S100 calcium binding protein B as a biomarker of delirium duration in the intensive care unit - An exploratory analysis

Babar A. Khan, Marker O. Farber, Noll Campbell, Anthony Perkins, Nagendra K. Prasad, Sui L. Hui, Douglas K. Miller, Enrique Calvo-Ayala, John D. Buckley, Ruxandra Ionescu, Anantha Shekhar, E. Wesley Ely, Malaz A. Boustani

Research output: Contribution to journalArticle

15 Scopus citations


Background: Currently, there are no valid and reliable biomarkers to identify delirious patients predisposed to longer delirium duration. We investigated the hypothesis that elevated S100 calcium binding protein B (S100β) levels will be associated with longer delirium duration in critically ill patients. Methods: A prospective observational cohort study was performed in the medical, surgical, and progressive intensive care units (ICUs) of a tertiary care, university affiliated, and urban hospital. Sixty-three delirious patients were selected for the analysis, with two samples of S100β collected on days 1 and 8 of enrollment. The main outcome measure was delirium duration. Using the cutoff of <0.1 ng/mL and ≥0.1 ng/mL as normal and abnormal levels of S100β, respectively, on day 1 and day 8, four exposure groups were created: Group A, normal S100β levels on day 1 and day 8; Group B, normal S100β level on day 1 and abnormal S100β level on day 8; Group C, abnormal S100β level on day 1 and normal on day 8; and Group D, abnormal S100β levels on both day 1 and day 8. Results: Patients with abnormal levels of S100β showed a trend towards higher delirium duration (P=0.076); Group B (standard deviation) (7.0 [3.2] days), Group C (5.5 [6.3] days), and Group D (5.3 [6.0] days), compared to patients in Group A (3.5 [5.4] days). Conclusion: This preliminary investigation identified a potentially novel role for S100β as a biomarker for delirium duration in critically ill patients. This finding may have important implications for refining future delirium management strategies in ICU patients.

Original languageEnglish (US)
Pages (from-to)855-861
Number of pages7
JournalInternational Journal of General Medicine
StatePublished - Jan 1 2013



  • Astrocytes
  • Blood-brain barrier
  • Coma
  • S100β

ASJC Scopus subject areas

  • Medicine(all)

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