Initial use of supplementary oxygen for trauma patients: a systematic review

Hypoxemia in trauma patients receiving two different oxygen strategies: a TRAUMOX2 substudy

BACKGROUND

The randomized controlled trial, TRAUMOX2, compared early restrictive vs. liberal oxygen strategies for trauma patients. The objective of this substudy was to quantify the occurrence and duration of hypoxemic episodes during the trial's eight-hour intervention.

METHODS

This observational substudy analyzed a subset of patients at two trial sites in Denmark. Continuous pulse oximetry recorded arterial oxygen saturation (SpO2) during the intervention. The primary outcome was the proportion of patients who had episodes of hypoxemia with SpO2 < 90% for at least five minutes. Additionally, the study assessed differences in the occurrence and duration of hypoxemia between the restrictive and liberal oxygen groups.

RESULTS

This substudy included 82 patients. After secondary exclusion, 60 patients (median age, 49 years [interquartile range 33-61] and 75% male) were analyzed. Three out of 60 patients (5%) had at least one episode of SpO2 < 90% for at least five minutes (95% confidence interval 1-14%); Two patients in the restrictive oxygen group and one in the liberal oxygen group. Two episodes occurred during initial resuscitation, and one episode occurred in the intensive care unit following a procedure related to thoracic injuries.

CONCLUSIONS

In this substudy of 60 patients from the TRAUMOX2 trial, hypoxemia (SpO2 < 90% for at least five minutes) was observed in 5% of patients, with no difference between the restrictive and liberal oxygen groups. These findings suggest that, among trauma patients not already requiring continuous monitoring, such episodes of hypoxemia are relatively rare early post-trauma.

Oxidative stress in trauma patients receiving a restrictive or liberal oxygen strategy - A sub-study of the TRAUMOX2 trial

INTRODUCTION

A liberal supplemental oxygen approach is recommended for all severely injured trauma patients despite limited evidence. Liberal oxygen administration may cause oxidative stress. The aim of this study was to investigate the effect of an early restrictive oxygen strategy versus a liberal oxygen strategy in adult trauma patients on biomarkers of oxidative stress within 48 h of hospital admission.

MATERIALS AND METHODS

This was a single-centre, sub-study of an international, randomised controlled trial TRAUMOX2. In TRAUMOX2, patients were randomised shortly after trauma to a restrictive oxygen strategy (arterial oxygen saturation target of 94 %) or a liberal oxygen strategy (12-15 L of oxygen per minute or fraction of inspired oxygen of 0.6-1.0) for 8 h. Blood samplings were performed at four time points within 48 h after randomisation: upon arrival at the trauma centre, and at eight, 24, and 48 h post-randomisation. The primary outcome was the plasma level of malondialdehyde (MDA) 24 h post-randomisation. Secondary outcomes were numerous, and included the level of MDA at other time points, superoxide dismutase (SOD) at all time points, 30-day mortality, and major respiratory complications.

RESULTS

The sub-study included 90 adult trauma patients. The median MDA levels at 24 h post-randomisation was 60.9 μM (95 % CI 49.5 to 73.4) in the restrictive oxygen group and 56.7 μM (95 % CI 46.9 to 68.2) in the liberal oxygen group, corresponding to a difference of -4.2 μM (95 % CI -19.8 to 10.5; P = 0.35). No significant differences were found in MDA or SOD at the other time points either. Neither did we find a significant difference in 30-day mortality or major respiratory complications.

CONCLUSIONS

In this sub-study of the TRAUMOX2 trial, no significant differences were found in biomarkers of oxidative stress between a restrictive oxygen strategy and liberal oxygen strategy in adult trauma patients.

Early Restrictive vs Liberal Oxygen for Trauma Patients: The TRAUMOX2 Randomized Clinical Trial

Importance

Early administration of supplemental oxygen for all severely injured trauma patients is recommended, but liberal oxygen treatment has been associated with increased risk of death and respiratory complications.

Objective

To determine whether an early 8-hour restrictive oxygen strategy compared with a liberal oxygen strategy in adult trauma patients would reduce death and/or major respiratory complications.

Design, Setting, and Participants

This randomized controlled trial enrolled adult trauma patients transferred directly to hospitals, triggering a full trauma team activation with an anticipated hospital stay of a minimum of 24 hours from December 7, 2021, to September 12, 2023. This multicenter trial was conducted at 15 prehospital bases and 5 major trauma centers in Denmark, the Netherlands, and Switzerland. The 30-day follow-up period ended on October 12, 2023. The primary outcome was assessed by medical specialists in anesthesia and intensive care medicine blinded to the randomization.

Interventions

In the prehospital setting or on trauma center admission, patients were randomly assigned 1:1 to a restrictive oxygen strategy (arterial oxygen saturation target of 94%) (n = 733) or liberal oxygen strategy (12-15 L of oxygen per minute or fraction of inspired oxygen of 0.6-1.0) (n = 724) for 8 hours.

Main Outcomes and Measures

The primary outcome was a composite of death and/or major respiratory complications within 30 days. The 2 key secondary outcomes, death and major respiratory complications within 30 days, were assessed individually.

Results

Among 1979 randomized patients, 1508 completed the trial (median [IQR] age, 50 [31-65] years; 73% male; and median Injury Severity Score was 14 [9-22]). Death and/or major respiratory complications within 30 days occurred in 118 of 733 patients (16.1%) in the restrictive oxygen group and 121 of 724 patients (16.7%) in the liberal oxygen group (odds ratio, 1.01 [95% CI, 0.75 to 1.37]; P = .94; absolute difference, 0.56 percentage points [95% CI, -2.70 to 3.82]). No significant differences were found between groups for each component of the composite outcome. Adverse and serious adverse events were similar across groups, with the exception of atelectasis, which was less common in the restrictive oxygen group compared with the liberal oxygen group (27.6% vs 34.7%, respectively).

Conclusions and Relevance

In adult trauma patients, an early restrictive oxygen strategy compared with a liberal oxygen strategy initiated in the prehospital setting or on trauma center admission for 8 hours did not significantly reduce death and/or major respiratory complications within 30 days.

Trial Registration

ClinicalTrials.gov Identifier: NCT05146700.

Clinicians' attitudes towards supplemental oxygen for trauma patients - A survey

INTRODUCTION

The Advanced Trauma Life Support guidelines (ATLS; 2018, 10th ed.) recommend an early and liberal supplemental oxygen for all severely injured trauma patients to prevent hypoxaemia. As of 2024, these guidelines remain the most current. This may lead to hyperoxaemia, which has been associated with increased mortality and respiratory complications. We aimed to investigate the attitudes among clinicians, defined as physicians and prehospital personnel, towards the use of supplemental oxygen in trauma cases.

MATERIALS AND METHODS

A European, web-based, cross-sectional survey was conducted consisting of 23 questions. The primary outcome was the question: "In your opinion, should all severely injured trauma patients always be given supplemental oxygen, regardless of arterial oxygen saturation measured by pulse oximetry?".

RESULTS

The survey was answered by 707 respondents, which corresponded to a response rate of 52 %. The respondents were predominantly male (76 %), with the largest representation from Denmark (82 %), and primarily educated as physicians (62 %). A majority of respondents (73 % [95 % CI: 70 to 76 %]) did not support that supplemental oxygen should always be provided to all severely injured trauma patients without consideration of their arterial oxygen saturation as measured by pulse oximetry (SpO2), with no significant difference between physicians and non-physicians (p = 0.08). Based on the respondents' preferred dosages, the median initial administered dosage of supplemental oxygen for spontaneously breathing trauma patients with a normal SpO2 in the first few hours after trauma was 0 (interquartile range [IQR] 0-3) litres per minute, with 58 % of respondents opting not to provide any supplemental oxygen. The lowest acceptable SpO2 goal in the first few hours after trauma was 94 % (IQR 92-95). In clinical scenarios with TBI, higher dosage of supplemental oxygen and fraction of inspired oxygen (FiO2) were preferred, as well as targeting partial pressure of oxygen in arterial blood as opposed to adjusting the FiO2 directly, compared to no TBI.

CONCLUSION

Almost three out of four clinicians did not support the administration of supplemental oxygen to all severely injured trauma patients, regardless of SpO2. This corresponds to a more restrictive approach than recommended in the current ATLS (2018, 10th ed.) guidelines.

Hyperoxaemia in acute trauma is common and associated with a longer hospital stay: a multicentre retrospective cohort study

BACKGROUND

Trauma poses a significant global health challenge. Despite advancements in the management of severely injured patients, (poly)trauma continues to be a primary contributor to morbidity and mortality worldwide. In the context of trauma resuscitation, supplemental oxygen is commonly administered generously as suggested by guidelines. Yet, it remains uncertain whether the trauma population might derive advantages from a more conservative approach to supplemental oxygen.

METHODS

In this retrospective cohort study from two Swiss trauma centers, severely injured adult (> 16 years) trauma patients with an Injury Severity Score (ISS) ≥ 16 were divided into four groups according to the first blood gas analysis taken: hypoxaemia (PaO2 < 10.7 kPa/80 mmHg), normoxaemia (PaO2 10.7-16.0 kPa/80-120 mmHg), which served as reference, moderate hyperoxaemia (PaO2 > 16.0-40 kPa/120-300 mmHg) and severe hyperoxaemia (PaO2 > 40 kPa/300 mmHg). The primary outcome was 28-day mortality. Length of hospital stay (LOS) and length of intensive care unit stay (LOS-ICU) were analyzed as secondary outcomes.

RESULTS

Of 1,189 trauma patients, 41.3% had hyperoxaemia (18.8% with severe hyperoxaemia) and 19.3% had hypoxaemia. No difference was found for 28-day mortality (hypoxaemia: 15.7%, normoxaemia: 14.1%, hyperoxaemia: 13.8%, severe hyperoxaemia: 16.0%, p = 0.846). Patients with severe hyperoxaemia had a significant prolonged LOS (median 12.5 [IQR 7-18.5] days vs. 10 [7-17], p = 0.040) and extended LOS-ICU (3.8 [1.8-9] vs. 2 [1-5] days, p = 0.149) compared to normoxaemic patients. In multivariable analysis, oxygen group was not associated with the primary outcome 28-day mortality or LOS-ICU. Severe hyperoxaemia patients had a tendency towards longer hospital stay (adjusted coefficient 2.23 days [95% CI: - 0.32; 4.79], p = 0.087).

CONCLUSION

Hyperoxaemia was not associated with an increased 28-day mortality when compared to normoxaemia. However, both moderate and severe hyperoxaemia is frequently observed in trauma patients, and the presence of severe hyperoxaemia showed a tendency with extended hospital stay compared to normoxaemia patients. Robust randomized controlled trials are imperative to thoroughly evaluate the potential correlation between hyperoxaemia and outcomes in trauma patients . Trial Registration Retrospectively registered.

Hemodynamic effects of supplemental oxygen versus air in simulated blood loss in healthy volunteers: a randomized, controlled, double-blind, crossover trial

BACKGROUND

Trauma patients frequently receive supplemental oxygen, but its hemodynamic effects in blood loss are poorly understood. We studied the effects of oxygen on the hemodynamic response and tolerance to simulated blood loss in healthy volunteers.

METHODS

Fifteen healthy volunteers were exposed to simulated blood loss by lower body negative pressure (LBNP) on two separate visits at least 24 h apart. They were randomized to inhale 100% oxygen or medical air on visit 1, while inhaling the other on visit 2. To simulate progressive blood loss LBNP was increased every 3 min in levels of 10 mmHg from 0 to 80 mmHg or until hemodynamic decompensation. Oxygen and air were delivered on a reservoired face mask at 15 L/min. The effect of oxygen compared to air on the changes in cardiac output, stroke volume and middle cerebral artery blood velocity (MCAV) was examined with mixed regression to account for repeated measurements within subjects. The effect of oxygen compared to air on the tolerance to blood loss was measured as the time to hemodynamic decompensation in a shared frailty model. Cardiac output was the primary outcome variable.

RESULTS

Oxygen had no statistically significant effect on the changes in cardiac output (0.031 L/min/LBNP level, 95% confidence interval (CI): - 0.015 to 0.077, P = 0.188), stroke volume (0.39 mL/LBNP level, 95% CI: - 0.39 to 1.2, P = 0.383), or MCAV (0.25 cm/s/LBNP level, 95% CI: - 0.11 to 0.61, P = 0.176). Four subjects exhibited hemodynamic decompensation when inhaling oxygen compared to 10 when inhaling air (proportional hazard ratio 0.24, 95% CI: 0.065 to 0.85, P = 0.027).

CONCLUSIONS

We found no effect of oxygen compared to air on the changes in cardiac output, stroke volume or MCAV during simulated blood loss in healthy volunteers. However, oxygen had a favorable effect on the tolerance to simulated blood loss with fewer hemodynamic decompensations. Our findings suggest that supplemental oxygen does not adversely affect the hemodynamic response to simulated blood loss. Trial registration This trial was registered in ClinicalTrials.gov (NCT05150418) December 9, 2021.

Higher versus lower fractions of inspired oxygen or targets of arterial oxygenation for adults admitted to the intensive care unit

BACKGROUND

This is an updated review concerning 'Higher versus lower fractions of inspired oxygen or targets of arterial oxygenation for adults admitted to the intensive care unit'. Supplementary oxygen is provided to most patients in intensive care units (ICUs) to prevent global and organ hypoxia (inadequate oxygen levels). Oxygen has been administered liberally, resulting in high proportions of patients with hyperoxemia (exposure of tissues to abnormally high concentrations of oxygen). This has been associated with increased mortality and morbidity in some settings, but not in others. Thus far, only limited data have been available to inform clinical practice guidelines, and the optimum oxygenation target for ICU patients is uncertain. Because of the publication of new trial evidence, we have updated this review.

OBJECTIVES

To update the assessment of benefits and harms of higher versus lower fractions of inspired oxygen (FiO2) or targets of arterial oxygenation for adults admitted to the ICU.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Science Citation Index Expanded, BIOSIS Previews, and LILACS. We searched for ongoing or unpublished trials in clinical trial registers and scanned the reference lists and citations of included trials. Literature searches for this updated review were conducted in November 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared higher versus lower FiO2 or targets of arterial oxygenation (partial pressure of oxygen (PaO2), peripheral or arterial oxygen saturation (SpO2 or SaO2)) for adults admitted to the ICU. We included trials irrespective of publication type, publication status, and language. We excluded trials randomising participants to hypoxaemia (FiO2 below 0.21, SaO2/SpO2 below 80%, or PaO2 below 6 kPa) or to hyperbaric oxygen, and cross-over trials and quasi-randomised trials.

DATA COLLECTION AND ANALYSIS

Four review authors independently, and in pairs, screened the references identified in the literature searches and extracted the data. Our primary outcomes were all-cause mortality, the proportion of participants with one or more serious adverse events (SAEs), and quality of life. We analysed all outcomes at maximum follow-up. Only three trials reported the proportion of participants with one or more SAEs as a composite outcome. However, most trials reported on events categorised as SAEs according to the International Conference on Harmonisation Good Clinical Practice (ICH-GCP) criteria. We, therefore, conducted two analyses of the effect of higher versus lower oxygenation strategies using 1) the single SAE with the highest reported proportion in each trial, and 2) the cumulated proportion of participants with an SAE in each trial. Two trials reported on quality of life. Secondary outcomes were lung injury, myocardial infarction, stroke, and sepsis. No trial reported on lung injury as a composite outcome, but four trials reported on the occurrence of acute respiratory distress syndrome (ARDS) and five on pneumonia. We, therefore, conducted two analyses of the effect of higher versus lower oxygenation strategies using 1) the single lung injury event with the highest reported proportion in each trial, and 2) the cumulated proportion of participants with ARDS or pneumonia in each trial. We assessed the risk of systematic errors by evaluating the risk of bias in the included trials using the Risk of Bias 2 tool. We used the GRADEpro tool to assess the overall certainty of the evidence. We also evaluated the risk of publication bias for outcomes reported by 10b or more trials.

MAIN RESULTS

We included 19 RCTs (10,385 participants), of which 17 reported relevant outcomes for this review (10,248 participants). For all-cause mortality, 10 trials were judged to be at overall low risk of bias, and six at overall high risk of bias. For the reported SAEs, 10 trials were judged to be at overall low risk of bias, and seven at overall high risk of bias. Two trials reported on quality of life, of which one was judged to be at overall low risk of bias and one at high risk of bias for this outcome. Meta-analysis of all trials, regardless of risk of bias, indicated no significant difference from higher or lower oxygenation strategies at maximum follow-up with regard to mortality (risk ratio (RR) 1.01, 95% confidence interval (C)I 0.96 to 1.06; I2 = 14%; 16 trials; 9408 participants; very low-certainty evidence); occurrence of SAEs: the highest proportion of any specific SAE in each trial RR 1.01 (95% CI 0.96 to 1.06; I2 = 36%; 9466 participants; 17 trials; very low-certainty evidence), or quality of life (mean difference (MD) 0.5 points in participants assigned to higher oxygenation strategies (95% CI -2.75 to 1.75; I2 = 34%, 1649 participants; 2 trials; very low-certainty evidence)). Meta-analysis of the cumulated number of SAEs suggested benefit of a lower oxygenation strategy (RR 1.04 (95% CI 1.02 to 1.07; I2 = 74%; 9489 participants; 17 trials; very low certainty evidence)). However, trial sequential analyses, with correction for sparse data and repetitive testing, could reject a relative risk increase or reduction of 10% for mortality and the highest proportion of SAEs, and 20% for both the cumulated number of SAEs and quality of life. Given the very low-certainty of evidence, it is necessary to interpret these findings with caution. Meta-analysis of all trials indicated no statistically significant evidence of a difference between higher or lower oxygenation strategies on the occurrence of lung injuries at maximum follow-up (the highest reported proportion of lung injury RR 1.08, 95% CI 0.85 to 1.38; I2 = 0%; 2048 participants; 8 trials; very low-certainty evidence). Meta-analysis of all trials indicated harm from higher oxygenation strategies as compared with lower on the occurrence of sepsis at maximum follow-up (RR 1.85, 95% CI 1.17 to 2.93; I2 = 0%; 752 participants; 3 trials; very low-certainty evidence). Meta-analysis indicated no differences regarding the occurrences of myocardial infarction or stroke.

AUTHORS' CONCLUSIONS

In adult ICU patients, it is still not possible to draw clear conclusions about the effects of higher versus lower oxygenation strategies on all-cause mortality, SAEs, quality of life, lung injuries, myocardial infarction, stroke, and sepsis at maximum follow-up. This is due to low or very low-certainty evidence.

Comparing restrictive versus liberal oxygen strategies for trauma patients - the TRAUMOX2 trial: protocol for a randomised clinical trial

INTRODUCTION

Supplemental oxygen is commonly used in trauma patients, although it may lead to hyperoxaemia that has been associated with pulmonary complications and increased mortality. The primary objective of this trial, TRAUMOX2, is to compare a restrictive versus liberal oxygen strategy the first 8 hours following trauma.

METHODS AND ANALYSIS

TRAUMOX2 is an investigator-initiated, international, parallel-grouped, superiority, outcome assessor-blinded and analyst-blinded, randomised, controlled, clinical trial.Adult patients with suspected major trauma are randomised to eight hours of a restrictive or liberal oxygen strategy. The restrictive group receives the lowest dosage of oxygen (>21%) that ensures an SpO₂ of 94%. The liberal group receives 12-15 L O₂/min or FiO₂=0.6-1.0.The primary outcome is a composite of 30-day mortality and/or development of major respiratory complications (pneumonia and/or acute respiratory distress syndrome).With 710 participants in each arm, we will be able to detect a 33% risk reduction with a restrictive oxygen strategy if the incidence of our primary outcome is 15% in the liberal group.

ETHICS AND DISSEMINATION

TRAUMOX2 is carried out in accordance with the Helsinki II Declaration. It has been approved by the Danish Committee on Health Research Ethics for the Capital Region (H-21018062) and The Danish Medicines Agency, as well as the Dutch Medical Research Ethics Committee Erasmus MS (NL79921.078.21 and MEC-2021-0932). A website (www.traumox2.org) is available for updates and study results will be published in an international peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBERS

EudraCT 2021-000556-19; NCT05146700.

Effects of supplemental oxygen on systemic and cerebral hemodynamics in experimental hypovolemia: Protocol for a randomized, double blinded crossover study

Supplemental oxygen is widely administered in trauma patients, often leading to hyperoxia. However, the clinical evidence for providing supplemental oxygen in all trauma patients is scarce, and hyperoxia has been found to increase mortality in some patient populations. Hypovolemia is a common finding in trauma patients, which affects many hemodynamic parameters, but little is known about how supplemental oxygen affects systemic and cerebral hemodynamics during hypovolemia. We therefore plan to conduct an experimental, randomized, double blinded crossover study to investigate the effect of 100% oxygen compared to room air delivered by a face mask with reservoir on systemic and cerebral hemodynamics during simulated hypovolemia in the lower body negative pressure model in 15 healthy volunteers. We will measure cardiac output, stroke volume, blood pressure, middle cerebral artery velocity and tolerance to hypovolemia continuously in all subjects at two visits to investigate whether oxygen affects the cardiovascular response to simulated hypovolemia. The effect of oxygen on the outcome variables will be analyzed with mixed linear regression.

Trial registration: The study is registered in the European Union Drug Regulating Authorities Clinical Trials Database (EudraCT, registration number 2021-003238-35).

Prehospital Airway Management for Trauma Patients by First Responders in Six Sub-Saharan African Countries and Five Other Low- and Middle-Income Countries: A Scoping Review

The global injury burden disproportionately affecting low- and middle-income countries (LMICs) is exacerbated by a lack of robust emergency medical services. Though airway management (AM) is an essential component of prehospital emergency care, the current standard of prehospital AM training and resources for first responders in LMICs is unknown. This scoping review includes articles published between January 2000 and June 2021, identified using PMC, MEDLINE, and SCOPUS databases, following PRISMA-ScR guidelines. Inclusion criteria spanned programs training formal or informal prehospital first responders. Included articles were assessed for quality using the Newcastle-Ottawa scale. Relevant characteristics were extracted by multiple authors to assess prehospital AM training. Of the initial 713 articles, 17 met inclusion criteria, representing 11 countries. Basic AM curricula were found in 11 studies and advanced AM curricula were found in nine studies. 35.3% (n = 6) of first responder programs provided no equipment to basic life support (BLS) AM training participants, reporting a median cost of $7.00USD per responder trained. Median frequency of prehospital AM intervention was reported in 31.0% (IQR: 6.0, 50.0) of patient encounters (advanced life support trainees: 12.1%, BLS trainees: 32.0%). In three studies, adverse event frequencies during intubation occurred with a median frequency of 22.0% (IQR: 21.0, 22.0). The training deficit in advanced AM interventions in LMICs suggests BLS AM courses should be prioritized, especially in sub-Saharan Africa. Prehospital AM resources are sparse and should be a priority for future development.

A high fraction of inspired oxygen may increase mortality in intubated trauma patients - A retrospective cohort study

BACKGROUND

Mechanical ventilation of trauma patients is common, and many will require a higher than normal fraction of inspired oxygen (FiO₂) to avoid hypoxaemia. The primary objective of this study was to assess the association between FiO₂ and all-cause, one-year mortality in intubated trauma patients.

METHODS

Adult trauma patients intubated in the initial phase post-trauma between 2015 and 2017 were retrospectively identified. Information on FiO₂ during the first 24 hours of hospitalisation and mortality was registered. For each patient the number of hours of the first 24 hours exposed to an FiO₂ ≥ 80%, ≥ 60%, and ≥ 40%, respectively, were determined and categorised into exposure durations. The associations of these FiO₂ exposures with mortality were evaluated using Cox regression adjusting for age, sex, body mass index (BMI), Injury Severity Score (ISS), prehospital Glasgow Coma Scale (GCS) score, and presence of thoracic injuries.

RESULTS

We included 218 intubated trauma patients. The median prehospital GCS score was 6 and the median ISS was 25. One-year mortality was significantly increased when patients had received an FiO₂ above 80% for 3-4 hours compared to <2 hours (hazard ratio (95% CI) 2.7 (1.3-6.0), p= 0.011). When an FiO₂ above 80% had been administered for more than 4 hours, there was a trend towards a higher mortality as well, but this was not statistically significant. There was a significant, time-dependent increase in mortality for patients who had received an FiO₂ ≥ 60%. There was no significant relationship observed between mortality and the duration of FiO₂ ≥ 40%.

CONCLUSION

A fraction of inspired oxygen above 60% for more than 2 hours during the first 24 hours of admission was associated with increased mortality in intubated trauma patients in a duration-dependent manner. However, given the limitations of this retrospective study, the findings need to be confirmed in a larger, randomized set-up.

Supplemental oxygen therapy in trauma patients: An exploratory registry-based study

BACKGROUND

Supplemental oxygen (SO) is one of the most commonly administered drugs in trauma patients and is recommended by guidelines. However, evidence supporting uniform administration is sparse, and excess oxygen use has been shown to be harmful in other patient populations. We hypothesized that SO may be harmful in patients with oxygen saturation > 97%.

METHODS

Patients with available information on SO-therapy in the American Trauma Quality Improvement Program 2017 database were included. Patients were categorized into 3 groups according to Emergency Department (ED) oxygen saturation: (1) saturation < 94%; (2) saturation 94%-97%; (3) saturation 98%-100%. Primary outcome was in-hospital mortality with comparisons made between patients who received SO or not. Secondary outcome was acute respiratory distress syndrome (ARDS). Patients were compared after propensity score matching.

RESULTS

Overall, 864 340 patients were identified. Mean age was 47.4 ± 24.4 years, and median injury severity score was 9. SO was associated with an increased risk of in-hospital mortality: (all patients: adjusted odds ratio [aOR] with 95% confidence interval [CI] 3.07 [2.92-3.22], ED saturation <94%: 2.63 [2.38-2.91], ED saturation 94%-97%: 2.71 [2.47-2.97], ED saturation >97%: 3.38 [3.16-3.61]. Same pattern was seen for in-hospital ARDS: (aOR 1.79, 95% CI [1.59-2.02], ED saturation <94%: aOR 1.75, 95% CI [1.37-2.24], ED saturation 94%-97%: aOR 1.81, 95% CI [1.43-2.29, ED saturation >97%: aOR 2.31, 95% CI [1.92-2.79]).

CONCLUSION

Based on propensity matched, registry data for trauma patients, the administration of SO was associated with a higher incidence of in-hospital mortality and ARDS. The highest risk was found in patients with an ED saturation >97%.

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

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.

Effect of early hyperoxemia on the outcome in servere blunt chest trauma: A propensity score-based analysis of a single-center retrospective cohort

PURPOSE

Our study aimed to explore the association between early hyperoxemia of the first 24 h on outcomes in patients with severe blunt chest trauma.

MATERIALS AND METHODS

In a level I trauma center, we conducted a retrospective study of 426 consecutive patients. Hyperoxemic groups were classified in severe (average PaO₂ ≥ 200 mmHg), moderate (≥150 and < 200 mmHg) or mild (≥ 100 and < 200 mmHg) and compared to control group (≥60 and < 100 mmHg) using a propensity score based analysis. The first endpoint was the incidence of a composite outcome including death and hospital-acquired pneumonia occurring from admission to day 28. The secondary endpoints were the incidence of death, the number of hospital-acquired pneumonia, mechanical ventilation-free days and intensive care unit-free day at day 28.

RESULTS

The incidence of the composite endpoint was lower in the severe hyperoxemia group(OR, 0.25; 95%CI, 0.09-0.73; P < 0.001) compared with control. The 28-day mortality incidence was lower in severe (OR, 0.23; 95%CI, 0.08-0.68; P < 0.001) hyperoxemia group (OR, 0.41; 95%CI, 0.17-0.97; P = 0.04). Significant association was found between hyperoxemia and secondary outcomes.

CONCLUSION

In our cohort early hyperoxemia during the first 24 h of admission after severe blunt chest trauma was not associated with worse outcome.

Mapping global evidence on strategies and interventions in neurotrauma and road traffic collisions prevention: a scoping review

BACKGROUND

Neurotrauma is an important global health problem. The largest cause of neurotrauma worldwide is road traffic collisions (RTCs), particularly in low- and middle-income countries (LMICs). Neurotrauma and RTCs are preventable, and many preventative interventions have been implemented over the last decades, especially in high-income countries (HICs). However, it is uncertain if these strategies are applicable globally due to variations in environment, resources, population, culture and infrastructure. Given this issue, this scoping review aims to identify, quantify and describe the evidence on approaches in neurotrauma and RTCs prevention, and ascertain contextual factors that influence their implementation in LMICs and HICs.

METHODS

A systematic search was conducted using five electronic databases (MEDLINE, EMBASE, CINAHL, Global Health on EBSCO host, Cochrane Database of Systematic Reviews), grey literature databases, government and non-government websites, as well as bibliographic and citation searching of selected articles. The extracted data were presented using figures, tables, and accompanying narrative summaries. The results of this review were reported using the PRISMA Extension for Scoping Reviews (PRISMA-ScR).

RESULTS

A total of 411 publications met the inclusion criteria, including 349 primary studies and 62 reviews. More than 80% of the primary studies were from HICs and described all levels of neurotrauma prevention. Only 65 papers came from LMICs, which mostly described primary prevention, focussing on road safety. For the reviews, 41 papers (66.1%) reviewed primary, 18 tertiary (29.1%), and three secondary preventative approaches. Most of the primary papers in the reviews came from HICs (67.7%) with 5 reviews on only LMIC papers. Fifteen reviews (24.1%) included papers from both HICs and LMICs. Intervention settings ranged from nationwide to community-based but were not reported in 44 papers (10.8%), most of which were reviews. Contextual factors were described in 62 papers and varied depending on the interventions.

CONCLUSIONS

There is a large quantity of global evidence on strategies and interventions for neurotrauma and RTCs prevention. However, fewer papers were from LMICs, especially on secondary and tertiary prevention. More primary research needs to be done in these countries to determine what strategies and interventions exist and the applicability of HIC interventions in LMICs.

Mapping global evidence on strategies and interventions in neurotrauma and road traffic collisions prevention: a scoping review protocol

INTRODUCTION

Neurotrauma is an important global health problem. This 'silent epidemic' is a major cause of death and disability in adolescents and young adults, with significant societal and economic impacts. Globally, the largest cause of neurotrauma is road traffic collisions (RTCs). Neurotrauma and RTCs are largely preventable, and many preventative strategies and interventions have been established and implemented over the last decades, particularly in high-income countries. However, these approaches may not be applicable globally, due to variations in environment, resources, population, culture and infrastructure. This paper outlines the protocol for a scoping review, which seeks to map the evidence on strategies and interventions in neurotrauma and RTCs prevention globally, and to ascertain contextual factors that influence their implementation.

METHODS AND ANALYSIS

This scoping review will use the established methodology by Arksey and O'Malley. Eligible studies will be identified from five electronic databases (MEDLINE, EMBASE, CINAHL, Global Health/EBSCO and Cochrane Database of Systematic Reviews) and grey literature sources. We will also carry out bibliographical and citation searching of included studies. A two-stage selection process, which involves screening of titles and abstracts, followed by full-text screening, will be used to determine eligible studies which will undergo data abstraction using a customised, piloted data extraction sheet. The extracted data will be presented using evidence mapping and a narrative summary.

ETHICS AND DISSEMINATION

Ethical approval is not required for this scoping review, which is the first step in a multiphase public health research project on the global prevention of neurotrauma. The final review will be submitted for publication to a scientific journal, and results will be presented at appropriate conferences, workshops and meetings. Protocol registered on 5 April 2019 with Open Science Framework (https://osf.io/s4zk3/).

Restrictive vs liberal oxygen for trauma patients-the TRAUMOX1 pilot randomised clinical trial

INTRODUCTION

Hyperoxaemia is commonly observed in trauma patients but has been associated with pulmonary complications and mortality in some patient populations. The objectives of this study were to evaluate whether maintenance of normoxia is feasible using a restrictive oxygen strategy in the initial phase after trauma and to evaluate the incidence of 30-day mortality and/or major pulmonary complications.

METHODS

Forty-one adult trauma patients admitted to our trauma centre were randomised to 24 hours of restrictive oxygen therapy (no supplemental oxygen if the arterial oxyhaemoglobin saturation (SpO₂ ) was at least 94%, n = 21) or liberal oxygen therapy (intubated patients: FiO₂ 1.0 in the trauma bay, 0.8-1.0 elsewhere; spontaneously breathing patients: 15 L/min via a non-rebreather mask, n = 20). Two blinded anaesthesiologists evaluated major in-hospital pulmonary complications within 30 days.

RESULTS

Protocol compliance was high, as the median arterial oxygen tension was significantly lower in the restrictive group (10.8 kPa [9.7-12.0] vs 30.4 kPa [23.7-39.0], P < 0.0001). There were seven episodes of SpO₂ below 90% in the restrictive group and one episode in the liberal group. Thirty-day mortality and/or major in-hospital pulmonary complications occurred in 4/20 (20%) in the restrictive group and in 6/18 (33%) in the liberal group: two patients in each group died within 30 days and the incidence of major in-hospital pulmonary complications was 2/20 (10%) in the restrictive group and 4/18 (22%) in the liberal group.

CONCLUSION

Maintenance of normoxia using a restrictive oxygen strategy following trauma is feasible. This pilot study serves as the basis for a larger clinical trial.

Supplemental oxygen and hyperoxemia in trauma patients: A prospective, observational study

BACKGROUND

Supplemental oxygen is recommended during the initial treatment of trauma patients according to several guidelines, but the supporting evidence is sparse. We aimed to describe the use of supplemental oxygen and occurrence of hyperoxemia in the initial phase of trauma management at two level 1 trauma centers, TC1 and TC2.

METHODS

In this prospective, observational study we included trauma patients ≥16 years of age. Data on pre- and in-hospital supplemental oxygen, arterial oxygen tension (PaO₂ ), and outcomes (in-hospital mortality, hospital- and intensive care unit length of stay) were collected.

RESULTS

We included 56 patients. There were 22 (39%) females with a mean age of 49 years (SD: 18) and a median Injury Severity Score of 9 (IQR: 4-14, n = 49). A total of 23 (45%) out of 51 spontaneously breathing patients received pre-hospital supplemental oxygen, but did not differ significantly from the patients that did not receive supplemental oxygen. In-hospital, 29 (59%) out of 49 spontaneously breathing patients received supplemental oxygen. The median PaO₂ was 26.5 kPa [IQR: 22.2-34.1] in four intubated patients and 12.3 kPa [IQR: 9.7-25.7] in eight patients with spontaneous respiration on supplemental oxygen. At TC1 a significantly greater proportion of spontaneously breathing patients received both pre-hospital (TC1: 18 [64%]; TC2: 5 [21%], P = 0.002) and in-hospital (TC1: 24 [92%]; TC2: 7 [30%], P < 0.001) supplemental oxygen.

CONCLUSION

Approximately 50% of trauma patients received supplemental oxygen during the initial treatment. Hyperoxemia was a common finding for patients treated with supplemental oxygen, and it was more pronounced in intubated patients.