Tag Archive for: Infectious Diseases

Procalcitonin: Useful Test or Useless Pest to Improve Antibiotic Stewardship with Acute Respiratory Infections in the ED?

27 Jul
July 27, 2018

Background: In patients with an acute respiratory illness (ARI), it is often difficult to determine whether a bacterial infection is the underlying etiology and whether antibiotics are warranted. Excess antibiotic use carries risk of bacterial resistance, medical costs, and adverse drug effects. However, underuse of antibiotics risks inadequate treatment and progression of disease. In the setting of a bacterial infection, cytokines stimulate procalcitonin production and release. The serum procalcitonin level increases with the progression of bacterial infection and decreases upon recovery. Procalcitonin production is actually blocked in the setting of viral infection, resulting in low serum levels. Numerous studies have investigated the use of procalcitonin for the determination of initiating antibiotics as well as for aiding in decisions to terminate their use.

This Evidence-Based Emergency Medicine (EBEM) article reviews the following systematic review:

Schuetz P et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev 2017. PMID: 29025194 Read more →

Bacterial Endocarditis

04 Dec
December 4, 2017

Background:

  • Definition
    • Infective Endocarditis (IE) = Inflammation of the endothelium of the heart, heart valves (or both) (Osman 2013)
  • Epidemiology
    • Annual incidence = 5-7 cases per 100,000 (Fraimow 2013)
    • 40,000 to 50,000 new cases in the US per year. Average hospital charges in excess of $120,000 per patient (Bor 2013)
    • Slightly higher male predominance (1.5:1 – 2:1) (Moreillon 2010)
    • In-hospital mortality of 14–22% and 1-year mortality of 20-40% (Gomes 2017, (Habib 2006)
    • Before antibiotics and surgery it was almost universally fatal  (Aretz 2010, Osman 2013)
  • Pathophysiology (Moreillon 2010, Faza 2013, Tan 2014, Osman 2013, Kokowski 2018)
    • The normal, undamaged valve endothelium is very resistant to colonization and infection by circulating bacteria
    • Micro-trauma (caused by turbulent flow, intracardiac devices, etc) or chronic diseases (rheumatic heart disease, congenital heart disease, prosthetic valves, previous IE) can cause damage to the endothelium
    • Damage to endothelium produces a fibin and platelet sterile thrombus.  Microbes can seed that thrombus during transient episodes of bacteremia, fungemia and viremia
  • Risk factors –  (Faza 2013, Moreillon 2010).
    • Diseased/damaged heart (highest risk)
    • IV drug use (IVDU)
    • Low immune function –
    • Poor oral hygiene. (Faza 2013)
    • Nosocomial

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