1. 1 Profiling Conductivity

2. 2 Cellular Solute/Fluid Exchange Gambro Basics 1 (1994) All the membranes are semi-permeable allowing water to move freely between the different compartments. Water will move based upon a concentration gradient, Osmotic pressures, or pressure exerted (Hydrostatic). The cellular Na+ and K+ pump is constantly transporting K+ into the cell and Na+ out of the cell (Active Transport), in an attempt to keep the K+ concentration high inside the cells, and the Na+ concentration high outside the cells and balance the osmolarity between the intracellular and extracellular fluid. The most important volume regulating solutes are 1.K+ inside the cells, 2.Na+ in the interstitial fluid 3.Plasma Proteins and Na+ in the vascular space

3. 3 Goals of Conductivity Profiling Minimize fluid shifts from Intravascular to Intracellular spaces Maintain vascular fluid volume Prevent undesirable patient symptoms

4. 4 Definitions: OSMOLALITY - The Concentration of particles in solution CONDUCTIVITY - The measure of how much current will pass through a solution.

5. 5 Osmolality Sodium is the major determinant of osmolality in the blood and in the dialysate Extracellular osmolality is determined by extracellular sodium (Na+) Extracellular osmolality determines intracellular volume

6. 6 In the Vascular space, if blood is: Hyperosmolar + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Plasma water moves into the vascular space + + + + + + + + + + + + + + Normosmolar Plasma water is stable and not shifting Hyposmolar + + + + + + + + + + + Plasma water moves toward the cells

7. 7 Conductivity Conductivity is the measure of how much current will pass through a solution Sodium (Na  ) ions carry an electrical charge and can be measured as conductivity 95% of the conductivity in the blood and in dialysate is sodium ions

8. 8 Conductivity Dialysate conductivity is adjusted to change sodium levels in dialysate and the patient’s blood Plasma Conductivity (PC) multiplied by 10 approximates patient plasma water sodium in mEq/l Plasma Conductivity can be measured using Diascan

9. 9 Plasma sodium as compared to Plasma Conductivity (PC): Ref: F.Locatelli et al. IJAO 1995. 10 x PC ≈ Na pw 130 135 140 145 150 13.514.014.515 Plasma Water Sodium mEq/l (Na pw) PC mS/cm This axis indicates patient serum sodium levels This axis indicates PC levels as measured by Diascan™ The data points fall within a directly proportional line which indicates that there is a direct correlation between serum sodium and Diascan™ readings.

10. 10 Conductivity Plasma Conductivity (PC) + + + + + + + + + + + 14.0 14.0 PC x10 ≈140 mEq Plasma Na+ + + + + + + + + + + + + + + + + + + + + 14.5 14.5 PC x10 ≈ 145 mEq Plasma Na+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 15.5 15.5 PC x10 ≈ 155 mEq Plasma Na+

11. 11 Symptom Etiology with Constant or Low Dialysate Conductivity Volume loss into cells Cellular Swelling Headache Nausea Disorientation Fatigue Solute loss into dialysate As a result of solute loss, blood has less solute than the extracellular fluid Water moves to spaces where there is more solute, causing symptoms

12. 12 Symptom Etiology Volume loss caused by UF and loss of fluid into the cells can cause symptoms such as: –Hypotension –Dizziness –Nausea, vomiting –Shock Cramping occurs as fluid moves out of the tissue due to muscle irritability from poorly diffused tissue. This can be caused by: –a drop in BP –a drop in plasma volume –patient is below his dry weight.

13. 13 Conductivity profiling While solute removal is highest, osmolality of the vascular space decreases Increase Plasma Conductivity (PC) by increasing dialysate conductivity to affect plasma osmolality Vascular fluid volume refills (Plasma Refill) from the interstitial space while fluid is removed by ultrafiltration Maintaining vascular volume prevents hypotension

14. 14 Note: The solute and fluid shifts begin on a cellular level when dialysis begins. Conductivity profiling must begin when the treatment is started in order to prevent undesirable symptoms.

15. 15 Adjust the Dialysate Conductivity to Control Osmolality of the Blood The higher the dialysate conductivity level, the easier it is to remove fluid Some sodium will move into the blood compartment to help maintain osmolality Plasma refill is defined as the refilling of the blood compartment (or vascular space) from the surrounding tissue spaces.

16. 16 Use of Conductivity Profiling will help: Prevent sodium overload Prevent thirst and excessive fluid gain between treatments Prevent side effects during treatment

17. 17 Short and long term effects of sodium for the patient Have the MD answer these questions: –At what conductivity level should the treatment start and end? –How will patient co-morbidities affect the prescription? –What is the patient’s normal serum sodium? –What type of profile would be best suited for the patient? Things to consider for Conductivity Profiling

18. 18 How to do Conductivity Profiling Identify patients with dialysis related symptoms Analyze the patient’s treatment records Decide if the patient will benefit from a profile Choose a profile that matches your analysis Using the patients three most recent treatment records you can anticipate how conductivity profiling might be most effective.

19. 19 Individualize the Prescription based upon the Patient’s Treatment History Determine when the patient typically demonstrates symptoms. Beginning – Mid – End of treatment? Evaluate the pre treatment Systolic Blood Pressures (SBP) Evaluate the patient’s weight gains between treatments

20. 20 Choosing the Right Profiles 80% of current literature supports the use of high to low conductivity profiles. This –Supports high solute loss early in the treatment –Removes excess sodium mid treatment –Returns patient’s sodium to baseline or below at the end of treatment Evaluate pre and post treatment Na+ levels Customize the profiles to the patient’s individual needs

21. 21 Monitor Plasma Conductivity with Diascan ™ The physician will have plasma conductivity information during each treatment Diascan™ allows monitoring of the patient’s plasma conductivity in the PROFILE/CON view.

22. 22 Plasma conductivity approximates the patient’s serum sodium. Multiply the plasma conductivity by 10 (13.85 x 10 = 138.5)

23. 23 Profile Types % 50 linear High to low 80% progressive High to low 20% progressive Variable Step Step 50% progressive curve delivers a high conductivity with a gradual decline throughout the treatment. Possibly useful for patients with large weight gains and shortness of breath 80% progressive curve delivers high conductivity for a longer period. Possibly useful for patients with large weight gains and symptoms of hypotension early in the treatment With a step profile, the machine may deliver different conductivity levels, maintain higher levels longer, and/or change levels rapidly and frequently. Possibly useful for patients with large weight gains that experiences random symptoms through the treatment and at the end of treatment 20% progressive curve delivers high conductivity for a short period and a lower conductivity for the majority of the treatment. Possibly useful for patients with low BP or hypotension and moderate weight gains.

24. 24 Case Studies How to select a conductivity profile for a patient

25. 25 Carl Kramper has weight gains typically of 3-4 kg and experiences moderate to severe leg cramps during the last 30 minutes of treatment.

26. 26 What is Carl’s sodium level pre treatment? What is his sodium level at the end treatment? Use Diascan™ measurements to help determine Carl’s plasma conductivity Things to consider

27. 27 220 200 180 160 140 120 100 80 60 40306090120150180210240 14.5 14.0 SBP Patient PC 14.1 Dialysate Conductivity Time in Minutes Supports the patient early in the treatment when most solute is being removed. Then decrease the sodium to remove any extra sodium so that the patient does not leave hypernatremic at the end of treatment.

28. 28 220 200 180 160 140 120 100 80 60 40306090120150180210240 14.0 14.5 SBP PC 14.1 Dialysate Conductivity If the patient remains symptomatic, a more aggressive profile can be applied. Prescriptions can be adjusted until the patient becomes asymptomatic. A UF profile could also be applied. Time in Minutes

29. 29 Harriet Hart arrives with a systolic blood pressure of 85 and a weight gain of 3 Kg. As fluid is removed her blood pressure rises

30. 30 220 200 180 160 140 120 100 80 60 40306090120150180210240 14.5 13.5 SBP PC 13.8 Dialysate Conductivity Time in Minutes The Physician may allow a short period of increased conductivity (sodium) to support initial solute and fluid removal. As the treatment progresses, conductivity should rapidly decrease to the patient’s pre treatment PC levels to help prevent thirst and hypernatremia between treatments.

31. 31 220 200 180 160 140 120 100 80 60 40306090120150180210240 14.5 13.7 SBP PC 13.8 Dialysate Conductivity More aggressive profiles allow conductivity support for most of treatment with a lower conductivity at the end of treatment to remove sodium. The patient’s treatment should end with her PC at her pre- treatment plasma conductivity. Time in Minutes

32. 32 Katy Glycemia is hypertensive and diabetic. She has fluid gains of 4-6 Kg between treatments and has symptoms of hypotension about 45 minutes into the treatment as well as mid and late treatment.

33. 33 Assessment and Plan Assessment: –Large fluid gains –Severe hypotensive episodes –Poor plasma refill Plan –Support plasma refill, especially during the first part of the treatment –Prevent hypovolemia –Consider UF profiling in addition to conductivity profiling

34. 34 220 200 180 160 140 120 100 80 60 40306090120150180210240 Systolic BP Time in Minutes PC14.0 Dialysate Conductivity 150 140 Dialysate Conductivity begins high and rapidly tapers to the patient’s PC. This allows for support during the first half of the treatment and removal of sodium during the last half of the treatment. This is done to try to prevent symptoms.

35. 35 220 200 180 160 140 120 100 80 60 40306090120150180210240 14.0 15.5 If the initial curve does not relieve symptoms, a more aggressive curve may be tried. Higher conductivity dialysate lasts longer into the treatment and is rapidly lowered at the end of treatment Time in Minutes Systolic BP PC 14.0Dialysate Conductivity

36. 36 Time in Minutes 220 200 180 160 140 120 100 80 60 40306090120150180210240 150 145 140 The highest conductivity is prescribed during the first 2 hours of the treatment when the most solute is being removed and also when the first symptoms appear. In the middle of the treatment, the conductivity is lowered in order to prevent sodium overload, and at the same time continue to support solute removal Toward the end of treatment, the dialysate conductivity is lowered to the patient’s baseline plasma conductivity so that excess sodium is removed and the patient does not develop hypernatremia, excessive thirst, fluid overload, and the cardiovascular complications associated with hypernatremia. Step profiling is more aggressive: It allows the dialysate conductivity to remain at a higher levels for longer time periods. It allows longer time periods at or below the plasma conductivity goal at end of treatment.

37. 37 220 200 180 160 140 120 100 80 60 40306090120150180210240 150 145 140 PC 14.0Dialysate Conductivity Time in Minutes Systolic BP Add UF profiling to promote early fluid removal

38. 38 Summary of Conductivity Profiling Allows unlimited variation of conductivity levels. Promotes plasma refill. Minimizes fluid shifts from the vascular space to intracellular spaces Decreases the patient’s symptoms May be used simultaneously with UF Profiling