Early hyperoxemia is associated with lower adjusted mortality after severe trauma: results from a French registry

Abstract

Background Hyperoxemia has been associated with increased mortality in critically ill patients, but little is known about its effect in trauma patients. The objective of this study was to assess the association between early hyperoxemia and in-hospital mortality after severe trauma. We hypothesized that a PaO2 ≥ 150 mmHg on admission was associated with increased in-hospital mortality. Methods Using data issued from a multicenter prospective trauma registry in France, we included trauma patients managed by the emergency medical services between May 2016 and March 2019 and admitted to a level I trauma center. Early hyperoxemia was defined as an arterial oxygen tension (PaO2) above 150 mmHg measured on hospital admission. In-hospital mortality was compared between normoxemic (150 > PaO2 ≥ 60 mmHg) and hyperoxemic patients using a propensity-score model with predetermined variables (gender, age, prehospital heart rate and systolic blood pressure, temperature, hemoglobin and arterial lactate, use of mechanical ventilation, presence of traumatic brain injury (TBI), initial Glasgow Coma Scale score, Injury Severity Score (ISS), American Society of Anesthesiologists physical health class > I, and presence of hemorrhagic shock). Results A total of 5912 patients were analyzed. The median age was 39 [26–55] years and 78% were male. More than half (53%) of the patients had an ISS above 15, and 32% had traumatic brain injury. On univariate analysis, the in-hospital mortality was higher in hyperoxemic patients compared to normoxemic patients (12% versus 9%, p < 0.0001). However, after propensity score matching, we found a significantly lower in-hospital mortality in hyperoxemic patients compared to normoxemic patients (OR 0.59 [0.50–0.70], p < 0.0001). Conclusion In this large observational study, early hyperoxemia in trauma patients was associated with reduced adjusted in-hospital mortality. This result contrasts the unadjusted in-hospital mortality as well as numerous other findings reported in acutely and critically ill patients. The study calls for a randomized clinical trial to further investigate this association.

Hyperoxemia during resuscitation of trauma patients and increased intensive care unit length of stay: inverse probability of treatment weighting analysis

“…(5-25) vs 22 (19)(20)(21)(22)(23)(24)(25)(26); median difference = − 5 (− 16 to 3) days; p = 0.300).…”

“…Fifty-eight patients were exposed to hyperoxemia (PaO 2 of ≥ 300 mmHg) within 3 h of arrival and included in the hyperoxemia group, whereas 186 were not exposed to hyperoxemia and included in the nonhyperoxemia group. (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)]. Furthermore, more patients in the hyperoxemia group required higher amount of blood products [red blood cell = 0 (0-4) vs 0 (0-2) and fresh frozen plasma = 0 (0-6) vs 0 (0-4)], had undergone craniotomy and angiography [19 (32.8%) vs 19 (10.5%) and 21 (36.2%) vs 37 (20.4%), respectively], and were intubated at the ED [47 (81.0%) vs 58 (31.2%)].…”

“…Given that other subsets of critically ill patients, such as severely injured trauma patients, suffer from systematic inflammation, this population would be potentially affected by hyperoxemia. However, studies on clinical consequences of trauma patients who were exposed to hyperoxemia have been limited other than traumatic brain injury [ 21 , 22 ]. Accordingly, this study aimed to elucidate whether hyperoxemia during resuscitation was associated with unfavorable clinical outcomes of trauma patients with severe injuries.…”

“…vs 23(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26) days; difference in median = − 4 days (95% CI = − 2 to − 7 days); p < 0.001; Table3]. IPW analysis revealed that hyperoxemia during resuscitation was significantly associated with prolonged ICU stay among patients not intubated at the ED [ICU-free days = 16(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) vs 23(19)(20)(21)(22)(23)(24)(25)(26); median difference = − 5 (− 3 to − 10) days; p = 0.004], but not among those intubated at the ED [ICU-free days = 18 (9-20) vs 15(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23); median difference = 0 (− 3 to 3) days; p = 0.777]. IPW analysis also identified that hyperoxemia exposure during resuscitation was associated with fewer ventilator-free days among patients not intubated[25 (15-26) vs 28…”

“…IPW analysis also identified that hyperoxemia exposure during resuscitation was associated with fewer ventilator-free days among patients not intubated[25 (15-26) vs 28(23)(24)(25)(26)(27)(28); p = 0.014], but not among those intubated at the ED. Survival to discharge were comparable between the two groups.Subgroup analysis, excluding patients who experienced hypoxia (PaO 2 of < 60 mmHg) within 3 h after hospital arrival, also revealed the association between hyperoxemia and prolonged ICU stay among patients not intubated at the ED [ICU-free days = 16(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) vs 23(20- 26); median difference = − 5 (− 3 to − 10) days; p = 0.003; TableS1(Additional file 1)]. Another subgroup analysis excluding patients with isolated brain injury revealed similar results [ICU-free days = 16(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) vs 22(19)(20)(21)(22)(23)(24)(25)(26); median difference = − 5 (− 2 to − 10) days; p = 0.006; TableS1(Additional file 1)].…”