Background: The mis- and overuse of antibiotics continues to be a growing problem in medicine; the results of which are increased health-care costs, increased antibiotic resistance and, ultimately, patient harm. Unnecessary antibiotics are particularly prevalent in the treatment of lower respiratory tract infections (LRTIs) including asthma exacerbations and bronchitis. While it would be nice to simply stop using antibiotics when they’re not indicated, issues in stewardship abound. Amongst these are legitimate concerns by providers that the patient may have a bacterial infection causing their symptoms and, thus, benefit from a course of antibiotics.
Procalcitonin has been touted in recent years as a lab test that can help with this conundrum. Ideally, an elevated procalcitonin level would indicate the presence of a bacterial infection and, thus, suggest benefit from use of antibiotics while a low procalcitonin level would suggest a viral or non-bacterial etiology and suggest an absence of benefit from antibiotics. A recent Cochrane review showed potential for a procalcitonin approach but, there was minimal Emergency Department based evidence....Read More
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
Neutropenia: An absolute neutrophil count less than 500 cells/mm3 or less than 1000 cells/mm3 with a predicted decline to less than 500 cells/mm3
ANC = WBC x (neutrophil% + band%)