Hyponatremia;

What is the role of measuring serum uric acid level in my patient with hyponatremia suspected of having syndrome of inappropriate antidiuretic hormone secretion (SIADH)?

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

The utility of checking serum uric acid (SUA) in hyponatremia primarily stems from the fact that it helps distinguish SIADH from volume contraction as the cause of hyponatremia.1 Whereas hyperuricemia commonly accompanies volume contraction, hypouricemia is found in the majority (70%) of patients with SIADH.2 This finding is caused by increased urinary excretion of SUA in patients with SIADH.3

There are several potential mechanisms for the association of SIADH with hypouricemia. First, the expanded vascular volume in these patients enhances UA clearance by decreasing its reabsorption, as supported by improved UA serum levels in SIADH patients on fluid restriction.4 Of note, UA normalization with fluid restriction is more pronounced in chronic SIADH patients compared to healthy individuals acutely volume overloaded via treatment with synthetic ADH (i.e. desmopressin).5 This may be due to the fact that, unlike endogenous ADH, desmopressin is a selective agonist of vasopressin 2 receptors (V2R), promoting water reabsorption in the collecting duct without binding to vasopressin 1 receptors (V1R), which promotes UA secretion and inhibits UA reabsorption in the proximal tubule.5,6  To make things worse, there is also evidence that chronic hyponatremia induced by SIADH can directly promote UA excretion!7

Last, keep in mind that salt-wasting disease, a less common cause of hyponatremia, may also be associated with hypouricemia. However, in contrast to patients with SIADH, UA excretion remains high and serum UA levels remain low in these patients even after their hyponatremia is corrected. 8

Bonus Pearl: Did you know that tolvaptan, a selective ADH (V2R) antagonist, has been shown to be effective in raising serum sodium and UA levels in SIADH patients with the caveat that its chronic use may also cause hyperuricemia? 9,10

Contributed by Stella Hoft, PhD, Medical Student, St. Louis University Medical School, St. Louis, Missouri

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References

  1. Liamis G, Christidis D, Alexandridis G, Bairaktari E, Madias NE, Elisaf M. Uric acid homeostasis in the evaluation of diuretic-induced hyponatremia. J Investig Med. 2007 Jan;55(1):36-44. doi: 10.2310/6650.2007.06027. PMID: 17441410. https://journals.sagepub.com/doi/10.2310/6650.2007.06027?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
  2. Decaux G, Musch W. Clinical laboratory evaluation of the syndrome of inappropriate secretion of antidiuretic hormone. Clin J Am Soc Nephrol. 2008 Jul;3(4):1175-84. doi: 10.2215/CJN.04431007. Epub 2008 Apr 23. PMID: 18434618. https://journals.lww.com/cjasn/abstract/2008/07000/clinical_laboratory_evaluation_of_the_syndrome_of.38.aspx
  3. Li R, Wu B, Han M, Li M, Yang X, Zhang J, Zhang Y, Liu Y. Uric Acid Metabolic Disorders in Pituitary-Target Gland Axis. Diabetes Metab Syndr Obes. 2024 Feb 7;17:661-673. doi: 10.2147/DMSO.S448547. PMID: 38343584; PMCID: PMC10859102. https://www.dovepress.com/uric-acid-metabolic-disorders-in-pituitary-target-gland-axis-peer-reviewed-fulltext-article-DMSO
  4. Beck LH. Hypouricemia in the syndrome of inappropriate secretion of antidiuretic hormone. N Engl J Med. 1979 Sep 6;301(10):528-30. doi: 10.1056/NEJM197909063011005. PMID: 460306. https://www.nejm.org/doi/abs/10.1056/NEJM197909063011005
  5. Decaux G, Namias B, Gulbis B, Soupart A. Evidence in hyponatremia related to inappropriate secretion of ADH that V1 receptor stimulation contributes to the increase in renal uric acid clearance. J Am Soc Nephrol. 1996 May;7(5):805-10. doi: 10.1681/ASN.V75805. PMID: 8738818. https://journals.lww.com/jasn/abstract/1996/05000/evidence_in_hyponatremia_related_to_inappropriate.23.aspx
  6. Taniguchi K, Tamura Y, Kumagai T, Shibata S, Uchida S. Stimulation of V1a receptor increases renal uric acid clearance via urate transporters: insight into pathogenesis of hypouricemia in SIADH. Clin Exp Nephrol. 2016 Dec;20(6):845-852. doi: 10.1007/s10157-016-1248-x. Epub 2016 Mar 2. PMID: 26935049. https://link.springer.com/article/10.1007/s10157-016-1248-x
  7. Decaux G, Prospert F, Soupart A, Musch W. Evidence that chronicity of hyponatremia contributes to the high urate clearance observed in the syndrome of inappropriate antidiuretic hormone secretion. Am J Kidney Dis. 2000 Oct;36(4):745-51. doi: 10.1053/ajkd.2000.17623. PMID: 11007676. https://www.ajkd.org/article/S0272-6386(00)08495-X/ppt
  8. Momi J, Tang CM, Abcar AC, Kujubu DA, Sim JJ. Hyponatremia-what is cerebral salt wasting? Perm J. 2010 Summer;14(2):62-5. doi: 10.7812/TPP/08-066. PMID: 20740122; PMCID: PMC2912080. https://www.thepermanentejournal.org/doi/10.7812/TPP/08-066
  9. Nagamine T. Uric acid levels with tolvaptan treatment for syndrome of inappropriate antidiuretic hormone secretion. Endocrine. 2024 Mar;83(3):826-827. doi: 10.1007/s12020-023-03612-3. Epub 2023 Nov 20. PMID: 37982946. https://link.springer.com/article/10.1007/s12020-023-03612-3
  10. Bondanelli M, Aliberti L, Gagliardi I, Ambrosio MR, Zatelli MC. Long-term low-dose tolvaptan efficacy and safety in SIADH. Endocrine. 2023 Nov;82(2):390-398. doi: 10.1007/s12020-023-03457-w. Epub 2023 Jul 28. PMID: 37507553; PMCID: PMC10543144. https://link.springer.com/article/10.1007/s12020-023-03457-w

Disclosures/Disclaimers: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

What is the role of measuring serum uric acid level in my patient with hyponatremia suspected of having syndrome of inappropriate antidiuretic hormone secretion (SIADH)?

How common is hyponatremia in patients with Covid-19 and what’s its significance?  

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

Hyponatremia has been reported between 20% and 35% of patients hospitalized for Covid-19, 1-5 with low serum sodium levels on admission often associated with progression to severe illness, mechanical ventilation, increased length of stay and death.1,2,4,5

A 2023 retrospective multicenter study involving over 2,600 hospitalized Covid-19 patients (between February 2020 and August 2022) found hyponatremia in 34.2%: Mild (Na 131-134 mmol/L) 25.1%, moderate (Na 126-130 mmol/L) 7.5% and severe (<126 mmol/L) 1.8%.3 There was a significant association between male sex at birth, hypertension, chronic kidney disease, immunosuppressives, thiazide diuretics and hyponatremia.3

Similarly, another retrospective study of hospitalized Covid-19 patients found an association between hyponatremia and several common chronic diseases, such as diabetes, hypertension, ischemic heart disease, chronic liver disease and chronic kidney disease.4 It’s important to note that since older age has also been found to be a risk factor for hyponatremia in Covid-19, the independent contribution of these conditions to hyponatremia is unclear.3

As with many other infectious diseases, the mechanism of hyponatremia in patients with Covid-19 likely has multiple causes, including hypovolemia, syndrome of inappropriate anti-diuretic hormone secretion (SIADH), diuretic use and corticosteroid deficiency, particularly in the critically ill. 1-4  

Interestingly, a study performed early in the pandemic (March 2020) found that the majority (57%)  of hospitalized Covid-19 patients with hyponatremic were euvolemic and that the administration of isotonic saline to such patients was independently associated with increased hospital mortality (cause unclear).2 The authors suggested closer attention to the volume status of Covid-19 patients with hyponatremia (eg, through closer attention to the jugular venous pressure on physical exam) before considering treatment with isotonic saline.

Last, Covid-19 may be associated with hyponatremia during the post-discharge period as well.  An intriguing 2024 study found nearly 25% of patients with Covid-19 developed hyponatremia (<135 mmol/L) during the 1-year follow-up period after discharge with most not reported to have hyponatremia during their index hospitalization.5 In the same study, hyponatremia was associated with older age, male sex, diabetes, hypertension, heart failure, previous invasive ventilatory support and increased rate of readmission.5

Bonus Pearl: Did you know that there is an inverse relationship between interleukin-6, a key pro-inflammatory cytokine, and plasma sodium levels in Covid-19 and that this association may be stronger than that of other viral or bacterial respiratory infections?2  

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

 

References

  1. Ayus JC, Klantar-Zadeh K, Tantisattamo E, et al. Is hyponatremia a novel marker of inflammation in patients with Covid-19? Nephrol Dial Transplant 2023;38:1921-24. Is hyponatremia a novel marker of inflammation in patients with COVID-19? – PubMed (nih.gov)
  2. Pazos-Guerra M, Ruiz-Sanchez JG, Perez-Candel X, et al. Inappropriate therapy of euvolemic hyponatremia, the most frequent type of hyponatremia in SARS-CoV-2 infection, is associated with increased mortality in COVID-19 patients. Front Endocrinol 2023; 14:1227058. Inappropriate therapy of euvolemic hyponatremia, the most frequent type of hyponatremia in SARS-CoV-2 infection, is associated with increased mortality in COVID-19 patients – PubMed (nih.gov)
  3. De Haan L, ten Wolde, Beudel M, et al. What is the aetiology of dynatreaemia in COVID-19 and how is this related to outcomes in patients admitted during earlier and later COVID-19 waves? A multicentre, restrospective observational study in 11 Dutch hospitals. BMJ Open 2023;13:e075232. Original research: What is the aetiology of dysnatraemia in COVID-19 and how is this related to outcomes in patients admitted during earlier and later COVID-19 waves? A multicentre, retrospective observational study in 11 Dutch hospitals – PMC (nih.gov)
  4. Rehman F, Rehan ST, Rind BJ, et al. Hyponatremia causing factors and its association with disease severity and length of stay in Covid-19 patients: A retrospective study from tertiary care hospital. Medicine 2023; 102:45(e35920) Hyponatremia causing factors and its association with disease severity and length of stay in COVID-19 patients: A retrospective study from tertiary care hospital – PubMed (nih.gov)
  5. Biagetti B, Sanchez-Montalva A, Puig-Perez A, et al. Hyponatremia after COVID-19 is frequent in the first year and increases re-admissions. Scientific Reports 2024:14:595. Hyponatremia after COVID-19 is frequent in the first year and increases re-admissions – PubMed (nih.gov)

 

Disclosures/Disclaimers: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

How common is hyponatremia in patients with Covid-19 and what’s its significance?  

My patient with Covid-19-related generalized weakness has rhabdomyolysis. How common is rhabdomyolysis in Covid-19?

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

Covid-19-associated rhabdomyolysis has been reported since the early years of the pandemic with an overall prevalence ranging from 4%-20% among hospitalized patients and nearly 50% in ICU patients.1-5

In a 2023 scoping review of Covid-19-associated rhabdomyolysis involving 117 cases (January 2020-July 2022),1 68.4% had at least one reported non-Covid-19 risk factor (excluding hypoxemia), including age 65 years or older, metabolic syndrome features, hypothyroidism, previous rhabdomyolysis, hemoglobinopathy, trauma/compression or selected rhabdomyolysis-associated medications.  Presenting symptoms did not always include myalgias or weakness with some patients only presenting with fever, back pain, respiratory symptoms, or fatigue. Mortality was high (32% and 21% in those with or without other risk factors, respectively).  Routine creatine kinase (CK) testing was suggested for hospitalized patients with a low threshold for testing outpatients with Covid-19.

A 2024 cross-sectional study involving hospitalized Covid-19-patients (March 2020-March 2021) reported the following independent factors for concurrent rhabdomyolysis: male gender, dyspnea, hyponatremia, myalgia, elevated D-dimer, aspartate transaminase-AST (3x higher than normal) and platelet count >450,000 (cells/L).2 In the same study, myalgia was reported in only 30% of patients with rhabdomyolysis.   

Potential mechanisms explaining the association between Covid-19 and rhabdomyolysis include hypoxemia, viral myositis (either directly or immune-mediated), viral-induced mitochondrial dysfunction, cytokine storm, hypovolemia and Covid-related coagulopathies.1,2,4

Bonus Pearl: Did you know that although the 3 most common symptoms of patients with rhabdomyolysis are myalgias, muscle weakness and dark urine, the triad is present in only 10% of patients? 6

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

 

References

  1. Preger A, Wei R, Berg B, et al. Covid-19-associated rhabomyolysis: A scoping review. Intern J Infect Dis 2023:136:115-126. COVID-19-associated rhabdomyolysis: A scoping review – PubMed (nih.gov)
  2. Hashemi B, Farhangi N, Toloul A, et al. Prevalence and predictive factors of rhabydomyolysis in Covid-19 patients: A cross-sectional study. Indian J of Nephrol 2024;34:144-48. Prevalence and Predictive Factors of Rhabdomyolysis in COVID-19 Patients: A Cross-sectional Study – PubMed (nih.gov)
  3. Samardzic T, Muradashvill T, Guirguis S, et al. Relationship between rhabdomyolysis and SARS-CoV-2 disease severity. Cureus 16:e53029 (January 27, 2024). Relationship Between Rhabdomyolysis and SARS-CoV-2 Disease Severity – PubMed (nih.gov)
  4. Haroun MW, Dielev V, Kang J, et al. Rhabdomyolysis in Covid-19 patients: A retrospective observational study. Cureus 13:e12552. Rhabdomyolysis in COVID-19 Patients: A Retrospective Observational Study – PubMed (nih.gov)
  5. Albaba I, Chopra A, Al-Tarbsheh AH, et al. Incidence, risk factors, and outcomes of rhabdomyolysis in hospitalized patients with Covid-19 infection. Cureus 13:e19802. Incidence, Risk Factors, and Outcomes of Rhabdomyolysis in Hospitalized Patients With COVID-19 Infection – PubMed (nih.gov)
  6. Lu W, Li X, You W, et al. Rhabdomyolysis in a patient with end-stage renal disease and SARS-CoV-2 infection: A case report. Medicine 2023;102:48(e36360). Rhabdomyolysis in a patient with end-stage renal disease and SARS-CoV-2 infection: A case report – PMC (nih.gov)

 

Disclosures/Disclaimers: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

 

My patient with Covid-19-related generalized weakness has rhabdomyolysis. How common is rhabdomyolysis in Covid-19?

My patient with renal insufficiency developed hyponatremia after an IV contrast study.  Is there a connection between hyponatremia and iodinated contrast media?

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

There are several reports in the literature of hyponatremia (sometimes severe) developing in patients undergoing coronary angiography or routine IV contrast CT studies. 1-3 Although generally asymptomatic, severe hyponatremia with symptoms may also occur, particularly in those at risk of hyponatremia due to other factors.  

In a case series of 5 patients with advanced renal disease who underwent cardiac catheterization and developed post-procedure hyponatremia, the mean plasma sodium concentration decreased from 138.6 mEq/L to 122.6 mEq/L within 2-22 hours post-procedure; no patient had any neurological symptoms associated with hyponatremia. There was a strong correlation between dose of contrast administered and change in sodium level. 2

Severe symptomatic hyponatremia (confusion, stupor) was also reported in an elderly woman with blood creatinine of 0.9 mg/dL following coronary angiography (baseline plasma sodium 142 mmo/L vs. 115 mmol/L >16 hours post-procedure).  The authors suggested that a diagnosis of hyponatremia be considered in any patient who develops behavioral or neurologic manifestations after coronary angiography.3

Aside from coronary angiography, a prospective study among 103 adults (mean serum creatinine 0.79 mg/dl) undergoing contrast-enhanced CT found a drop in serum sodium from a mean concentration of 136 mmol/L to 132 mmol/L 24 hours after the procedure without any associated symptoms.1

Potential mechanisms for the development of hyponatremia after IV contrast studies include hemodilution due to translocation of fluid from intracellular space caused by high osmolality of the contrast media.1  

Bonus Pearl

Did you know that even the newer “low osmolar contrast” agents are more than 3 times the osmolality of blood?4

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References

  1. Sankaran S, Saharia GK, Naik S, et al. Effect of iodinated contrast media on serum electrolyte concentrations in patients undergoing routine contrast computed tomography scan procedure. Int J Appl Basic Med Res 2019;9:217-220. https://www.ijabmr.org/article.asp?issn=2229-516X;year=2019;volume=9;issue=4;spage=217;epage=220;aulast=Sankaran
  2. Sirken G, Raja R, Garces J, et al. Contrast-induced translocational hyponatremia and hyperkalemia in advanced kidney disease. Am J Kidney Dis 2004;43:e9.1-e9.5. https://www.sciencedirect.com/science/article/abs/pii/S0272638603013854?via%3Dihub
  3. Jung ES, Kang WC, Jang YR, et al. Acute severe symptomatic hyponatremia following coronary angiography. Korean Circ J 2011;41:552-554. https://europepmc.org/article/pmc/pmc3193049
  4. Bucher AM, De Cecco CN, Schoefpf UJ, et al. Is contrast medium osmolality a causal factor for contrast-induced nephropathy? BioMed Res International 2014; Volume 2014, article ID 931413. https://www.hindawi.com/journals/bmri/2014/931413/

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My patient with renal insufficiency developed hyponatremia after an IV contrast study.  Is there a connection between hyponatremia and iodinated contrast media?

Should I continue nadolol in my patient with cirrhosis and refractory ascites?

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

Under certain circumstances, you may need to! Although nonselective beta blockers (NSBBs), such as nadolol and propranolol, have been the cornerstone of medical treatment of portal hypertension in preventing variceal bleeding in patients with cirrhosis for decades, recent reports of their association with worsening survival, increased risk of hepatorenal syndrome and acute kidney injury in patients with refractory ascites or spontaneous bacterial peritonitis [SBP]) 1,2 have added controversy to their routine use in end-stage cirrhosis.

This is because patients with end-stage cirrhosis may be highly dependent on their cardiac output (particularly the heart rate) in maintaining an adequate arterial blood pressure 3-5 and the negative inotropic and chronotropic effects of NSBBs blunt this compensatory mechanism. The result is a drop in the cardiac output that may be particularly significant in the presence of conditions already associated with hypotension, such as sepsis, spontaneous bacterial peritonitis (SBP), or hemorrhage, further increasing the risk of renal hypoperfusion and hepatorenal syndrome.3

Although 2 meta-analysis studies failed to find an association between NSBBs and increased mortality among patients with cirrhosis and ascites, 6,7 serious concerns over the adverse effects of these drugs in at least a subset of patients has not waned.  Some have recommended reducing NSBB dose or discontinuing treatment in patients with refractory ascites or SBP and any of the following parameters: 4

  • Systolic blood pressure <90 mmHg
  • Serum creatinine >1.5 mg/dL
  • Hyponatremia <130 mmol/L

Similar recommendations were made by a 2015 consensus conference on individualizing the care of patients with portal hypertension. 8 

In the absence of randomized-controlled studies, it seems prudent to proceed with more caution when using NSBBs in patients with end-stage cirrhosis and watch closely for any signs of hypotension or renal function deterioration.

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

[blog_subscription_form]

 References

  1. Serste T, Njimi H, Degre D, et al. The use of beta-lackers is associated with the occurrence of acute kidney injury in severe hepatitis. Liver In 2015;35:1974-82. https://www.ncbi.nlm.nih.gov/pubmed/25611961
  2. Mandorfer M, Bota S, Schwabl P, et al. Nonselective beta blockers increase risk of hepatorenal syndrome and death in patients with cirrhosis and spontaneous bacterial peritonitis. Gastroenterol 2014;146:1680-90. https://www.sciencedirect.com/science/article/pii/S0016508514003060?via%3Dihub
  3. Garcia-Tsao G. The use of nonselective beta blockers for treatment of portal hypertension. Gastroenterol Hepatol 2017;13: 617-19. http://www.gastroenterologyandhepatology.net/archives/october-2017/the-use-of-nonselective-beta-blockers-for-treatment-of-portal-hypertension/
  4. Reiberger T, Mandorfer M. Beta adrenergic blockade and decompensated cirrhosis. J Hepatol 2017;66: 849-59. https://www.ncbi.nlm.nih.gov/pubmed/27864004
  5. Giannelli V, Lattanzi, Thalheimer U, et al. Beta-blockers in liver cirrhosis. Ann Gastroenterol 2014;27:20-26. https://www.ncbi.nlm.nih.gov/pubmed/24714633
  6. Facciorusso A, Roy S, Livadas S, et al. Nonselective beta-blockers do not affect survival in cirrhotic patients with ascites. Digest Dis Sci 2018;63:1737-46. https://link.springer.com/article/10.1007%2Fs10620-018-5092-6
  7. Njei B, McCarty TR, Garcia-Tsao G. Beta-blockers in patients with cirrhosis and ascites: type of betablocker matters. Gut 206;65:1393-4. https://gut.bmj.com/content/gutjnl/65/8/1393.full.pdf
  8. De Franchis R. Expanding consensus in portal hypertension. Report of the Baveno VI Consensus Workshop: stratifying risk and individualizing care for portal hypertension.  J Hepatol 2015;63:743-52.  https://www.ncbi.nlm.nih.gov/pubmed/26047908  

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you

Should I continue nadolol in my patient with cirrhosis and refractory ascites?

My patient with cirrhosis now has an upper gastrointestinal bleed (UGIB) with hepatic encephalopathy (HE). What’s the connection between UGIB and HE?

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

Hepatic encephalopathy (HE) may be precipitated by a variety of factors including infection, hypovolemia, electrolyte imbalance (eg, hyponatremia, hypokalemia), metabolic alkalosis, sedatives, and of course UGIB. 1-3

Ammonia is often considered to play a central role in the the pathogenesis of HE, particularly when associated with UGIB. The ammoniagenic potential of UGIB is primarily attributed to the presence of hemoglobin protein in the intestinal tract. One-half of the ammoniagenesis originates from amino acid metabolism (mainly glutamine) in the mucosa of the small bowel, while the other half is due to the splitting of urea by the resident bacteria in the colon (eg, Proteus spp., Enterobacteriaceae, and anerobes).1,2

A large protein load in the GI tract, as occurs in UGIB, may result in hyperammonemia in patients with cirrhosis due to the limited capacity of the liver to convert ammonia to urea through the urea cycle as well as by the shunting of blood around hepatic sinusoids. Recent studies, however, also implicate the kidneys as an important source of ammonia in this setting, further compounding HE.3

It’s important to stress that ammonia is not likely to be the only mediator of HE. Enhanced production of cytokines due to infection or other inflammatory states, neurosteroids, endogenous benzodiazepines, and other bacterial byproducts may also play an important role in precipitating HE.2,4-6  So stay tuned!

Bonus pearl: Did you know that proinflammatory cytokines tumor necrosis factor-alpha and inerleukin-6 increase ammonia permeability across central nervous system-derived endothelial cells? 7

 

References

  1. Olde Damink SWM, Jalan R, Deutz NEP, et al. The kidney plays a major role in the hyperammonemia seen after simulated or actual GI bleeding in patients with cirrhosis. Hepatology 2003;37:1277-85.
  2. Frederick RT. Current concepts in the pathophysiology and management of hepatic encephalopathy. Gastroenterol Hepatol 2011;7:222-233.
  3. Tapper EB, Jiang ZG, Patwardhan VR. Refining the ammonia hypothesis: a physiology-driven approach to the treatment of hepatic encephalopathy. Mayo Clin Proc 2015;90:646-58.
  4. Shawcross DL, Davies NA, Williams R, et al. Systemic inflammatory response exacerbates the neuropsychological effects of induced hyperammonemia in cirrhosis. J Hepatol 2004;40:247-254.
  5. Shawcross DL, Sharifi Y, Canavan JB, et al. Infection and systemic inflammation, not ammonia, are associated with grade ¾ hepatic encephalopathy, but not mortality in controls. J Hepatol 2011;54:640-49.
  6. Shawcross D, Jalan R. The pathophysiologic basis of hepatic encephalopathy: central role for ammonia and inflammation.Cell Mol Life Sci 2005;62:2295-2304.
  7. Duchini A, Govindarajan S, Santucci M, et al. Effects of tumor necrosis factor-alpha and interleukin-6 on fluid-phase permeability and ammonia diffusion in CNS-derived endothelial cells. J Investig Med 1996;44:474-82.

If you liked this pearl, sign up under menu and receive future pearls straight into your mailbox!

My patient with cirrhosis now has an upper gastrointestinal bleed (UGIB) with hepatic encephalopathy (HE). What’s the connection between UGIB and HE?

Can I rule out primary adrenal insufficiency by obtaining a single morning serum cortisol level in my hospitalized patient with unexplained hyponatremia?

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

Primary adrenal insufficiency (PAI) can be confidently ruled out when the morning (eg, 6 AM) serum cortisol level is greater than 17 ug/dl. Lower cut-off values are associated with lower probability of excluding PAI: > 10 ug/dl, 62%-67% and ≥5 ug/dl, 36%. 1,2 Conversely, PAI is highly likely when the morning serum cortisol level is less than 3 ug/dl. 3

Since many patients may have serum cortisol levels between 3 ug/dl and 17 ug/dl (ie, in the “indeterminate” range), confirmatory testing commonly performed through cosyntropin stimulation test (CST) is often necessary.

Although the standard CST involves measuring serum cortisol levels at baseline, 30 min, and 60 min with peak cortisol level <18 ug/dl indicative of PAI, several studies have reported that a single post-CST cortisol level obtained at 60 min may also be diagnostic. 3

If you liked this post, sign up under MENU and get future pearls straight into your mailbox!

 

References

  1. Erturk E, Jaffe CA, Barkan AL. Evaluation of the integrity of the hypothalamic-pituitary-adrenal axis by insulin hypoglycemia test. J Clin Endocrinol Metab 83;2350-54. https://www.ncbi.nlm.nih.gov/pubmed/9661607
  2. Bornstein SR, Allolio B, Arlt W, et al. Diagnosis and treatment of primary adrenal insufficiency: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2016;101:364-89. https://academic.oup.com/jcem/article/101/2/364/2810222
  3. Odom DC, Gronowski AM, Odom E, et al. A single, post-ACTH cortisol measurement to screen for adrenal insufficiency in the hospitalized patient. J Hosp Med 2018;13: E1-E5. https://www.ncbi.nlm.nih.gov/pubmed/29444197
Can I rule out primary adrenal insufficiency by obtaining a single morning serum cortisol level in my hospitalized patient with unexplained hyponatremia?

What is the significance of hyponatremia in my patient with acute decompensated congestive heart failure (ADCHF)?

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

Hyponatremia, defined as a serum sodium <135 meq/L, is observed in ~20% of patients hospitalized with ADCHF, and is often dilutional, not “depletional” (ie, not associated with hypovolemia) in this condition1.

In ADCHF, hyponatremia is primarily caused by the production of arginine vasopressin (AVP) (also known as anti-diuretic hormone, or ADH) as a result of decreased perfusion pressures in the aortic arch and renal afferent arterioles, and increased thirst due to the activation of the renin-angiotensin system.  Hyponatremia correlates with the severity of ADCHF and adverse clinical outcomes2.   

 A common approach to dilutional hyponatremia in ADCHF is fluid restriction. Other potential therapies include angiotension converting enzyme inhibitors (by increasing cardiac output and decreasing thirst), loop diuretics (by reducing water reabsorption in the renal distal tubule), and AVP antagonists (eg, tolvapatan, satavaptan)1,3.  Otherwise, in the absence of symptoms, no specific therapy is generally indicated for serum sodium levels ≥ 120mEq/L.

If you liked this post, sign up under MENU and catch future pearls right into your mailbox!

References 

  1. Verbrugge FH, Steels P, Grieten L, Nijst P, Tang WHW, Mullens W. Hyponatremia in acute decompensated heart failure: Depletion versus dilution. J Am Coll Cardiol 2015;65:480-92. https://www.sciencedirect.com/science/article/pii/S073510971407394X?via%3Dihub
  2. Leier CV, Dei Cas L, Metra M. Clinical relevance and management of the major electrolyte abnormalities in congestive heart failure: hyponatremia, hypokalemia, and hypomagnesemia. Am Heart J. 1994;128:564.  https://www.sciencedirect.com/science/article/pii/0002870394906335
  3. Schrier RW, Gross P, Gheorghiade M, Berl T, Verbalis JG, Czerwiec FS, Orlandi C, SALT Investigators. Tolvaptan, a selective oral vasopressin V2-receptor antagonist, for hyponatremia. N Engl J Med. 2006;355:2099. https://www.ncbi.nlm.nih.gov/pubmed/17105757

 

Contributed by Ricardo Ortiz, Medical Student, Harvard Medical School

What is the significance of hyponatremia in my patient with acute decompensated congestive heart failure (ADCHF)?