#192 Dialysis for the Internist with Joel Topf MD

January 27, 2020 | By Matthew Watto, MD

Management of end stage renal disease in primary care

Kidney Boy Returns! Compare the types of dialysis, learn how nephrologists approach medication management in ESRD, and avoid the most common mistakes non-nephrologists make in patients on dialysis! Kashlak Chief of Nephrology Dr. Joel Topf, @kidney_boy, walks us through what you need to know to take care of a patient on dialysis and gives us an idea of how nephrologists think through mineral bone disease (calcium, phosphorus and vitamin D), anemia, iron repletion, and hypertension. We answer all your questions about co-managing patients on dialysis!

Show Notes | Subscribe | Spotify | Swag! | Top Picks | Mailing List | thecurbsiders@gmail.com

Credits

Producer: Hannah R. Abrams

Written and produced by: Hannah R. Abrams

Cover Art and Infographic by: Hannah R. Abrams

Hosts: Hannah R. Abrams, Matthew Watto MD, FACP; Paul Williams MD, FACP   

Editor: Matthew Watto MD, FACP (written materials), Clair Morgan of Nodderly.com (audio)

Guest: Joel Topf MD

Sponsor

ACP’s Internal Medicine Meeting 2020 April 23-25th in Los Angeles, CA at the LA Convention Center. Early bird rates are available through January 31, 2020. Don’t forget to use the code: IMCURB20

Time Stamps

• 00:00 Sponsor –ACP’s Internal Medicine Meeting 2020
• 00:15 Intro, disclaimer, guest bio
• 01:45 Guest one-liner, Picks of the Week*: KidneyCon, CATS (film)
• 06:00 Sponsor –ACP’s Internal Medicine Meeting 2020
• 06:50 Case of Anne Yuric; Assessing risk of progression to dialysis; Candidacy for dialysis and renal transplant
• 12:20 Why is mortality so high on dialysis
• 15:47 When to initiate dialysis
• 19:40 Types of dialysis; the importance of residual renal function
• 25:45 Why is peritoneal dialysis underutilized
• 28:10 Dialysis access
• 34:25 Return to our case: Mineral bone disease, and phos binders; Calcyphylaxis
• 44:40 Which problems are under the domain of the nephrologist and the dialysis unit?; Hypertension management in ESRD; Midodrine; 48:18 ACEI/ARB, spironolactone
• 51:55 Anemia and iron in ESRD; Screening in Primary Care for patients on dialysis; Statins in patients on dialysis
• 57:42 Medications to avoid
• 61:50 Renal diet; Warfarin and DOACs on dialysis
• 66:48 Common inpatient mistakes: Labs, PICC lines
• 69:36 Takes Home Points; Plug: NephMadness 2020 is coming!
• 72:19 Outro

“Nephrologists are just internists that like diffusion”

-Joel Topf MD, @kidney_boy

Dialysis Pearls for the Internist

When counseling patients approaching dialysis, use the Tangri Kidney Failure Risk Calculator to give them more appropriate expectations of the timeline and probability of dialysis; they may be further from dialysis than you think!

There are several options for treatment of kidney failure. Transplant is best, but if your patient is going to need dialysis, Dr. Topf urges you to be a ‘cheerleader’ for peritoneal dialysis. It allows more independence and longer maintenance of residual renal function!

The Nephrology team will manage volume status, anemia, and mineral bone disease (i.e. calcium, phosphorus, vitamin D, PTH); hypertension management is an opportunity for primary care physicians to add helpful clinical data.

Medications to avoid: As a general rule, any drug that is neuroactive (i.e. baclofen, gabapentin) will have greater toxicity in dialysis patients, so avoid these drugs. Also avoid sodium phosphate (Fleet^Ⓡ) enemas. NSAIDS can be used with caution if patient has no residual renal function, but cardiac, GI risks remain a concern.

How to differentiate an AVG from an AVF on exam. An AVF is soft and appears tortuous when matured. An AVG is synthetic. It feels firm and is less compressible. 

Dialysis Show Notes 

Approaching Dialysis

Dr. Topf describes the four key categories of treatment for kidney failure, how to counsel patients about the likelihood that they will need renal replacement therapy, and how he as a nephrologist approaches the decision to initiate dialysis. 

Treatments for Kidney Failure

Transplant

For patients who are transplant candidates, kidney transplantation has a survival advantage and should be preferred; patients should be referred for transplant evaluation while GFR is in the low 20’s. (Sakhuja, 2014)

Peritoneal Dialysis

Of dialysis options, peritoneal dialysis (PD) has the advantages of improved patient independence and preservation of residual renal function; barriers to implementation include patient and practitioner discomfort. (Saxena, 2006)

Peritoneal dialysis catheters can usually be used 2 weeks after insertion (Sakhuja, 2014), though Dr. Topf notes that with some emergent-use protocols, timing should not be considered a barrier to initiation of PD.

Dr. Topf interprets the early survival benefit for PD as associated with preservation of residual renal function (USRDS, 2018), and will make medication changes to protect renal function for PD patients making >400 ml of urine daily. Ask the patient, “can you fill a beer can?” -Dr Topf.

Hemodialysis

Hemodialysis (HD) is the most commonly used type of dialysis in the United States. (Kaplan, 2017) HD requires vascular access, which can be accomplished by tunneled catheter (TDC), arteriovenous graft (AVG), or arteriovenous fistula (AVF).

Arteriovenous Fistula

An AVF is the most preferred option for HD access. It is a surgically-created fistula that requires 1-3 months to “mature” prior to use for HD. However, there is a high rate of surgical failure (~60%) and alternate forms of access often must be used. (Dember, 2008, Sakhuja, 2014) For patients in whom AVF is an option, Dr. Topf recommends early referral for vein mapping. 

Arteriovenous Graft 

An AVG is a synthetic tube connecting an artery and vein. It can be used in patients without suitable vessels for AVF or in whom AVF has failed; its maturation time is approximately 2 weeks. (Sakhuja, 2014) Like AVF, AVG has a high rate of failure, with limited evidence of benefit of antiplatelet benefit in maintaining patency (Dixon, 2009). Kashlak Pearl: How to differentiate an AVG from an AVF on exam. An AVF is soft and appears tortuous when matured. An AVG is synthetic. It feels firm and is less compressible. 

Temporary Dialysis Catheter

A TDC represents the least preferred choice for HD access. It is a line placed in a large central vein, most commonly the internal jugular vein, and has a high risk of infection and thrombosis. It can be used immediately and is most commonly used for situations in which urgent HD is required. (Sakhuja, 2014)

Conservative Care

Dr. Topf uses the metaphor of a game of Jenga^TM for elderly patients with several comorbidities who are approaching kidney failure: the hemodynamic and logistical stresses of dialysis are like shaking the table. He includes medication management of electrolytes, hypertension, and uremic symptoms in his definition of conservative care.

A key area on which to counsel patients on this decision is functional status. In nursing home residents with kidney failure, initiating dialysis was associated with a significant decrease in functional status at 1 year and still had a high mortality rate. (Kurella Tamura, 2009)

Counseling Pre-Dialysis

Risk of Kidney Failure

Many clinicians overestimate their patients’ risk and timeline for initiating dialysis (Potok, 2019). He recommends using the Tangri Kidney Failure Risk Calculator to determine the risk of kidney failure at two and five years. His practice is to begin discussing dialysis with patients who have >20% risk of kidney failure in that time.

Decision to Initiate Dialysis

GFR vs. Symptomatic Considerations

The IDEAL trial found no difference in survival or clinical outcomes in patients initiating dialysis at a GFR 10-14 ml/min (early start) or the point of symptom development or GFR 5-7 ml/min (late start.) (Cooper, 2010) Dr. Topf considers loss of appetite, weight loss, nausea, pruritus, difficulty with blood pressure control, electrolyte abnormalities, and refractory volume overload when he is deciding to initiate dialysis.

Co-managment of Patients on Dialysis

For some dialysis patients, one way to conceptualize co-management is to think of the nephrologist as the patient’s main source of primary care and the primary care provider as a consultant. (Sakhuja, 2014)

What Should Primary Care vs. Nephrology Manage?

Dr. Topf notes that hemodialysis patients will receive protocol-based management for mineral bone disease, anemia, volume status, and influenza vaccination at the dialysis center. He considers hypertension and non-CKD related primary care key areas in which primary care providers can contribute.

Approach to Hypertension

Hypertension is a key opportunity for primary care to add valuable information for the care of a dialysis patient. During dialysis, avoiding hypotension is prioritized, and thus non-dialysis day blood pressures may be more indicative of the patient’s baseline. Dr. Topf recommends communicating with the patient’s nephrologist if the patient’s BP is uncommonly high or low on their non-dialysis day visit.

Dr. Topf notes that restarting an ACEi/ARB or spironolactone that was stopped prior to dialysis to preserve residual renal function may be appropriate for patients who are anuric. He prefers not to use minoxidil or hydralazine in these patients because of the risk of pericarditis.

Preventative Care

Limited evidence exists regarding the value of cancer screening for patients on dialysis. Non-invasive colorectal cancer screening methods may result in a high false positive rate due to mucosal GI bleeding in these patients. (Collins, 2019) Dr. Topf does not recommend routine cancer screening for the majority of patients on dialysis; however, this should be considered on a case-by-case basis.

Mixed evidence exists on the benefit of statins for patients with CKD on dialysis. (Sakhuja, 2014) Dr. Topf’s practice is to continue statins for those patients for whom they were initiated prior to dialysis, but he does not initiate statins in patients already on dialysis.

Approach to Mineral Bone Disease

Dialysis does not clear phosphorus as effectively as other electrolytes; phosphorus binders keep phosphorus from being absorbed. Common phosphorus binding agents include calcium acetate (or carbonate), sevelamer, lanthanum carbonate, and iron citrate.

Dr. Topf explains that mineral bone disease, phosphorus, and PTH are usually managed by protocol by the patient’s dialysis physician. However, he explains his approach: there is no compelling evidence for calcium vs. non-calcium based phosphorus binders, and no clear clinical outcomes benefit for clinical lowering PTH. (EVOLVE, 2012) He uses the KDIGO guidelines of a phosphorus (serum phosphate) target in normal range and intact PTH between 2-9 times the upper limit of assay. (KDIGO, 2017)

Approach to Anemia

Reasons for anemia in ESRD include decreased hepcidin clearance, GI mucosal bleeding, and blood loss during hemodialysis. Following the results of the PIVOTAL trial, many centers are using a proactive high-dose IV iron protocol. (Collister, 2019)

What to Avoid for Patients on Dialysis

Medications

Sodium Phosphate (Fleet^Ⓡ ) enemas: The high phosphorus load of these enemas can precipitate severe hyperphosphatemia and subsequent hypocalcemia, resulting in coma, cardiac arrest, and death. (See Dr. Topf’s post on the topic at his blog pbfluids.com)

High dose gabapentin: Do not exceed doses of 300 mg per day in patients on dialysis. Gabapentin is renally cleared and at high doses can cause significant altered mental status; coadministration with opioids is associated with significant increase in opioid-related death. (Gomes, 2017)

Non-synthetic opioids: Morphine and codeine both are cleared by the kidney and have active metabolites that can have a long duration of CNS effects; synthetic- and semisynthetic- opioids (e.g. hydromorphone) are less likely to accumulate.

Baclofen: Baclofen is renally cleared and can lead to severe neurotoxicity, including coma, in patients with kidney failure.

NSAIDs: While kidney injury is not applicable to patients without residual renal function, Dr. Topf cautions that NSAIDs still carry risk for cardiac events and GI bleeding.

Warfarin: Limited evidence for treatment of dialysis patients with Afib exists. However, Dr. Topf points out the risk for calciphylaxis, so proceed with caution.

Common Mistakes Made By Inpatient Teams

Dialysis works! Avoid checking a post-dialysis BMP and reflexively repleting the potassium; it is expected for patients to be hypokalemic after dialysis.

Protect potential vascular access sites: be extremely cautious with PICC lines in patients with advanced CKD or on dialysis; these lines may compromise future fistula placement sites. 

Goal

Listeners will comprehend the role of the general internist in caring for the patient on or approaching dialysis.

Learning objectives

After listening to this episode listeners will…  

1. Define the types of dialysis and dialysis access
2. Identify which patients should be referred for dialysis
3. Develop an approach for co-management of patients on dialysis as general internists
4. Apply evidence-based practices for population screening of patients on dialysis
5. Recognize common pitfalls of medication management in patients on dialysis
6. Employ best practices in counseling patients about dialysis

Links*

1. KidneyCon
2. Cats (Movie)
3. Tangri Kidney Failure Risk Calculator

*The Curbsiders participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising commissions by linking to Amazon. Simply put, if you click on my Amazon.com links and buy something we earn a (very) small commission, yet you don’t pay any extra.

References

1. Sakhuja A, Hyland J, Simon JF. Managing advanced chronic kidney disease: a primary care guide. Cleve Clin J Med. 2014. [https://pubmed.ncbi.nlm.nih.gov/24789588]
2. Saxena R, West C. Peritoneal dialysis: a primary care perspective. J Am Board Fam Med. 2006.  [https://pubmed.ncbi.nlm.nih.gov/16809653]
3. Kaplan AA. Peritoneal Dialysis or Hemodialysis: Present and Future Trends in the United States. Contrib Nephrol. 2017 [https://pubmed.ncbi.nlm.nih.gov/27951550]
4. Dixon BS, Beck GJ, Vazquez MA, et al. Effect of dipyridamole plus aspirin on hemodialysis graft patency. N Engl J Med. 2009. [https://pubmed.ncbi.nlm.nih.gov/19458364]
5. Dember LM, Beck GJ, Allon M, et al. Effect of Clopidogrel on Early Failure of Arteriovenous Fistulas for Hemodialysis: A Randomized Controlled Trial. JAMA. 2008 [https://pubmed.ncbi.nlm.nih.gov/18477783]
6. Cooper BA, Branley P, Bulfone L, et al. A randomized, controlled trial of early versus late initiation of dialysis. N Engl J Med. 2010 [https://pubmed.ncbi.nlm.nih.gov/20581422]
7. 2018 USRDS Annual Data Report | Volume 2: ESRD in the United States. Chapter 5: Mortality. [https://www.usrds.org/2018/download/v2_c05_Mortality_18_usrds.pdf]
8. Collins MG, Symonds EL, Bampton PA, Coates PT. Fecal Immunochemical Screening for Advanced Colorectal Neoplasia in Patients with CKD: Accurate or Not?. J Am Soc Nephrol. 2019 [https://pubmed.ncbi.nlm.nih.gov/31597716]
9. Kurella Tamura M, Covinsky KE, Chertow GM, Yaffe K, Landefeld CS, McCulloch CE. Functional status of elderly adults before and after initiation of dialysis. N Engl J Med. 2009 [https://pubmed.ncbi.nlm.nih.gov/19828531] 
10. Potok OA, Nguyen HA, Abdelmalek JA, Beben T, Woodell TB, Rifkin DE. Patients,’ Nephrologists,’ and Predicted Estimations of ESKD Risk Compared with 2-Year Incidence of ESKD. Clin J Am Soc Nephrol. 2019 [https://pubmed.ncbi.nlm.nih.gov/30630859] 
11. EVOLVE Trial Investigators, Chertow GM, Block GA, et al. Effect of cinacalcet on cardiovascular disease in patients undergoing dialysis. N Engl J Med. 2012 [https://pubmed.ncbi.nlm.nih.gov/23121374] 
12. KDIGO. 2017 CKD-MBD Guideline update. [https://kdigo.org/wp-content/uploads/2017/02/2017-KDIGO-CKD-MBD-GL-Update.pdf]
13. Macdougall IC, White C, Anker SD, et al. Intravenous Iron in Patients Undergoing Maintenance Hemodialysis. N Engl J Med. 2019 [https://pubmed.ncbi.nlm.nih.gov/30365356] 
14. Collister D, Tangri N. Post-PIVOTAL Iron Dosing with Maintenance Hemodialysis. Clin J Am Soc Nephrol. 2019 [https://pubmed.ncbi.nlm.nih.gov/31182556] 
15. Topf J. No! No! No! Never! Give a dialysis patient a Fleets Enema!. PB Fluids Blog. 2011. [http://pbfluids.com/2011/11/no-no-no-never-give-a-dialysis-patient-a-fleets-enema/] 
16. Gelfand S. #NephMadness 2019: Pain Region. AJKD Blog. 2019. [https://ajkdblog.org/2019/03/15/nephmadness-2019-pain-region/] 
17. Gomes T, Juurlink DN, Antoniou T, Mamdani MM, Paterson JM, van den Brink W. Gabapentin, opioids, and the risk of opioid-related death: A population-based nested case-control study. PLoS Med. 2017 [https://pubmed.ncbi.nlm.nih.gov/28972983] 
18. Saifan C, Saad M, El-Charabaty E, El-Sayegh S. Warfarin-induced calciphylaxis: a case report and review of literature. Int J Gen Med. 2013 [https://pubmed.ncbi.nlm.nih.gov/20677545] 

Disclosures

Dr Topf lists the following disclosures on his website: “I have an ownership stake in a few Davita run dialysis clinics and a vascular access center. Takeda Oncology made a donation to MM4MM the program that is taking me to Mount Everest in 2018”. The Curbsiders report no relevant financial disclosures. 

Citation

Topf, J, Abrams, HR, Williams PN, Watto MF. “#192 Dialysis for the Internist with Joel Topf MD”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list. January 27, 2020.