCs) inserted into large central veins, most commonly the right internal jugular vein (preferred due to lower complication rates and ease of access), but they can also be placed in the subclavian or femoral veins.
Types and Usage: They can be non-tunneled (designed for short-term, acute access, such as in emergencies or for acute kidney injury, typically left in for days to a few weeks) or tunneled (designed for longer-term use, embedded under the skin to reduce infection risk, utilized for patients awaiting AVF/AVG maturation, or as a permanent access if other options are exhausted or contraindicated). These catheters provide immediate access.
Lumens: Temporary catheters typically feature two distinct lumens: one for arterial blood withdrawal (taking deoxygenated blood from the patient to the dialyzer, often color-coded red) and another for venous blood return (returning cleaned and oxygenated blood back to the patient, often color-coded blue). Some advanced catheters may have a third port for IV fluid administration or medication delivery, particularly in non-dialysis settings.
Risks: These catheters carry the highest risk of complications among all access types, including catheter-related bloodstream infections (CRBSIs), central venous stenosis (narrowing of the vein, especially with subclavian placement), thrombosis, catheter malfunction (e.g., clotting, kinking, dislodgement, fibrin sheath formation), and even air embolism.
Care: Meticulous care is paramount, including strict aseptic technique during dressing changes, regular flushing of lumens with anticoagulant lock solutions (e.g., heparin, citrate, or alteplase) to maintain patency and prevent clot formation, and ensuring that only qualified dialysis personnel access the lumens for hemodialysis to minimize risks.
Pre-Dialysis Patient Preparation
Weight Measurement
Action Required: Obtain an accurate body weight immediately before each hemodialysis treatment. It is crucial to use the same calibrated scale consistently to ensure reliable comparisons and accurate fluid removal calculations.
Expected Change: Patients with ESRD typically present with significant interdialytic weight gain (often exceeding or more) due to fluid retention between dialysis sessions, a direct result of impaired kidney function.
Importance: This precise pre-dialysis weight is critical for determining the prescribed amount of fluid (ultrafiltration goal) that needs to be removed during the dialysis session. The ultimate goal is to achieve the patient's "dry weight"—the weight at which the patient is euvolemic (without excess fluid), normotensive, and free of signs of fluid overload or dehydration. Inadequate or excessive fluid removal can lead to severe complications such as hypotension, hypertension, pulmonary edema, and cardiovascular stress during and after dialysis.
Vital Signs Assessment
Blood Pressure (BP)
Considerations: Assess blood pressure comprehensively in an arm without an AVF or AVG to prevent damage, compression, or potential thrombosis of the access site. Monitor closely for both hypertension (which could indicate fluid overload, uncontrolled underlying hypertension, or inappropriate dry weight setting) and hypotension (which may indicate over-diuresis in previous sessions, cardiovascular instability, or orthostatic changes). Intradialytic hypotension is a common and serious complication, risking poor perfusion to vital organs, access complications, and increased mortality.
Temperature
Significance: A temperature elevation or fever (oral temperature >37.5^ ext{o} ext{C} or ) could indicate an underlying infection, potentially related to the vascular access site (CRBSI), a systemic infection, or an intradialytic fever response. Prompt investigation and intervention are required.
Respiratory Rate and Quality
Observation: Assess respiratory rate, rhythm, and effort. Observe for signs of dyspnea (shortness of breath), tachypnea, orthopnea (difficulty breathing when supine), crackles (rales heard on auscultation), or diminished breath sounds, all of which are common indicators of pulmonary edema resulting from fluid overload. Also, monitor heart rate and rhythm; irregular rhythms or dysrhythmias can be exacerbated by electrolyte imbalances (e.g., hyperkalemia) common in ESRD.
Overall Patient Condition
Assessment Areas: Conduct a comprehensive, holistic assessment including the patient's mental status (level of alertness, orientation, presence of confusion, drowsiness, or apprehension), skin condition (turgor, color, presence of peripheral or sacral edema, excoriations from uremia), and any subjective complaints such as pain, nausea, vomiting, dizziness, chills, fatigue, or muscle cramps, all of which can significantly impact the tolerance and safety of the dialysis session.
Access Site Examination
Checking for: Meticulously inspect and palpate the vascular access site (AVF, AVG, or catheter insertion site).
Signs of Infection: Look for localized redness (erythema), warmth, swelling (edema), tenderness to palpation, or purulent drainage, which are hallmark signs of infection.
Bleeding/Hematoma: Check for any active bleeding, oozing, or signs of hematoma formation at previous cannulation sites or around the graft/fistula.
Circulation and Patency (for AVF/AVG): Palpate gently over the AVF or AVG to detect a palpable thrill (a continuous, buzzing vibration, often described as feeling like a purring cat). Auscultate with a stethoscope over the entire length of the access to hear a distinct bruit (a soft, continuous, pulsatile, 'whooshing' sound). Both a strong thrill and a distinct bruit are crucial indicators of adequate blood flow and access patency. Also, assess for the presence and quality of distal pulses in the access extremity and capillary refill time.
Action if Absent: The absence or a significant change in the quality (e.g., weak or intermittent) of the thrill or bruit, the presence of a new pulsatile mass along the vein (suggesting aneurysm formation), or significant edema in the access arm, should be immediately reported to the healthcare provider. These findings could signal potential access complications such as thrombosis, stenosis (narrowing), or aneurysm formation, all requiring urgent evaluation and intervention.
Lab Results Review
Essential Labs: Review recent laboratory results, focusing on key indicators of renal function and electrolyte balance. These include blood urea nitrogen (BUN), creatinine, sodium, potassium, phosphorus, calcium, and bicarbonate levels. Pre-dialysis, these levels are typically significantly elevated and are expected to decrease post-dialysis, indicating effective solute and fluid removal. Baseline labs (e.g., albumin, liver function tests) are also important to consider.
Complete Blood Cell Count (CBC):
Particular Focus: Pay close attention to the red blood cell (RBC) count, hemoglobin (often < 10 ext{ g/dL} due to erythropoietin deficiency, iron deficiency, and chronic blood loss), and hematocrit levels, as anemia is nearly universal in ESRD patients. Also, review the white blood cell (WBC) count for any signs of infection or inflammation, and platelet count for bleeding risk.
Drug Considerations:
Antihypertensive Drugs: It is generally crucial to hold antihypertensive medications (e.g., ACE inhibitors, ARBs, beta-blockers) immediately before dialysis to prevent intradialytic hypotension, which can result from rapid fluid removal and lead to patient discomfort, poor organ perfusion, and access complications. This decision is always made by the prescribing physician.
Dialyzable Medications: Review the patient's scheduled medications. Hold drugs that are highly water-soluble, have small molecular weights, or are not highly protein-bound, as they are likely to be removed by the dialyzer (e.g., certain antibiotics, water-soluble vitamins like B and C, some anticonvulsants, certain antiarrhythmics). These medications should typically be administered post-dialysis to ensure therapeutic effectiveness and maintain adequate drug levels, or as specifically prescribed by the physician's dialysis medication order set.
Post-Dialysis Nursing Interventions
Immediate Actions: Obtain a complete set of vital signs (BP, HR, RR, Temp) and an accurate post-dialysis weight immediately after the treatment. The post-dialysis weight should approximate the patient's prescribed "dry weight," which is the target weight at which the patient is normotensive and euvolemic without fluid overload. A significant deviation (either too high or too low) indicates inadequate or excessive fluid removal, necessitating adjustments for future sessions or further assessment.
Access Site Monitoring: Similar to pre-dialysis, meticulously inspect the vascular access site for any signs of bleeding, oozing, persistent oozing, or hematoma formation after needle removal. Apply firm but gentle pressure with sterile gauze over the cannulation sites for several minutes until complete hemostasis is achieved. Also, continue to monitor for signs of infection (redness, warmth, swelling, tenderness, drainage) at the puncture sites. Educate the patient on self-monitoring for signs of complications and when to seek immediate medical attention.
Observing for Complications:
Hypotension: The most common acute complication post-dialysis. Monitor closely for symptoms such as dizziness, lightheadedness, syncope, nausea, vomiting, or altered mental status. Administer IV fluids (e.g., normal saline) as prescribed to restore circulating volume, and notify the healthcare provider. Adjustments to ultrafiltration volume or rate may be necessary for future treatments.
Disequilibrium Syndrome: Monitor for neurologic changes such as confusion, disorientation, decreased consciousness, restlessness, generalized weakness, severe headaches, nausea, vomiting, or seizures. This syndrome occurs due to a rapid decrease in blood urea nitrogen (BUN) levels during dialysis, creating an osmotic gradient that causes fluid to shift into brain cells, leading to cerebral edema. It is more common in new dialysis patients or those with very high BUN levels and can be prevented by shorter, less aggressive dialysis sessions initially.
Muscle Cramps: May occur due to rapid fluid and electrolyte shifts, particularly sodium and calcium. Provide comfort measures and oral hydration if appropriate.
Chest Pain: Promptly assess for angina or other cardiac symptoms, as dialysis can sometimes exacerbate existing cardiovascular conditions or cause new cardiac events. Myocardial ischemia can be related to rapid fluid shifts and hypotension.
Bleeding: Monitor for prolonged bleeding from access sites due to heparinization during dialysis. Ensure protamine sulfate is available if needed to reverse heparin effects.
Lab Collection Review: Ensure familiarity with when post-dialysis labs are due (e.g., electrolytes, BUN, creatinine, often drawn post-treatment) and track results closely to assess the effectiveness of the treatment and guide future dialysis prescriptions. Anticipate significant decreases in BUN, creatinine, and potassium levels, confirming adequate solute clearance.
Medication Administration: Re-evaluate and administer medications that were held before treatment only after patient stability is verified and strictly based on the physician's orders, generally 2 to 4 hours after treatment. This delayed timing prevents rapid removal of the medication by the dialyzer and ensures therapeutic levels are maintained in the patient's system. For example, water-soluble vitamins (B and C) and certain antibiotics are typically given post-dialysis.
Conclusion
Professional Responsibility: Nurses play a crucial and dynamic role in the comprehensive care and meticulous preparation of patients undergoing hemodialysis. They must possess an in-depth understanding of the necessary protocols, evidence-based nursing interventions, and the critical importance of continuous monitoring to ensure paramount patient safety, maximize treatment efficacy, and mitigate potential complications. Their expertise is vital for optimizing clinical outcomes and supporting patient well-being in the complex setting of renal replacement therapy.
References
Ignatavicius DD, Workman ML. Medical-Surgical Nursing: Patient-Centered Collaborative Care. 6th ed. St. Louis, MO: Saunders; 2010.
National Kidney and Urologic Diseases Information Clearinghouse. Treatment methods for kidney failure: hemodialysis. http://kidney.niddk.nih.gov/Kudiseases/pubs/hemodialysis