Month: June 2018

My hypertensive patient needs hemodialysis. How dialyzable are common antihypertensives?

FA Manian MD, MPH, , , , , , , , , , , , , , , , , , , , , , , Leave a comment

Among antihypertensives, most commonly used angiotensin converting enzyme inhibitors (ACE-Is) such as captopril, enalapril, lisinopril, and benazepril are at least partially removed by hemodialysis; ramipril and fosinopril are not appreciably removed.1,2

In contrast, none of the commonly used angiotensin receptor blockers such as losartan, valsartan, and irbesartan are removed by hemodialysis.

Among β-blockers and combined α- and β-blockers, atenolol and metoprolol are removed by hemodialysis while carvedilol, bisoprolol, propranolol and labetalol are not.

Many other antihypertensives such as calcium channel blockers, α-blockers, clonidine, and hydralazine are not appreciably removed by hemodialysis, while isosorbide dinitrate appears to be.

Of interest, a 2015 retrospective cohort study found that initiation of high- dialyzability β-blockers (atenolol, acebutolol, or metoprolol) was associated with a higher risk of death in the following 180 days compared to that of low-dialyzability  β-blockers (bisoprolol or propranolol), suggesting that perhaps we should be more selective in our choice of β-blockers in this patient population.2 In contrast, no significant difference in all-cause mortality was noted among older patients receiving ACE-Is with high vs low dialyzability potential.3

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References

  1. Inrig JK, Antihypertensive agents in hemodialysis patients: A current perspective. Semin dial 2010;23:290-7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3061334/pdf/nihms206964.pdf
  2. β-Blocker dialyzability and mortality in older patients receiving hemodialysis. J Am Soc Nephrol 2015;26:987-96. https://www.ncbi.nlm.nih.gov/pubmed/25359874
  3. Weir MA, Fleet JL, Dixon SN, et al. Angiotensin converting enzyme inhibitor dialyzability and outcomes in older patients receiving hemodialysis. Blood Purif 2015;40:232-42.  https://www.ncbi.nlm.nih.gov/pubmed/26382240   

Contributed in part by Andrew Lundquist, MD, PhD, Mass General Hospital, Boston, MA.

 

My hypertensive patient needs hemodialysis. How dialyzable are common antihypertensives?

Why has my patient with Clostridium difficile diarrhea developed Klebsiella bacteremia?

FA Manian MD, MPH, , , , , , , , Leave a comment

Although there are many potential sources for Klebsiella sp. bacteremia, C. difficile infection (CDI) itself may be associated with GI translocation of enteric organisms.

A retrospective study of over 1300 patients found an incidence of 1.8% for CDI-associated bacteremia. E. coli, Klebsiella sp. , or Enterococcus sp. accounted for 72% of cases. History of malignancy, neutropenia (at the time of CDAD), and younger age (mean 59 y) were among the risk factors.1 Another study reported over 20 cases of bacteremia caused by C. difficile plus other bacteria often of enteric origin such the aforementioned organisms, Bacteroides sp, Candida sp, and Enterobacter sp.2

CDI is thought to predispose to bacterial translocation through the GI tract by alteration of mucosal indigenous microflora, overgrowth of certain pathogens, and presence of inflammation in the mucosa.3 Interestingly, C. difficile toxin A or B may play an active role in the bacterial adherence and penetration of the intestinal epithelial barrier.4  

Bonus pearl: Did you know that C. difficile may be found in the normal intestinal flora of 3% of healthy adults, 15-30% of hospitalized patients, and up to 50% of neonates? Why neonates seem immune to CDI is another fascinating story!

 

References

  1. Censullo A, Grein J, Madhusudhan M, et al. Bacteremia associated with Clostridium difficile colitis: incidence, risk factors, and outcomes. Open Forum Infectious Diseases, Volume 2, Issue suppl_1, 1 December 2015, 943, https://doi.org/10.1093/ofid/ofv133.659 https://academic.oup.com/ofid/article/2/suppl_1/943/2635179
  2. Kazanji N, Gjeorgjievski M, Yadav S, et al. Monomicrobial vs polymicrobial Clostridum difficile bacteremia: A case report and review of the literature. Am J Med 2015;128:e19-e26. https://www.amjmed.com/article/S0002-9343(15)00458-1/abstract
  3. Naaber P, Mikelsaar RH, Salminen S, et al. Bacterial translocation, intestinal microflora and morphological changes of intestinal mucosa in experimental models of Clostridium difficile infection. J Med Microbiol 1998; 47: 591-8. https://www.ncbi.nlm.nih.gov/pubmed/9839563 
  4. Clostridium difficile toxins may augment bacterial penetration of intestinal epithelium. Arch Surg 1999;134: 1235-1242. https://jamanetwork.com/journals/jamasurgery/fullarticle/390434
Why has my patient with Clostridium difficile diarrhea developed Klebsiella bacteremia?

Should Aerococcus urinae growth from the urine of my elderly patient be considered a pathogen?

FA Manian MD, MPH, , , , , , , , , , , , , , , , , , , , Leave a comment

Although for many years Aerococcus urinae was considered a urinary contaminant, increasingly it is recognized as an emerging pathogen capable of causing not only urinary tract infection (UTI) but also secondary bacteremia and endocarditis, among others.1   

The proportion of patients with aerococcal bacteriuria with symptoms suggestive of UTI ranges from 55-98%.1 So A. urinae can no longer be assumed to be a contaminant, particularly in the presence of symptoms suggestive of UTI.

A. urinae UTI often affects the elderly (median age 79 y) and those with pre-existing urinary tract pathologies, such as prostatic hyperplasia, urethral stricture, renal calculi, and prior urinary tract surgery.2,3 Many patients also have underlying comorbidities such as diabetes, heart disease, dementia, and chronic renal failure.3

One clue to the presence of A. urinae in the urine is its particularly pungent odor reminiscent of that of patients with trimethylaminuria (fish odor syndrome).4

Once you decide you should treat A. urinae, keep in mind that it is NOT predictably susceptible to trimethoprim-sulfamethoxazole, fluoroquinolones, or fosfomycin!  Instead, consider penicillin, ampicillin, cephalosporin, or nitrofurantoin to which most strains are susceptible.5,6.

 

References

  1. Rasmussen M. Aerococcus: an increasingly acknowledged human pathogen. Clin Microbiol Infect 2016;22:22-27. https://www.ncbi.nlm.nih.gov/pubmed/26454061
  2. Tathireddy H, Settypalli S, Farrell JJ. A rare case of aerococcus urinae infective endocarditis. J Community Hosp Intern Med Perspectives 2017; 7:126-129. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5473194/
  3. Higgins A, Garg T. Aerococcus urinae: An emerging cause of urinary tract infection in older adults with multimordidity and urologic cancer. Urology Case Reports 2017;24-25. https://www.ncbi.nlm.nih.gov/pubmed/28435789
  4. Lenherr N, Berndt A, Ritz N, et al. Aerococcus urinae: a possible reason for malodorus urine in otherwise healthy children. Eur J Pediatr. 2014;173:1115-7 https://www.ncbi.nlm.nih.gov/pubmed/24913181
  5. Christensen JJ, Nielsen XC. Aerococcus urinae. Antimicrobe @ http://www.antimicrobe.orgb75.asp , accessed June 14, 2018.
  6. Dimitriadi D, Charitidou C, Pittaras T, et al. A case of urinary tract infection caused by Aerococcus urinae. J Bacteriol Mycol 2016; 2: 00041. https://pdfs.semanticscholar.org/a1cf/048d8444ce054ca9a332f7c2b4a218325ff6.pdf

 

Should Aerococcus urinae growth from the urine of my elderly patient be considered a pathogen?

Should I be concerned about the umbilical hernia in my patient with cirrhosis and ascites?

FA Manian MD, MPH, , , , , , , , , , , Leave a comment

Although umbilical hernia in patients with cirrhosis and ascites is common and often “expected” (a rate of 20% during the course of their disease), it can be associated with significant risk of complications such as incarceration, ascites drainage, peritonitis, and spontaneous rupture or evisceration from necrosis of overlying skin.1,2

A 2007 retrospective study involving patients with cirrhosis and umbilical hernia reported a complication rate of 77% and related mortality of 15% among those managed conservatively (mean period of observation ~ 5 years); MELD score could not predict failure of conservative management (median 22 in complicated vs 24 in uncomplicated).3

Because the risk of death with hernia repair in urgent settings is 7x higher than for elective hernia repair in cirrhotic patients, there has been increasing interest in elective repair in patients with well-compensated cirrhosis.3 Interestingly, the reported surgical complication rates among patients with well-compensated cirrhosis appear similar to those in noncirrhotic patients.3 If the patient is expected to undergo liver transplantation in the near future, elective hernia repair can be postponed and managed concomitantly.

Bonus pearl: Did you know that spontaneous umbilical hernia rupture is also known as “Flood syndrome” (should be easy to remember!), first described by Frank B Flood, a surgical resident back in 1961? 4

References

  1. Marsman HA, Heisterkamp J, Halm JA, et al. Management in patients with liver cirrhosis and an umbilical hernia. Surgery 2007;142:372-5. https://www.ncbi.nlm.nih.gov/pubmed/17723889
  2. Coelho, JCU, Claus CMP, Campos ACL, et al. Umbilical hernia in patients with liver cirrhosis: a surgical challenge. World J Gastrointest Surg 2016;8:476-82. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942747/
  3. Martens P, Laleman W. Umbilical hernia in a patient with cirrhosis. Cleveland Clin J Med 2015;82: 404-5. https://www.mdedge.com/ccjm/article/100682/hepatology/umbilical-hernia-patient-cirrhosis
  4. Nguyen ET, Tudtud-Hans LA. Flood syndrome: spontaneous umbilical hernia rupture leaking ascitic fluid-a case report. Perm J 2017;21:16-152. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5499604/ 

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Should I be concerned about the umbilical hernia in my patient with cirrhosis and ascites?

What is the evidence that atrial fibrillation (AF) of less than 48 hour duration may not require anticoagulation?

FA Manian MD, MPHLeave a comment

Although it is often postulated that it takes 48 h for a clot to form in a fibrillating atrium, there are no conclusive studies to back this claim (1). In fact, several studies challenge this presumption by suggesting that atrial thrombus may form within 48-72 h of AF.

A study of patients with acute AF (86% for 48 h or less) reported that 14% of patients developed atrial thrombus within 72 h (2). Another study found that ~1% of patients with AF for 48 h or less had an embolic event (3). A 2016 study of patients undergoing electrical cardioversion within 48 h of AF onset also found a risk of neurological events of ~1% among those who underwent cardioversion without therapeutic AC; none had a CHA2DS2-VASc score <2 or had postoperative AF, however (4).

The 2014 ACC guidelines state that for patients with AF or atrial flutter of less than 48 h duration at “high risk of stroke” (often defined as CHA2DS2-VASc score 2 or greater, or history of stroke or transient ischemic attack), AC is recommended as soon as possible before or immediately after cardioversion, followed by long-term AC therapy (Class I, level of evidence C) (5). For those who are at lower thromboembolic risk, AC before cardioversion is optional without the need for its continuation post-cardioversion (Class IIa, level of evidence C).

 

Bonus Pearl: Did you know that up until 1980s, it was generally held that only freshly formed thrombi broke off and embolized and that “organized” clot developing subsequently within a few days was unlikely to embolize! Another 180!

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References

1. Kaufman E, Lagu T, Hannon NS, et al. Mythmaking in medical education and medical practice. Euro J Intern Med 2013;24:222-26. https://www.ncbi.nlm.nih.gov/pubmed/23312964   
2. Stoddard MF, Dawkins PR, Prince CR, et al. Left atrial appendage thrombus is not uncommon in patients with acute atrial fibrillation and a recent embolic event: a transesophageal echocardiographic study. J Am Coll Cardiol 1995;25:452-9. https://www.ncbi.nlm.nih.gov/pubmed/7829800  
3. Weigner MJ, Caulfield TA, Danias PG, et al. Left atrial appendage thrombus is not uncommon in patients with acute atrial fibrillation and and a recent embolic event: A transesophageal echocardiographic study. J Am Coll Cardiol 1995;25:452-9. https://www.ncbi.nlm.nih.gov/pubmed/9103128  
4. Garg, A, Khunger M, Seicean S, et al. Incidence of thromboembolic complications within 30 days of electrical cardioversion performed within 48 hours of atrial fibrillation onset. JACC: Clinical Electrophysiology 2016;2:487-494. https://cwru.pure.elsevier.com/en/publications/incidence-of-thromboembolic-complications-within-30-days-of-elect
5. Wann LS, Curtis AB, January CT, et al. 2011 CCF/AHA/HRS focused update on the management of patients with atrial fibrillation/American Heart Association task force on practice guidelines. J Am Coll Cardiol 2011;57;223-42. https://www.ncbi.nlm.nih.gov/pubmed/21324629

 

 

What is the evidence that atrial fibrillation (AF) of less than 48 hour duration may not require anticoagulation?

Should my patient with non-valvular atrial fibrillation on hemodialysis be anticoagulated?

FA Manian MD, MPH, , , , , , , , Leave a comment

Whether patients with end-stage kidney disease (ESKD) and non-valvular atrial fibrillation (AF) benefit from anticoagulation is a matter of controversy. 1,3 Although there may be some suggestion of benefit of warfarin for stroke prevention in this patient population, 2 there is also a higher concern for bleeding. 4-6 An increased risk of stroke among patients with ESKD and AF on warfarin has also been reported. 7

A 2018 Kidney Disease:Improving Global Outcomes (KDIGO) Controversies Conference concluded that there is “insufficient high-quality evidence” to recommend anticoagulation for prevention of stroke in patients with ESKD and atrial fibrillation. 8

However, the 2014 American College of Cardiology (ACC)/American Heart Association (AHA)/ Heart Rhythm (HRS) guideline states that it is reasonable to consider warfarin therapy in patients with ESKD and non-valvular AF with CHA2DS2 -VASc score of 2 or greater (Class IIa recommendation, level of evidence B).8 Of interest, the FDA recently approved the use of a direct oral anticoagulant (DOAC), apixaban, in ESKD potentially providing an alternative to the use of warfarin when anticoagulation is considered.10

Perhaps the decision to anticoagulate patients with ESKD for atrial fibrillation is best made on a case-by-case basis taking into account a variety of factors, including the risk of thromboembolic event, the risk of bleeding complications as well as patient preference.

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References

1. Genovesi S, Vincenti A, Rossi E, et al. Atrial fibrillation and morbidity and mortality in a cohort of long-term hemodialysis patients. Am J Kidney Dis 2008;51:255-62. https://www.ncbi.nlm.nih.gov/pubmed/18215703

2. Olesen JB, Lip GY, Kamper AL, et al. Stroke and bleeding in atrial fibrillation with chronic kidney disease. N Engl J Med 2012;367:625-35. https://www.ncbi.nlm.nih.gov/pubmed/22894575

3. Shah M, Avgil TM, Jackevicius CA, et al. Warfarin use and the risk for stroke and bleeding in patients with atrial fibrillation undergoing dialysis. Circulation2014;129:1196-203. https://www.ncbi.nlm.nih.gov/pubmed/24452752

4. Elliott MJ, Zimmerman D, Holden RM. Warfarin anticoagulation in hemodialysis patients: a systematic review of bleeding rates. Am J Kidney Dis 2007;50:433-40. https://www.ncbi.nlm.nih.gov/pubmed/17720522

5. Holden RM, Harman GJ, Wang M, Holland D, Day AG. Major bleeding in hemodialysis patients. Clin J Am Soc Nephrol 2008;3:105-10. https://www.ncbi.nlm.nih.gov/pubmed/18003768

6. Wizemann V, Tong L, Satayathum S, et al. Atrial fibrillation in hemodialysis patients: clinical features and associations with anticoagulant therapy. Kidney Int 2010;77:1098-106. https://www.ncbi.nlm.nih.gov/pubmed/20054291

7. Chan KE, Lazarus JM, Thadhani R, Hakim RM. Warfarin use associates with increased risk for stroke in hemodialysis patients with atrial fibrillation. J Am Soc Nephrol2009;20:2223-33. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2754104/

8. Turakhia MP, Blankestijn PJ, Carrero J, et al. Chronic kidney disease and arrythias: conclusions from a Kidney Disease:Improving Global Outcomes (KDIGO) Controversies Conference. Eur Heart J, ehy060. Published 07 March 2018. https://www.ncbi.nlm.nih.gov/pubmed/29522134

9. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation. Circulation 2014;130:2071-104. http://circ.ahajournals.org/content/130/23/2071 

10. Moll S. Use of direct oral anticoagulants in patients on hemodialysis. Diffusion, October 11, 2017. http://www.hematology.org/Thehematologist/Diffusion/7794.aspx 

Contributed by Brad Lander, MD, Mass General Hospital, Boston, MA.

Should my patient with non-valvular atrial fibrillation on hemodialysis be anticoagulated?