Predicting the Length of Mechanical Ventilation in Acute Respiratory Disease Syndrome Using Machine Learning: The PIONEER Study.

Background: The ability to predict a long duration of mechanical ventilation (MV) by clinicians is very limited. We assessed the value of machine learning (ML) for early prediction of the duration of MV > 14 days in patients with moderate-to-severe acute respiratory distress syndrome (ARDS). Methods: This is a development, testing, and external validation study using data from 1173 patients on MV ≥ 3 days with moderate-to-severe ARDS. We first developed and tested prediction models in 920 ARDS patients using relevant features captured at the time of moderate/severe ARDS diagnosis, at 24 h and 72 h after diagnosis with logistic regression, and Multilayer Perceptron, Support Vector Machine, and Random Forest ML techniques. For external validation, we used an independent cohort of 253 patients on MV ≥ 3 days with moderate/severe ARDS. Results: A total of 441 patients (48%) from the derivation cohort (n = 920) and 100 patients (40%) from the validation cohort (n = 253) were mechanically ventilated for >14 days [median 14 days (IQR 8-25) vs. 13 days (IQR 7-21), respectively]. The best early prediction model was obtained with data collected at 72 h after moderate/severe ARDS diagnosis. Multilayer Perceptron risk modeling identified major prognostic factors for the duration of MV > 14 days, including PaO2/FiO2, PaCO2, pH, and positive end-expiratory pressure. Predictions of the duration of MV > 14 days showed modest discrimination [AUC 0.71 (95%CI 0.65-0.76)]. Conclusions: Prolonged MV duration in moderate/severe ARDS patients remains difficult to predict early even with ML techniques such as Multilayer Perceptron and using data at 72 h of diagnosis. More research is needed to identify markers for predicting the length of MV. This study was registered on 14 August 2023 at ClinicalTrials.gov (NCT NCT05993377).

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.

Stratification for Identification of Prognostic Categories In the Acute RESpiratory Distress Syndrome (SPIRES) Score.

OBJECTIVES: To develop a scoring model for stratifying patients with acute respiratory distress syndrome into risk categories (Stratification for identification of Prognostic categories In the acute RESpiratory distress syndrome score) for early prediction of death in the ICU, independent of the underlying disease and cause of death. DESIGN: A development and validation study using clinical data from four prospective, multicenter, observational cohorts. SETTING: A network of multidisciplinary ICUs. PATIENTS: One-thousand three-hundred one patients with moderate-to-severe acute respiratory distress syndrome managed with lung-protective ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The study followed Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis guidelines for prediction models. We performed logistic regression analysis, bootstrapping, and internal-external validation of prediction models with variables collected within 24 hours of acute respiratory distress syndrome diagnosis in 1,000 patients for model development. Primary outcome was ICU death. The Stratification for identification of Prognostic categories In the acute RESpiratory distress syndrome score was based on patient's age, number of extrapulmonary organ failures, values of end-inspiratory plateau pressure, and ratio of Pao2 to Fio2 assessed at 24 hours of acute respiratory distress syndrome diagnosis. The pooled area under the receiver operating characteristic curve across internal-external validations was 0.860 (95% CI, 0.831-0.890). External validation in a new cohort of 301 acute respiratory distress syndrome patients confirmed the accuracy and robustness of the scoring model (area under the receiver operating characteristic curve = 0.870; 95% CI, 0.829-0.911). The Stratification for identification of Prognostic categories In the acute RESpiratory distress syndrome score stratified patients in three distinct prognostic classes and achieved better prediction of ICU death than ratio of Pao2 to Fio2 at acute respiratory distress syndrome onset or at 24 hours, Acute Physiology and Chronic Health Evaluation II score, or Sequential Organ Failure Assessment scale. CONCLUSIONS: The Stratification for identification of Prognostic categories In the acute RESpiratory distress syndrome score represents a novel strategy for early stratification of acute respiratory distress syndrome patients into prognostic categories and for selecting patients for therapeutic trials.

Reconnection to mechanical ventilation for 1 h after a successful spontaneous breathing trial reduces reintubation in critically ill patients: a multicenter randomized controlled trial.

BACKGROUND: Spontaneous breathing trials (SBT) can be exhausting, but the preventive role of rest has never been studied. This study aimed to evaluate whether reconnection to mechanical ventilation (MV) for 1 h after the effort of a successful SBT could reduce the need for reintubation in critically ill patients. METHODS: Randomized multicenter trial conducted in 17 Spanish medical-surgical intensive care units (Oct 2013-Jan 2015). Patients under MV for longer than 12 h who fulfilled criteria for planned extubation were randomly allocated after a successful SBT to direct extubation (control group) or reconnection to the ventilator for a 1-h rest before extubation (rest group). The primary outcome was reintubation within 48 h. Analysis was by intention to treat. RESULTS: We recruited 243 patients randomized to the control group and 227 to the rest group. Median time from intubation to SBT did not differ between groups [5.5 (2.7, 9.6) days in the control group vs. 5.7 (2.7, 10.6) in the rest group; p = 0.85]. Reintubation within 48 h after extubation was more common in the control than in the rest group [35 (14%) vs. 12 (5%) patients; OR 0.33; 95% CI 0.16-0.65; p < 0.001]. A multivariable regression model demonstrated that the variables independently associated with reintubation were rest [OR 0.34 (95%CI 0.17-0.68)], APACHE II [OR 1.04 (1.002-1.077)], and days of MV before SBT [OR 1.04 (1.001-1.073)], whereas age, reason for admission, and type and duration of SBT were not. CONCLUSION: One-hour rest after a successful SBT reduced the rates of reintubation within 48 h after extubation in critically ill patients. Trial registration Clinicaltrials.gov identifier NCT01915563.

Effect of Solution Composition on the Energy Production by Capacitive Mixing in Membrane-Electrode Assembly.

In this work, we consider the extent to which the presence of multivalent ions in solution modifies the equilibrium and dynamics of the energy production in a capacitive cell built with ion-exchange membranes in contact with high surface area electrodes. The cell potential in open circuit (OCV) is controlled by the difference between both membrane potentials, simulated as constant volume charge regions. A theoretical model is elaborated for steady state OCV, first in the case of monovalent solutions, as a reference. This is compared to the results in multi-ionic systems, containing divalent cations in concentrations similar to those in real seawater. It is found that the OCV is reduced by about 25% (as compared to the results in pure NaCl solutions) due to the presence of the divalent ions, even in low concentrations. Interestingly, this can be related to the "uphill" transport of such ions against their concentration gradients. On the contrary, their effect on the dynamics of the cell potential is negligible in the case of highly charged membranes. The comparison between model predictions and experimental results shows a very satisfactory agreement, and gives clues for the practical application of these recently introduced energy production methods.

Tratamiento del tabaquismo en los centros de drogodependencias y alcoholismo en España. Estado de la situación y perspectivas / Smoking cessation programs in centres specialised in treating drug abuse and alcoholism in Spain: present situation and future

Se analiza en una muestra de 142 centros, la mayoría de drogodependencias y algunos de alcoholismo, de 11 comunidades autónomas españolas, los programas que realizan para el tratamiento del tabaquismo. El 55.6% llevan a cabo tratamiento de fumadores. A lo largo del año 2004 en dichos centros hubo una demanda de tratamiento por parte de 3.771 personas. Fueron tratadas unas 3.000, finalizando el tratamiento la mitad de ellas. Los niveles de abstinencia indicados para el final del tratamiento como en los seguimientos a los 6 y 12 meses son buenos, en relación a los estudios clínicos publicados. El tratamiento más utilizado es el combinado (psicológico y farmacológico) seguido del psicológico. Suelen ser los distintos profesionales del equipo terapéutico los que llevan a cabo el tratamiento. Indican varias limitaciones para realizar este tratamiento, incluidos los presentes en cualquier adicción (ej., baja motivación de los fumadores), carencia de tiempo, poco personal, etc. Aprecian un claro incremento de la demanda, tanto de personas que acuden con solo dependencia de la nicotina como de sus usuarios clásicos que están a tratamiento por otras dependencias. Tienen clara su relevancia profesional en el tratamiento de esta adicción y la alta eficacia de los tratamientos que llevan a cabo con los fumadores. Ven necesario que se les aporten más medios para hacer frente al incremento continuo de demanda que están teniendo para el tratamiento de la dependencia de la nicotina en sus centros

We analyzed in a sample of 142 Centers of Drug Abuse and Alcoholism, in 11 regions of Spain, the programs that they carry out for smoking cessation. The 55.6% of centers carries out treatment of smokers. Along the year 2004 in this centers had a treatment demand of 3,771 smokers, 3,000 were treated, concluding the treatment half of them. The levels of abstinence for the end of the treatment and in the 6- and 12-months followup are good, in relation to the published clinical studies. The most utilized treatment are the combined (psychological and pharmacological) followed by the psychological treatment. They are usually apply by diferent professionals as therapits. They indicate several limitations to carry out this treatment, included usual in any addiction (e.g., the smokers’ low motivation), lack of time, limited personal, etc. They appreciates a clear increment of the demand, so much of people that they go with single nicotine dependence like of its classic users that are to treatment for other dependences. This data indicated the professional relevance of Centers of Drug Dependence in the treatment of nicotine dependence and the high effectiveness of the treatments that carry out with the smokers. They consider necessary that they have more means to make in front of the continuous increment of demand that they are having for the treatment of the nicotine dependence in their centers