The Certified Clinical Hemodialysis Technician examination, commonly known as the CCHT exam, is one of the top assessments for nephrology nurses. The exam consists of 150 multiple-choice questions and lasts three hours. In order to pass the test, you must score a minimum of 70 to 75%. There is a slight variation in the minimum score required to pass the CCHT exam because of differences in test version.
The CCHT exam includes questions about the role and responsibilities of the dialysis technician, the complications of dialysis (for example, hypotension, allergic reactions, etc.), and the management of access complications. There are questions about complications of ESRD (for example, anemia, renal osteodystrophy, etc.); the effectiveness of hemodialysis treatment; and the major causes of renal failure (for example, hypertension, diabetes mellitus, etc.). More generally, the exam includes questions about the metric system, basic medical terminology (in hemodialysis), basic fluids and electrolytes, and the patient’s rights and responsibilities. The CCHT exam was developed by the Nephrology Nursing Certification Commission.
CCHT Examination Practice Questions
Certified Clinical Hemodialysis Technician Study Guide Transferring
CCHT Practice Questions
1. The molecular weight cutoff of a dialyzer is 12,000 daltons. Which of the following molecules would not pass through the membrane into the dialysate?
2. A disadvantage of high-flux dialysis is:
A. acetate must be used instead bicarbonate buffer.
B. membrane biocompatibility is reduced.
C. pyrogen reactions are common.
D. postdialysis fatigue is common.
3. Drip chambers in the extracorporeal circulation do all the following EXCEPT:
A. monitor arterial and venous pressure by attached gauges.
B. trap air.
C. prevent blood clots from reaching the patient.
D. pump blood into the dialyzer.
4. A low-pressure alarm in the venous (postdialyzer) line is likely to be set off by:
A. a blockage in the blood tubing between the monitoring site and the venous needle.
B. an infiltration of the venous needle.
C. a clot in the venous access.
D. a blockage in the blood tubing before the monitoring site.
5. High-output cardiac failure is a complication of arteriovenous fistula or grafting. All of the following actions are a part of this condition EXCEPT:
A. increased venous return to the heart.
B. decreased cardiac workload.
C. reduced resistance in the arterial bed.
D. activation of the renin–angiotensin system.
6. A patient undergoing hemodialysis complains of muscle cramps in the calves and feet. All of the following are likely causes EXCEPT:
A. hypernatremia (high-sodium level).
B. excess fluid removal.
C. hypercalcemia (high-calcium level).
D. hypokalemia (low potassium).
7. A hemodialysis patient suddenly develops trouble breathing, hives, itching, and hypotension. The most likely cause is:
A. an air embolism.
B. an anaphylactic reaction.
D. disequilibrium syndrome.
8. One difference between peritoneal dialysis (PD) and hemodialysis (HD) is:
A. there is a greater incidence of disequilibrium syndrome in PD.
B. there are more dietary restrictions in PD.
C. fluid buildup is less of a problem in HD.
D. the patient is subjected to constant dialysis in PD rather than intermittent dialysis in HD.
9. Which of the following statements about administering erythropoietin to a hemodialysis patient is correct
A. Administer it until the hemoglobin level is normal.
B. Give supplemental iron if ferritin is low.
C. Give it subcutaneously only.
D. Double the dose if the hemoglobin has not increased by 1 g/dL in 4 weeks.
10. What pattern of blood chemistries would you expect in renal osteodystrophy?
A. High-calcium and low-phosphate levels
B. Low–parathyroid hormone levels
C. Elevated calcitriol
D. Low-calcium and high-phosphate levels
Answers & Explanations
1. C: Molecular weights of a chemical compound represent the sum of the atomic weights of the atoms that make up the molecule. Each dialyzer membrane has a molecular weight cutoff (in daltons) that determines the size of the molecules that can pass through it. These may range from 3000 to 15,000 daltons. Small molecules (e.g., sodium, potassium, phosphate, urea, water) pass through the filter easily, while large molecules, such as proteins (e.g., albumin with a molecular weight of 66,000 daltons) cannot. Choosing the appropriate molecular cutoff for a membrane helps to determine what size molecule may be removed from the blood. This is particularly important for drug overdoses and toxins.
2. C: Bicarbonate buffer is used for the dialysate since the acetate previously used caused vasodilation and hypotension. Immunologic reactions and fluctuations in the white blood cell count are less common since the membranes used are more biocompatible. Pyrogenic reactions in high-flux dialysis are common, causing fever and discomfort for the patient, and sometimes require hospitalization for observation. This may be because the high-flux membranes have larger pores that allow fragments of bacterial particles to pass into the blood. Such pyrogens have been found in the dialysate. Generally, patients experience less postdialysis fatigue and may in fact feel better because of the more efficient removal and shorter dialysis times.
3. D: The extracorporeal circuit refers to the system of tubes, drip chambers, pressure gauges, and pump that connect the arterial and venous accesses to the dialyzer. The drip chambers have gauges to measure arterial and venous pressures by monitoring lines with transducer protectors. The drip chamber also traps any air that gets into the line and prevents blood clots in the extracorporeal circulation from entering the patient by use of a fine wire mesh on the venous side before the patient’s venous access. The arterial blood is propelled from the drip chamber into the dialyzer by a blood pump in which the pliable and slightly larger-in-diameter arterial tubing is threaded through the pump rollers.
4. D: Postdialyzer or venous pressure is that in the tubing returning blood from the dialyzer to the patient’s venous access. A low-pressure alarm may be set off by a separation of the blood tubing from the venous needle or catheter, a fall in the blood flow rate, a blockage in the tubing before the venous monitor, or a major clot in the dialyzer. The high-pressure venous alarm may be set off by a blockage of the blood tubing between the monitoring site and the patient’s venous access, poor positioning or infiltration of the venous needle, a poorly working central venous catheter, or a clot in the venous access.
5. B: High-output cardiac failure may be seen in patients with anemia, hyperthyroidism, or arteriovenous shunts. The latter increases the venous return to the heart (by 20% or more), increasing the cardiac workload and decreasing the arterial resistance. Tachycardia and hypotension may occur. Symptoms of heart failure, such as dyspnea (shortness of breath) and peripheral edema, will ensue. Often patients with end stage renal disease are anemic or have coexisting heart disease, which worsens the problem. Treating anemia to hemoglobin levels above 10–11 g/dL and perhaps use of inotropic (heart contraction stimulants) drugs may help. Because the kidneys are not functional, diuretics are not useful. Reducing fluid gain between dialyses and removing more fluid by longer or more frequent dialyses may also be beneficial.
6. C: Removal of too much fluid during the dialysis procedure may induce muscle cramps, especially in the hands, arms, and feet. Dehydration leads to electrolyte imbalance, especially hypernatremia that results in severe muscular cramping. Low-potassium levels (hypokalemia) may also result in muscle cramps. Low-calcium levels are more likely to cause myalgias and muscle spasms than hypercalcemia. Hypotension may also be a cause of muscle cramps. Preventive measures include obtaining the patient’s correct weight, calculating the correct volume of fluid to be removed, checking and using the prescribed dialysate concentrate, and reviewing the salt and fluid dietary limits with the patient.
7. B: Anaphylactic reactions are severe allergic reactions that may be caused by residual germicide in the dialysis tubing (e.g., ethylene oxide) or drugs, such as heparin, iron dextran, or certain antibiotics. The pattern is one of dyspnea, often due to laryngeal spasm; hives; itching; and hypotension. This is a medical emergency and requires immediate treatment with epinephrine, steroids, and antihistamine plus vascular support. An air embolus from a broken connection in the extracorporeal circuit or empty intravenous bag may cause chest pain, dyspnea, and cyanosis but not itching or hives. Angina is also a potential cause of dyspnea and chest pain, as many patients have a history of coronary artery disease with episodes of angina; however, hives and itching are unusual; Sublingual nitroglycerin spray or tablets may be used. Disequilibrium syndrome is characterized by neurologic symptoms in reaction to rapid removal of urea from the blood, resulting in water entry into the brain.
8. D: One advantage of peritoneal dialysis (PD) is that there is more or less constant fluid in the abdomen; thus, the patient is exposed to more or less constant dialysis. It usually requires four or five exchanges of dialysate daily with so-called continuous ambulatory PD; however, a cycler that allows the process to be done at night during sleep (continuous cycling PD) is also quite popular. Since fluid is constantly in the abdomen, the dialysis duration is longer than in hemodialysis (HD), leading to less disequilibrium. Dietary restrictions may be lessened in PD. Fluid buildup is less of a problem in PD because it is within the abdomen and frequently exchanged. The biggest problem with PD is clogging or infection related to the intraperitoneal catheter. If an infection ensues, replacement may be required, and the patient must be maintained on HD in the interim.
9. B: Erythropoietin is a glycoprotein hormone released by the kidney in response to hypoxic stimuli. It stimulates the red cell precursors in the bone marrow to increase the rate of erythropoiesis to raise the red blood cell number (increases the hemoglobin concentration). The blood level of the hormone is elevated in polycythemia and low in chronic kidney disease (CKD). Several different commercial formulations are available for CKD patients on hemodialysis. It may be given subcutaneously or intravenously, preferably the latter into the venous line at the end of a dialysis session. Iron should also be given if the ferritin (iron storage protein) level is low. Current recommendations are to give the hormone to obtain a hemoglobin level of 10–12 g/dL. Higher levels may predispose to thrombosis. If the hemoglobin level does not respond by 1 g/dL in 4 weeks, the dose may be increased by 25%.
10. D: Renal osteodystrophy refers to the bone demineralization seen in chronic kidney disease. It may be divided into high- or low-bone turnover types. Symptoms may be bone or joint pain, fractures, or bone deformation. Blood tests usually show a low-calcium and high-phosphate levels since the diseased kidney is unable to excrete phosphate. Calcitriol, the active form of vitamin D, is low, which contributes to poor absorption of calcium. The parathyroid hormone is elevated due to low-calcium levels that stimulate the parathyroid glands so that this disorder is associated with secondary hyperparathyroidism. Calcium and vitamin D supplements, phosphate binders, and hemodialysis are all indicated. Renal transplantation may be curative.