Quiz on Basics of Nephrology by Dr. Hardik Patel at Dialysis Update 2018

1. Which of the following practices helps to build a patient’s immunity to Hepatitis B?

A.Isolation.

B.Decontamination.

C.Vaccination.

D.AntIoxidents.

Ans 1. Option 3

Hepatitis B vaccination stimulates immune system so it protects body from future infection, for better immune response vaccination should be done in early stage of CKD. CKD patient requires extra and double dose of vaccination compared to healthy individual. Body’s response can be assessed by Anti Hbs titer. Anti Hbs titer more than 12 mIU is considered protective. In case of lower titer repeat vaccination or booster dose is recommended. For details of vaccination reading of vaccination guideline by Indian society of Nephrology is recommended.

2. Of the four available dialyser membrane materials, which is the least biocompatible?

1. Cellulose
2. Modified cellulose
3. Cellulo-synthetic
4. Synthetic

Ans 2. Option 1

Because cellulose membrane are made up of molecular chains that contains free hydroxyl which reacts with blood which is largely responsible for dialyzer reaction. This reaction now a days rare due to availability of newer synthetic biocompatible polymer like polysulfone, PMMA, PAN.

3. Before a dialysis treatment, the patient tells the technician, “Yesterday, I felt terrible and vomited up some blood. I feel much better today.” The technician can expect the patient’s treatment will be modified by

1. decreasing the heparin dose.
2. decreasing the blood flow.
3. increasing the dialysis flow rate.
4.  increasing the ultrafiltration rate.

Ans 3. Option 1

Heparin is used for prevention of blood clotting in extracorporeal circuit during dialysis. Correct dose of heparin can be monitored by aPTT monitoring during dialysis. Heparin use in patient at increased of bleeding like recent surgery, altered clotting parameter, GI bleeding can result in blood loss. In patient with increased bleeding risk tight heparinization or heparin free dialysis is recommended.

4. The technician is unsure which one of a patient’s arteriovenous (AV) graft’s anastomoses is arterial and which one is venous. In order to differentiate between the two, the technician should

1. cannulate both sides of the graft and check the colour of the blood.
2. apply a tourniquet to the arm and feel for venous resistance.
3. compress the graft in the middle and palpate each side.
4. determine the anatomical structure of the area and palpate the radial pulse.

Ans 4. Option 3

Special care should be taken when cannulating fore arm loop graft. In majority of graft the arterial limb will be medial for reference, a road map of the access from surgeon is very useful. When road map from surgeon is not available in that case careful examination with transient occlusion of the access and palpation on either side of occluding finger will reveal direction of blood flow.

5. Why are dialysis patients more likely to become infected with germs like methicillin-resistant Staphylococcus aureus (MRSA)?

1. Their diet is usually restricted in vitamin C
2. They usually have weak immune systems.
3. Their kidneys cannot filter out toxins.
4. They often have allergies to most antibiotics.

Ans 5. Option 2

Dialysis patient have weak immune system, their response to bacterial, viral and fungal is impaired leading to increased risk of infection.

6. During the last hour of his hemodialysis treatment, patient’s blood pressure measures 82/40 mm Hg. After changing the fluid removal rate, the technician should place patient in which of these positions?

1. Prone.
2. Sims.
3. Trendelenburg.
4. Fowler’s.

Ans 6. Option 3

Management of hypotensive patient is straightforward. The patient should be placed in Trendelenburg position and bolus of 0.9 % saline should be administered and UF should be stopped. Patient should be closed observed till normalization of blood pressure. After treatment patient should be evaluated for cause for hypotension like cardiac disease, Dry weight adjustment, Anti-hypertensive medication adjustment, infection, electrolyte imbalance.

7. The most common cause of a low conductivity alarm during hemodialysis is

1. an exhausted concentrate supply.
2. depleted salt in the brine tank.
3. residual sterilant.
4. a clotted dialyzer.

Ans 7. Option 1

Common cause of low conductivity alarm is exhausted concentrate supply. This can result in severe electrolyte imbalance and dialysis should not be started until problem is corrected.

8. At Dry Weight, patient is likely to be

1. edematous.
2. dehydrated.
3. normotensive.
4. hypotensive.

Ans 8. Option 3

Dry weight is defined as lowest weight for a patient can tolerate without development of symptoms of hypotension. At dry weight patient requirement for antihypertensive medication should be minimum. Dry weight adjustment is continuous process which should be monitored during each hemodialysis session.

9. After her hemodialysis treatment, patient’s standing blood pressure is 90/58 mm Hg. She complains of “feeling dizzy” but insists that she can walk to the scale.The technician’s initial response should be to

1. assist her to the scale.
2. instruct her to sit down.
3. give tablet Vertin or PCM.
4. administer normal saline.

Ans 9. Option 2

Any patient having hypotensive episode like giddiness, dizziness should be allowed to walk. Patient should be asked to lie down flat on bed with leg end elevated. Until correction of blood pressure and identification of cause for the hypotension patient should be allowed to walk.

10. At Mrs. Paresh’s next treatment, the technician suspects that her access is clotted. The technician’s suspicion would be true if

1. there was redness over the area.
2. there was swelling over the area
3. a bruit was absent.
4. a thrill was present.

Ans 10. Option 3

Continues, soft pitched bruit should be present over a well-functioning access site. Absence of thrill on palpation and bruit would be indicating an access clotting/ thrombosis and immediate intervention. This access should be never punctured.

11. A hemodialysis patient tests positive for hepatitis B surface antigen. The technician should take which of these actions to prevent the spread of hepatitis B?

1. After dialyzing the patient in the main treatment area, rinse the machine
2. Ask the nurse to vaccinate the patient
3. Require the patient to wear a mask during hemodialysis treatments
4. Dialyze the patient using a dedicated machine in an assigned area.

And 11. Option 4

Patient with hepatitis B infection should be dialyzed on dedicated machine and assigned area. Hepatitis B virus having high risk of transmission and longer virus survival outside body, care should be taken for this patient to prevent transmission infection to other patients. Universal precaution should be taken for all patient, in case of lack of availability of dedicated machine this patient can be dialyzed alongside of patient having high anti HBs titer.

12. Which of these parts of the water treatment system removes endotoxins?

1. Ultrafilter.
2. Resin bed.
3. Deionization tank.
4. Softener.

Ans 12. Option 1

Each part of Water treatment has different function. Depending on source of water and quality of water, different center requires different water treatment. RO and ultrafiltration are mainly used for bacteriological impurities. Resin bed, softener and deionization are used for removal chemical impurities.

13. A patient asks the technician, “Why do I need ultrafiltration/sodium profiling?” The technician’s response should be based on the understanding that the purpose of profiling is to

1. minimize clotting.
2. minimize hypotension.
3. maximize flow rate.
4. maximize clearance.

Ans 13. option 2

Sodium and ultrafiltration profiling are used for prevention of hypotension during hemodialysis. Different profile can be adjusted based on patient’s need. Profiling allows redistribution of fluid to intravascular compartment. Profiling should be done carefully to avoid volume overload at the end of dialysis. Profile with high sodium at the end can result in increase thirst and more fluid intake.

14. Which of the following occurs when the dialysis machine alarms and goes into bypass?

1. Arterial pressure increases.
2. Heparin is not administered.
3. Dialysate stops flowing through the dialyzer
4. Ultrafiltration does not occur

Ans 14. Option 3

Dialysis machine has multiple alarms. Arterial, venous pressure alarms are useful for detection of poor flow, clotting in circuit, accidental removal of needles, resistance to outflow. There are no separate alarms for heparin. Stopping of dialysate, temperature change or conductivity change in dialysate leads to activation of alarm and machine will go into bypass mode.

15. A patient asks the technician why a high venous pressure alarm is sounding. The technician should explain that a high venous pressure alarm might indicate a

1. decrease in the blood flow rate.
2. kink in the arterial blood tubing.
3. separation of venous blood tubing.
4. clotting of blood in the access.

Ans 15. Option 4

High venous pressure alarm indicates resistance to outflow. Causes for resistance to outflow can be due to clotting in circuit, smaller size needle for return, stenosis in fistula, blockage in venous limb of catheter. Separation of blood tubing can lead to low venous pressure alarm, which can be seen even with low blood flow.

16. What is isolated ultrafiltration?

1. Removal of fluid
2. Removal of selected electrolytes
3. Removal of fluid with little/no change in solute concentration
4. All of the above

Ans 16. Option 3

Isolated ultrafiltration means only fluid removal. It allows more fluid removal without much hemodynamic instability. Although no exchange of electrolyte should happen during isolated ultrafiltration but practically some degree of change is expected in electrolyte with isolated ultrafiltration. In patient with volume overload with much uremia or need of dialysis this can be used for removal of excess fluid when medical therapy fails or patient requires rapid removal fluid.

17. What is the main factor contributing to arterial (pre-pump) pressure?

1. Blood pump speed
2.  Arterial tubing diameter
3. Blood pump over occlusion
4. Gauge of arterial access needle

Answer 17. Option 4

Arterial pressure dependence on flow in fistula, arterial needle size. Compared to venous pressure arterial pressure is negative pressure, more negative pressure indirectly means poor flow in fistula, smaller size arterial needle.

18. What is the purpose of the bypass function in a hemodialysis delivery system?

1. To protect the patient from dialysate that is not within safety margins
2. To stop dialysis treatment when treatment time is completed
3. To change concentrates in mid treatment
4. To simplify calibration

Answer 18. Option 1

Newer machines are programmed to provide maximum safety to patient. Machine measure conductivity at multiple level, conductivity depends on electrolyte concentrate. Any change in concentration of electrolyte from set limit results in change in conductivity and machine will go into bypass mode for patient’s safety.

19. What is the purpose of having a transducer to measure the dialysate flow pressure?

1. To ensure proper dialysate flow.
2. To ensure the transfer of electrolytes to the patient.
3. To stop blood from crossing the dialyser membrane
4. To ensure that pressure is lower on the dialysate side to reduce back filtration.

Answer 19. Option 4

Transducer protector are attached between pressure monitor system inside the machine and extracorpeal circuit. It is potential site where blood can enter inside the machine. Transducer protector are used to prevent any passage of blood inside machine. It also prevents cross infection from one patient to other. New transducer should be used for each dialysis session.

20. What causes rejection of a transplanted kidney?

1. Poor blood supply
2. Surgical wound infection
3. Inadequate antibiotic therapy
4. Sensitization to human leukocyte antigen(HLA)

Answer 20. Option 4

Rejection in transplant is mainly because of antibodies against antigen present in transplant kidney. Every person has unique HLA system which helps body to identify which antigen are from outside. For transplant patient transplant kidney has antigen which are foreign for recipient of transplant. Any previous exposure to this antigen can result formation of antibodies which are responsible for rejection. These antibodies can form due to prior sensitization event like blood transfusion, pregnancy, previous transplant.

21. Which of the following is routinely use to measure dialysis adequacy?

1. Kt/V
2. UF rate
3. PCR (protein catabolic rate)
4. BMI (body mass index)

Answer 21. Option 1

Dialysis adequacy means how effectively patient is being dialyzed. Kt/v include urea reduction during dialysis, it also depends on time on dialysis, blood flow, dialysate flow, recirculation in access. Pre and post dialysis BUN sample are taken, value of which is entered in preformed software which used different calculator for calculation of kt/v. kt/v should be monitored on regular basis to assess efficacy of dialysis.

22. What is the heparin prescription where a PTT during dialysis is maintained at 1.5 – 2 times baseline?

1. A routine heparin prescription
2. A “tight” heparin prescription
3. A regional heparin prescription
4. A citrated heparin prescription

Answer 22. Option 2

Heparin dose during dialysis is decided by aPTT value. For routine heparinization value above 2 (2.5 to 3) times is considered as adequate anticoagulation. For patient at risk of bleeding tight heparinization practice is followed in which dose of heparin is adjusted to achieve aPTT of 1.5 to 2 times to normal. Because each patient’s body behaves differently so it important to check aPTT value for adjustment of heparin.

23. If you are on home nocturnal hemodialysis, how many treatments for how long each treatment will you need per week?

1. One for 12 hours.
2. 5-7 for 8-12 hours.
3. Three for four hours.
4. Seven for seven hours.

Answer 23. Option 2

Conventional in-center hemodialysis is three times per week and four hours session each time. Different dialysis prescription are used based on patient’s need. Dialysis dose delivery can be changed by changing frequency and time on dialysis. Frequent incenter hemodialysis means 2.5 to 3 hrs session and 5-7 session per day. Long nocturnal terminology is used for patients who are on home hemodialysis which has longer (8-12 hrs) and frequent session (5-7 per week). Advantage of these type of modalities are better blood pressure control, phosphate control, increase in serum albumin. However no significant survival advantage has been found in any of trials.

24. Which is this Catheter?

1. Femoral DLC
2. Femoral perm cath
3. IJV Permcath
4. Hickman Catheter

Answer 24. Option 2

Permacath is term commonly used for tunneled cuffed catheter(TCC). TCC is preferred vascular access for patient on long term MHD when no AVF is possible. It has advantage of long life, less episode of catheter related infection. Photograph here shows femoral TCC , femoral TCC are last option when upper limb access are exhausted.

25. What is your interpretation in a patient who is on maintenance hemodialysis through left brachiocephalic AVF but with poor flow?

1. Central canal stenosis
2. Severe malnutrition
3. Cyanosis
4. Volume overload

Answer 25. Option 1

Central venous stenosis is complication often seen with use of dialysis catheter. It manifests more after construction of fistula. High blood in fistula and narrow passage for return of blood results in increase in venous pressure during dialysis. If not treated in time it results in prolong bleeding through AVF after needle removal followed by odema in AVF arm. Depending on sit of obstruction it can also result in face odema, pleural effusion, arm odema.

Article Courtesy: Dr. Hardik B Patel

Dr. Hardik B Patel has done DNB Nephrology from Muljibhai Patel Urological Hospital, Nadiad (Gujarat) and MD from B J Medical College. He is currently working at Muljibhai Patel Urological Hospital, Nadiad as a Consultant Nephrologist and Transplant physician. He is having active interest in Intervention Nephrology.

Recommended reading for detailed answers:

1. Indian hemodialysis guideline, updated version will be available soon.
2. Textbook of Dialysis Therapy by Dr Jigar Shrimali.
3. Handbook of dialysis by Daugirdas.