How can I distinguish cardiac asthma from typical bronchial asthma?

Certain clinical features of cardiac asthma, defined as congestive heart failure (CHF) associated with wheezing, may be useful in distinguishing it from bronchial asthma, particularly in older patients with COPD (1-3).

• Paroxysmal nocturnal dyspnea associated with wheezing
• Presence of rales or crackles, ascites or other signs of CHF
• Poor response to bronchodilators and corticosteroids
• Formal pulmonary function test with bronchoprovocation demonstrating minimal methacholine response.

 
Cardiac asthma is not uncommon. In a prospective study of patients 65 yrs of age or older (mean age 82 yrs) presenting with dyspnea due to CHF, cardiac asthma was diagnosed in 35% of subjects. Even in non-elderly patients, cardiac asthma has been reported in 10-15% of patients with CHF (2).

 
The mechanism(s) underlying cardiac asthma is likely multifactorial. Pulmonary edema and pulmonary vascular congestion have traditionally been considered as key factors either through edema in the interstitial fluid of bronchi squeezing the bronchiolar lumen or by externally compressing the entire airway structure and the bronchiole wall. Reflex bronchoconstriction involving the vagus nerve, bronchial hyperreactivity, systemic inflammation, and airway remodeling may also play a role (1,3). 

 
Treatment of choice for cardiac asthma typically includes diuretics, nitrates and morphine, not bronchodilators or corticosteroids (1,3). 

 
Bonus Pearl: Did you know that the term “cardiac asthma” was first coined by the Scottish physician, James Hope, way back in 1832 to distinguish it from bronchial asthma!

 

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References
1. Litzinger MHJ, Aluen JKN, Cereceres R, et al. Cardiac asthma: not your typical asthma. US Pharm. 2013;38:HS-12-HS-18. https://www.uspharmacist.com/article/cardiac-asthma-not-your-typical-asthma
2. Jorge S, Becquemin MH, Delerme S, et al. Cardiac asthma in elderly patients: incidence, clinical presentation and outcome. BMC Cardiovascular Disorders 2007;7:16. https://www.ncbi.nlm.nih.gov/pubmed/17498318
3. Tanabe T, Rozycki HJ, Kanoh S, et al. Cardiac asthma: new insights into an old disease. Expert Rev Respir Med 2012;6(6), 00-00. https://www.ncbi.nlm.nih.gov/pubmed/23234454

 

How can I distinguish cardiac asthma from typical bronchial asthma?

Should I avoid intravenous furosemide for management of ascites in my patient with cirrhosis?

Generally, yes! IV furosemide for treatment of ascites in patients with cirrhosis should be avoided for couple of reasons.

First, in contrast to patients with congestive heart failure in whom the absorption of oral furosemide may be impaired due to bowel wall edema, patients with cirrhosis and ascites appear to absorb oral furosemide efficiently, similarly to that of control patients.1   Another reason for avoiding IV furosemide in this setting is the possibility of a significant drop in the GFR with its attendant rise in BUN and serum creatinine, clinically resembling a picture of hepatorenal syndrome.2

Although the mechanism of the adverse effect of IV furosemide on the renal function of patients with cirrhosis is not totally clear, furosemide-induced vasoconstriction, not intrasvascular volume depletion due to sodium wasting, seems to play an important role.3

Nevertheless, certain situations may necessitate the use of IV furosemide in patients with cirrhosis and ascites, such as in single doses to help identify patients who will be responsive to diuretics, and in patients in need of prompt diuresis such as those with concurrent pulmonary edema. In a somewhat reassuring study, a single dose of 80 mg IV furosemide reliably identified cirrhotic patients with ascites responsive to diuretics, without a significant risk of deteriorating renal function.3

 

References

  1. Sawhney VK, Gregory PB, Swezey SE, et al. Furosemide disposition in cirrhotic patients. Gastroenterology 1981; 81: 1012-16. https://www.ncbi.nlm.nih.gov/pubmed/7286579
  2. Daskalopoulos G, Laffi G, Morgan T, et al. Immediate effects of furosemide on renal hemodynamics in chronic liver disease with ascites. Gastroenterology 1987;92:1859-1863. https://www.ncbi.nlm.nih.gov/pubmed/3569760
  3. Spahr, L., Villeneuve, J., Tran, H. K., & Pomier-Layrargues, G. Furosemide-induced natriuresis as a test to identify cirrhotic patients with refractory ascites. Hepatology 2001;33:28-31. https://www.ncbi.nlm.nih.gov/pubmed/11124817

 

Contributed by Sam Miller, MD, Mass General Hospital, Boston, MA.

 

Should I avoid intravenous furosemide for management of ascites in my patient with cirrhosis?

My patient with acute exacerbation of heart failure and pulmonary edema also has pneumonia. How often do heart failure and pneumonia coexist?

More often than you might think! The relationship between pneumonia and heart failure (HF) appears bidirectional with pneumonia precipitating heart failure (HF) and HF predisposing to it.

Although It’s often quoted that acute respiratory tract infection accounts for 3-16% of patients hospitalized with decompensated heart failure (HF) (based primarily on small observational studies),1 a 2016 large prospective study involving nearly 100,000 HF admission from 305 US hospitals has reported “pneumonia/respiratory process” as the most common precipitating clinical factor, present in 28.2% of cases (arrhythmia and medication noncompliance came in as 2nd and 3rd).2

Interestingly, the same study reported that pneumonia/respiratory process was most prevalent among patients with preserved (≥50%) ejection fraction (EF) compared to those with borderline ( 40%-49%) or reduced (<40%) EF (33% vs 30% vs 24%, respectively). 2

Pulmonary edema may in turn predispose to bacterial pneumonia through adverse effects of edema fluid on lung bacterial defense mechanisms and establishment of a culture medium for bacterial growth by the presence of fluid in the alveolar space.3

So don’t be surprised if you have to treat for both!

 

References

  1. Thomsen RW, Kasatpibal N, Riis A, et al. The impact of pre-existing heart failure on pneumonia prognosis: Population-based cohort study. J Gen Intern Med 2008;23:1407-13. https://www.ncbi.nlm.nih.gov/pubmed/18574639
  2. Kapoor JR, Kapoor R, Ju C, et al. Precipitating clinical factors, heart failure characterization, and outcomes in patients hospitalized with heart failure with reduced, borderline, and preserved ejection fraction. JACC 2016;4:464-72. https://www.scholars.northwestern.edu/en/publications/precipitating-clinical-factors-heart-failure-characterization-and 
  3. Harris GD, Woods DE, Fine R, et al. The effect of intraalveolar fluid on lung bacterial clearance. Lung 1980; 158;91-100 Harris GD, Woods DE, Fine R, et al. The effect of intraalveolar fluid on lung bacterial clearance. Lung 1980; 158;91-100. https://link.springer.com/article/10.1007/BF02713708

 

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My patient with acute exacerbation of heart failure and pulmonary edema also has pneumonia. How often do heart failure and pneumonia coexist?

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?

When evaluating for an esophageal perforation, is a water-soluble contrast agent such as Gastrografin a better and safer alternative to barium swallow study?

Water-soluble contrast agents (WCAs) (eg, meglumine diatrizoate or Gastrografin) are often ordered as the initial radiographic test for evaluation of esophageal perforation or leaks, followed by barium swallow if the test is negative because small leaks are better detected with the more radiopaque barium1.  Such practice, however, is based on extrapolation of data on the deleterious effect of barium when extravasated into the peritoneal cavity, not the mediastinum1.   In fact, clinical evidence linking mediastinitis to extravasated barium is lacking, and even in experimental studies, injection of barium into the mediastinum of cats have failed to cause clinically significant mediastinitis2.

When ordering a contrast swallow study, no medium should be considered totally safe or effective in detecting esophageal perforations or leaks and WCAs are no different. Potential disadvantages of WCAs include: 1. Inferior sensitivity (as low as 50%)—due to decreased radio-opacity—when compared to barium3; 2. Risk of pulmonary edema—occasionally lethal— when aspirated into the lung due to high osmolality (analogous to salt water drowning) and intense inflammatory reaction4,5; 3. Contraindication in the setting of tracheoesophageal fistula,6; 4. Risk of serious allergic reaction due to reabsorption of iodinated compounds1; and 5. Added exposure to radiation and cost of testing when the swallow study is repeated with barium.  For these reasons, the standard practice of an initial WCA followed by a barium swallow`study if the former is negative, has been questioned, with some centers foregoing the WCA study altogether in favor of barium swallow in certain patients 1,6.

In short, when evaluating for esophageal perforation, WCAs should not categorically be considered a “better” or “safer” alternative to barium; in certain situations, barium may be the preferred agent. When in doubt, input from a thoracic surgeon is recommended.  

 

References

  1. Gollub MJ, Bains MS. Barium sulfate: a new (old) contrast agent for diagnosis of postoperative esophageal leaks. Radiology 1997;202:360-62. https://www.ncbi.nlm.nih.gov/pubmed/9015057
  2. James AE, Montali RJ, Chaffee V, et al. Barium or gastrografin: which contrast media for diagnosis of esophageal tears? Gastroenterology 1975;68:1103-1113. https://www.ncbi.nlm.nih.gov/pubmed/1126592
  3. Berry BE, Ochsner JL. Perforation of the esophagus: a 30 year review. J Thorac Cardiovasc Surg 1973;65:1-7. http://www.jpedsurg.org/article/0022-3468(73)90248-0/abstract
  4. Trulzsch DV, PenmetsaA, Karim A, et al. Gastrografin-induced aspiration pneumonia: A lethal complication of computed tomography. South Med J 1992;85:1255-56. https://www.ncbi.nlm.nih.gov/pubmed/1470976
  5. Tuladhar R, Patole S, Whitehall J. Gastrografin aspiration in a neonate with tracheoesophageal fistula. J Paediatr Child Health 2000; 36:94-6. https://www.ncbi.nlm.nih.gov/pubmed/10723703
  6. FDA https://www.drugs.com/pro/gastrografin.html.
  7. Roh S, Iannettoni MD, Keech JC, et al. Role of barium swallow in diagnosing clinically significant anastomotic leak following esophagectomy. Korean J Thorac Cardiovasc Surg 2016;49:99-109. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4825910/pdf/kjtcv-49-099.pdf

 

When evaluating for an esophageal perforation, is a water-soluble contrast agent such as Gastrografin a better and safer alternative to barium swallow study?

My patient on methadone complains of lower extremity edema. Could they be related?

Yes! As early as 1979, case series of patients on methadone developing peripheral edema within 3-6 months of therapy appeared in the literature1.  

Subsequent studies revealed that edema may develop from 1 week  to 6 months or longer following initiation of methadone, its severity is dose-dependent, and that it improves with reduction of methadone dose or discontinuation of therapy.  Distal extremities or the face are often involved and pulmonary edema may also occur1-3.  It is often resistant to diuretics.

The mechanism by which methadone causes peripheral edema is unclear but several hypotheses have been forwarded. The high volume of distribution and accumulation of methadone in tissues results in higher oncotic pressures in the extravascular space which in combination with reduced oncotic pressures in blood vessels due to venodilatation may lead to edema.  Other potential mechanisms include opioid-induced histamine release directly from mast cells causing venous permeability, and opioid-induced secretion of antidiuretic hormone 1-3.  

 

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References

  1. Dawson C, Paterson F, McFatter F, Buchanan D. Methadone and oedema in the palliative care setting: a case report and review of the literature. Scottish Med J 2014;59: e-11-e14. https://www.ncbi.nlm.nih.gov/pubmed/24676025.  
  2. Mahè I, Chassany O, Grenard A-S, Caulin C, Bergmann J-F. Methadone and edema: a case-report and literature review. Eur J Clin Pharmacol 2004;59:923-924. \https://www.deepdyve.com/lp/springer-journals/methadone-and-edema-a-case-report-and-literature-review-PfvnmhB1ia
  3. Kharlamb V, Kourlas H. Edema in a patient receiving methadone for chronic low back pain. Am J Health-Syst Pharm 2007;64:2557-60.https://www.ncbi.nlm.nih.gov/pubmed/18056943

 

My patient on methadone complains of lower extremity edema. Could they be related?

What is the utility of pulmonary auscultation for crackles (rales) in diagnosing congestive heart failure (CHF) or pneumonia?

The evidence for the accuracy of crackles in CHF is not as robust as often assumed, with wide variations in its sensitivity (13%-70%), specificity (35%-100%), positive predictive value (19%-100%), and negative predictive value (17%-85%) (1).

In a study  of patients at high risk for CHF but without valvular heart disease, symptoms of CHF, or comorbid pulmonary disease,  the prevalence of baseline crackles in one or both lungs increased with age: 45-64 y , 11%; 65-79 y, 34%; and 80-95 y, 70%.  At best, fair or poor positive and negative likelihood ratios (LRs) have been reported for crackles in CHF (3.4, and 0.8, respectively) (2). 

The accuracy of crackles in diagnosing pneumonia in patients with cough and fever is not much better: sensitivity 19-67%, specificity 36-94%, and poor positive and negative LRs (1.8 and 0.8, respectively) (2).

So don’t overestimate the accuracy of crackles in CHF or pneumonia, especially if your suspicion for these conditions is high!

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References

  1. Kataoka H, Matsuno O. Age-related pulmonary crackles (rales) in asymptomatic cardiovascular patients. Ann Fam Med 2008;6:239-245.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2384982/ 
  2. McGee S. Auscultation of the lungs. In Evidence-based physical diagnosis (3rd ed.). Elsevier Saunders, Philadelphia, 2012.
What is the utility of pulmonary auscultation for crackles (rales) in diagnosing congestive heart failure (CHF) or pneumonia?