Certified Nephrology Nurse (CNN) Exam
Nephrology nurses who obtain the Certified Nephrology Nurse (CNN) certification have a competitive advantage over uncertified nephrology nurses in the work force. Certification also gives patients and their families some peace of mind; knowing that they, or their loved ones, are receiving the best quality care from the most highly qualified professionals available in the nephrology profession.
To take the CNN examination, an applicant must meet the following eligibility requirements:
- The applicant must hold a full and unrestricted license as a Registered Nurse (RN) in the
- United States or in one of its occupied territories.
- The applicant must have a minimum of two years experience in nephrology nursing, either as a registered nurse in a clinical staff, an administrator, a teacher, or as a researcher. This experience must be within the three years prior to submitting the application.
- At least 50 percent of the employment hours outlined above must be in nephrology nursing.
- The applicant must hold a bachelor’s degree or a master’s degree in the field of nursing.
- The applicant must have completed a minimum of 30 contact hours of approved Continuing Education (CE) credit in nephrology nursing within the three years prior to submitting the application.
All continuing education credits must be approved by one of the following organizations:
- Organizations accredited by the American Nurses’ Credentialing Center-Commission on Accreditation (ANCC-COA), the credentialing body of the American Nurses’ Association, and the American Nephrology Nurses’ Association (ANNA).
- The American Association of Critical Care Nurses (AACN)
- The Council of Continuing Education
- The California, Florida, Iowa, Kansas, or Ohio state boards of nursing
The CNN examination is available in both a hand-written and a computer-based format. The hand-written examination consists of 200 questions and must be completed in four hours. The computer-based examination contains 175 questions and must be completed in three hours. The minimum passing score is between 70 and 75 percent, depending on the test version.
The categories covered on the CNN examination and the weight of each category is as follows:
- Renal failure concepts: 35 percent
- Hemodialysis: 30 percent
- Peritoneal dialysis: 18 percent
- Transplants: 12 percent
- Acute therapies: 5 percent
The examination objectives that CNN candidates are expected to perform and the weight each objective carries can be broken down as follows:
- Recognize pathologic processes that occur in renal failure and/or treatment modalities:
- Select interventions that are appropriate to the pathologic processes and complications that occur in kidney disease and/or treatment modalities: 15 percent
- Apply physiologic and technical principles of renal replacement therapies: 12 percent
- Select the appropriate teaching and learning strategies to educate patients and their families, other health professionals, and the public: 10 percent
- Choose appropriate actions in administering medications to patients being treated for kidney disease: 12 percent
- Recognize the importance of an interdisciplinary approach in order to promote optimum functioning across the continuum of care: 5 percent
- Apply principles of infection control: 16 percent
- Recognize the importance of utilizing professional nursing practices in order to promote the best patient outcomes possible in each individual circumstance: 4 percent
CNN Practice Questions
1. There are two mechanisms of dialysis: diffusion and ultrafiltration. Which of the following statements best describe ultrafiltration (convective transport)?
A. Hydrostatic or osmotic pressure forces water through a semipermeable membrane, creating a “solvent drag,” in which water carries solutes at or near their original concentration.
B. Large molecules flow through the semipermeable membrane during “solvent drag.”
C. Particles in low concentration flow through the membrane to an area of high particle concentration.
D. Solutes and catabolic wastes transfer into the blood from the high dialysate concentration.
2. Which of the following dialyzers uses the rectangular cross section for basic blood flow geometries?
A. Synthetic membranes
B. Parallel plate dialyzers
C. Hollow fiber dialyzers
D. Cellulose membranes
3. Cellulose is a complex carbohydrate polymer, which is the main structural material found in plant life. Membranes manufactured from cellulose are frequently used in dialysis. What are the advantages and disadvantages of this type of membrane?
A. It is reusable, but it is expensive.
B. It is easy to use, but waste disposal is a problem.
C. It is low cost, but it is bioincompatible with blood.
D. It is biocompatible, but it uses back filtration from dialysate to blood.
4. A peritoneal dialysis patient presents with complaints of abdominal pain, nausea, and vomiting. He states that the solution he emptied from his dialysis outflow was cloudy. What tests should the physician order at this time?
A. Peritoneal cell count
B. Culture of peritoneal effluent
C. Stool culture
D. A and B
E. A and C
5. A patient is admitted for testing as a renal transplantation recipient. Upon reviewing the blood work, the nurse notices that his blood type is B-. When determining kidney compatibility for this patient, what are the factors involving blood type that must be considered?
A. The kidney donor must be B-.
B. The kidney donor must be B, but the Rh (Rhesus) factor is not a consideration.
C. Human leukocyte antigen (HLA) tests must be done.
D. Both A and B are true.
E. Both B and C are true.
1. A: Ultrafiltration occurs when hydrostatic pressure or an osmotic pressure forces water through the semipermeable membrane. The water carries solutes, at or near their original concentration, in a process called “solvent drag.” Larger molecules remain, with the membrane acting as a filter, or sieve. When the concentration of a certain type of particle is higher on one side of a membrane than on the other side, a concentration gradient exists. In this situation, particles in high concentration flow through the membrane to the low concentration side. Solutes and catabolic waste products transfer from the blood where a high concentration exists into the lower dialysate concentration.
2. B: There are two blood flow geometries, the rectangular cross section seen in parallel plate dialyzers and the circular cross section found in hollow fiber dialyzers. Synthetic and cellulose are descriptions of the materials used to produce the membranes used in dialysis.
3. C: The advantage of cellulose membrane usage is low cost; the disadvantage is that all cellulose membranes have some bioincompatibility with blood. Synthetic membranes are reusable and biocompatible. The disadvantages of synthetic membranes include their expense in comparison to cellulose membranes, their high-water permeability that results in the need for ultrafiltration, the absorption of protein to the membrane surface, and the risk of backfiltration from dialysate to blood. There is no major disadvantage resulting from waste disposal problems.
4. D: One of the possible complications of peritoneal dialyses is an infection of the peritoneum (peritonitis). The usual cause is a break in the closed system, allowing the entrance of microorganisms into the peritoneal cavity. Signs and symptoms of this type of infection include: cloudy effluent; abdominal pain; nausea and vomiting; peritoneal cell count greater than 100 white blood cells, more than 50% of which are neutrophils; and culture results, such as Gram +, Gram-, multiple organisms, and fungi. Treatment involves prompt diagnosis, peritoneal flushes with 1.5% dialysate, and intraperitoneal antibiotics with added heparin to prevent fibrin and adhesion formation, (appropriate antibiotic based on culture results). A stool culture may be applicable if the diagnosis of peritoneal infection is eliminated.
5. E: Transplant researchers have identified two main antigen systems: blood groups (ABO) and human leukocyte antigen. The ABO blood groups are the first consideration when determining organ compatibility with the recipient, with potential recipients divided by blood type. Rh (Rhesus) factor does not affect solid organ transplantation.