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?

What’s the connection between Covid-19 and cytokine release syndrome?

Severe Covid-19 is associated with a high inflammatory state similar to that seen in cytokine release syndrome (CRS) in adults with secondary hemophagocytic lymphohistiocytosis (sHLH) which is often due to viral infections.1,2

sHLH is characterized by unremitting fever, pulmonary involvement (including ARDS), pancytopenias, and high serum levels of ferritin, C-reactive protein (CRP) and many inflammatory cytokines, such as Interleukin (IL)-6. These features are also often seen in severe Covid-19 disease. In fact, elevated serum IL-6 has been shown to be associated with respiratory failure, ARDS, adverse clinical outcomes, and death in Covid-19.1,2  

Why CRS in Covid-19? It all begins with SARS-CoV2 activation of monocytes, macrophages and dendritic cells leading to IL-6 release. IL-6 in turn activates B and T lymphocytes as well as the innate immune system. In addition, IL-6 has a profound effect on endothelial cells resulting in vascular permeability, neutrophil recruitment and further increase in IL-6 production, setting the stage for a “perfect  cytokine storm.”  IL-6 also induces the liver to synthesize CRP and ferritin.

The importance of IL-6 in severe Covid-19 is further highlighted by the excitement surrounding drugs that block its action, potentially improving morbidity and mortality in this disease. Tocilizumab, a monoclonal antibody against IL-6 receptor used in the treatment of certain rheumatological diseases and CRS in CAR T cell therapy, looks promising.3

Bonus Pearl: Did you know that IL-6 was formally called B-cell stimulatory factor-2 because it induced B cells to produce immunoglobulins?

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References

 

  1. Moore JB, June CH. Cytokine release syndrome in severe Covid-19. Science 2020;368:473-4. doi:10.1126/science.abb8925
  2. Mehta P, McAuley DF, Brown M, et al. Covid-19:consider cytokine storm syndromes and immunosuppression. Lancet 2020;395:1033-4. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30628-0/fulltext
  3. Fu B, Xu X, Wei H. Why tocilizumab could be an effective treatment for severe COVID-19. J Transl Med 2020;18:164. https://translational-medicine.biomedcentral.com/track/pdf/10.1186/s12967-020-02339-3
  4. Kishimoto T. IL-6: From its discovery to clinical applications. Int Immunol 2010;22:347-52. https://pubmed.ncbi.nlm.nih.gov/20410258/

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 Covid-19 and cytokine release syndrome?

Do statins have a role in treating novel Coronavirus infection, COVID-19?

There is currently no firm clinical evidence that statins improve the outcome of COVID-19. However, there are some theoretical reasons for believing that statins may have a role in the treatment of COVID-19.  That’s because beyond their cholesterol lowering action, statins may also have clinically relevant anti-inflammatory and antiviral (pleotropic) properties.  

Anti-inflammatory: Anti-inflammatory effect of statins is well known and is thought to occur through a variety of molecular pathways of the innate and adaptive immune systems as well as attenuation of several circulating proinflammatory cytokines.1 Although observational studies have suggested that statins lower hospitalization and mortality among outpatients hospitalized with infection, pneumonia or sepsis, several randomized controlled trials (RCTs) have failed to show any mortality benefit among ICU patients with sepsis and ARDS treated with statins.2

In contrast, an RCT involving patients with sepsis (majority with pneumonia, mean CRP 195 mg/dL) reported significant reduction in progression to severe sepsis among statin-naïve patients  placed on atorvastatin 40 mg/day at the time of hospitalization.3 So, perhaps timing of statin therapy before florid sepsis and ARDS is an important factor.  

Some have suggested that statins may decrease the fatality rate of a related Coronavirus, Middle East Respiratory Syndrome (MERS) virus, by blunting exuberant inflammatory response that may result in a fatal outcome. 4

Antiviral: Statins may also have antiviral properties, including activity against influenza, hepatitis C virus, Zika and dengue viruses.2,5 Whether statins have activity against coronaviruses such as the agent of COVID-19 is unclear at this time.

It’s interesting to note that cholesterol may have an important role in the membrane attachment, fusion and replication of many enveloped viruses, including influenza.5 Covid-19 is also an enveloped virus.

So what do we do? Based on the current data, it makes sense to continue statins in patients who have known clinical indications for their use and no obvious contraindications because of COVID-19 (eg. rhabdomyolysis).6 As for statin-naïve patients, particularly those in early stages of sepsis and increased risk of cardiovascular events, benefit may outweigh the risk.  Only proper clinical studies will give us more definitive answers.

Bonus Pearl: Did you know that lipids make up a major component of the envelope in enveloped viruses and that cholesterol makes up nearly one-half of total lipid and over 10% the total mass of influenza viruses?

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References

  1. Tousoulis D, Psarros C, Demosthenous M, et al. Innate and adaptive inflammation as a therapeutic target in vascular diseae: The emerging role of statins. J Am Coll Cardiol 2014;63:2491-2502. https://www.sciencedirect.com/science/article/pii/S0735109714011553?via%3Dihub
  2. Fedson DS. Treating the host response to emerging virus diseases: lessons learned from sepsis, pneumonia, influenza and Ebola. Ann Transl Med 2016;4:421. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5124618/pdf/atm-04-21-421.pdf
  3. Patel JM, Snaith C, Thickette DR. Randomized double-blind placebo-controlled trial of 40 mg/day of atorvastatin in reducing the severity of sepsis in ward patients (ASEPSIS Trial) Critical Care 2012;16:R231. https://ccforum.biomedcentral.com/track/pdf/10.1186/cc11895
  4. Espano E, Nam JH, Song EJ, et al. Lipophilic statins inhibit Zika virus production in Vero cells. Scientific Reports 2019;9:11461. https://www.nature.com/articles/s41598-019-47956-1
  5. Sun X, Whittaker GR. Role for influenza virus envelope cholesterol in virus entry and infection. J Virol 2003;77:12543-12551. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC262566/
  6. Virani SS. Is there a role for statin therapy in acute viral infections. Am Coll Cardiol March 18, 2020. https://www.acc.org/latest-in-cardiology/articles/2020/03/18/15/09/is-there-a-role-for-statin-therapy-in-acute-viral-infections-covid-19

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!

Do statins have a role in treating novel Coronavirus infection, COVID-19?

Key clinical pearls in the medical management of hospitalized patients with coronavirus (Covid-19) infection

First, a shout-out to dedicated healthcare workers everywhere who have selflessly given of themselves to care for the sick during this pandemic. Thank you! Together, I know we will get through it!

Although our understanding of Covid-19 infection is far from complete, in the spirit of clarity and brevity of my posts on Pearls4Peers, here are some key points I have gleaned from review of existing literature and the CDC that may be useful as we care for our hospitalized patients with suspected or confirmed Covid-19 infection.

  • Isolation precautions.1 Per CDC, follow a combination of airborne (particularly when aerosol generating procedures is anticipated, including nebulizer treatment) and contact precaution protocols. Routinely use masks or respirators, such as N-95s (subject to local availability and policy) and eye protection. Don gowns (subject to local availability and policy) and gloves and adhere to strict hand hygiene practices.

 

  • Diagnostic tests1-9
    • Laboratory tests. Routine admission labs include CBC, electrolytes, coagulation panels and liver and renal tests. Other frequently reported labs include LDH, C-reactive protein (CRP) and procalcitonin. Testing for high sensitivity troponin I has also been performed in some patients, presumably due to concern over ischemic cardiac injury or myocarditis.2 Check other labs as clinically indicated.
    • Chest radiograph/CT chest. One or both have been obtained in virtually all reported cases with CT having higher sensitivity for detection of lung abnormalities.
    • EKG. Frequency of checking EKGs not reported in many published reports thought 1 study reported “acute cardiac injury” in some patients, based in part on EKG findings.4 Suspect we will be checking EKGs in many patients, particularly those who are older or are at risk of heart disease.
    • Point-of-care ultrasound (POCUS). This relatively new technology appears promising in Covid-19 infections, including in rapid assessment of the severity of pneumonia or ARDS at presentation and tracking the evolution of the disease. 9 Don’t forget to disinfect the probe between uses!

 

  • Treatment 1-8
    • Specific therapies are not currently available for treatment of Covid-19 infections, but studies are underway.
    • Supportive care includes IV fluids, 02 supplementation and nutrition, as needed. Plenty of emotional support for patients and their families will likely be needed during these times.
    • Antibiotics have been used in the majority of reported cases, either on admission or during hospitalization when superimposed bacterial pneumonia or sepsis could not be excluded.
      • Prescribe antibiotics against common community-acquired pneumonia (CAP) pathogens, including those associated with post-viral/influenza pneumonia such as Streptococcus pneumoniae (eg, ceftriaxone), and Staphylococcus aureus (eg, vancomycin or linezolid if MRSA is suspected) when concurrent CAP is suspected.
      • Prescribe antibiotics against common hospital-acquired pneumonia (HAP) (eg, vancomycin plus cefepime) when HAP is suspected.
    • Corticosteroids should be avoided because of the potential for prolonging viral replication, unless indicated for other reasons such as COPD exacerbation or septic shock. 1
    • Monitor for deterioration in clinical status even when your hospitalized patient has relatively minor symptoms. This is because progression to lower respiratory tract disease due to Covid-19 often develops during the 2nd week of illness (average 9 days).
    • ICU transfer may be necessary in up to 30% of hospitalized patients due to complications such as ARDS, secondary infections, and multi-organ failure.

 

Again, thank you for caring for the sick and be safe! Feel free to leave comments or questions.

 

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References

  1. CDC. Interim clinical guidance for management of patients with confirmed coronavirus disease (COVID-19). https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
  2. Ruan Q, Yang K, Wang W, Jiang L, et al. Clinical predictors of mortality due to COVID-19 based on analysis of data of 150 patients with Wuhan, China. Intensive Care Med 2020. https://link.springer.com/article/10.1007/s00134-020-05991-x
  3. Holshue ML, BeBohlt 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
  4. Huang C, Wang Y, Li Xingwang, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506. https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(20)30183-5.pdf
  5. Young BE, Ong SWX, Kalimuddin S, et al. Epideomiologic features and clinical course of patients infected with SARS-CoV-2 Singapore. JAMA, March 3, 2020. Doi.10.1001/jama.2020.3204 https://www.ncbi.nlm.nih.gov/pubmed/32125362
  6. Chen N, Zhou M, Dong X, et al. Epidemiological and clinical chacteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 2020;395:507-13. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30211-7/fulltext
  7. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl Med 2020, Feb 28, 2020. https://www.nejm.org/doi/full/10.1056/NEJMoa2002032
  8. Zhang J, Zhou L, Yang Y, et al. Therapeutic and triage strategies for 2019 novel coronavirus disease in fever clinics. Lancet 2020;8: e11-e12. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30071-0/fulltext 9.
  9. Peng QY, Wang XT, Zhang LN, et al. Findings of lung ultrasonography of novel corona virus pneumonia during the 2019-2020 epidemic. Intensive Care Med 2020. https://doi.org/10.1007/s00134-020-05996-
Key clinical pearls in the medical management of hospitalized patients with coronavirus (Covid-19) infection

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

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?

Should I routinely treat my patients with acute COPD exacerbation with antibiotics?

The answer is “NO”! With an estimated 20% to 50% of acute chronic obstructive pulmonary disease (COPD) exacerbations attributed to noninfectious factors (1,2), routine inclusion of antibiotics in the treatment of this condition is not only unnecessary but potentially harmful.

 
Although the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines recommends the use of antibiotics in patients who have dyspnea, increased sputum volume, and increased sputum purulence—or at least 2 of these 3 criteria when sputum purulence is one of them (3)—, these recommendations are not based on robust evidence and have not been widely corroborated (2,4-6).

 
That’s why the findings of a 2019 New England Journal of Medicine study (PACE) supporting the use of serum C-reactive protein (CRP) as an adjunctive test in COPD exacerbation is particularly welcome (1). In this multicenter randomized controlled trial performed in the U.K., the following CRP guidelines (arrived from prior studies) were provided to primary care clinicians to be used as part of their decision making in determining which patients with COPD exacerbation may not need antibiotic therapy:
• CRP less than 20 mg/L: Antibiotics unlikely to be beneficial
• CRP 20-40 mg/L: Antibiotics may be beneficial, mainly if purulent sputum is present
• CRP greater than 40 mg/L: Antibiotics likely to be beneficial

 
Adoption of these guidelines resulted in significantlly fewer patients being placed on antibiotics without evidence of harm over a 4-week follow-up period (1).  Despite its inherent limitations (eg, single country, outpatient setting), CRP testing may be a step in the right direction in curbing unnecessary use of antibiotics in COPD exacerbation.  

 

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References
1. Butler CC, Gillespie D, White P, et al. C-reactive protein testing to guide antibiotic prescribing for COPD exacerbations. N Engl J Med 2019;381:111-20. https://www.ncbi.nlm.nih.gov/pubmed/31291514
2. Llor C, Moragas A, Hernandez S, et al. Efficacy of antibiotic therapy for acute exacerbations of mild to moderate chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2012;186:716-23. https://www.ncbi.nlm.nih.gov/pubmed/22923662
3. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. GOLD, 2019 (http://www.goldcopd.org).
4. Brett AS, Al-Hasan MN. COPD exacerbations—A target for antibiotic stewardship. N Engl J Med 2018;381:174-75. https://www.ncbi.nlm.nih.gov/pubmed/31291521
5. Miravitlles M, Moragas A, Hernandez S, et al. Is it possible to identify exacerbations of mild to moderate COPD that do not require antibiotic treatment? Chest 2013;144:1571-7. https://www.ncbi.nlm.nih.gov/pubmed/23807094
6. Van Vezen P, Ter Riet G, Bresser P, et al. Doxycycline for outpatient-treated acute exacerbations of COPD: a randomized double-blind placebo-controlled trial. Lancet Respir Med 2017;5:492-9. https://www.ncbi.nlm.nih.gov/pubmed/28483402

Should I routinely treat my patients with acute COPD exacerbation with antibiotics?

How is prealbumin related to albumin?

Aside from being synthesized in the liver and serving as a transport protein in the blood, prealbumin (PA) doesn’t really have much in common with albumin. More specifically, PA is not derived from albumin and, in fact, the two proteins are structurally distinct from each other!

So where does PA get its name? PA is the original name for transthyretin (TTR), a transport protein that primarily carries thyroxine (T4) and a protein bound to retinol (vitamin A). The name arose because TTR migrated faster than albumin on gel electrophoresis of human serum.1

Because of its much shorter serum half-life compared to that of albumin ( ~2 days vs ~20 days),2 PA is more sensitive to recent changes in protein synthesis and more accurately reflects recent dietary intake (not necessarily overall nutritional status) than albumin. 3

But, just like albumin, PA may represent a negative acute phase reactant, as its synthesis drops during inflammatory states in favor of acute phase reactants such as C-reactive protein. 4 So be cautious about interpreting low PA levels in patients with active infection, inflammation or trauma.

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Reference

  1. Socolow EL, Woeber KA, Purdy RH, et al. Preparation of I-131-labeled human serum prealbumin and its metabolism in normal and sick patients. J. Clin Invest 1965; 44: 1600-1609. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC292644/
  2. Oppenheimer JH, Surks MI, Bernstein G, and Smith JC. Metabolism of Iodine-131-labeled Thyroxine-Binding Prealbumin in Man. Science 1965; 149: 748-750. https://www.ncbi.nlm.nih.gov/pubmed/14330531
  3. Ingenbleek Y, Young VR. Significance of prealbumin in protein metabolism. Clin Chem Lab Med 2002; 40: 1281-1291. https://www.ncbi.nlm.nih.gov/pubmed/12553432
  4. Shenkin A. Serum prealbumin: is it a marker of nutritional status or of risk of malnutrition? Clin Chem 2006;52:2177 – 2179. http://clinchem.aaccjnls.org/content/52/12/2177

Contributed by Colin Fadzen, Medical Student, Harvard Medical School, Boston, MA.

 

 

How is prealbumin related to albumin?

Why are patients with acute exacerbation of COPD at higher risk of venous thromboembolism (VTE)?

Patients admitted to the hospital for acute exacerbation of COPD are generally regarded as being at high risk of venous thromboembolism (VTE) (prevalence 5%-29%), possibly due to the frequent coexistence of other risk factors, such as immobility, history of smoking, and venous stasis.1 The exact mechanism(s) behind this association remains poorly understood, however.

Among patients with moderate-very severe COPD (GOLD criteria stage II-IV),  high BMI, low exercise tolerance, history of pneumothorax, congestive heart failure, and peripheral vascular disease have also been associated with VTE.1

Systemic inflammation has also been implicated in increasing the risk of VTE in patients with COPD. Although the pathophysiology of COPD is largely defined by the local inflammatory response to airway injury, evidence suggests that there is also a systemic inflammatory response in COPD.2,3 This systemic inflammation could in turn contribute to the increased risk of vascular disease, including VTE, coronary artery disease, and cerebrovascular disease.4

Bonus pearl: Did you know that VTE may be 3x more prevalent among patients with COPD exacerbation without known cause (vs those with identifiable cause) and is associated with a 1-year mortality of 61.9%! 5

References:

  1. Kim V, Goel N, Gangar J, et al. Risk factors for venous thromboembolism in chronic obstructive pulmonary disease. Chronic Obstr Pulm Dis 2014;1: 239-249. https://www.ncbi.nlm.nih.gov/pubmed/25844397
  2. Lankeit M, Held M. Incidence of venous thromboembolism in COPD: linking inflammation and thrombosis? Eur Respir J 2016;47(2):369-73. https://www.ncbi.nlm.nih.gov/pubmed/26828045
  3. Sinden NJ1, Stockley RA. Systemic inflammation and comorbidity in COPD: a result of ‘overspill’ of inflammatory mediators from the lungs? Review of the evidence. Thorax 2010;65:930-6. https://www.ncbi.nlm.nih.gov/pubmed/20627907
  4. King PT. Inflammation in chronic obstructive pulmonary disease and its role in cardiovascular disease and lung cancer. Clinical and Translational Medicine 2015;4:26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4518022/
  5. Gunen H, Gulbas G, In E, et al. Venous thromboemboli and exacerbations of COPD. Eur Respir J 2010;36:1243-8.  https://www.ncbi.nlm.nih.gov/pubmed/19926740 

Contributed by Camilo Campo, Medical Student, Harvard Medical School, Boston, MA.

Why are patients with acute exacerbation of COPD at higher risk of venous thromboembolism (VTE)?

Should I order serum procalcitonin on my patient with suspected infection?

Two things to ask before you order procalcitonin (PCT): 1. Will it impact patient management?; and 2. If so, will the result be available in a timely manner ie, within hours not days?

Whatever the result, PCT should always be interpreted in the context of the patient’s illness and other objective data. Not surprisingly then, as a “screening” test, PCT may be more useful in patients with low pre-test likelihood of having bacterial infection, not dissimilar to the use of D-dimer in patients with low pre-test probability of pulmonary embolism1.  

Several potential clinical uses of this biomarker have emerged in recent years,  including:1,2

  • Helping decide when to initiate antibiotics in patients with upper acute respiratory tract infections and bronchitis. A normal or low PCT supports viral infection.
  • Helping decide when to discontinue antibiotics (ie, when PCT normalizes) in community-acquired or ventilator-associated pneumonia.
  • Helping monitor patient progress with an expected drop in PCT of about 50% per day (half-life ~ 24 hrs) with effective therapy.

Few caveats…

  • PCT may be unremarkable in about a third of patients with bacteremia (especially due to less virulent bacteria, including many gram-positives)3.  
  • PCT levels are lowered by high-flux membrane hemodialysis, so check a baseline level before, not after, hemodialysis4.
  • Lastly, despite its higher specificity for bacterial infections compared to other biomarkers such as C-reactive protein, PCT may be elevated in a variety of non-infectious conditions, including pancreatitis, burns, pulmonary edema or aspiration, mesenteric infarction (ischemic bowel), cardiogenic shock, and hypotension during surgery2.

 

References:

  1. Schuetz P, Muller B, Chirst-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections (review). Evid-Based Child Health (A Cochrane Review Journal) 2013;8:4;1297-137. http://onlinelibrary.wiley.com/doi/10.1002/ebch.1927/pdf
  2. Gilbert GN. Use of plasma procalcitonin levels as an adjunct to clinical microbiology. J Clin Microbiol 2010;48:2325-29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897488/pdf/0655-10.pdf
  3. Yan ST, Sun LC, Jia HB. Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria. Am J Emerg Med 2017;35:779-83. https://www.ncbi.nlm.nih.gov/m/pubmed/27979420/#fft
  4. Grace E, Turner RM. Use of procalcitonin in patients with various degrees of chronic kidney disease including renal replacement therapy. Clin Infect Dis 2014;59:1761-7. https://www.ncbi.nlm.nih.gov/pubmed/25228701
Should I order serum procalcitonin on my patient with suspected infection?