A pilot clinical trial to evaluate a novel time-to-positivity assay to measure the effectiveness of antibiotic therapy for septic patients in intensive care.

Purpose: The purpose of the study was to investigate whether a novel assay of antibiotic efficacy could predict clinical outcome measures in septic patients in the intensive care unit (ICU).

Methods: A prospective, noninterventional clinical study was performed involving 48 adult patients with sepsis in a single adult general ICU, with measurement of the time-to-positivity (Tpos) at 2 time points (Tpos1, Tpos2).

Results: The mean length of stay for all patients was 14.1 days (range, 2-98; median, 10 days). There was no significant difference between the Tpos1-adequate and the Tpos1-inadequate patients in day 1 Sequential Organ Failure Assessment or Acute Physiology and Chronic Health Evaluation II scores. However, there were a significant difference for the length of stay in ICU, with median stay in the Tpos1-adequate group of 7.8 days compared with 14.4 days in the Tpos1-inadequate group (Mann-Whitney U test, P = .028), and a significant difference in the length of stay in hospital, with a median stay in the Tpos1-adequate group of 13 days compared with 31 days in the Tpos1-inadequate group (P = .001). There was no statistical association between Tpos1 and 28-day survival (P > .05). The Tpos2 data added no further information.

Conclusions: This pilot study provides preliminary evidence that measurement of Tpos1 24 hours after the initiation of antibiotic therapy is associated with ICU length of stay and might be of value as a surrogate marker of antibiotic activity.