Quality improvement project to improve adherence to lung protective ventilation guidelines.

INTRODUCTION: Lung protective ventilation (LPV) is advocated for all patients requiring mechanical ventilation (MV), for any duration of time, to prevent worsening lung injury. Previous studies proved simple interventions can increase awareness of LPV and disease pathophysiology as well as improve adherence to LPV guidelines. OBJECTIVE: To assess the impact of a multi-component LPV quality improvement project (QIP) on adherence to LPV guidelines. METHODS: Tidal volume data for all patients requiring MV at a large, tertiary UK critical care unit were collected retrospectively over 3, 6 months, Plan-Do-Study-Act cycles between September 2019 and August 2022. These cycles included the sequential implementation of LPV reports, bedside whiteboards and targeted education led by a multispecialty working group. MAIN OUTCOME MEASURE: Adherence against predetermined targets of <5% of MV hours spent at >10 mL/kg predicted body weight (PBW) and >75% of MV hours spent <8 mL/kg PBW for all patients requiring MV. RESULTS: 408 949 hours (17 040 days) of MV data were analysed. Improved LPV adherence was demonstrated throughout the QIP. During mandated MV, time spent >10 mL/kg PBW reduced from 7.65% of MV hours to 4.04% and time spent <8 mL/kg PBW improved from 68.86% of MV hours to 71.87% following the QIP. During spontaneous MV, adherence improved with a reduction in time spent >10 mL/kg PBW from baseline to completion (13.2% vs 6.75%) with increased time spent <8 mL/kg PBW (62.74% vs 72.25%). Despite demonstrating improvements in adherence, we were unable to achieve success in all our predetermined targets. CONCLUSION: This multicomponent intervention including the use of LPV reports, bedside whiteboards and education improves adherence to LPV guidelines. More robust data analysis of reasons for non-adherence to our predetermined targets is required to guide future interventions that may allow further improvement in adherence to LPV guidelines.

Are instructors correctly gauging ventilation competence acquired by course attendees?

Achievement of adequate ventilation skills during training courses is mainly based on instructors' perception of attendees' capability to ventilate with correct rate and chest compression:ventilation ratio, while leading to chest raising, as evidence of adequate tidal volume. Accuracy in evaluating ventilation competence was assessed in 20 ACLS provider course attendees, by comparing course instructors' evaluation with measures from a ventilation feedback device. According to course instructors, all candidates acquired adequate ventilation competence. However, data from the feedback device indicated a ventilation not aligned with current guidelines, with higher tidal volume and lower rate (p < 0.01). Deploying quality ventilation during CPR is a skill whose acquisition starts with effective training. Therefore, course instructors' capability to accurately evaluate attendees' ventilation maneuvers is crucial.

Implementation of an Extubation Readiness Guideline for Preterm Infants.

BACKGROUND: Intubated preterm infants 32 6 / 7 weeks or less of gestation in a mid-Atlantic level IV neonatal intensive care unit (NICU) faced a high number of ventilator days. Based on 6 weeks of electronic health record (EHR) chart audits of extubations in this NICU in 2021, 44% of preterm infants 32 6 / 7 weeks or less of gestation were intubated for more than 28 days, with an average of 23 days on a ventilator. This NICU lacked a standardized extubation guideline providing criteria to drive extubation eligibility. PURPOSE: The purpose of this quality improvement (QI) project was to implement and evaluate the effectiveness of an extubation readiness guideline in preterm infants 32 6 / 7 weeks or less of gestation in a mid-Atlantic level IV NICU. METHODS: This project occurred over a 17-week period in 2021. Implementation included a multidisciplinary committee formation, identification of champions, NICU staff education, completion of a guideline checklist by bedside nursing (for eligible patients), clinician reminders, and chart audits for collection of pre-/postimplementation data. Staff education completion, guideline use and compliance, demographic patient data, ventilator days, time to first extubation, and need for reintubation were tracked. RESULTS: Postimplementation data indicated decreased need for intubation for more than 28 days, ventilator days, and days to first extubation attempt. IMPLICATIONS FOR PRACTICE AND RESEARCH: Results suggested that implementation of the evidence-based guideline was effective in decreasing average total ventilator days for preterm infants 32 6 / 7 weeks or less of gestation.

AARC Clinical Practice Guideline: Spontaneous Breathing Trials for Liberation From Adult Mechanical Ventilation.

Despite prior publications of clinical practice guidelines related to ventilator liberation, some questions remain unanswered. Many of these questions relate to the details of bedside implementation. We, therefore, formed a guidelines committee of individuals with experience and knowledge of ventilator liberation as well as a medical librarian. Using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, we make the following recommendations: (1) We suggest that calculation of a rapid shallow breathing index is not needed to determine readiness for a spontaneous breathing trial (SBT) (conditional recommendation; moderate certainty); (2) We suggest that SBTs can be conducted with or without pressure support ventilation (conditional recommendation, moderate certainty); (3) We suggest a standardized approach to assessment and, if appropriate, completion of an SBT before noon each day (conditional recommendation, very low certainty); and (4) We suggest that FIO2 should not be increased during an SBT (conditional recommendation, very low certainty). These recommendations are intended to assist bedside clinicians to liberate adult critically ill patients more rapidly from mechanical ventilation.

Implementing the Pediatric Ventilator Liberation Guidelines Using the Most Current Evidence.

Invasive mechanical ventilation is prevalent and associated with considerable morbidity. Pediatric critical care teams must identify the best timing and approach to liberating (extubating) children from this supportive care modality. Unsurprisingly, practice variation varies widely. As a first step to minimizing that variation, the first evidence-based pediatric ventilator liberation guidelines were published in 2023 and included 15 recommendations. Unfortunately, there is often a substantial delay before clinical guidelines reach widespread clinical practice. As such, it is important to consider barriers and facilitators using a systematic approach during implementation planning and design. In this narrative review, we will (1) summarize guideline recommendations, (2) discuss recent evidence and identify practice gaps relating to those recommendations, and (3) hypothesize about potential barriers and facilitators to their implementation in clinical practice.

Effect of body position on the redistribution of regional lung aeration during invasive and non-invasive ventilation of COVID-19 patients.

Severe COVID-19-related acute respiratory distress syndrome (C-ARDS) requires mechanical ventilation. While this intervention is often performed in the prone position to improve oxygenation, the underlying mechanisms responsible for the improvement in respiratory function during invasive ventilation and awake prone positioning in C-ARDS have not yet been elucidated. In this prospective observational trial, we evaluated the respiratory function of C-ARDS patients while in the supine and prone positions during invasive (n = 13) or non-invasive ventilation (n = 15). The primary endpoint was the positional change in lung regional aeration, assessed with electrical impedance tomography. Secondary endpoints included parameters of ventilation and oxygenation, volumetric capnography, respiratory system mechanics and intrapulmonary shunt fraction. In comparison to the supine position, the prone position significantly increased ventilation distribution in dorsal lung zones for patients under invasive ventilation (53.3 ± 18.3% vs. 43.8 ± 12.3%, percentage of dorsal lung aeration ± standard deviation in prone and supine positions, respectively; p = 0.014); whereas, regional aeration in both positions did not change during non-invasive ventilation (36.4 ± 11.4% vs. 33.7 ± 10.1%; p = 0.43). Prone positioning significantly improved the oxygenation both during invasive and non-invasive ventilation. For invasively ventilated patients reduced intrapulmonary shunt fraction, ventilation dead space and respiratory resistance were observed in the prone position. Oxygenation is improved during non-invasive and invasive ventilation with prone positioning in patients with C-ARDS. Different mechanisms may underly this benefit during these two ventilation modalities, driven by improved distribution of lung regional aeration, intrapulmonary shunt fraction and ventilation-perfusion matching. However, the differences in the severity of C-ARDS may have biased the sensitivity of electrical impedance tomography when comparing positional changes between the protocol groups.Trial registration: ClinicalTrials.gov (NCT04359407) and Registered 24 April 2020, https://clinicaltrials.gov/ct2/show/NCT04359407 .

Lung- and Diaphragm-Protective Ventilation by Titrating Inspiratory Support to Diaphragm Effort: A Randomized Clinical Trial.

OBJECTIVES: Lung- and diaphragm-protective ventilation is a novel concept that aims to limit the detrimental effects of mechanical ventilation on the diaphragm while remaining within limits of lung-protective ventilation. The premise is that low breathing effort under mechanical ventilation causes diaphragm atrophy, whereas excessive breathing effort induces diaphragm and lung injury. In a proof-of-concept study, we aimed to assess whether titration of inspiratory support based on diaphragm effort increases the time that patients have effort in a predefined "diaphragm-protective" range, without compromising lung-protective ventilation. DESIGN: Randomized clinical trial. SETTING: Mixed medical-surgical ICU in a tertiary academic hospital in the Netherlands. PATIENTS: Patients (n = 40) with respiratory failure ventilated in a partially-supported mode. INTERVENTIONS: In the intervention group, inspiratory support was titrated hourly to obtain transdiaphragmatic pressure swings in the predefined "diaphragm-protective" range (3-12 cm H2O). The control group received standard-of-care. MEASUREMENTS AND MAIN RESULTS: Transdiaphragmatic pressure, transpulmonary pressure, and tidal volume were monitored continuously for 24 hours in both groups. In the intervention group, more breaths were within "diaphragm-protective" range compared with the control group (median 81%; interquartile range [64-86%] vs 35% [16-60%], respectively; p < 0.001). Dynamic transpulmonary pressures (20.5 ± 7.1 vs 18.5 ± 7.0 cm H2O; p = 0.321) and tidal volumes (7.56 ± 1.47 vs 7.54 ± 1.22 mL/kg; p = 0.961) were not different in the intervention and control group, respectively. CONCLUSIONS: Titration of inspiratory support based on patient breathing effort greatly increased the time that patients had diaphragm effort in the predefined "diaphragm-protective" range without compromising tidal volumes and transpulmonary pressures. This study provides a strong rationale for further studies powered on patient-centered outcomes.

Mechanical ventilation in COVID-19: A physiological perspective.

NEW FINDINGS: What is the topic of this review? This review presents the fundamental concepts of respiratory physiology and pathophysiology, with particular reference to lung mechanics and the pulmonary phenotype associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and subsequent coronavirus disease 2019 (COVID-19) pneumonia. What advances does it highlight? The review provides a critical summary of the main physiological aspects to be considered for safe and effective mechanical ventilation in patients with severe COVID-19 in the intensive care unit. ABSTRACT: Severe respiratory failure from coronavirus disease 2019 (COVID-19) pneumonia not responding to non-invasive respiratory support requires mechanical ventilation. Although ventilation can be a life-saving therapy, it can cause further lung injury if airway pressure and flow and their timing are not tailored to the respiratory system mechanics of the individual patient. The pathophysiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to a pattern of lung injury in patients with severe COVID-19 pneumonia typically associated with two distinct phenotypes, along a temporal and pathophysiological continuum, characterized by different levels of elastance, ventilation-to-perfusion ratio, right-to-left shunt, lung weight and recruitability. Understanding the underlying pathophysiology, duration of symptoms, radiological characteristics and lung mechanics at the individual patient level is crucial for the appropriate choice of mechanical ventilation settings to optimize gas exchange and prevent further lung injury. By critical analysis of the literature, we propose fundamental physiological and mechanical criteria for the selection of ventilation settings for COVID-19 patients in intensive care units. In particular, the choice of tidal volume should be based on obtaining a driving pressure < 14 cmH2 O, ensuring the avoidance of hypoventilation in patients with preserved compliance and of excessive strain in patients with smaller lung volumes and lower lung compliance. The level of positive end-expiratory pressure (PEEP) should be informed by the measurement of the potential for lung recruitability, where patients with greater recruitability potential may benefit from higher PEEP levels. Prone positioning is often beneficial and should be considered early. The rationale for the proposed mechanical ventilation settings criteria is presented and discussed.

Implementation of a ventilator-associated pneumonia prevention bundle in a teaching hospital / Implementação de um bundle de prevenção de pneumonia associada à ventilação mecânica em um hospital universitário / Implementación de un paquete de prevención de neumonía asociada a ventilador en un hospital escuela

Background and objectives: the implementation of ventilator-associated pneumonia (VAP) prevention bundles in Intensive Care Units (ICU) has been recommended due to the considerable increase in hospital costs, length of stay, morbidity and mortality in affected hospitalized patients. However, the results of its effectiveness are still controversial. This study aimed to assess the impact of implementing a VAP prevention bundle in an Adult ICU of a university hospital. Methods: a quasi-experimental study, with implementation of a VAP prevention bundle in an Adult ICU and analysis of indicators. This study addressed secondary data from hospital records recommended in the routine of the Hospital Infection Control Commission team and from the medical records of patients undergoing mechanical ventilation, from June 2016 to July 2019, who developed VAP. Results: VAP incidence density before the intervention was 4.13 infections, and after the intervention, it was 7.15 infections per thousand patients on ventilation/day. When performing the linear regression test, we showed that VAP density decreased as sedation was reduced, extubation was increased, and when compliance with all bundle elements occurred. Conclusion: there was no reduction in VAP incidence after the adoption of preventive measures, perhaps due to an underreporting of cases in the period prior to the bundle and a low team compliance with the bundle components. However, we noticed a decrease in VAP notifications after the eighth month of implementation of bundle of measures.(AU)

Justificativa e objetivos: a implementação de bundles de prevenção de pneumonia associada à ventilação mecânica (PAV) em Unidades de Terapia Intensiva (UTI) tem sido recomendada devido ao aumento considerável dos custos hospitalares, tempo de internação, morbidade e mortalidade em pacientes hospitalizados acometidos. No entanto, os resultados de sua eficácia ainda são controversos. Este estudo teve como objetivo avaliar o impacto da implantação de um bundle de prevenção de PAV em uma UTI Adulto de um hospital universitário. Métodos: estudo quase experimental, com implantação de bundle de prevenção de PAV em UTI Adulto e análise de indicadores. Este estudo abordou dados secundários de prontuários hospitalares recomendados na rotina da equipe da Comissão de Controle de Infecção Hospitalar e dos prontuários de pacientes em ventilação mecânica, no período de junho de 2016 a julho de 2019, que desenvolveram PAV. Resultados: A densidade de incidência de PAV antes da intervenção foi de 4,13 infecções e após a intervenção foi de 7,15 infecções por mil pacientes em ventilação/dia. Ao realizar o teste de regressão linear, mostramos que a densidade da PAV diminuiu à medida que a sedação era reduzida, a extubação aumentava e quando ocorria complacência com todos os elementos do feixe. Conclusão: não houve redução da incidência de PAV após a adoção de medidas preventivas, talvez pela subnotificação de casos no período anterior ao bundle e baixa adesão da equipe aos componentes do bundle. No entanto, notamos diminuição das notificações de PAV após o oitavo mês de implantação do bundle de medidas.(AU)

Justificación y objetivos: la implementación de paquetes de prevención de neumonía asociada al ventilador (NAV) en las Unidades de Cuidados Intensivos (UCI) ha sido recomendada debido al aumento considerable de los costos hospitalarios, la estancia hospitalaria, la morbilidad y la mortalidad en los pacientes hospitalizados afectados. Sin embargo, los resultados de su eficacia aún son controvertidos. Este estudio tuvo como objetivo evaluar el impacto de la implementación de un paquete de prevención de NAVM en una UCI de adultos de un hospital universitario. Métodos: estudio cuasi-experimental, con implementación de un paquete de prevención de NAVM en una UCI de Adultos y análisis de indicadores. Este estudio abordó datos secundarios de registros hospitalarios recomendados en la rutina del equipo de la Comisión de Control de Infecciones Hospitalarias y de los registros médicos de pacientes en ventilación mecánica, de junio de 2016 a julio de 2019, que desarrollaron NAV. Resultados: La densidad de incidencia de NAVM antes de la intervención fue de 4,13 infecciones y después de la intervención fue de 7,15 infecciones por mil pacientes en ventilación/día. Al realizar la prueba de regresión lineal, mostramos que la densidad de VAP disminuyó a medida que se redujo la sedación, se incrementó la extubación y cuando se produjo el cumplimiento de todos los elementos del paquete. Conclusión: no hubo reducción en la incidencia de NAVM después de la adopción de las medidas preventivas, quizás debido a un subregistro de casos en el período anterior al paquete y al bajo cumplimiento del equipo con los componentes del paquete. Sin embargo, notamos una disminución en las notificaciones de VAP después del octavo mes de implementación del paquete de medidas.(Au)

Modos ventilatorios usados en pacientes críticos con covid-19 en la región de Lombardía, Italia / Ventilation modes used in critical patient with COVID-19 in the region of Lombardy, Italy

RESUMEN Introducción: la covid-19 es una enfermedad donde la ventilación mecánica artificial cobra vital importancia. Se estima que el 50 % de los casos graves o críticos que requieren manejo en unidades de cuidados intensivos fallecen. Objetivos: se evaluó el impacto de los modos ventilatorios usados en pacientes con covid-19 en Lombardía, Italia, en la oxigenación, la hemodinámica y la mortalidad. Materiales y métodos: se realizó un estudio analítico longitudinal retrospectivo en 86 pacientes críticos con covid-19, en el Hospital Mayor de Crema, en Lombardía, Italia, desde el 1 de abril al 20 de mayo de 2020. Se realizaron análisis no paramétrico y de la varianza. Resultados: Hubo una supervivencia del 76,7 %. El modo utilizado tuvo igual comportamiento en occisos (BiPAP-3, PCV-4, VCRP-4, APRV-5, VCV-4) y en vivos (BiPAP-10, PCV-17, VCRP-14, APRV-15, VCV-10); test de x2 = 0,59; test de análisis de la varianza media índice PO2/FIO2 (PCV = 132), (BiPAP = 132) (VCV = 115) p = 0,924. La presión de final de espiración positiva (BiPAP-12, PCV-13, VCRP-13, APRV-13, VCV-14) con p = 0,205. PCO2 (BiPAP-55, PCV-52, VCRP-57, APRV-59, VCV-57) con p = 0,512. La tensión arterial media (BiPAP-84, PCV-83, VCRP-84, APRV-82, VCV-83) con p = 0,988. Modelos de cálculo de la presión de final de espiración positiva, según modo ventilatorio: BiPAP: PEEP = -0,0331 (índice PO2/FiO2) +18,215; PCV: PEEP = -0,0047 (índice PO2/FiO2) +13,717; VCRP: PEEP = -0,0204 (índice PO2/FiO2) +15,678; APRV: PEEP = -0,0092 (índice PO2/FiO2) +14,889. Conclusiones: la evolución del paciente crítico con covid-19 está determinada en gran medida por la ventilación mecánica invasiva; sin embargo, no existió suficiente evidencia para recomendar una u otra modalidad ventilatoria. El éxito está en conocer con exactitud las características del respirador, su modalidad y el paciente en cuestión. (AU)

ABSTRACT Introduction: COVID-19 is a disease in which mechanical ventilation acquires vital importance. It is estimated that 50 % of the serious and critical patients requiring management in intensive care units die. Objectives: to assess the impact of the ventilation modes used in patients with COVID-19 in Lombardy, Italy, on oxygenation, hemodynamics and mortality. Materials and methods: a retrospective, longitudinal, analytic study was carried out in 86 critical patients with COVID-19 who entered the Main Hospital of Crema, in Lombardy, Italy, from April 1st to May 20, 2020. Results: the survival was 76.7 %. The used mode showed the same behavior in deceased patients (BiPAP-3, PCV-4, VCRP-4, APRV-5, VCV-4) and in alive patients (BiPAP-10, PCV-17, VCRP-14, APRV-15, VCV-10). X2 = 0.59. ANOVA test index PO2/FIO2 (PCV = 132), (BiPAP = 132) (VCV=115) p = 0.924. PEEP (BiPAP-12, PCV-13, VCRP-13, APRV-13, VCV-14) p = 0.205. PCO2 (BiPAP-55, PCV-52, VCRP-57, APRV-59, VCV-57) p = 0.512. Average blood pressure (BiPAP-84, PCV-83, VCRP-84, APRV-82, VCV-83) p = 0.988. PEEP models according to ventilation mode: BiPAP: PEEP = -0.0331 (PO2/FiO2 index) +18.215. PCV: PEEP = -0.0047 (PO2/FiO2 index) + 13.717; VCRP: PEEP = -0.0204 (PO2/FiO2 index) + 15.678; APRV: PEEP = -0.0092 (PO2/FiO2 index) +14.889. Conclusion: the evolution of the critical patient with COVID-19 is determined mostly by the invasive mechanical ventilation; but we did not find evidence enough to recommend one or the other ventilation mode. The success stands in knowing accurately the characteristics of the ventilator, the ventilation modes and the patient (AU).

COVID-19-associated acute respiratory distress syndrome (CARDS): Current knowledge on pathophysiology and ICU treatment - A narrative review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus-19 disease (COVID-19) and is a major health concern. Following two SARS-CoV-2 pandemic "waves," intensive care unit (ICU) specialists are treating a large number of COVID19-associated acute respiratory distress syndrome (ARDS) patients. From a pathophysiological perspective, prominent mechanisms of COVID19-associated ARDS (CARDS) include severe pulmonary infiltration/edema and inflammation leading to impaired alveolar homeostasis, alteration of pulmonary physiology resulting in pulmonary fibrosis, endothelial inflammation (endotheliitis), vascular thrombosis, and immune cell activation. Although the syndrome ARDS serves as an umbrella term, distinct, i.e., CARDS-specific pathomechanisms and comorbidities can be noted (e.g., virus-induced endotheliitis associated with thromboembolism) and some aspects of CARDS can be considered ARDS "atypical." Importantly, specific evidence-based medical interventions for CARDS (with the potential exception of corticosteroid use) are currently unavailable, limiting treatment efforts to mostly supportive ICU care. In this article, we will discuss the underlying pulmonary pathophysiology and the clinical management of CARDS. In addition, we will outline current and potential future treatment approaches.

Treatment of the lung injury of drowning: a systematic review.

BACKGROUND: Drowning is a cause of significant global mortality. The mechanism of injury involves inhalation of water, lung injury and hypoxia. This systematic review addressed the following question: In drowning patients with lung injury, what is the evidence from primary studies regarding treatment strategies and subsequent patient outcomes? METHODS: The search strategy utilised PRISMA guidelines. Databases searched were MEDLINE, EMBASE, CINAHL, Web of Science and SCOPUS. There were no restrictions on publication date or age of participants. Quality of evidence was evaluated using GRADE methodology. RESULTS: Forty-one papers were included. The quality of evidence was very low. Seventeen papers addressed the lung injury of drowning in their research question and 24 had less specific research questions, however included relevant outcome data. There were 21 studies regarding extra-corporeal life support, 14 papers covering the theme of ventilation strategies, 14 addressed antibiotic use, seven papers addressed steroid use and five studies investigating diuretic use. There were no clinical trials. One retrospective comparison of therapeutic strategies was found. There was insufficient evidence to make recommendations as to best practice when supplemental oxygen alone is insufficient. Mechanical ventilation is associated with barotrauma in drowning patients, but the evidence predates the practice of lung protective ventilation. There was insufficient evidence to make recommendations regarding adjuvant therapies. CONCLUSIONS: Treating the lung injury of drowning has a limited evidentiary basis. There is an urgent need for comparative studies of therapeutic strategies in drowning.

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.

Higher versus lower positive end-expiratory pressure in patients without acute respiratory distress syndrome: a meta-analysis of randomized controlled trials.

BACKGROUND: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the association of higher positive end-expiratory pressure (PEEP), as opposed to lower PEEP, with hospital mortality in adult intensive care unit (ICU) patients undergoing invasive mechanical ventilation for reasons other than acute respiratory distress syndrome (ARDS). METHODS: We performed an electronic search of MEDLINE, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, and Web of Science from inception until June 16, 2021 with no language restrictions. In addition, a research-in-progress database and grey literature were searched. RESULTS: We identified 22 RCTs (2225 patients) comparing higher PEEP (1007 patients) with lower PEEP (991 patients). No statistically significant association between higher PEEP and hospital mortality was observed (risk ratio 1.02, 95% confidence interval 0.89-1.16; I2 = 0%, p = 0.62; low certainty of evidence). Among secondary outcomes, higher PEEP was associated with better oxygenation, higher respiratory system compliance, and lower risk of hypoxemia and ARDS occurrence. Furthermore, barotrauma, hypotension, duration of ventilation, lengths of stay, and ICU mortality were similar between the two groups. CONCLUSIONS: In our meta-analysis of RCTs, higher PEEP, compared with lower PEEP, was not associated with mortality in patients without ARDS receiving invasive mechanical ventilation. Further large high-quality RCTs are required to confirm these findings.

Unmatched ventilation and perfusion measured by electrical impedance tomography predicts the outcome of ARDS.

BACKGROUND: In acute respiratory distress syndrome (ARDS), non-ventilated perfused regions coexist with non-perfused ventilated regions within lungs. The number of unmatched regions might reflect ARDS severity and affect the risk of ventilation-induced lung injury. Despite pathophysiological relevance, unmatched ventilation and perfusion are not routinely assessed at the bedside. The aims of this study were to quantify unmatched ventilation and perfusion at the bedside by electrical impedance tomography (EIT) investigating their association with mortality in patients with ARDS and to explore the effects of positive end-expiratory pressure (PEEP) on unmatched ventilation and perfusion in subgroups of patients with different ARDS severity based on PaO2/FiO2 and compliance. METHODS: Prospective observational study in 50 patients with mild (36%), moderate (46%), and severe (18%) ARDS under clinical ventilation settings. EIT was applied to measure the regional distribution of ventilation and perfusion using central venous bolus of saline 5% during end-inspiratory pause. We defined unmatched units as the percentage of only ventilated units plus the percentage of only perfused units. RESULTS: Percentage of unmatched units was significantly higher in non-survivors compared to survivors (32[27-47]% vs. 21[17-27]%, p < 0.001). Percentage of unmatched units was an independent predictor of mortality (OR 1.22, 95% CI 1.07-1.39, p = 0.004) with an area under the ROC curve of 0.88 (95% CI 0.79-0.97, p < 0.001). The percentage of ventilation to the ventral region of the lung was higher than the percentage of ventilation to the dorsal region (32 [27-38]% vs. 18 [13-21]%, p < 0.001), while the opposite was true for perfusion (28 [22-38]% vs. 36 [32-44]%, p < 0.001). Higher percentage of only perfused units was correlated with lower dorsal ventilation (r = - 0.486, p < 0.001) and with lower PaO2/FiO2 ratio (r = - 0.293, p = 0.039). CONCLUSIONS: EIT allows bedside assessment of unmatched ventilation and perfusion in mechanically ventilated patients with ARDS. Measurement of unmatched units could identify patients at higher risk of death and could guide personalized treatment.

Management of ARDS - What Works and What Does Not.

Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disorder associated with a variety of disease processes that lead to acute lung injury with increased non-hydrostatic extravascular lung water, reduced compliance, and severe hypoxemia. Despite significant advances, mortality associated with this syndrome remains high. Mechanical ventilation remains the most important aspect of managing patients with ARDS. An in-depth knowledge of lung protective ventilation, optimal PEEP strategies, modes of ventilation and recruitment maneuvers are essential for ventilatory management of ARDS. Although, the management of ARDS is constantly evolving as new studies are published and guidelines being updated; we present a detailed review of the literature including the most up-to-date studies and guidelines in the management of ARDS. We believe this review is particularly helpful in the current times where more than half of the acute care hospitals lack in-house intensivists and the burden of ARDS is at large.