Alveolar macrophages are epigenetically altered after inflammation, leading to long-term lung immunoparalysis.

Sepsis and trauma cause inflammation and elevated susceptibility to hospital-acquired pneumonia. As phagocytosis by macrophages plays a critical role in the control of bacteria, we investigated the phagocytic activity of macrophages after resolution of inflammation. After resolution of primary pneumonia, murine alveolar macrophages (AMs) exhibited poor phagocytic capacity for several weeks. These paralyzed AMs developed from resident AMs that underwent an epigenetic program of tolerogenic training. Such adaptation was not induced by direct encounter of the pathogen but by secondary immunosuppressive signals established locally upon resolution of primary infection. Signal-regulatory protein α (SIRPα) played a critical role in the establishment of the microenvironment that induced tolerogenic training. In humans with systemic inflammation, AMs and also circulating monocytes still displayed alterations consistent with reprogramming six months after resolution of inflammation. Antibody blockade of SIRPα restored phagocytosis in monocytes of critically ill patients in vitro, which suggests a potential strategy to prevent hospital-acquired pneumonia.

Author Correction: Alveolar macrophages are epigenetically altered after inflammation, leading to long-term lung immunoparalysis.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Mechanical ventilation in patients with acute brain injury: a systematic review with meta-analysis.

OBJECTIVE: To describe the potential effects of ventilatory strategies on the outcome of acute brain-injured patients undergoing invasive mechanical ventilation. DESIGN: Systematic review with an individual data meta-analysis. SETTING: Observational and interventional (before/after) studies published up to August 22nd, 2022, were considered for inclusion. We investigated the effects of low tidal volume Vt < 8 ml/Kg of IBW versus Vt > = 8 ml/Kg of IBW, positive end-expiratory pressure (PEEP) < or > = 5 cmH2O and protective ventilation (association of both) on relevant clinical outcomes. POPULATION: Patients with acute brain injury (trauma or haemorrhagic stroke) with invasive mechanical ventilation for ≥ 24 h. MAIN OUTCOME MEASURES: The primary outcome was mortality at 28 days or in-hospital mortality. Secondary outcomes were the incidence of acute respiratory distress syndrome (ARDS), the duration of mechanical ventilation and the partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio. RESULTS: The meta-analysis included eight studies with a total of 5639 patients. There was no difference in mortality between low and high tidal volume [Odds Ratio, OR 0.88 (95%Confidence Interval, CI 0.74 to 1.05), p = 0.16, I2 = 20%], low and moderate to high PEEP [OR 0.8 (95% CI 0.59 to 1.07), p = 0.13, I2 = 80%] or protective and non-protective ventilation [OR 1.03 (95% CI 0.93 to 1.15), p = 0.6, I2 = 11]. Low tidal volume [OR 0.74 (95% CI 0.45 to 1.21, p = 0.23, I2 = 88%], moderate PEEP [OR 0.98 (95% CI 0.76 to 1.26), p = 0.9, I2 = 21%] or protective ventilation [OR 1.22 (95% CI 0.94 to 1.58), p = 0.13, I2 = 22%] did not affect the incidence of acute respiratory distress syndrome. Protective ventilation improved the PaO2/FiO2 ratio in the first five days of mechanical ventilation (p < 0.01). CONCLUSIONS: Low tidal volume, moderate to high PEEP, or protective ventilation were not associated with mortality and lower incidence of ARDS in patients with acute brain injury undergoing invasive mechanical ventilation. However, protective ventilation improved oxygenation and could be safely considered in this setting. The exact role of ventilatory management on the outcome of patients with a severe brain injury needs to be more accurately delineated.

Tranexamic acid: a narrative review of its current role in perioperative medicine and acute medical bleeding.

Purpose: Tranexamic acid (TXA) is the most widely prescribed antifibrinolytic for active bleeding or to prevent surgical bleeding. Despite numerous large multi-center randomized trials involving thousands of patients being conducted, TXA remains underutilized in indications where it has demonstrated efficacy and a lack of harmful effects. This narrative review aims to provide basic concepts about fibrinolysis and TXA's mode of action and is focused on the most recent and important trials evaluating this drug in different hemorrhagic situations. Methods: We selected every low bias RCT, and we highlighted their strengths and limitations throughout this review. Principal findings: While TXA appears to have a favorable benefit-risk ratio in most situations (trauma, obstetrics, at-risk for bleeding surgeries) evidence of benefit is lacking in certain medical settings (SAH, digestive bleeding). Conclusion: Although in some situations the drug's effect on significant outcomes is modest, its favorable safety profile allows it to be recommended for trauma patients, in obstetrics, and in scheduled surgeries at risk of bleeding. However, it cannot be recommended in cases of spontaneous intracranial bleeding, subarachnoid hemorrhage (SAH), or gastrointestinal bleeding.

Influence of mechanical ventilation and loading modifications on left ventricular global longitudinal strain in patients undergoing general anesthesia: a pilot study.

BACKGROUND: The modifications of left ventricular systolic function assessed with global longitudinal strain (GLS) after general anesthesia and invasive mechanical ventilation are poorly described. METHODS: This was a single-center observational study. ASA I-II patients undergoing routine surgical procedures requiring anesthesia with invasive mechanical ventilation had serial trans-thoracic speckle-tracking echocardiography: at baseline, five minutes after anesthesia and invasive mechanical ventilation, one minute after passive leg raising and after extubation. The primary objective was to evaluate the modification of left ventricular systolic function, assessed with GLS, under anesthesia and mechanical ventilation. Secondary objectives were to evaluate the alterations of GLS after pre-load modifications with passive leg raising and after extubation. RESULTS: From November 2016 to July 2017, 27 patients were included. Baseline left ventricular ejection fraction (LVEF: 60% [56-63]) and GLS (-20.6% [-23.2/-19.2]) were within normal ranges. After anesthesia, LVEF was not altered but GLS showed a significant decrease (-18.2% [-20.4/-17.1], P<0.05). After passive leg raising, GLS was significantly impaired compared with baseline (-17.6% [-19.7/-15], P<0.05) and seven (26%) patients presented systolic function impairment (GLS >-16%). GLS was similar to baseline after extubation (-21.7% [-23.1/-19.5], P>0.05). CONCLUSIONS: Systolic function assessed with GLS is impaired after general anesthesia and invasive mechanical ventilation in patients without cardiovascular co-morbidities but remains within normal range.

Epidural analgesia in ICU chest trauma patients with fractured ribs: retrospective study of pain control and intubation requirements.

BACKGROUND: Nonintubated chest trauma patients with fractured ribs admitted to the intensive care unit (ICU) are at risk for complications and may require invasive ventilation at some point. Effective pain control is essential. We assessed whether epidural analgesia (EA) in patients with fractured ribs who were not intubated at ICU admission decreased the need for invasive mechanical ventilation (IMV). We also looked for risk factors for IMV. STUDY DESIGN AND METHODS: This retrospective, observational, multicenter study conducted in 40 ICUs in France included consecutive patients with three or more fractured ribs who were not intubated at admission between July 2013 and July 2015. RESULTS: Of the 974 study patients, 788 were included in the analysis of intubation predictors. EA was used in 130 (16.5%) patients, and 65 (8.2%) patients required IMV. Factors independently associated with IMV were chronic respiratory disease (P = 0.008), worse SAPS II (P < 0.0001), flail chest (P = 0.02), worse Injury Severity Score (P = 0.0003), higher respiratory rate at admission (P = 0.02), alcohol withdrawal syndrome (P < 0.001), and noninvasive ventilation (P = 0.04). EA was not associated with decreases in IMV requirements, median numerical rating scale pain score, or intravenous morphine requirements from day 1 to day 7. CONCLUSIONS: EA was not associated with a lower risk of IMV in chest trauma patients with at least 3 fractured ribs, moderate pain, and no intubation on admission. Further studies are needed to clarify the optimal pain control strategy in chest trauma patients admitted to the ICU, notably those with severe pain or high opioid requirements.

Impact of a Quality Improvement Program on the Neurological Outcome of Patients with Traumatic Spinal Cord Injury: A Before-After Mono-Centric Study.

Spinal cord injury (SCI) is a major cause of severe disability. This study aims to assess the effectiveness of a quality improvement program on neurological recovery after SCI. Before-after study during two phases was done in one intensive care unit in a university hospital. The quality improvement project comprised protective mechanical ventilation, early tracheostomy in anatomical injury above the sixth cervical vertebra, early enteral nutrition, early mobilization, and active perineal care in adult SCI patients. The primary endpoint was the difference between the American Spinal Injury Association (ASIA) motor score between discharge and intensive care unit (ICU) admission (Delta ASIA). Fifty-seven and 60 patients were included in the control and in the intervention period respectively. The ASIA motor score upon ICU admission was 16 (7-37) before and 11 (2-30) after the implementation (p = 0.30). The implementation phase was associated with lower tidal volumes (p < 0.001), higher positive end-expiratory pressure (p < 0.001), earlier tracheostomy (p = 0.01), earlier enteral nutrition initiation (p < 0.05), earlier mobilization (p < 0.05), and more active perineal care (p < 0.05). The Delta ASIA was +16 [4-32] after versus +6 [0-14] before the intervention (p < 0.05). After adjustment for potential cofounders, the intervention phase was significantly associated with higher Delta ASIA (ß coefficient, 11.4; CI95 [1.9-21]; p = 0.01) in multi-variable analysis. No secular time trend unrelated to the intervention was highlighted. One year after trauma, the Delta ASIA was higher in the intervention period than in the control period (+34 [15-60] vs. +11 [0-33]; p < 0.05). After adjustment on potential confounders, an early in-ICU rehabilitation program in SCI patients was associated with higher neurological score upon ICU discharge.