My elderly hospitalized patient with pneumonia has developed hypoglycemia within days of initiating piperacillin/tazobactam (Zosyn). Is there a connection between piperacillin/tazobactam and hypoglycemia?

Hypoglycemia is a rare (<1%) reported side effect of piperacillin/tazobactam (P/T) [1].  While the exact mechanism is unclear, hypoglycemia in this setting may be related to the adverse impact of P/T on renal function or possibly competitive inhibition of renal organic anion transporter 3 (OAT3).

The association of P/T with acute kidney injury (AKI) is well known. In a retrospective cohort analysis of 11,650 patients, P/T was associated with AKI in 7.8% of patients [2]. Of interest, compared to other antibiotics, P/T has also been shown to delay renal recovery in critically ill patients [3].  Decline in renal function may in turn reduce clearance of insulin and lead to hypoglycemia, particularly in patients who already have risk factors for hypoglycemia, such as malnutrition [4]. This is not surprising because renal clearance accounts for 25% of insulin clearance (rest is hepatic).  

Another plausible mechanism is the impact of P/T on glucose metabolism through competitive inhibition of OAT3 [5]. OAT3 is important in reabsorption of gluconeogenic precursors as well as excretion of uremic metabolites [6], which may further dysregulate hepatic gluconeogenesis and precipitate hypoglycemia. Fascinating!

Bonus pearl: Did you know that elderly patients may be at risk of reactive (post-prandial) hypoglycemia particularly in the setting of pre-diabetes or diabetes due to loss of coordination between glucose load and insulin secretion [7]? 

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Contributed by Michael Nance, MD, PhD, Department of Medicine, Mercy Hospital-St. Louis, St. Louis, Missouri

References:

  1. Wyeth Pharmaceutical Inc. Zosyn (piperacillin/tazobactam) [package insert]. U.S. Food and Drug Administration website. https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/050684s88s89s90_050750s37s38s39lbl.pdf. Revised May 2017. Accessed January 16, 2021.
  2. Rutter WC, Burgess DR, Talbert JC, Burgess DS. Acute kidney injury in patients treated with vancomycin and piperacillin-tazobactam: A retrospective cohort analysis. J Hosp Med. 2017 Feb;12(2):77-82. doi: 10.12788/jhm.2684. PMID: 28182801; PMCID: PMC5573255. https://pubmed.ncbi.nlm.nih.gov/28182801/
  3. Jensen JS, Hein L, Lundgren B, et al. Kidney failure related to broad-spectrum antibiotics in critically ill patients: secondary end point results from a 1200 patient randomised trial. BMJ Open 2012;2:doi: 10.1136/bmjopen-2011-000635  https://bmjopen.bmj.com/content/2/2/e000635
  4. Leibovitz E, Adler H, Giryes S, Ditch M, Burg NF, Boaz M. Malnutrition risk is associated with hypoglycemia among general population admitted to internal medicine units. Results from the MENU study. Eur J Clin Nutr. 2018 Jun;72(6):888-893. doi: 10.1038/s41430-018-0143-9. Epub 2018 Mar 27. PMID: 29588529. https://pubmed.ncbi.nlm.nih.gov/29588529/
  5. Wen S, Wang C, Duan Y, Huo X, Meng Q, Liu Z, Yang S, Zhu Y, Sun H, Ma X, Yang S, Liu K. OAT1 and OAT3 also mediate the drug-drug interaction between piperacillin and tazobactam. Int J Pharm. 2018 Feb 15;537(1-2):172-182. doi: 10.1016/j.ijpharm.2017.12.037. Epub 2017 Dec 23. PMID: 29277663. https://pubmed.ncbi.nlm.nih.gov/29277663/
  6. Wu, W., Bush, K.T. & Nigam, S.K. Key Role for the Organic Anion Transporters, OAT1 and OAT3, in the in vivoHandling of Uremic Toxins and Solutes. Sci Rep 7, 4939 (2017). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5504054/
  7. Tamura Y, Araki A, Chiba Y, Horiuchi T, Mori S, Hosoi T. Postprandial reactive hypoglycemia in an oldest-old patient effectively treated with low-dose acarbose. Endocr J. 2006 Dec;53(6):767-71. doi: 10.1507/endocrj.k05-140. Epub 2006 Sep 12. PMID: 16966825. https://pubmed.ncbi.nlm.nih.gov/16966825/ 

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, 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 elderly hospitalized patient with pneumonia has developed hypoglycemia within days of initiating piperacillin/tazobactam (Zosyn). Is there a connection between piperacillin/tazobactam and hypoglycemia?

Why doesn’t my patient with lactic acidosis have hyperkalemia?

Although hyperkalemia may be observed in a variety of conditions associated with metabolic acidosis, it is less likely to be seen in conditions associated with excess organic acids (eg, in lactic acidosis or diabetic ketoacidosis). A likely explanation for this finding revolves around the amazing organic anion transporter (OAT) and its attendant role in counteracting hyperkalemia by bringing potassium (K+) back into the cells.1-5 See details of impact of extracellular and intracellular pH on K+ homeostasis in Figure.1 

Recall that in metabolic acidosis the increased concentration of hydrogen ion (H+) outside the cell reduces sodium (Na+) influx into cells through the Na+-H+ exchange channel resulting in a drop in the intracellular Na+.  Since the Na+K+ATPase ion channel depends on the intracellular Na+ for bringing K+ into the cells, the end-result is higher K+ concentrations in the extracellular space, potentially resulting in hyperkalemia.  This is what is often seen in conditions of mineral (non-organic) acid excess (eg, in respiratory acidosis or poor renal function).

In the case of organic acidosis, however, the OAT also plays an important factor in K+ homeostasis (Figure)1.  As the name suggests, this transporter allows  organic acids such as lactic acid or ketones to enter the cell. As the H+ concentration increases intracellularly, there is more Na+-H+ exchange and more influx of Na+ into the cell.  More available Na+ intracellularly means more Na+ is pumped out by Na+K+ATPase, and more K+ is brought into the cell,1-5 mitigating the impact of metabolic acidosis on K+ efflux into the  extracellular space and potentially even causing hypokalemia! 

Concurrent hyperkalemia and lactic acidosis or diabetic ketoacidosis may of course still occur.  However, in such cases, hyperkalemia is often due to an epiphenomenon related to complicating factors.  In the case of lactic acidosis, this may be related to concurrent renal dysfunction,3 while in diabetic ketoacidosis it may be related to hyperosmolarity or insulin deficiency.1

So next time you see a patient who has hyperkalemia and lactic acidosis, ask yourself  “What else am I missing that can explain the hyperkalemia?“.

Bonus Pearl

Did you know that lactic acid in human blood was first discovered by the German physician–chemist, Johann Joseph Sherer, who sampled post-mortem blood from 2 women who died of puerperal fever in 1843? 6

Contributed by Nabi Chaudhri-Martinez MD, Mercy Hospital-St. Louis, St. Louis, Missouri

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References:

  1. Aronson PS, Giebisch G. Effects of pH on potassium: new explanations for old observations. J Am Soc Nephrol. 2011 Nov;22(11):1981-9. doi: 10.1681/ASN.2011040414. Epub 2011 Oct 6. PMID: 21980112; PMCID: PMC3231780. https://jasn.asnjournals.org/content/22/11/1981.long
  2. Orringer CE, Eustace JC, Wunsch CD, Gardner LB. Natural history of lactic acidosis after grand-mal seizures. A model for the study of an anion-gap acidosis not associated with hyperkalemia. N Engl J Med. 1977 Oct 13;297(15):796-9. doi: 10.1056/NEJM197710132971502. PMID: 19702. https://www.nejm.org/doi/10.1056/NEJM197710132971502?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
  3. Fulop M. Serum potassium in lactic acidosis and ketoacidosis. N Engl J Med. 1979 May 10;300(19):1087-9. doi: 10.1056/NEJM197905103001905. PMID: 34793. https://www.nejm.org/doi/10.1056/NEJM197905103001905?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
  4. Adrogué HJ, Madias NE. Changes in plasma potassium concentration during acute acid-base disturbances. Am J Med. 1981 Sep;71(3):456-67. doi: 10.1016/0002-9343(81)90182-0. PMID: 7025622. https://www.amjmed.com/article/0002-9343(81)90182-0/pdf
  5. Nigam SK, Bush KT, Martovetsky G, et al. The organic anion transporter (OAT) family: A systems biology perspective. Physiol Rev 2015;95:83:123. The Organic Anion Transporter (OAT) Family: A Systems Biology Perspective (physiology.org)
  6. Kompanje EJ, Jansen TC, van der Hoven B, Bakker J. The first demonstration of lactic acid in human blood in shock by Johann Joseph Scherer (1814-1869) in January 1843. Intensive Care Med. 2007;33(11):1967-1971. doi:10.1007/s00134-007-0788-7 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2040486/

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, 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!

Why doesn’t my patient with lactic acidosis have hyperkalemia?

Should patients previously immunized against Covid-19 receive selected monoclonal antibodies when diagnosed with a breakthrough infection?

Although published studies supporting monoclonal antibody therapy in mild to moderate Covid-19 preceded availability of Covid-19 vaccines and the emergence of new variants of concern,1,2 given the possibility of severe breakthrough Covid-19 in high risk vaccinated patients with suboptimal immunity and the retained activity of certain monoclonal antibody products (ie, casirivimab and imdevimab-Regeneron-Cov and sotrovimab) against common variants of SARS-CoV-2 , their use is recommended even in vaccinated individuals with mild to moderate Covid-19.3-5

In fact, the CDC states that “For people who have received one or more doses of Covid-19 vaccine and subsequently experience SARS-CoV-2 infection, prior receipt of a Covid-19 vaccine should not affect treatment decisions (including use of monoclonal antibodies, convalescent plasma, antiviral treatment, or corticosteroid administration) or timing of such treatment.”3

In its July 30, 2021 Emergency Authorization Use (EUA) letter regarding use of casirivimab and imdevimab – REGEN-COV), the FDA does not distinguish between vaccinated and unvaccinated individuals for its indications,4 similar to those of guidelines posted by the Department of Health and Human Services and the NIH.5-6

When indicated, high risk vaccinated individuals with Covid-19 should be offered  an FDA approved (under EUA currently) monoclonal antibody product (such as  casirivimab and imdevimab antibody cocktail or sotrovimab) soon after diagnosis and certainly no later than 10 days.

Vaccinated individuals with mild to moderate Covid-19 not requiring hospitalization and for whom monoclonal antibody treatment may be indicated include older patients and those with risk factors for severe disease, such as obesity, pregnancy, chronic kidney disease, chronic lung disease (including COPD), immunocompromised state, serious heart conditions (eg, heart failure, coronary artery disease, cardiomyopathies), sickle cell disease and type 2 diabetes.7

Of note, casirivimab and imdevimab is indicated for adults (weighing at least 40 kg) and children 12 years or older and is administered by IV infusion or subcutaneously, if IV infusion is not feasible and would lead to delay in treatment.4

Bonus Pearl: Did you know that in phase III trials, casirivimab and imdevimab  antibody cocktail reduced hospitalization or death by 70% in non-hospitalized patients with Covid-19?2

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References

  1. Interim clinical considerations for use of Covid-19 vaccines currently authorized in the United States. 2021. Available at https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html. Accessed August 22, 2021.
  2. March 23, 2021 https://www.roche.com/media/releases/med-cor-2021-03-23.htm
  3. Dougan M, Nirula A, Azizad M, et al. Bamlanivimab plus Etesevimab in mild or moderate Covid-19. N Engl J Med, July 14, 2021. https://www.nejm.org/doi/10.1056/NEJMoa2102685
  4. Letter, EUA REGEN-COV, July 30, 2021. https://www.fda.gov/media/145610/download
  5. Department of Health and Human Services. High risk Covid-19 outpatients may avoid hospitalization with monoclonal antibody treatment. July 16, 2021. https://combatcovid.hhs.gov/sites/default/files/documents/High-Risk-COVID-19-Outpatients-072021.pdf
  6. Anti-SARS Cov-2 monoclonal antibodies. Accessed August 22, 2021. https://www.covid19treatmentguidelines.nih.gov/therapies/anti-sars-cov-2-antibody-products/anti-sars-cov-2-monoclonal-antibodies/
  7. Science brief: evidence used to update the list of underlying medical conditions that increase a person’s risk of severe illness from Covid-19. Accessed August 22, 2021. https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/underlying-evidence-table.html

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate 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!

Should patients previously immunized against Covid-19 receive selected monoclonal antibodies when diagnosed with a breakthrough infection?

My patient with Covid-19 and abdominal pain has an elevated lipase. Is there a connection between Covid-19 and acute pancreatitis?

Acute pancreatitis as a complication of Covid-19 is infrequent.1 Despite reports of elevated amylase/lipase and/or acute pancreatitis in some patients with Covid-19,2 the exact role that SARS-CoV-2 plays in causing acute pancreatitis is unclear at this time.

A retrospective study of over 11,000 hospitalized patients with Covid-19 in the U.S. found a point prevalence of acute pancreatitis of only 0.27%,3 while another retrospective study of Covid-19 patients seen in Spanish emergency rooms reported acute pancreatitis in only 0.07% of cases.4 Of interest, in the latter study, Covid-19 was associated with lower frequency of acute pancreatitis. Further adding to the controversy on the causative role of Covid-19 is lack of an observed increase in the incidence of acute pancreatitis during Covid-19 pandemic. 1

An earlier study from China reported mild elevation (<3x upper limits of normal) of amylase and/or lipase in 17% of patients with Covid-19 pneumonia, none of whom had abdominal pain. 5

The temporal relationship between Covid-19 and acute pancreatitis has varied from abdominal symptoms at the onset of Covid-19 symptoms to days after diagnosis of Covid-19? 1

Despite these disparate findings, Covid-19 related acute pancreatitis or pancreatic injury is plausible. Pancreatic ductal, acinar and islet cells express ACE2, an important receptor for SARS-CoV-2.1 Infection in the GI tract (virus can easily be found in the stool) may potentially spread from the duodenal epithelium to the pancreatic duct and the pancreatic parenchyma itself. Immune-mediated inflammatory response or endotheliitis caused by SARS-CoV-2 may also potentially explain reports of pancreatic injury in Covid-19. 1,2

Bonus Pearl: Did you know that SARS-CoV-2 has been found in pancreatic tissue of some patients who succumbed to Covid-19 and has been shown to infect human pancreatic beta cells in-vitro.6  Perhaps we should be on the lookout for diabetes as a consequence of Covid-19 as well!

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 References

  1. De-Madaria E, Capurso G. Covid-19 and acute pancreatitis: examining the causality. Nature Reviews Gastroenterol Hepatol 2021;18: 3-4. https://www.nature.com/articles/s41575-020-00389-y
  2. Kandasamy S. An unusual presentation of Covid-19: acute pancreatitis. Ann Hepatobiliary Pancreat Surg 2020;24:539-41. https://synapse.koreamed.org/upload/SynapseXML/2110ahbps/pdf/AHBPS-24-539.pdf
  3. Inamdar S, Benias PC, Liu Y, et al. Prevalence, risk factors, and outcomes of hospitalized patients with coronavirus disease 2019 presenting as acute pancreatitis. Gastroenterol 2020;159:2226-28. https://www.gastrojournal.org/article/S0016-5085(20)35115-5/pdf
  4. Miro O, Llorens P, Jimenez S, et al. Frequency of five unusual presentations in patients with Covid-19: results of the UMC-19-S. Epidemiol Infect 2020;148:e189. https://pubmed.ncbi.nlm.nih.gov/32843127/
  5. Wang F, Wang H, Fan J, et al. Pancreatic injury patterns in patients with coronavirus disease 19 pneumonia. Gastroenterology 2020;159:367-70. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118654/
  6. Wu C-T, Lidsky PV, Xiao Y, et al. SARS-CoV-2 infects human pancreatic beta cells and elicits beta cell impairment. Cell Metab 2021 May 18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8130512/

 

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, Mass General Hospital, Harvard Medical School or its affiliated institutions. 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 and abdominal pain has an elevated lipase. Is there a connection between Covid-19 and acute pancreatitis?

What’s the connection between severe hypoglycemia and hypothermia?

The association of severe hypoglycemia and low body temperatures has been well documented at least since 1960s.  Hypothermia is thought to be caused by low blood glucose in the brain (neuroglucopenia) which may serve as a protective mechanism for decreasing energy demand during glucose deprivation.1-2

A 2012 retrospective study involving mostly patients with diabetes mellitus with severe hypoglycemia (majority with serum glucose 18-54 mg/dl) found that 23% of patients had hypothermia (defined as body temperature < 95◦F or 35◦C). The incidence of hypothermia was not affected by age, diabetes, season or time of day.  Two patients had extremely low temperatures (<90◦F).  There was an association between hypothermia and severity of hypoglycemia.1

An older experimental study (1974) involving 36 recumbent nude men in thermoneutral environment found that that insulin-induced hypoglycemia was associated with rectal temperatures below 96.2◦F (36◦C) in 33%.  Cooling was attributed to reduction in heat production and to secretion of sweat, peripheral vasodilatation and hyperventilation.2

But before you attribute hypothermia to hypoglycemia, make sure other causes of hypothermia such as sepsis, hypoadrenalism, hypothyroidism, alcohol and stroke are ruled out.3  

Bonus Pearl: Did you know that heat production is accomplished by shivering, which can increase the normal basal metabolic rate by 2-5 times as well as via non-shivering thermogenesis through increased levels of thyroxine and epinephrine?3

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References

  1. Tran C, Gariani K, Hermann FR, et al. Hypothermia is a frequent sign of severe hypoglycaemia in patients with diabetes. Diab Metab 2012;38:370-72. https://www.sciencedirect.com/science/article/abs/pii/S1262363612000535?via%3Dihub
  2. Strauch BS, Felig P, Baxter JD, et al. Hypothermia in hypoglycemia. JAMA 1969;210:345-46. https://jamanetwork.com/journals/jama/article-abstract/349081
  3. McCullough L, Arora S. Diagnosis and treatment of hypothermia. Am Fam Physician 2004;70:2325-2332. https://www.aafp.org/afp/2004/1215/p2325.html

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, Mass General Hospital, Harvard Medical School or its affiliated institutions. 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’s the connection between severe hypoglycemia and hypothermia?

What’s the connection between elevated troponins and Covid-19?

Elevated cardiac troponins or myocardial injury (defined as troponin levels above the 99th percentile upper reference range) are not uncommon in Covid-19, having been reported in ~10-30% of hospitalized patient and usually observed in the absence of acute coronary syndrome (ACS) (1-4).

 
Elevated troponins have been associated with increased risk of in-hospital mortality in Covid-19. The prevalence of elevated troponins among patients who died was 76% compared to 10% among survivors in 1 Chinese study (3). Another study from China found increasing troponin levels over a 22 day period among those who died while troponin levels remained low in those who survived (5).

 
Risk factors for elevated troponins in Covid-19 include older age, cardiovascular comorbidities (eg, hypertension, coronary heart disease, heart failure), diabetes, chronic obstructive pulmonary disease, chronic renal failure, and the presence of a high inflammatory state, as indicated by elevated inflammatory markers such as C-reactive protein (CRP) (3).

 
Several mechanisms have been proposed to explain elevated troponins in Covid-19, including cytokine-induced myocardial injury, microangiopathy due to prothrombotic state, myocardial infarction (type I due to plaque rupture or type II due to oxygen supply/demand imbalance), and myocarditis either due to direct viral invasion or indirectly through immune-mediated mechanisms (1,2).

 
Patients with Covid-19 and modest troponin elevation with rapid fall in the absence of signs or symptoms of ACS, may have type II myocardial infarction due to demand ischemia, particularly in the setting of coronary disease. In contrast, more protracted elevation of troponins associated with high inflammatory markers such as CRP is suggestive of hyperinflammatory myocardial injury (1).

 

It will be interesting to see if trials of anti-inflammatory agents, such as colchicine and anti-interleukin-I, will have an impact on the troponin levels in Covid-19 patients (1).

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References
1. Cremer PC. SARS-CoV-2 and myocardial injury: few answers, many questions. Clev Clin J Med. Posted April 8, 2020. Doi:10.3949/ccjm.87a.ccc001 https://www.ccjm.org/content/early/2020/05/12/ccjm.87a.ccc001
2. Tersalvi G, Vicenzi M, Calabretta D, et al. Elevated troponin in patients with coronavirus disease 2019:possible mechanisms. J Card Failure 2020; https://pubmed.ncbi.nlm.nih.gov/32315733/
3. Shi S, Qin M, Cai Y, et al. Characteristics and clinical significance of myocardial injury in patients with severe coronavirus disease 2019. Eur Heart J 2020. https://pubmed.ncbi.nlm.nih.gov/32391877/
4. Richardson S, Hirsch JS, Narasimhan M, et al. Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area. JAMA 2020;323:2052-59. https://jamanetwork.com/journals/jama/fullarticle/2765184
5. Zhou F, YU T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020;395:1054-62. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30566-3/fulltext

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!

 

What’s the connection between elevated troponins and Covid-19?

Catch these selected key clinical pearls on coronavirus disease (Covid-19)!

Although the Covid-19 pandemic is continuing to evolve and our knowledge of its epidemiology and pathophysiology is still far from complete, you may find the following pearls based on published literature to date useful when discussing this disease with your colleagues or the public. 1-11

  • Age group: Primarily an adult disease. Children (< 15-year-old) account for only a minority of symptomatic patients (<1%); ~50% of patients are between 15-49 years of age with 15% in the ≥ 65 year group. 1
  • Incubation period: A bit longer than seasonal flu. Median 4.0 days (IQR 2.0-7.0 days); an upper range up to 24 days has also been reported. In contrast, for seasonal flu the median incubation period is shorter (median 2.0 days, 1.0-7.0 days. 1,4,11
  • Transmission: Contact, droplet, and possibly airborne. On average each person may transmit Covid-19 virus to 2-3 other persons (vs <2 people for seasonal flu). Unlike SARS or MERS, but more akin to the seasonal flu, asymptomatic persons may also be able to transmit the disease. 4,5,11
  • Comorbid conditions (eg, diabetes, hypertension, COPD…): Present in about 1/3 of reported patients. 1
  • Symptoms 1,5
    • ~80% of patients may be either asymptomatic or have mild disease
    • Fever may be absent in ~50% of patients on presentation but will eventually develop in ~90% of hospitalized patients
    • Cough (2/3 dry) is present in majority (~80%) of cases
    • Rhinorrhea is uncommon (<10%), in contrast to the seasonal influenza
    • GI symptoms (nausea/vomiting/diarrhea) are uncommon by some reports(<10%), but not by others (>30.0%). 12
    • May take 9-12 days from onset of symptoms to severe disease
  • Labs 1
    • Lymphopenia is common (up to ~80%)
    • Abnormal liver function (AST and ALT) is found in about 1/3 of patients
    • C-reactive protein (CRP) is usually elevated (~80% of severe cases)
    • Procalcitonin is usually normal
  • Treatment: Supportive for now. Candidate drugs include remdesivir, lopinavir/ritonavir, chloroquine phosphate, ribavirin and several others.4
  • Mortality: Reported mortality among mostly symptomatic hospitalized cases is ~2.0% (0.9% without comorbidities, 5-10% in those with comorbidities, 50% among critically ill). Overall mortality rates will likely drop as more patients without symptoms or with mild disease are tested. In contrast, 2 other coronavirus diseases, SARS and MERS, have mortality rates of ~9.0% and 36.0%, respectively. 1,4,5

 

Bonus pearl: Did you know that, Covid-19-infected patients shed the virus in their nasopharyngeal secretions on the average for 12 days, some as long as 24 days?3

 

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References

  1. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of Coronavirus disease 2019 in China. N Engl J Med 2020. First published Feb 28, 220, last updated March 6, 2020. https://www.nejm.org/doi/10.1056/NEJMoa2002032
  2. Holshue ML, DeBolt C, Lindquist S, et al. First case of 2019 novel Coronavirus in the United States. N Engl J Med 2020; 382:929-36. https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
  3. Young BE, Ong SWX, Kalimuddin S, et al. Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore. JAMA. Doi:10.1001/jama.2020.3204. Published online March 3, 2020. https://jamanetwork.com/journals/jama/fullarticle/2762688
  4. Wang Y, Wang Y, Chen Y, et al. Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures. J Med Virol 2020. Doi: 10.1002/jmv.25748. https://www.ncbi.nlm.nih.gov/pubmed/32134116
  5. Fauci AS, Lane HC, Redfield RR. Covid-19—Navigating the uncharted. N Eng J Med 2020. DOI:10.1056/NEJMe2002387. https://www.nejm.org/doi/full/10.1056/NEJMe2002387
  6. Del Rio C, Malani PN. 2019 novel coronavirus—important information for clinicians. JAMA 2020, Feb 5. https://www.ncbi.nlm.nih.gov/pubmed/32022836
  7. Lipsitch M, Swerdlow DL, Finelli L. Defining the epidemiology of Covid-19—studies needed. N Engl J Med 2020. Feb 19. DOI:10.1056/NEJMp2002125. https://www.ncbi.nlm.nih.gov/pubmed/32074416/
  8. Morens DM, Daszak P, Taubenberger JK. Escaping Pandora’s box—another novel coronavirus. N Eng J Med 2020. Feb 26. DOI:10.1056/NEJMp2002106. https://www.nejm.org/doi/full/10.1056/NEJMp2002106
  9. She J, Jiang J, Ye L, et al. 2019 novel coronavirus of pneumonia in Wuhan, China: merging attack and management strategies. Clin Trans Med 2020;9:19. https://clintransmed.springeropen.com/articles/10.1186/s40169-020-00271-z
  10. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020; 395: 497-506. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30183-5/fulltext
  11. Bai Y, Yao L, Wei T, et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA 2020. Feb 21. https://jamanetwork.com/journals/jama/fullarticle/2762028
  12. Pan L, Mu M, Yang P, et al. Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study. Am j Gastroenterol 2020. https://journals.lww.com/ajg/Documents/COVID_Digestive_Symptoms_AJG_Preproof.pdf
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Why is my diabetic patient complaining of arm pain and localized edema for couple of weeks without an obvious cause?

Aside from the usual suspects associated with a painful extremity (eg, trauma, deep venous thrombosis and soft tissue infections), think of spontaneous diabetic myonecrosis (DMN), also known as diabetic muscle infarction (1-3).

DMN is characterized by abrupt onset of painful swelling of the affected muscle, most often of the lower extremities, but also occasionally upper extremities. DMN occurs in patients with longstanding DM whose blood glucose control has deteriorated over time, often with nephropathy, retinopathy and/or neuropathy (1-3).

Couple of things to remember when considering DMN in your differential of a painful extremity. First, except for localized edema and tenderness over the involved muscle, the exam may be unremarkable. Specifically, there is no erythema or signs of compartment syndrome and fever is absent in the great majority of patients (~90%) (2). Even white blood cell count and creatine kinase (CK) are usually normal. The reason for normal CK at presentation is not clear but CK might have already peaked by the time of patient presentation (3). In contrast, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are usually elevated (>80%) (1).

MRI (without contrast in patients with renal insufficiency) is the imaging of choice with muscle enlargement and edema with hyperintense signal on T2-weighted images and other changes, including perifascial, perimuscular and or subcutaneous edema (1-3). Muscle biopsy is not currently recommended because of its adverse impact on time to symptomatic improvement. Non-surgical therapy, with rest, analgesia and glycemic control is usually recommended (1-3).

 
Though its exact cause is still unclear, atherosclerosis, diabetic microangiopathy, vasculitis with thrombosis and ischemia-reperfusion injury have been posited as potential precipitants for DMN. The role of anti-phospholipid syndrome, particularly in patients with type I DM, is unclear (1,2).

 
Bonus pearl: Did you know that symptoms of DMN may last for weeks with at least one-third of patients having a recurrence in the same muscle or elsewhere (1)?

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Reference
1. Horton WB, Taylor JS, Ragland TJ, et al. Diabetic muscle infarction: a systematic review. BMJ Open Diabetes Research and Care 2015;3:e000082.
2. Trujillo-Santos AJ. Diabetic muscle infarction. An underdiagnosed complication of long-standing diabetes. Diabetes Care 2003;26:211-15.
3. Diabetes muscle infarction in end-stage renal disease:A scoping review on epidemiology, diagnosis and treatment. World J Nephrol 2018;7:58-64.

Why is my diabetic patient complaining of arm pain and localized edema for couple of weeks without an obvious cause?

My patient with peripheral neuropathy was just diagnosed with monoclonal gammopathy of unclear significance (MGUS). Can these two conditions be related?

The presence of MGUS in patients with peripheral neuropathy (PN) may be either coincidental or causal. Younger age group (<50 y) and the presence of IgM MGUS increase the likelihood of a causal relationship between MGUS and peripheral neuropathy. 1

The likelihood of a causal relationship is higher in the younger age group because of the very low prevalence of M proteins (less than 1.5%) in this population making coincidental presence of MGUS and PN much less likely. In contrast, this relationship may just be coincidental in older patients because of higher baseline prevalence of MGUS (7% in those over 70 y old). 1  

Similarly, a causal relationship between MGUS and PN may be more likely when the M protein is IgM (vs IgG or IgA). In a study of patients with MGUS and peripheral neuropathy,  31% of patients with IgM MGUS had neuropathy vs 14% for IgA and 6% for IgG MGUS. In fact, among patients with PN without an obvious cause, the prevalence of an M protein may be as high as 10%.2  Whether the relationship between non-IgM MGUS and PN is causal remains unclear.3

Although the exact mechanism of MGUS-related PN is not known, pathologic studies in Waldenstrom macroglobulinemia and multiple myeloma have demonstrated demyelination and widened myelin lamellae associated with monoclonal IgM deposits.1

But before you implicate MGUS as the cause of PN, make sure to exclude common causes of PN, such as diabetes mellitus, alcoholism and potential drugs.

 

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References

  1. Chaudhry HM, Mauermann ML, Rajkumar SV. Monoclonal gammopathy—associated peripheral neuropathy: diagnosis and management. Mayo Clin Proc 2017; 92:838-50. https://www.mayoclinicproceedings.org/article/S0025-6196(17)30118-0/pdf
  2. Kelly JJ Jr, Kyle RA, O’Brien PC, et al. Prevalence of monoclonal protein in peripheral neuropathy. Neurology 1981;31:1480-83. https://www.ncbi.nlm.nih.gov/pubmed/6273767
  3. Nobile-Orazio E, Barbien L, Baldini L, et al. Peripheral neuropathy in monoclonal gammopathy of undetermined significance: prevalence and immunopathogenetic studies. Acta neurol Scand 1992;85:383-90. https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0404.1992.tb06033.x
My patient with peripheral neuropathy was just diagnosed with monoclonal gammopathy of unclear significance (MGUS). Can these two conditions be related?

Why is my patient with diabetic ketoacidosis (DKA) and hypovolemia hypertensive?

Although we may expect patients with DKA to present with hypotension due to hypovolemia, many patients with DKA may actually be hypertensive. This finding is particularly intriguing because hyperinsulinemia, not insulinopenia as found in DKA, has been associated with hypertension. 1,2

Though not proven, potential explanations for hypertension in DKA include elevated serum levels of catecholamines, pro-inflammatory cytokines, renin, angiotension II and aldosterone.3-5 Hyperosmolality may also lead to the release of antidiuretic hormone (ADH) which increases blood pressure via V2 receptors.  Another possibility is that the high insulin levels associated with the treatment of DKA suppress the catecholamine-stimulated production of vasodilative eicosanoids (eg, prostaglandins) by adipose tissue. 1 It’s possible that in any given patient, 1 or more of these mechanisms may be enough to override the potential hypotensive effect of insulin deficiency in DKA.

We should note that reports of frequent hypertension in DKA have primarily involved pediatric patients. A 2011 study found that 82% of pediatric patients with DKA had hypertension during the first 6 hours of admission with no patient having hypotension.3  

On the other extreme, refractory hypotension without obvious cause (eg, sepsis, acute adrenal insufficiency, cardiogenic causes) has also been reported in DKA.5Because insulin inhibits the production of vasodilative prostaglandins (eg, PGI2 and PGE2), severe insulin deficiency in DKA can also contribute to hypotension along with volume depletion. 

Potential genetic polymorphism in the synthesis and metabolism of prostaglandins may at least partially explain the varied blood pressure response and whether a patient with DKA presents with hypertension or hypotension. 5  

The author would like to acknowledge the valuable contribution of Lloyd Axelrod MD, Massachusetts General Hospital, to this post.

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References

  1. Axelrod L. Insulin, prostaglandins, and the pathogenesis of hypertension. Diabetes 1991;40:1223-1227. https://diabetes.diabetesjournals.org/content/40/10/1223&nbsp;
  2. Chatzipantelli K, Head C, Megerman J, et al. The relationship between plasma insulin level, prostaglandin productin by adipose tissue and blood pressure in normal rats and rats with diabetes mellitus and diabetic ketoacidosis. Metabolism 1996;45:691-98. https://www.sciencedirect.com/science/article/abs/pii/S002604959690133X&nbsp;
  3. Deeter KH, Roberts JS, Bradford H, et al. Hypertension despite dehydration during severe pediatric diabetic ketoacidosis. Pediatr Diabetes 2011;12:295-301. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1399-5448.2010.00695.x&nbsp;
  4. Ferris JB, O’Hare JA, Kelleher CM, et al. Diabetic control and the renin-angiotensin system, catecholamines and blood pressure. Hypertension 1985 7(Suppl II):II-58-II-63. https://www.ahajournals.org/doi/abs/10.1161/01.HYP.7.6_Pt_2.II58  
  5. Singh D, Cantu M, Marx MHM, et al. Diabetic ketoacidosis and fluid refractory hypotension. Clin Pediatrics 2016;55:182-84. https://journals.sagepub.com/doi/abs/10.1177/0009922815584549?journalCode=cpja&nbsp;

 

Why is my patient with diabetic ketoacidosis (DKA) and hypovolemia hypertensive?