Outcomes of patients with traumatic brain injury after stress ulcer prophylaxis: a retrospective multicenter study

Background Stress ulcers in patients with traumatic brain injury (TBI) and spinal cord injury (SCI) present significant morbidity and mortality risks. Despite the low reported stress ulcer rates, stress ulcer prophylaxis (SUP) is widely administered in neurocritical care. It was hypothesized that universal SUP administration may not be associated with reduced rates of complications across all neurocritical care patients.Methods This retrospective study encompassed neurocritical care patients aged ≥18 with moderate or severe TBI or SCI, admitted to the intensive care unit (ICU) between October 2020 and September 2021, across six level I trauma centers. Exclusions included patients with an ICU stay <2 days, prior SUP medication use, and pre-existing SUP diagnoses. The primary exposure was SUP, with the primary outcome being clinically significant gastrointestinal bleeds (CSGIBs). Secondary outcomes included pneumonia and in-hospital mortality. Patients were stratified by admission Glasgow Coma Scale (GCS) groups.Results Among 407 patients, 83% received SUP, primarily H2 receptor antagonists (88%) and proton pump inhibitors (12%). Patients on SUP were significantly younger, had lower admission GCS scores, higher Injury Severity Scores, longer ICU stays, and higher rates of mechanical ventilation than non-SUP patients. Overall, CSGIBs were rare (1%) and not significantly different between the SUP and non-SUP groups (p=0.06). However, CSGIBs exclusively occurred in patients with GCS scores of 3–8, and SUP was associated with a significantly lower rate of CSGIBs in this subgroup (p=0.03). SUP was also linked to significantly higher pneumonia rates in both GCS 3–8 and GCS 9–12 patients.Conclusions This study highlights the low incidence of CSGIBs in neurocritical trauma patients and suggests potential benefits of SUP, particularly for those with severe neurological impairment. Nevertheless, the increased risk of pneumonia associated with SUP in these patients warrants caution. Further research is crucial to refine SUP guidelines for neurocritical care patients and inform optimal strategies.Level of evidence Level III, retrospective

Microglial priming through the lung-brain axis: the role of air pollution-induced circulating factors

Air pollution is implicated in neurodegenerative disease risk and progression and in microglial activation, but the mechanisms are unknown. In this study, microglia remained activated 24 h after ozone (O3) exposure in rats, suggesting a persistent signal from lung to brain. Ex vivo analysis of serum from O3-treated rats revealed an augmented microglial proinflammatory response and β-amyloid 42 (Aβ42) neurotoxicity independent of traditional circulating cytokines, where macrophage-1 antigen-mediated microglia proinflammatory priming. Aged mice exhibited reduced pulmonary immune profiles and the most pronounced neuroinflammation and microglial activation in response to mixed vehicle emissions. Consistent with this premise, cluster of differentiation 36 (CD36)(-/-) mice exhibited impaired pulmonary immune responses concurrent with augmented neuroinflammation and microglial activation in response to O3 Further, aging glia were more sensitive to the proinflammatory effects of O3 serum. Together, these findings outline the lung-brain axis, where air pollutant exposures result in circulating, cytokine-independent signals present in serum that elevate the brain proinflammatory milieu, which is linked to the pulmonary response and is further augmented with age

Rethinking the definition of major trauma: The need for trauma intervention outperforms Injury Severity Score and Revised Trauma Score in 38 adult and pediatric trauma centers

BACKGROUND Patients\u27 trauma burdens are a combination of anatomic damage, physiologic derangement, and the resultant depletion of reserve. Typically, Injury Severity Score (ISS) \u3e15 defines major anatomic injury and Revised Trauma Score (RTS) \u3c7.84 defines major physiologic derangement, but there is no standard definition for reserve. The Need For Trauma Intervention (NFTI) identifies severely depleted reserves (NFTI+) with emergent interventions and/or early mortality. We hypothesized NFTI would have stronger associations with outcomes and better model fit than ISS and RTS. METHODS Thirty-eight adult and pediatric U.S. trauma centers submitted data for 88,488 encounters. Mixed models tested ISS greater than 15, RTS less than 7.84, and NFTI\u27s associations with complications, survivors\u27 discharge to continuing care, and survivors\u27 length of stay (LOS). RESULTS The NFTI had stronger associations with complications and LOS than ISS and RTS (odds ratios [99.5% confidence interval]: NFTI = 9.44 [8.46-10.53]; ISS = 5.94 [5.36-6.60], RTS = 4.79 [4.29-5.34]; LOS incidence rate ratios (99.5% confidence interval): NFTI = 3.15 [3.08-3.22], ISS = 2.87 [2.80-2.94], RTS = 2.37 [2.30-2.45]). NFTI was more strongly associated with continuing care discharge but not significantly more than ISS (relative risk [99.5% confidence interval]: NFTI = 2.59 [2.52-2.66], ISS = 2.51 [2.44-2.59], RTS = 2.37 [2.28-2.46]). Cross-validation revealed that in all cases NFTI\u27s model provided a much better fit than ISS greater than 15 or RTS less than 7.84. CONCLUSION In this multicenter study, NFTI had better model fit and stronger associations with the outcomes than ISS and RTS. By determining depletion of reserve via resource consumption, NFTI+ may be a better definition of major trauma than the standard definitions of ISS greater than 15 and RTS less than 7.84. Using NFTI may improve retrospective triage monitoring and statistical risk adjustments. LEVEL OF EVIDENCE Prognostic, level IV