Prehospital shock index to assess 28-day mortality for septic shock.

CONTEXT: In the prehospital setting, early identification of septic shock (SS) with high risk of mortality aims to initiate early treatments and to decide delivery unit (emergency department (ED) or intensive care unit (ICU)). In this context, there is a need for a prognostic measure of severity and death in order to early detect patients with a higher risk of pejorative evolution. In this study, we describe the association between prehospital shock index (SI) and mortality at day 28 of patients with SS initially cared for in the prehospital setting by a mobile intensive care unit (MICU).

METHODS

Patients with SS cared for by a MICU between January 2016 and May 2019 were retrospectively analyzed. Using propensity score, the association between SI and mortality was assessed by Odd Ratio (OR) with 95 percent confidence interval [95 CI].

RESULTS

One-hundred and fourteen patients among which 78 males (68%) were analysed. The mean age was 71 ± 14 years old. SS was mainly associated with pulmonary (55%), digestive (20%) or urinary (11%) infection. Overall mortality reached 33% (n = 38) at day 28. Median SI [interquartile range] differed between alive and deceased patients: 0.73 [0.61-1.00] vs 0.80 [0.66-1.10], p < 0.001*). After adjusting for confounding factors, the OR of SI > 0.9 was 1.17 [1.03-1.32].

CONCLUSION

In this study, we report an association between prehospital SI and mortality of patients with prehospital SS. A SI > 0.9 is a readily available tool correlated with increased mortality of patients with SS initially cared for in the prehospital setting.