Respiratory Subsets in Patients with Moderate to Severe Acute Respiratory Distress Syndrome for Early Prediction of Death.

Introduction: In patients with acute respiratory distress syndrome (ARDS), the PaO2/FiO2 ratio at the time of ARDS diagnosis is weakly associated with mortality. We hypothesized that setting a PaO2/FiO2 threshold in 150 mm Hg at 24 h from moderate/severe ARDS diagnosis would improve predictions of death in the intensive care unit (ICU). Methods: We conducted an ancillary study in 1303 patients with moderate to severe ARDS managed with lung-protective ventilation enrolled consecutively in four prospective multicenter cohorts in a network of ICUs. The first three cohorts were pooled (n = 1000) as a testing cohort; the fourth cohort (n = 303) served as a confirmatory cohort. Based on the thresholds for PaO2/FiO2 (150 mm Hg) and positive end-expiratory pressure (PEEP) (10 cm H2O), the patients were classified into four possible subsets at baseline and at 24 h using a standardized PEEP-FiO2 approach: (I) PaO2/FiO2 ≥ 150 at PEEP < 10, (II) PaO2/FiO2 ≥ 150 at PEEP ≥ 10, (III) PaO2/FiO2 < 150 at PEEP < 10, and (IV) PaO2/FiO2 < 150 at PEEP ≥ 10. Primary outcome was death in the ICU. Results: ICU mortalities were similar in the testing and confirmatory cohorts (375/1000, 37.5% vs. 112/303, 37.0%, respectively). At baseline, most patients from the testing cohort (n = 792/1000, 79.2%) had a PaO2/FiO2 < 150, with similar mortality among the four subsets (p = 0.23). When assessed at 24 h, ICU mortality increased with an advance in the subset: 17.9%, 22.8%, 40.0%, and 49.3% (p < 0.0001). The findings were replicated in the confirmatory cohort (p < 0.0001). However, independent of the PEEP levels, patients with PaO2/FiO2 < 150 at 24 h followed a distinct 30-day ICU survival compared with patients with PaO2/FiO2 ≥ 150 (hazard ratio 2.8, 95% CI 2.2−3.5, p < 0.0001). Conclusions: Subsets based on PaO2/FiO2 thresholds of 150 mm Hg assessed after 24 h of moderate/severe ARDS diagnosis are clinically relevant for establishing prognosis, and are helpful for selecting adjunctive therapies for hypoxemia and for enrolling patients into therapeutic trials.

The PANDORA Study: Prevalence and Outcome of Acute Hypoxemic Respiratory Failure in the Pre-COVID-19 Era.

OBJECTIVES: To establish the epidemiological characteristics, ventilator management, and outcomes in patients with acute hypoxemic respiratory failure (AHRF), with or without acute respiratory distress syndrome (ARDS), in the era of lung-protective mechanical ventilation (MV). DESIGN: A 6-month prospective, epidemiological, observational study. SETTING: A network of 22 multidisciplinary ICUs in Spain. PATIENTS: Consecutive mechanically ventilated patients with AHRF (defined as Pao2/Fio2 ≤ 300 mm Hg on positive end-expiratory pressure [PEEP] ≥ 5 cm H2O and Fio2 ≥ 0.3) and followed-up until hospital discharge. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Primary outcomes were prevalence of AHRF and ICU mortality. Secondary outcomes included prevalence of ARDS, ventilatory management, and use of adjunctive therapies. During the study period, 9,803 patients were admitted: 4,456 (45.5%) received MV, 1,271 (13%) met AHRF criteria (1,241 were included into the study: 333 [26.8%] met Berlin ARDS criteria and 908 [73.2%] did not). At baseline, tidal volume was 6.9 ± 1.1 mL/kg predicted body weight, PEEP 8.4 ± 3.1 cm H2O, Fio2 0.63 ± 0.22, and plateau pressure 21.5 ± 5.4 cm H2O. ARDS patients received higher Fio2 and PEEP than non-ARDS (0.75 ± 0.22 vs 0.59 ± 0.20 cm H2O and 10.3 ± 3.4 vs 7.7 ± 2.6 cm H2O, respectively [p < 0.0001]). Adjunctive therapies were rarely used in non-ARDS patients. Patients without ARDS had higher ventilator-free days than ARDS (12.2 ± 11.6 vs 9.3 ± 9.7 d; p < 0.001). All-cause ICU mortality was similar in AHRF with or without ARDS (34.8% [95% CI, 29.7-40.2] vs 35.5% [95% CI, 32.3-38.7]; p = 0.837). CONCLUSIONS: AHRF without ARDS is a very common syndrome in the ICU with a high mortality that requires specific studies into its epidemiology and ventilatory management. We found that the prevalence of ARDS was much lower than reported in recent observational studies.

Associated risk factors and outcomes of acute kidney injury in severe trauma: Results from the Spanish trauma ICU registry (RETRAUCI).

INTRODUCTION: Acute kidney injury (AKI) constitutes a common complication after severe trauma. Our objective was to analyse the associated risk factors and outcomes of AKI in a large, multicentre sample of trauma ICU patients. MATERIALS AND METHODS: Observational, prospective and multicentre nationwide registry (RETRAUCI). We included all patients admitted to the participating ICUs from November 2013 to May 2017. We analysed the impact of AKI evaluated by the Risk, Injury, Failure, Loss of kidney function and End-stage kidney disease (RIFLE) definition. Comparison of groups was performed using Wilcoxon test, Chi-Square Test or Fisher's exact test as appropriate. A multiple logistic regression analysis was performed to analyse associated factors to the development of AKI. Logistic regression was used to calculate AKI-related mortality. A P value<0.05 was considered significant. RESULTS: During the study period, 5882 trauma patients were admitted. Complete data were available for 5740 patients. Among them, 871 had AKI (15.17%), distributed by RIFLE R 458 (7.98%), RIFLE I 234 (4.08%) and RIFLE F 179 (3.12%). Associated risk factors were: age (OR 3.05), haemodynamic instability (OR 2.90 to OR 8.34 depending on the severity of hypotension), coagulopathy (OR 1.82), rhabdomyolysis (OR 4.67) and AIS abdomen (OR 1.54). AKI was associated with mortality (crude OR 1.93 (1.59-2.36)), even after adjusting by potential confounders (adjusted OR 1.40 (1.13-1.73)). CONCLUSION: In our large sample of trauma ICU patients we found an incidence of AKI of 15%, which was associated with an increased mortality.

Age-related injury patterns in Spanish trauma ICU patients. Results from the RETRAUCI.

BACKGROUND: Injury patterns may differ in trauma patients when age is considered. This information is relevant in the management of trauma patients and for planning preventive measures. METHODS: We included in the study all patients admitted for traumatic disease in the participating ICUs from November 23rd, 2012 to July 31st, 2015 with complete records. Data on epidemiology, injury patterns, severity scores, acute management, resources utilisation and outcome were recorded and compared in the following groups of age: ≤55years (young adults), 56-65 years (adults), 66-75 years (elderly), >75years (very elderly). Quantitative data were reported as median (Interquartile Range (IQR) 25-75) and categorical data as number and percentage. Comparison between groups of age with quantitative variables was performed using the analysis of variance (ANOVA) test. Differences between groups with categorical variables were compared using the chi-square test. A value of p<0.05 was considered significant. RESULTS: We included 2700 patients (78.9% male). Median age was 46 (31-62) years. Blunt trauma was present in 93.7% of the patients. Median RTS was 7.55 (5.97-7.84). Median ISS was 20 (13-26). High-energy trauma secondary to motor-vehicle accident with rhabdomyolysis and drugs abuse showed an inverse linear association with ageing, whilst pedestrian falls with isolated brain injury, being run-over and pre-injury antiplatelets or anticoagulant treatment increased with age (in all cases p<0.001). Multiple injuries were more common in young adults (p<0.001). Acute kidney injury prevalence was higher in elderly and very elderly patients (p<0.001). ICU Mortality increased with age in spite of similar severity scores in all groups (p<0.001). The main cause of death in all groups was intracranial hypertension. CONCLUSIONS: Different injury patterns exist in relation with ageing in trauma ICU patients. Adult patients were more likely to present high-energy trauma with significant injuries in different areas whilst elderly patients were prone to low-energy falls, complicated by antiplatelets or anticoagulants use, resulting in severe brain injury and increased mortality.