Laboratory Best Practice Blog Author Guidelines

Laboratory Best Practice Blog Author Guidelines 2017-06-13T12:17:40+00:00


The Laboratory Best Practice blog is intended to provide succinct recommendations to improve test quality, utilization, and education. Topics can span the entire spectrum of pathology and laboratory medicine. The target audience for the blog are non-laboratory personnel, therefore, avoid the use of obscure abbreviations or jargon, and provide adequate background for the average healthcare provider.


Blog articles should have the following items:

  • Title: Provide a concise title that describes the topic.
  • Author Name (s): First and last name of authors, as well as highest degree, position, and departmental affiliation as needed.
  • Background: Provide a description about the problem that is being addressed by the laboratory best practice article.
  • Laboratory Best Practice Description/Discussion: Discuss best practices for the problem(s) identified in the background section. Figures and tables are encouraged. This section can be organized at the author’s discretion and does not have to be called “Laboratory Best Practice Description/Discussion”. See example for details.
  • References: References should be used where appropriate and follow standard MEDLINE formatting and numerically refer to superscripted citations in the text.

Other Considerations

  • Use of Abbreviations: Minimize the use of abbreviations. Abbreviations should only be used if the word is repeated more than two times in the text. Try to use abbreviations that are used as part of routine practice (e., CBC for complete blood count).
  • Units of Measurement: Use units of measurements applicable to UC Davis Medical Center practice. Alternative units may be included if parentheses. For example, 100 mg/dL (5.56 mmol/L) for glucose.
  • Length of Text: A typical blog article should be 1 to 2 pages in length when using MS Word with font size Arial 11 and 1 inch margins.



Nam Tran, PhD, MS, FACB, Clinical Chemistry / POCT / SARC

Background: Procalcitonin (PCT) is a peptide precursor to calcitonin that is associated with the inflammatory response to bacterial infection. Studies have shown PCT levels increasing following bacterial infection (6 hours) and aids in the risk assessment of critically ill patients on their first day of intensive care unit admission for progression to severe sepsis and septic shock.1-3 Other PCT applications include recognition of infection in febrile infants4 and antimicrobial stewardship3. On average, the half-life of PCT is about 24 hours and is unaffected by neutropenia, corticosteroid therapy, or other immunosuppressive states. In contrast, legacy biomarkers such as C-reactive protein (CRP) have been shown to rise more slowly (12-24 hours) and achieving maximum levels at 48 hours after infection.

Sepsis Biomarker Time Course Following Pathogen Exposure

Sepsis Management: PCT levels at ICU admission >2.0 ng/mL are associated with increased risk for severe sepsis or septic shock compared to patients with levels <0.5 ng/mL.4 Decreasing PCT of ≤80% from the day that severe sepsis or septic shock was clinically diagnosed to four days after clinical diagnosis is associated with higher 28-day risk of all-cause mortality compared to patients with a decline >80%. The combination of the initial PCT level (≤ 2.0 ng/mL or > 2.0 ng/mL) at diagnosis of severe sepsis or septic shock with the patient’s clinical course and PCT change (“delta”) over time until Day 4 provides critical additional information about the mortality risk. The PCT level on Day 1 can be used to calculate the percent change in PCT level at Day 4 if the Day 0 measurement is unavailable. Figure 1 illustrates the time course of PCT levels over time following infection and relation to other sepsis biomarkers.5 PCT results should always be used with other indicators of sepsis, severe sepsis, and septic shock (e.g., vital signs, white blood cell count, lactate, etc).

Antimicrobial Stewardship: PCT has also been used to support antimicrobial stewardship applications.6 Studies have shown 50% of antimicrobial use in the inpatient setting as inappropriate or unnecessary. Evidence now supports the use of PCT for antimicrobial stewardship in lower respiratory tract infections including pneumonia, exacerbations of chronic bronchitis, and asthma exacerbation.

Special Populations: Certain populations such as patients with cardiogenic shock and/or severe tissue injury (e.g., trauma and burns) may exhibit false elevations of PCT.1,5 The clinical performance of PCT in pediatrics is currently not defined, however, recent studies support further evaluation of this unique population including febrile infants using an algorithm-based approach.4


  1. Christ-Crain and Muller. Biomarkers in respiratory tract infections: diagnostic guides to antibiotic prescription, prognostic markers an mediators. Eur Respir J. 2007;30:556-73.
  2. Kibe S, et al. Diagnostic and prognostic biomarkers of sepsis in critical care. J Antimicrob Chemother. 2011;66(S2):33-40.
  3. Schuetz P, et al. Procalcitonin for diagnosis of infection and guide to antibiotic decisions: past, present and future. BMC Medicine. 2011;9:107.
  4. Gomez B, et al. Validation of the “Step-by-Step” approach in the management of young febrile infants. Pediatrics 2016;138:1-9.
  5. BioMerieux BRAHMS Procalcitonin Assay Product Insert, Accessed on September 22, 2016.
  6. Tran NK, et al. Clinical utility of procalcitonin testing in burn patients with severe sepsis. J Burn Care Res [submitted].
  7. Li H, et al. Meta-analysis and systematic review of procalcitonin-guided therapy in respiratory tract infections. Antimicrob Agents Chemother. 2011;55:5900-6.