Complete your Hemodialysis Technician continuing education with these practice questions and answers. This guide covers dialysis procedures, patient care, infection control, and safety protocols.
Q: At end of 2009, > 550, 000 patients had end stage renal disease (ESRD)
Answer: -370,274 were receiving hemodialysis (HD).-27,522 were receiving peritoneal dialysis (PD).-172,553 had received a renal transplant.
Q: Primary diagnosis for new patients with ESRD
Answer: -diabetes (DM).
Q: Morbidity/mortality
Answer: -Increase in hospitalizations due to infection and cardiovascular disease.-Hospitalizations whites> blacks and freq and duration increase in age for both.-2/3 of all dialysis patients die within 5 years of dialysis initiation.-In pts > 65 , risk of dying is 2x higher if receiving dialysis.-Death: Most common cause of death is due to cardiovascular (50%), 2nd cause of death is due to dialysis access.
Q: hemodialysis (HD) quality of life
Answer: -May impact a patient’s physical endurance , sex life, employment, social life, and diet.-Patient’s complain of fatigue, fear.
Q: Dialysis indications
Answer: -Providers and patients should start planning for dialysis when pt reaches CKD stage 4 (eGFR < 30).
Q: Dialysis initiation
Answer: -Primary criterion for starting dialysis is the patient’s clinical status:-persistent nausea, vomiting and anorexia accompanied by weight loss, fatigue, declining serum albumin concentrations, uncontrolled HTN or CHF, and neurologic deficits (confusion, coma) or pruritus.-Risks and benefits should be evaluated when eGFR or CrCl < 15.
Q: Hemodialysis (HD)
Answer: -Most common type of renal replacement therapy for ERSD.-Consists of the perfusion of blood and physiologic solution on opposite sides of a semipermeable membrane.-Water, urea, creatinine, uremic toxins, and drugs move from the blood through a membrane into the dialysate by passive diffusion or convection as the result of ultrafiltration.-HD prescription can be individualized to degree of solute and fluid removal.
Q: HD permanent access
Answer: -AV fistula.-AV graft.-Central venous catheter.
Q: AV fistula
Answer: -most commonly used.-An artery is joined to a vein SC to provide a bigger blood vessel.-Advantages: longest lasting access, easiest to create, lowest rate of infection and thrombosis, patients survive longer and have less hospitalizations, and cost effective (placement/maintenance).-Cons- takes 1-2 months to mature in order to be used.
Q: AV graft
Answer: -Used if fistula not an option.-Plastic tube used to join and vein and artery SC.-Advantage: requires 2-3 weeks in order to be used.-Cons: shorter lasting, more chance of infection and thrombosis compared to fistula.
Q: Central Venous Catheter
Answer: -Least desired access.-Placed in femoral, subclavian, or internal jugular veins.-Advantage- can be used immediately after placement (option if unable to access other viable sites for permanent access).-Disadvantage- short life span, more prone to infections and thrombosis compared to fistula and grafts, may not be able to provide adequate blood flow rates thus limiting dose of dialysis, increased morbidity, mortality, and cost are associated with this access.
Q: HD procedure
Answer: -Blood is transferred through a polyethylene tubing to a dialyzer via a mechanical pump.-The patients anticoagulated blood then passes through the dialyzer* on one side of the semi permeable membrane and returned to the patient.-The dialysate solution ** is pumped through the dialyzer countercurrent to the flow of blood on the opposite side of the semi permeable membrane.-Result of dialysis is the removal of metabolic waste products and water and replenishment of body buffers.
Q: 3 dialysis membranes:
Answer: -Low flux (conventional)-limiting clearance to small molecules (< 500 daltrons) such as urea and creatinine.-High efficiency-have large surface areas. Able to remove water, urea, and other small molecules.-High flux-remove high-molecule weight substances such as B2 microglobulin and vancomycin, in addition to other larger molecular weight drugs.
Q: When high efficiency and high flux used
Answer: -clearance of both low- and high-molecular weight substance is much greater than conventional membranes allowing shorter treatment times.-Require blood flow rates > 400 mL/min and dialysate flow rate > 500 mL/min along with strict controls on fluid removal.
Q: HD
Answer: -Typically performed in a “dialysis center” (in-center hemodialysis), three times every week x 3-4 hrs each session.-Can do hemodialysis at home. This is called home hemodialysis. Performed 5-7x /week; each session ~2-2.5 hrs.
Q: Post dialysis assessment
Answer: -Labs monitored monthly and HD prescription adjusted.-HD prescription includes weight, duration, Kt/V, blood flow rate, dialysate flow rate, and dialyzers.
Q: 2 goals of a dialysis prescription
Answer: -achievement of dry weight and adequately remove waste products.
Q: Desired dry weight
Answer: -wt at which pt is normotensive and free of edema.
Q: Adequate removal of solute removal
Answer: -delivered dose/desired dose of dialysis determined by:-URR (urea reduction rate) – goal is 70% reduction in each dialysis session or URR= Predialysis BUN-Postdialysis BUN x100 OR Kt/V > 1.4.-K=dialyzer clearance or urea in L/h, t= duration of dialysis in hours, V= urea distribution volume in L.
Q: Common Complications during hemodialysis
Answer: -Hypotension (20-30%).-Cramps (5-20%).-NV (5-15%).-HA (5%).-Chest & Back Pain (2-5%).-Pruritus (5%).-Fever & Chills (<1%).
Q: Itradialytic hypotension (IDH) Acute Treatment
Answer: -place pt in Trendelenburg position.-decrease ultrafiltration rate.-give 100-200mL bolus of normal saline IV.-give 10-20mL of hypertonic saline (23.4%) IV over 3-5 mins. -12.5 g mannitol.
Q: Itradialytic hypotension (IDH) Prevention Nonpharmacologic
Answer: -accurately set “dry weight”.-use steady constant ultrafiltration rate.-keep dialysate sodium greater than serum sodium.-lower dialysate temperatures.-bicarbonate dialysate.-avoid food before or during HD.
Q: Itradialytic hypotension (IDH) Prevention Pharmacologic
Answer: -Midodrine 2.5-10mg orally 30 minutes before HD (start at 2.5mg and titrate).-Others (limited evidence):-Levocarnitine 20mg/kg IV after HD.-Sertraline 50-100mg daily.-Fludrocortisone 0.1mg before HD.-DDAVP 1-2 intranasal sprays (150mcg per spray).
Q: Muscle cramps acute treatment
Answer: -give 100-200mL bolus of normal saline IV.-give 10-20mL of hypertonic saline (23.4%) IV over 3-5 mins.-Give 50mL of 50% IV glucose (non diabetic patients).
Q: Muscle Cramps Prevention nonpharmacologic
Answer: -accurately set “dry weight”.-keep dialysate sodium greater than serum sodium.-Stretching exercises, massage, flexing, or compression devices.
Q: Muscle Cramps Prevention Pharmacologic
Answer: -Vitamin E 400 IU qHS.-Quinine 324mg qd (second line).
Q: Managing Infections
Answer: -Anyone with a fever should be evaluated.-Culture before treating.-Hemodialysis access-Infectious Disease Society of America (IDSA)- 2009 and 2011, Kidney Dialysis Outcomes Quality Initiative (KDOQI)-2006.
Q: Advantages of Hemodialysis
Answer: -Higher solute clearance allows intermittent treatment.-parameters of adequacy of dialysis are better defined and therefore under dialysis can be detected early.-technique failure rate is low.-even though intermittent heparinization is required, hemostasis parameters are better corrected with HD than PD.-in-center HD enables closer monitoring of the patient.
Q: Disadvantages of Hemodialysis
Answer: -requires multiple visits each week to the HD center, which translates into loss of patient independence.-disequilibrium, dialysis-induced hypotension, and muscle cramps are common. may require months before the patient adjusts to HD.-infections in HD patients may be related to the choice of membranes, the complement-activating membranes being more deleterious.-vascular access is frequently associated with infection and thrombosis.-decline of RRF is more rapid compared to PD.
Q: Continuous renal replacement (CRRT)
Answer: -Used in critical ill patients with acute renal failure.-Reserved for those that can not tolerate HD or due to hemodynamic instability.-Removes fluids, electrolytes, low and mid weight molecules.-Types:-CAVH- continuous arteriovenous hemofiltration.-CVVH- continuous venovenous hemofiltration.
Q: Intermittent peritoneal dialysis (IPD)
Answer: -Dialysis option for patients with hemodynamic instability (eg hypotension), significant residual kidney function, or who desire to maintain a significant degree of self care.
Q: Peritoneum
Answer: -acts as the semipermeable membrane.-An indwelling catheter, is surgically placed through the abdominal wall to provide access-Can be used immediately if small amts of fluid; preferred maturation is 2-6 weeks.
Q: PD procedure
Answer: -~2-3 L of dialysate are placed via catheter into the empty peritoneal cavity.-Waste products and extra fluid will pass through the membrane and into the dialysate during the dwell period (time fluid remains inside).-Then it is drained out and replaced with dialysate during the fill.-These three steps are called an exchange or cycle.-Several exchanges or cycles cleanse the waste products from the blood.-As in hemodialysis, waste products are removed by diffusion.-In PD, fluid removal occurs through osmosis using different strengths of solutions – 1.5%, 2.5% and 4.25% dextrose.
Q: 2 types of PD
Answer: -CAPD (continuous ambulatory peritoneal dialysis).-APD (automated peritoneal dialysis).
Q: CAPD (continuous ambulatory peritoneal dialysis)
Answer: -Typically performed daily, with 4-5exchanges/day without the use of a machine.-A system of bags and tubing is attached to the catheter only during the exchange. Each exchange, or draining of the used dialysate and replacement with fresh dialysate, lasts about 30″ and is done Q4-6 hrs with the last (or evening) exchange which remains inside the peritoneal cavity overnight.
Q: APD (automated peritoneal dialysis)
Answer: -Uses a cycler machine to perform exchanges (cycles) during the night while pt sleeps. The catheter is connected to the cycler every night for about 8-10 hours .-The machine controls all three phases of the cycles: draining used dialysate, refilling with fresh dialysate, and monitoring the dwell time. A final fill is performed in the morning. No additional dialysis is required until the evening treatment.
Q: CAPD prescriptions-post PD assessment
Answer: -dwell volumes and frequency of daily exchanges (typically 4 exhanges x 2 L) and increasing tonicity of dialysis solution.-Increases ultrafiltration and clearance may lead to side effects (eg hyperglycemia, hyperlipidemia, etc).
Q: APD prescriptions-post PD assessment
Answer: -Number of day dwells, tonicity of day dwells, time on cycler, cycle frequency (3-5/9 hr cycles), cycler dwell volumes (2-2.5 L), tonicity of cycler solution.
Q: Adequacy
Answer: -calculated weekly Kt/V should be > 1.7 per week to be considered adequate.
Q: Medical Complications of Peritoneal Dialysis
Answer: -Exacerbation of DM.-Exacerbation of CHF.-Edema.-Pulmonary Congestion.-Hypercalcemia/hypocalcemia.-Chemical peritonitis.-Albumin loss.-Loss of amino acids.-muscle wasting.-increased adipose tissue.-fibrin formulation in dialysate.
Q: Exacerbation of DM
Answer: -cause-glucose load.-tx-IP insulin.
Q: Exacerbation of CHF, Edema, Pulmonary Congestion
Answer: -cause-fluid overload.-tx-increase ultrafiltration, diuretics if the patient has RRF.
Q: Hypercalcemia/hypocalcemia.
Answer: -Cause-electrolyte abnormalities.-tx-alter dialysate calcium content.
Q: Chemical Peritonitis
Answer: -cause-PD additives.-tx-d/c PD additives.
Q: Albumin loss, Loss of amino acids, muscle wasting, increased adipose tissue
Answer: -cause-malnutrition.-tx-dietary changes, parenteral nutrition, d/c PD.
Q: Fibrin formation in dialysate
Answer: -cause-unknown.-tx-IP heparin.
Q: Other Complications of PD
Answer: -Peritonitis -Guidelines stress importance of dialysis center antibiotics , the effect on RRF on antibiotic kinetics, and updated recs on use of vancomycin and aminoglycosides in PD.-Catheter site infections.
Q: Some medications can be administered through IP
Answer: -Antibiotics, heparin, insulin.
Q: Advantages of Peritoneal Dialysis
Answer: -hemodynamic stability due to slow ultrafiltration rate.-higher clearance of larger solutes, which may explain good clinical status in spite of lower urea clearance.-better preservation of RRF.-convenient IP route for administration of drugs such as antibiotics and insulin.-suitable for elderly and very young patients who may not tolerate HD well.-freedom from the “machine” gives the patient a sense of independence (for continuous ambulatory PD).-less blood loss and iron deficiency, resulting in easier management of anemia or reduced requirements for erythropoietin and parenteral iron.-no systemic heparinization required.-Subq versus IV erythropoietin or darbepoetin may reduce overall doses and be more physiologic.
Q: Disadvantages of Peritoneal Dialysis
Answer: -Protein and amino acid losses through peritoneum and reduced appetite from continuous glucose load and sense of abdominal fullness predispose patients to malnutrition.-risk of peritonitis.-catheter malfunction, exit site, and tunnel infection.-inadequate ultrafiltration and solute clearance in patients with a large body size, unless large volumes and frequent exchanges are employed.-patient burnout and high rate of technique failure.-risk of obesity with excessive glucose absorption.-mechanical problems such as hernias, dialysate leaks, hemorrhoids, or back pain are more common than HD.-extensive abdominal surgery may preclude PD.-no convenient access for IV iron administration.
Q: Medication dosing in dialysis
Answer: -If a patient is being started on drug, know which type of dialysis the patient is receiving.-Evaluate other drug-related factors that play a role in determining how much drug is removed during dialysis (see next couple of slides).
Q: Drug characteristics that effect dialysis removal
Answer: -Molecular size (low flux, high flux).-water solubility.
Q: Molecular size: Low-flux
Answer: -Most commonly used.-Small drug molecules (MW < 500 Da) pass through pores easily and are readily eliminated by dialysis.-Moderate drug molecules (MW 500-1000 Da)-Decreased ability to pass through low-flux membrane and will require postdialysis replacement doses.-Large drug molecules (MW > 1000 Da)-Not removed to a significant extent due to pore size.
Q: Molecular size: High-flux
Answer: -Large weight drugs removed easily and in many cases supplemental postdialysis drug doses will be needed.
Q: Water solubility
Answer: -High degree of water solubility drugs easily move into water based dialysis fluid whereas lipid-soluble drugs remain in blood.-Plasma protein binding-Only unbound drug molecules pass through pores in membrane and are removed.-Volume of distribution-Large Vd drugs are not easily removed from the body because they are principally located at tissue binding sites and only a small amount of total drug is removed from the blood. When dialysis is complete, re-equilibration between blood and tissue may occur resulting in increased serum concentrations of the drug.
Q: Considerations
Answer: -Effect of dialysis on removal of a drug must be considered.-Supplemental doses needed?-Dose need altered (reduced dose or interval change).-Load doses usually same.-DO NOT CALCULATE CRCL!!!