European Journal of Medical Research (May 2024)

Association between prehospital ROX index with 30-day mortality among septic shock

  • Romain Jouffroy,
  • Tristan Fabre,
  • Basile Gilbert,
  • Stéphane Travers,
  • Emmanuel Bloch-Laine,
  • Patrick Ecollan,
  • Josiane Boularan,
  • Vincent Bounes,
  • Benoît Vivien,
  • Papa Gueye

DOI
https://doi.org/10.1186/s40001-024-01902-8
Journal volume & issue
Vol. 29, no. 1
pp. 1 – 9

Abstract

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Abstract Purpose Respiratory dysfunction is one of the most frequent symptoms observed during sepsis reflecting hypoxemia and/or acidosis that may be assessed by the ROX index (ratio of oxygen saturation by pulse oximetry/fraction of inspired oxygen to respiratory rate). This study aimed to describe the relationship between the prehospital ROX index and 30-day mortality rate among septic shock patients cared for in the prehospital setting by a mobile intensive care unit (MICU). Methods From May 2016 to December 2021, 530 septic shock patients cared for by a prehospital MICU were retrospectively analysed. Initial ROX index value was calculated at the first contact with MICU. A Cox regression analysis after propensity score matching was performed to assess the relationship between 30-day mortality rate and a ROX index ≤ 10. Results Pulmonary, digestive and urinary sepsis were suspected among 43%, 25% and 17% patients, respectively. The 30-day overall mortality reached 31%. Cox regression analysis showed a significant association between 30-day mortality and a ROX index ≤ 10: adjusted hazard ratio of 1.54 [1.08–2.31], p < 0.05. Conclusions During the prehospital stage of septic shock patients cared for by a MICU, ROX index is significantly associated with 30-day mortality. A prehospital ROX ≤ 10 value is associated with a 1.5-fold 30-day mortality rate increase. Prospective studies are needed to confirm the ability of prehospital ROX to predict sepsis outcome since the prehospital setting.

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