Almost all studies that have investigated the immune response to trauma have analysed blood samples acquired post-hospital admission. Thus, we know little of the immune status of patients in the immediate postinjury phase and how this might influence patient outcomes. The objective of this study was therefore to comprehensively assess the ultra-early, within 1-hour, immune response to trauma and perform an exploratory analysis of its relationship with the development of multiple organ dysfunction syndrome (MODS). The immune and inflammatory response to trauma was analysed in 89 adult trauma patients (mean age 41 years, range 18–90 years, 75 males) with a mean injury severity score (ISS) of 24 (range 9–66), from whom blood samples were acquired within 1 hour of injury (mean time to sample 42 minutes, range 17–60 minutes). Within minutes of trauma, a comprehensive leukocytosis, elevated serum pro- and anti-inflammatory cytokines, and evidence of innate cell activation that included neutrophil extracellular trap generation and elevated surface expression of toll-like receptor 2 and CD11b on monocytes and neutrophils, respectively, were observed. Features consistent with immune compromise were also detected, notably elevated numbers of immune suppressive CD16^BRIGHT CD62L^DIM neutrophils (82.07 x 10⁶/l ± 18.94 control versus 1,092 x 10⁶/l ± 165 trauma, p < 0.0005) and CD14⁺HLA-DR^low/− monocytes (34.96 x 10⁶/l ± 4.48 control versus 95.72 x 10⁶/l ± 8.0 trauma, p < 0.05) and reduced leukocyte cytokine secretion in response to lipopolysaccharide stimulation. Exploratory analysis via binary logistic regression found a potential association between absolute natural killer T (NKT) cell numbers and the subsequent development of MODS. Study limitations include the relatively small sample size and the absence of data relating to adaptive immune cell function. Our study highlighted the dynamic and complex nature of the immune response to trauma, with immune alterations consistent with both activation and suppression evident within 1 hour of injury. The relationship of these changes, especially in NKT cell numbers, to patient outcomes such as MODS warrants further investigation.

Background: Trauma patients are vulnerable to coagulopathy and inflammatory dysfunction associated with endotheliopathy of trauma (EoT). In vitro evidence has suggested that tranexamic acid (TXA) may ameliorate endotheliopathy. We aimed to investigate how soon after injury EoT occurs, its association with multiple organ dysfunction syndrome (MODS), and whether TXA ameliorates it. Methods: A prospective observational study included 91 trauma patients enrolled within 60 min of injury and 19 healthy controls. Blood was sampled on enrolment and again 4 to 12 h later. ELISAs measured serum concentrations of syndecan-1 and thrombomodulin as biomarkers of EoT. MODS was compared between groups according to biomarker dynamics: persistently abnormal; abnormal to normal; and persistently normal. Timing of EoT was estimated by plotting biomarker data against time, and then fitting generalized additive models. Biomarker dynamics were compared between those who did or did not receive prehospital TXA. Results: Median age was 38 (interquartile range [IQR] 24–55) years; 78 of 91 were male. Median injury severity score (ISS) was 22 (IQR 12–36). EoT was estimated to occur at 5 to 8 min after injury. There were no significant differences in ISS between those with or without prehospital EoT. Forty-two patients developed MODS; 31 of 42 with persistently abnormal; 8 of 42 with abnormal to normal; and 3 of 42 with persistently normal biomarkers; P < 0.05. There were no significant differences between TXA and non-TXA groups. Conclusions: EoT was present at the scene of injury. MODS was more likely when biomarkers of EoT were persistently raised. There were no significant differences between TXA and non-TXA groups. Prehospital interventions aimed at endothelial restoration may represent a clinically meaningful target for prehospital resuscitation.

Background Haemorrhage is a major cause of mortality and morbidity following both military and civilian trauma. Haemostatic dressings may offer effective haemorrhage control as part of prehospital treatment. Aim To conduct a systematic review of the clinical literature to assess the prehospital use of haemostatic dressings in controlling traumatic haemorrhage, and determine whether any haemostatic dressings are clinically superior. Methods MEDLINE and EMBASE databases were searched using predetermined criteria. The reference lists of all returned review articles were screened for eligible studies. Two authors independently undertook the search, performed data extraction, and risk of bias and Grading of Recommendations, Assessment, Development and Evaluation quality assessments. Meta-analysis could not be undertaken due to study and clinical heterogeneity. Results Our search yielded 470 studies, of which 17 met eligibility criteria, and included 809 patients (469 military and 340 civilian). There were 15 observational studies, 1 case report and 1 randomised controlled trial. Indications for prehospital haemostatic dressing use, wound location, mechanism of injury, and source of bleeding were variable. Seven different haemostatic dressings were reported with QuikClot Combat Gauze being the most frequently applied (420 applications). Cessation of bleeding ranged from 67% to 100%, with a median of 90.5%. Adverse events were only reported with QuikClot granules, resulting in burns. No adverse events were reported with QuikClot Combat Gauze use in three studies. Seven of the 17 studies did not report safety data. All studies were at risk of bias and assessed of ‘very low’ to ‘moderate’ quality. Conclusions Haemostatic dressings offer effective prehospital treatment for traumatic haemorrhage. QuikClot Combat Gauze may be justified as the optimal agent due to the volume of clinical data and its safety profile, but there is a lack of high-quality clinical evidence, and randomised controlled trials are warranted. Level of evidence Systematic review, level IV.

Background: The coronavirus disease 2019 (COVID-19) pandemic is likely to lead to a significant increase in mental health disorders among healthcare workers (HCW). Aims: We evaluated the rates of anxiety, depressive and post-traumatic stress disorder (PTSD) symptoms in a population of HCW in the UK. Method: An electronic survey was conducted between the 5 June 2020 and 31 July 2020 of all hospital HCW in the West Midlands, UK using clinically validated questionnaires: the 4-item Patient Health Questionnaire(PHQ-4) and the Impact of Event Scale-Revised (IES-R). Univariate analyses and adjusted logistic regression analyses were performed to estimate the strengths in associations between 24 independent variables and anxiety, depressive or PTSD symptoms. Results: There were 2638 eligible participants who completed the survey (female: 79.5%, median age: 42 years, interquartile range: 32–51). The rates of clinically significant symptoms of anxiety, depression and PTSD were 34.3%, 31.2% and 24.5%, respectively. In adjusted analysis a history of mental health conditions was associated with clinically significant symptoms of anxiety (odds ratio (OR) = 2.3, 95% CI 1.9–2.7, P < 0.001), depression (OR = 2.5, 95% CI 2.1–3.0, P < 0.001) and PTSD (OR = 2.1, 95% CI 1.7–2.5, P < 0.001). The availability of adequate personal protective equipment (PPE), well-being support and lower exposure to moral dilemmas at work demonstrated significant negative associations with these symptoms (P ≤ 0.001). Conclusions: We report higher rates of clinically significant mental health symptoms among hospital HCW following the initial COVID-19 pandemic peak in the UK. Those with a history of mental health conditions were most at risk. Adequate PPE availability, access to well-being support and reduced exposure to moral dilemmas may protect hospital HCW from mental health symptoms.

BACKGROUND: Endothelial cell damage and glycocalyx shedding after trauma can increase the risk of inflammation, coagulopathy, vascular permeability, and death. Bedside sublingual video-microscopy may detect worse flow and perfusion associated with this endotheliopathy. We compared markers of endotheliopathy with physical flow dynamics after traumatic hemorrhagic shock. METHODS: Sublingual incident dark field video-microscopy was performed at three time points after injury (<10 hours, 10–30 hours, and 30–50 hours). Values for microcirculatory flow index (MFI), Point Of carE Microcirculation assessment (POEM) score, proportion of perfused vessels (PPV), microcirculatory heterogeneity index (MHI), perfused vessel density (PVD), and total vessel density (TVD) were obtained. ELISAs were performed to measure concentrations of thrombomodulin and syndecan-1 as biomarkers of endothelial cell damage and glycocalyx shedding respectively. Flow parameters were dichotomized to above and below average, and biomarkers compared between groups; below average MFI, POEM, PPV, PVD, and TVD, and above average MHI were considered poor microcirculatory flow dynamics. RESULTS: A total of 155 sublingual video-microscopy clips corresponding to 39 time points from 17 trauma patients were analyzed. Median age was 35 (IQR 25–52); 16/17 were men. Within 10 hours of injury, syndecan-1 concentrations were significantly higher compared to 17 age- and sex-matched healthy controls (30 [IQR 20–44] ng/mL) for worse TVD (78 [IQR 63–417] ng/mL), PVD (156 [IQR 63–590] ng/mL), PPV (249 [IQR 64–578] ng/mL), MFI (249 [IQR 64–578] ng/mL), MHI (45 [IQR] 38–68) ng/mL), and POEM scores (108 [IQR 44–462] ng/mL) (all p < 0.01). Thrombomodulin was also raised within 10 hours of injury when compared to healthy controls (2.9 [IQR 2.2–3.4] ng/mL) for worse PPV (4.1 [IQR 3.4–6.2] ng/mL) and MFI (4.1 [IQR 3.4–6.2] ng/mL) (both p < 0.05). CONCLUSIONS: Endothelial cell damage and glycocalyx shedding are associated with worse flow, density, and heterogeneity within microvessels after traumatic hemorrhagic shock. The clinical utility of these biomarkers and flow parameters at the bedside are yet to be elucidated. LEVEL OF EVIDENCE: Prognostic study, level III.