Patterns of Use of Adjunctive Therapies in Patients With Early Moderate to Severe ARDS: Insights From the LUNG SAFE Study

Mortality Due to Acute Respiratory Distress Syndrome in Latin America

OBJECTIVES

Mortality due to acute respiratory distress syndrome (ARDS) is a major global health problem. Knowledge of epidemiological data on ARDS is crucial to design management, treatment strategies, and optimize resources. There is ample data regarding mortality of ARDS from high-income countries; in this review, we evaluated mortality due to ARDS in Latin America.

DATA SOURCES

We searched in PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Latin American and Caribbean Health Science Literature databases from 1967 to March 2023.

STUDY SELECTION

We searched prospective or retrospective observational studies and randomized controlled trials conducted in Latin American countries reporting ARDS mortality.

DATA EXTRACTION

Three pairs of independent reviewers checked all studies for eligibility based on their titles and abstracts. We performed meta-analysis of proportions using a random-effects model. We performed sensitivity analyses including studies with low risk of bias and with diagnosis using the Berlin definition. Subgroup analysis comparing different study designs, time of publication (up to 2000 and from 2001 to present), and studies in which the diagnosis of ARDS was made using Pa o2 /F io2 less than or equal to 200 and regional variations. Subsequently, we performed meta-regression analyses. Finally, we graded the certainty of the evidence (Grading of Recommendations Assessment, Development, and Evaluation).

DATA SYNTHESIS

Of 3315 articles identified, 32 were included (3627 patients). Mortality was 52% in the pooled group (low certainty of evidence). In the sensitivity analysis (according to the Berlin definition), mortality was 46% (moderate certainty of evidence). In the subgroup analysis mortality was 53% (randomized controlled trials), 51% (observational studies), 66% (studies published up to 2000), 50% (studies after 2000), 44% (studies with Pa o2 /F io2 ≤ 200), 56% (studies from Argentina/Brazil), and 40% (others countries). No variables were associated with mortality in the meta-regression.

CONCLUSIONS

ARDS mortality in Latin America remains high, as in other regions. These results should constitute the basis for action planning to improve the prognosis of patients with ARDS (PROSPERO [CRD42022354035]).

Potential Impact of Subphenotyping in Pharmacologic Management of Acute Respiratory Distress Syndrome

Background: Acute respiratory distress syndrome (ARDS) is an acute inflammatory process in the lungs associated with high morbidity and mortality. Previous research has studied both nonpharmacologic and pharmacologic interventions aimed at targeting this inflammatory process and improving ventilation. Hypothesis: To date, only nonpharmacologic interventions including lung protective ventilation, prone positioning, and high positive end-expiratory pressure ventilation strategies have resulted in significant improvements in patient outcomes. Given the high mortality associated with ARDS despite these advancements, interest in subphenotyping has grown, aiming to improve diagnosis and develop personalized treatment approaches. Data Collection: Previous trials evaluating pharmacologic therapies in heterogeneous populations have primarily demonstrated no positive effect, but hope to show benefit when targeting specific subphenotypes, thus increasing their efficacy, while simultaneously decreasing adverse effects. Results: Although most studies evaluating pharmacologic therapies for ARDS have not demonstrated a mortality benefit, there is limited data evaluating pharmacologic therapies in ARDS subphenotypes, which have found promising results. Neuromuscular blocking agents, corticosteroids, and simvastatin have resulted in a mortality benefit when used in patients with the hyper-inflammatory ARDS subphenotype. Therapeutic Opinion: The use of subphenotyping could revolutionize the way ARDS therapies are applied and therefore improve outcomes while also limiting the adverse effects associated with their ineffective use. Future studies should evaluate ARDS subphenotypes and their response to pharmacologic intervention to advance this area of precision medicine.

Prone-position decreases airway closure in a patient with ARDS undergoing venovenous extracorporeal membrane oxygenation

PURPOSE

Airway closure is a interruption of communication between larger and smaller airways. The presence of airway closure during mechanical ventilation may lead to the overestimation of driving pressure (DP), introducing errors in the assessment of respiratory mechanics and in positive end-expiratory pressure (PEEP) setting on the ventilator. Patients with severe acute respiratory distress syndrome (ARDS) may exhibit the airway closure phenomenon, which can be easily diagnosed with a low-flow inflation. Prone positioning is a therapeutic manoeuver proven to reduce mortality in ARDS patients, and has been widely implemented also in patients requiring veno-venous extracorporeal membrane oxygenation (V-V ECMO). To date, the impact of prone positioning on changes in airway closure has not been described.

METHODS

We present an image analysis of the pressure waveform during volume-controlled ventilation and low-flow inflations before and after prone positioning in an ARDS patient on VV ECMO.

RESULTS

A high airway opening pressure level (23 cmH2O) was detected in the supine position during tidal ventilation. Airway closure was confirmed by using a low-flow inflation. Prone positioning significantly attenuated airway closure, with the airway opening pressure decreasing to 13 cmH2O. After re-supination, airway closure was lower as compared with supine position at baseline (17 cmH2O).

CONCLUSION

Prone positioning reduced airway closure in an ARDS patient on VV ECMO support.

Changing clinical practice and prognosis for severe respiratory failure over time: A nationwide inpatient database study

BACKGROUND

Severe respiratory failure requires numerous interventions and its clinical implementation changes over time. We aimed to clarify the clinical practice and prognosis of severe respiratory failure and its changes over time.

METHODS

In a nationwide Japanese administrative database from 2016 to 2019, we identified nonoperative patients with severe respiratory failure without congestive heart failure as the main diagnosis who received mechanical ventilation (MV) for more than four days. We examined trends in patient characteristics, adjunctive interventions, and prognosis.

RESULTS

Among 66,905 patients included in this study, patients received antibiotics (90%), high-dose corticosteroids (14%), low-dose corticosteroids (18%), and 51% were admitted to the critical care unit. Hospital mortality was 35%. Median mechanical ventilation lasted 10 days. Tracheostomy occurred in 23% of cases. Median critical care and hospital stays were 10 and 25 days, respectively. Among survivors, 23% had mechanical ventilation dependency at hospital discharge. Large relative changes in adjunctive therapies included fentanyl (30%-38%), rocuronium (4.4%-6.7%), vasopressin (3.8%-6.0%), early rehabilitation (27%-38%), extracorporeal membrane oxygenation (0.7%-1.2%), dopamine (15%-10%), and sivelestat (8.6%-3.5%). No notable changes were seen in mechanical ventilation duration, tracheostomy, critical care unit stay, hospital stay, or ventilator dependency at discharge, except for a slight reduction in hospital mortality (36%-34%).

CONCLUSIONS

Several adjunctive therapies for severe respiratory failure changed from 2016 to 2019, with an increase in evidence-based practices and a slight decrease in hospital mortality.

Perfusion deficits may underlie lung and kidney injury in severe COVID-19 disease: insights from a multicenter international cohort study

BACKGROUND

Lung perfusion defects, mainly due to endothelial and coagulation activation, are a key contributor to COVID-19 respiratory failure. COVID-19 patients may also develop acute kidney injury (AKI) because of renal perfusion deficit. We aimed to explore AKI-associated factors and the independent prediction of standardized minute ventilation (MV)-a proxy of alveolar dead space-on AKI onset and persistence in COVID-19 mechanically ventilated patients.

METHODS

This is a multicenter observational cohort study. We enrolled 157 COVID-19 patients requiring mechanical ventilation and intensive care unit (ICU) admission. We collected clinical information, ventilation, and laboratory data. AKI was defined by the 2012 KDIGO guidelines and classified as transient or persistent according to serum creatinine criteria persistence within 48 h. Ordered univariate and multivariate logistic regression analyses were employed to identify variables associated with AKI onset and persistence.

RESULTS

Among 157 COVID-19 patients on mechanical ventilation, 47% developed AKI: 10% had transient AKI, and 37% had persistent AKI. The degree of hypoxia was not associated with differences in AKI severity. Across increasing severity of AKI groups, despite similar levels of paCO2, we observed an increased MV and standardized MV, a robust proxy of alveolar dead space. After adjusting for other clinical and laboratory covariates, standardized MV remained an independent predictor of AKI development and persistence. D-dimer levels were higher in patients with persistent AKI.

CONCLUSIONS

In critically ill COVID-19 patients with respiratory failure, increased wasted ventilation is independently associated with a greater risk of persistent AKI. These hypothesis-generating findings may suggest that perfusion derangements may link the pathophysiology of both wasted ventilation and acute kidney injury in our population.

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

Adjunctive Therapies in Acute Respiratory Distress Syndrome

Despite significant advances in understanding acute respiratory distress syndrome (ARDS), mortality rates remain high. The appropriate use of adjunctive therapies can improve outcomes, particularly for patients with moderate to severe hypoxia. In this review, the authors discuss the evidence basis behind prone positioning, recruitment maneuvers, neuromuscular blocking agents, corticosteroids, pulmonary vasodilators, and extracorporeal membrane oxygenation and considerations for their use in individual patients and specific clinical scenarios. Because the heterogeneity of ARDS poses challenges in finding universally effective treatments, an individualized approach and continued research efforts are crucial for optimizing the utilization of adjunctive therapies and improving patient outcomes.

An Update on Management of Adult Patients with Acute Respiratory Distress Syndrome: An Official American Thoracic Society Clinical Practice Guideline

Background: This document updates previously published Clinical Practice Guidelines for the management of patients with acute respiratory distress syndrome (ARDS), incorporating new evidence addressing the use of corticosteroids, venovenous extracorporeal membrane oxygenation, neuromuscular blocking agents, and positive end-expiratory pressure (PEEP). Methods: We summarized evidence addressing four "PICO questions" (patient, intervention, comparison, and outcome). A multidisciplinary panel with expertise in ARDS used the Grading of Recommendations, Assessment, Development, and Evaluation framework to develop clinical recommendations. Results: We suggest the use of: 1) corticosteroids for patients with ARDS (conditional recommendation, moderate certainty of evidence), 2) venovenous extracorporeal membrane oxygenation in selected patients with severe ARDS (conditional recommendation, low certainty of evidence), 3) neuromuscular blockers in patients with early severe ARDS (conditional recommendation, low certainty of evidence), and 4) higher PEEP without lung recruitment maneuvers as opposed to lower PEEP in patients with moderate to severe ARDS (conditional recommendation, low to moderate certainty), and 5) we recommend against using prolonged lung recruitment maneuvers in patients with moderate to severe ARDS (strong recommendation, moderate certainty). Conclusions: We provide updated evidence-based recommendations for the management of ARDS. Individual patient and illness characteristics should be factored into clinical decision making and implementation of these recommendations while additional evidence is generated from much-needed clinical trials.

Unraveling the protective mechanisms of Chuanfangyihao against acute lung injury: Insights from experimental validation

Chuanfangyihao (CFYH) is an effective treatment for acute lung injury (ALI) in clinical practice; however, its underlying mechanism of action remains unclear. Therefore, the aim of the present study was to elucidate the pharmacological mechanism of action of CFYH in ALI through experimental validation. First, a rat model of ALI was established using lipopolysaccharide (LPS). Next, the pathological changes in the lungs of the rats and the pathological damage were scored. The wet/dry weight ratios were measured, and ROS content was detected using flow cytometry. ELISA was used to examine IL-6, TNF-α, IL-1β, IL-18, and LDH levels. Immunohistochemistry was used to detect Beclin-1 and NLRP3 expression. Western blotting was performed to analyze the expression of HMGB1, RAGE, TLR4, NF-κB p65, AMPK, p-AMPK, mTOR, p-mTOR, Beclin-1, LC3-II/I, p62, Bcl-2, Bax, Caspase-3, Caspase-1, and GSDMD-NT. The mRNA levels of HMGB1, RAGE, AMPK, mTOR, and HIF-1α were determined using reverse transcription quantitative PCR. CFYH alleviated pulmonary edema and decreased the expression of IL-6, TNF-α, TLR4, NF-κB p65, HMGB1/RAGE, ROS, and HIF-1α. In addition, pretreatment with CFYH reversed ALI-induced programmed cell death. In conclusion, CFYH alleviates LPS-induced ALI, and these findings provide a preliminary clarification of the predominant mechanism of action of CFYH in ALI.

Clinical Applicability of Electrical Impedance Tomography in Patient-Tailored Ventilation: A Narrative Review

Electrical Impedance Tomography (EIT) is a non-invasive bedside imaging technique that provides real-time lung ventilation information on critically ill patients. EIT can potentially become a valuable tool for optimising mechanical ventilation, especially in patients with acute respiratory distress syndrome (ARDS). In addition, EIT has been shown to improve the understanding of ventilation distribution and lung aeration, which can help tailor ventilatory strategies according to patient needs. Evidence from critically ill patients shows that EIT can reduce the duration of mechanical ventilation and prevent lung injury due to overdistension or collapse. EIT can also identify the presence of lung collapse or recruitment during a recruitment manoeuvre, which may guide further therapy. Despite its potential benefits, EIT has not yet been widely used in clinical practice. This may, in part, be due to the challenges associated with its implementation, including the need for specialised equipment and trained personnel and further validation of its usefulness in clinical settings. Nevertheless, ongoing research focuses on improving mechanical ventilation and clinical outcomes in critically ill patients.

Adaptation and Uncertainty: A Qualitative Examination of Provider Experiences With Prone Positioning for Intubated Patients With COVID-19 ARDS

BACKGROUND

Prone positioning was widely adopted for use in patients with ARDS from COVID-19. However, proning was also delivered in ways that differed from historical evidence and practice. In implementation research, these changes are referred to as adaptations, and they occur constantly as evidence-based interventions are used in real-world practice. Adaptations can alter the delivered intervention, impacting patient and implementation outcomes.

RESEARCH QUESTION

How have clinicians adapted prone positioning to COVID-19 ARDS, and what uncertainties remain regarding optimal proning use?

STUDY DESIGN AND METHODS

We conducted a qualitative study using semi-structured interviews with ICU clinicians from two hospitals in Baltimore, MD, from February to July 2021. We interviewed physicians (MDs), registered nurses (RNs), respiratory therapists (RTs), advanced practice providers (APPs), and physical therapists (PTs) involved with proning mechanically ventilated patients with COVID-19 ARDS. We used thematic analysis of interviews to classify proning adaptations and clinician uncertainties about best practice for prone positioning.

RESULTS

Forty ICU clinicians (12 MDs, 4 APPs, 12 RNs, 7 RTs, and 5 PTs) were interviewed. Clinicians described several adaptations to the practice of prone positioning, including earlier proning initiation, extended duration of proning sessions, and less use of concomitant neuromuscular blockade. Clinicians expressed uncertainty regarding the optimal timing of initiation and duration of prone positioning. This uncertainty was viewed as a driver of practice variation. Although prescribers intended to use less deep sedation and paralysis in proned patients compared with historical evidence and practice, this raised concerns regarding patient comfort and safety amongst RNs and RTs.

INTERPRETATION

Prone positioning in patients with COVID-19 ARDS has been adapted from historically described practice. Understanding the impact of these adaptations on patient and implementation outcomes and addressing clinician uncertainties are priority areas for future research to optimize the use of prone positioning.

Inhaled Nitric Oxide in Acute Respiratory Distress Syndrome Subsets: Rationale and Clinical Applications

Acute respiratory distress syndrome (ARDS) is a life-threatening condition, characterized by diffuse inflammatory lung injury. Since the coronavirus disease 2019 (COVID-19) pandemic spread worldwide, the most common cause of ARDS has been the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Both the COVID-19-associated ARDS and the ARDS related to other causes-also defined as classical ARDS-are burdened by high mortality and morbidity. For these reasons, effective therapeutic interventions are urgently needed. Among them, inhaled nitric oxide (iNO) has been studied in patients with ARDS since 1993 and it is currently under investigation. In this review, we aim at describing the biological and pharmacological rationale of iNO treatment in ARDS by elucidating similarities and differences between classical and COVID-19 ARDS. Thereafter, we present the available evidence on the use of iNO in clinical practice in both types of respiratory failure. Overall, iNO seems a promising agent as it could improve the ventilation/perfusion mismatch, gas exchange impairment, and right ventricular failure, which are reported in ARDS. In addition, iNO may act as a viricidal agent and prevent lung hyperinflammation and thrombosis of the pulmonary vasculature in the specific setting of COVID-19 ARDS. However, the current evidence on the effects of iNO on outcomes is limited and clinical studies are yet to demonstrate any survival benefit by administering iNO in ARDS.

A Framework for Developing a Multidisciplinary Approach to Prone Positioning in Acute Respiratory Distress Syndrome

Prone position ventilation (PPV) is one of the few interventions with a proven mortality benefit in the management of acute respiratory distress syndrome (ARDS), yet it is underutilized as demonstrated by multiple large observational studies. Significant barriers to its consistent application have been identified and studied. But the complex interplay of a multidisciplinary team makes its consistent application challenging. We present a framework of multidisciplinary collaboration that identifies the appropriate patients for this intervention and discuss our institutional experience applying a multidisciplinary team to implement prone position (PP) leading up to and through the current COVID-19 pandemic. We also highlight the role of such multidisciplinary teams in the effective implementation of prone positioning in ARDS throughout a large health care system. We emphasize the importance of proper selection of patients and provide guidance on how a protocolized approach can be utilized for proper patient selection.

Comparison of 2 different inhaled epoprostenol dosing strategies for acute respiratory distress syndrome in critically ill adults: Weight-based vs fixed-dose administration

PURPOSE

Inhaled epoprostenol (iEPO) is a viable, temporizing option for acute respiratory distress syndrome (ARDS), although the optimal iEPO dosing strategy remains inconclusive. The purpose of this study was to evaluate oxygenation and ventilation parameters in a comparison of weight-based and fixed-dose iEPO in adult patients with moderate-to-severe ARDS.

METHODS

A retrospective cohort study was conducted at 2 academic medical centers in adult intensive care unit (ICU) patients administered either fixed-dose or weight-based iEPO for moderate-to-severe ARDS. The primary endpoint was the highest recorded change in the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) within 4 hours of baseline. Secondary analyses compared responder rates within 4 hours of initiation, oxygenation and ventilation parameters, in-hospital mortality rates, mechanical ventilation duration, length of stay (ICU and hospital), and tracheostomy rates between the study groups.

RESULTS

A total of 294 patients were included, n = 194 with 100 (34.0%) and 194 (66.0%) in the weight-based and fixed-dose iEPO groups, respectively. The mean (SD) change in the highest recorded PaO2/FiO2 value from baseline up to 4 hours after initiation in the fixed-dose and weight-based groups was 81.1 (106.0) and 41.0 (72.5) mm Hg, respectively (P = 0.0015). The responder rate at 4 hours after iEPO initiation was significantly higher in the fixed-dose group (69.9%) than in the weight-based group (30.1%) (P = 0.02). The only predictor of response was fixed-dose administration (odds ratio, 3.28; 95% confidence interval, 1.6-6.7; P = 0.0012). Clinical outcomes were comparable between the groups.

CONCLUSION

Fixed-dose iEPO was associated with significantly higher response rates then weight-based iEPO during the first 4 hours of therapy. Fixed-dose iEPO is a more convenient strategy than weight-based approaches.

Factors Influencing the Implementation of Prone Positioning during the COVID-19 Pandemic: A Qualitative Study

Rationale: The adoption of prone positioning for patients with acute respiratory distress syndrome (ARDS) has historically been poor. However, in mechanically ventilated patients with coronavirus disease (COVID-19) ARDS, proning has increased. Understanding the factors influencing this change is important for further expanding and sustaining the use of prone positioning in appropriate clinical settings. Objectives: To characterize factors influencing the implementation of prone positioning in mechanically ventilated patients with COVID-19 ARDS. Methods: We conducted a qualitative study using semistructured interviews with 40 intensive care unit (ICU) team members (physicians, nurses, advanced practice providers, respiratory therapists, and physical therapists) working at two academic hospitals. We used the Consolidated Framework for Implementation Research, a widely used implementation science framework outlining important features of implementation, to structure the interview guide and thematic analysis of interviews. Results: ICU clinicians reported that during the COVID-19 pandemic, proning was viewed as standard early therapy for COVID-19 ARDS rather than salvage therapy for refractory hypoxemia. By caring for large volumes of proned patients, clinicians gained increased comfort with proning and now view proning as a low-risk, high-benefit intervention. Within ICUs, adequate numbers of trained staff members, increased team agreement around proning, and the availability of specific equipment (e.g., to limit pressure injuries) facilitated greater proning use. Hospital-level supports included proning teams, centralized educational resources specific to the management of COVID-19 (including a recommendation for prone positioning), and an electronic medical record proning order. Important implementation processes included informal dissemination of best practices through on-the-job learning and team interactions during routine bedside care. Conclusions: The implementation of prone positioning for COVID-19 ARDS took place in the context of evolving clinician viewpoints and ICU team cultures. Proning was facilitated by hospital support and buy-in and leadership from bedside clinicians. The successful implementation of prone positioning during the COVID-19 pandemic may serve as a model for the implementation of other evidence-based therapies in critical care.

Timing of Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome

OBJECTIVES

To assess the association of timing to prone positioning (PP) during venovenous extracorporeal membrane oxygenation (V-V ECMO) with the probability of being discharged alive from the ICU at 90 days (primary endpoint) and the improvement of the respiratory system compliance (Cpl,rs).

DESIGN

Pooled individual data analysis from five original observational cohort studies.

SETTING

European extracorporeal membrane oxygenation (ECMO) centers.

PATIENTS

Acute respiratory distress syndrome (ARDS) patients who underwent PP during ECMO.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Time to PP during V-V ECMO was explored both as a continuous and a categorical variable with Cox proportional hazard models. Three hundred patients were included in the analysis. The longer the time to PP during V-V ECMO, the lower the adjusted probability of alive ICU discharge (adjusted hazard ratio [HR] 0.90 for each day increase; 95% CI, 0.87-0.93). Two hundred twenty-three and 77 patients were included in the early PP (≤ 5 d) and late PP (> 5 d) groups, respectively. The cumulative 90-day probability of being discharged alive from the ICU was 61% in the early PP group vs 36% in the late PP group (log-rank test, p <0.001). This benefit was maintained after adjustment for confounders (adjusted HR, 2.52; 95% CI, 1.66-3.81; p <0.001). In the early PP group, PP was associated with a significant improvement of Cpl,rs (4 ± 9 mL/cm H2O vs 0 ± 12 in the late PP group, p=0.038).

CONCLUSIONS

In a large cohort of ARDS patients on ECMO, early PP during ECMO was associated with a higher probability of being discharged alive from the ICU at 90 days and a greater improvement of Cpl,rs.

The PROVENT-C19 registry: A study protocol for international multicenter SIAARTI registry on the use of prone positioning in mechanically ventilated patients with COVID-19 ARDS

BACKGROUND

The worldwide use of prone position (PP) for invasively ventilated patients with COVID-19 is progressively increasing from the first pandemic wave in everyday clinical practice. Among the suggested treatments for the management of ARDS patients, PP was recommended in the Surviving Sepsis Campaign COVID-19 guidelines as an adjuvant therapy for improving ventilation. In patients with severe classical ARDS, some authors reported that early application of prolonged PP sessions significantly decreases 28-day and 90-day mortality.

METHODS AND ANALYSIS

Since January 2021, the COVID19 Veneto ICU Network research group has developed and implemented nationally and internationally the "PROVENT-C19 Registry", endorsed by the Italian Society of Anesthesia Analgesia Resuscitation and Intensive Care…'(SIAARTI). The PROVENT-C19 Registry wishes to describe 1. The real clinical practice on the use of PP in COVID-19 patients during the pandemic at a National and International level; and 2. Potential baseline and clinical characteristics that identify subpopulations of invasively ventilated patients with COVID-19 that may improve daily from PP therapy. This web-based registry will provide relevant information on how the database research tools may improve our daily clinical practice.

CONCLUSIONS

This multicenter, prospective registry is the first to identify and characterize the role of PP on clinical outcome in COVID-19 patients. In recent years, data emerging from large registries have been increasingly used to provide real-world evidence on the effectiveness, quality, and safety of a clinical intervention. Indeed observation-based registries could be effective tools aimed at identifying specific clusters of patients within a large study population with widely heterogeneous clinical characteristics.

TRIAL REGISTRATION

The registry was registered (ClinicalTrial.Gov Trials Register NCT04905875) on May 28,2021.

Effect of prone positioning on end-expiratory lung volume, strain and oxygenation change over time in COVID-19 acute respiratory distress syndrome: A prospective physiological study

BACKGROUND

Prone position (PP) is a recommended intervention in severe classical acute respiratory distress syndrome (ARDS). Changes in lung resting volume, respiratory mechanics and gas exchange during a 16-h cycle of PP in COVID-19 ARDS has not been yet elucidated.

METHODS

Patients with severe COVID-19 ARDS were enrolled between May and September 2021 in a prospective cohort study in a University Teaching Hospital. Lung resting volume was quantitatively assessed by multiple breath nitrogen wash-in/wash-out technique to measure the end-expiratory lung volume (EELV). Timepoints included the following: Baseline, Supine Position (S1); start of PP (P0), and every 4-h (P4; P8; P12) until the end of PP (P16); and Supine Position (S2). Respiratory mechanics and gas exchange were assessed at each timepoint.

MEASUREMENTS AND MAIN RESULTS

40 mechanically ventilated patients were included. EELV/predicted body weight (PBW) increased significantly over time. The highest increase was observed at P4. The highest absolute EELV/PBW values were observed at the end of the PP (P16 vs S1; median 33.5 ml/kg [InterQuartileRange, 28.2-38.7] vs 23.4 ml/kg [18.5-26.4], p < 0.001). Strain decreased immediately after PP and remained stable between P4 and P16. PaO2/FiO2 increased during PP reaching the highest level at P12 (P12 vs S1; 163 [138-217] vs 81 [65-97], p < 0.001). EELV/PBW, strain and PaO2/FiO2 decreased at S2 although EELV/PBW and PaO2/FiO2 were still significantly higher as compared to S1. Both absolute values over time and changes of strain and PaO2/FiO2 at P16 and S2 versus S1 were strongly associated with EELV/PBW levels.

CONCLUSION

In severe COVID-19 ARDS, EELV steadily increased over a 16-h cycle of PP peaking at P16. Strain gradually decreased, and oxygenation improved over time. Changes in strain and oxygenation at the end of PP and back to SP were strongly associated with changes in EELV/PBW. Whether the change in EELV and oxygenation during PP may play a role on outcomes in COVID-ARDS deserves further investigation.

CLINICAL TRIAL REGISTRATION

[www.ClinicalTrials.gov], identifier [NCT04818164].

Inhaled nitric oxide: role in the pathophysiology of cardio-cerebrovascular and respiratory diseases

Nitric oxide (NO) is a key molecule in the biology of human life. NO is involved in the physiology of organ viability and in the pathophysiology of organ dysfunction, respectively. In this narrative review, we aimed at elucidating the mechanisms behind the role of NO in the respiratory and cardio-cerebrovascular systems, in the presence of a healthy or dysfunctional endothelium. NO is a key player in maintaining multiorgan viability with adequate organ blood perfusion. We report on its physiological endogenous production and effects in the circulation and within the lungs, as well as the pathophysiological implication of its disturbances related to NO depletion and excess. The review covers from preclinical information about endogenous NO produced by nitric oxide synthase (NOS) to the potential therapeutic role of exogenous NO (inhaled nitric oxide, iNO). Moreover, the importance of NO in several clinical conditions in critically ill patients such as hypoxemia, pulmonary hypertension, hemolysis, cerebrovascular events and ischemia-reperfusion syndrome is evaluated in preclinical and clinical settings. Accordingly, the mechanism behind the beneficial iNO treatment in hypoxemia and pulmonary hypertension is investigated. Furthermore, investigating the pathophysiology of brain injury, cardiopulmonary bypass, and red blood cell and artificial hemoglobin transfusion provides a focus on the potential role of NO as a protective molecule in multiorgan dysfunction. Finally, the preclinical toxicology of iNO and the antimicrobial role of NO-including its recent investigation on its role against the Sars-CoV2 infection during the COVID-19 pandemic-are described.

Presence of comorbidities alters management and worsens outcome of patients with acute respiratory distress syndrome: insights from the LUNG SAFE study

Background

The impact of underlying comorbidities on the clinical presentation, management and outcomes in patients with ARDS is poorly understood and deserves further investigation.

Objectives

We examined these issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study.

Methods

In this secondary analysis of the patient cohort enrolled in the LUNG SAFE study, our primary objective was to determine the frequency, and impact of comorbidities on the management and ICU survival of patients with ARDS. Secondary outcomes relating to comorbidities included their impact on ventilatory management, the development of organ failures, and on end-of-life care.

Results

Of 2813 patients in the study population, 1692 (60%) had 1 or more comorbidities, of whom 631 (22.4%) had chronic respiratory impairment, 290 (10.3%) had congestive heart failure, 286 (10.2%) had chronic renal failure, 112 (4%) had chronic liver failure, 584 (20.8%) had immune incompetence, and 613 (21.8%) had diabetes. Multiple comorbidities were frequently present, with 423 (25%) having 2 and 182 (11%) having at least 3 or more comorbidities. The use of invasive ventilation (1379 versus 998, 82 versus 89%), neuromuscular blockade (301 versus 249, 18 versus 22%), prone positioning (97 versus 104, 6 versus 9%) and ECMO (32 versus 46, 2 versus 4%) were each significantly reduced in patients with comorbidities as compared to patients with no comorbidity (1692 versus 1121, 60 versus 40%). ICU mortality increased from 27% (n = 303) in patients with no comorbidity to 39% (n = 661) in patients with any comorbidity. Congestive heart failure, chronic liver failure and immune incompetence were each independently associated with increased ICU mortality. Chronic liver failure and immune incompetence were independently associated with more decisions to limitation of life supporting measures.

Conclusions

Most patients with ARDS have significant comorbidities, they receive less aggressive care, and have worse outcomes. Enhancing the care of these patients must be a priority for future clinical studies.

Trial registration LUNG-SAFE is registered with ClinicalTrials.gov, number NCT02010073.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01015-7.

Comparing Prone Positioning Use in COVID-19 Versus Historic Acute Respiratory Distress Syndrome

Use of prone positioning in patients with acute respiratory distress syndrome (ARDS) from COVID-19 may be greater than in patients treated for ARDS before the pandemic. However, the magnitude of this increase, sources of practice variation, and the extent to which use adheres to guidelines is unknown.

Incidence and Practice of Early Prone Positioning in Invasively Ventilated COVID-19 Patients-Insights from the PRoVENT-COVID Observational Study

We describe the incidence and practice of prone positioning and determined the association of use of prone positioning with outcomes in invasively ventilated patients with acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19) in a national, multicenter observational study, performed at 22 intensive care units in the Netherlands. Patients were categorized into 4 groups, based on indication for and actual use of prone positioning. The primary outcome was 28-day mortality. Secondary endpoints were 90-day mortality, and ICU and hospital length of stay. In 734 patients, prone positioning was indicated in 60%-the incidence of prone positioning was higher in patients with an indication than in patients without an indication for prone positioning (77 vs. 48%, p = 0.001). Patients were left in the prone position for median 15.0 (10.5-21.0) hours per full calendar day-the duration was longer in patients with an indication than in patients without an indication for prone positioning (16.0 (11.0-23.0) vs. 14.0 (10.0-19.0) hours, p < 0.001). Ventilator settings and ventilation parameters were not different between the four groups, except for FiO₂ which was higher in patients having an indication for and actually receiving prone positioning. Our data showed no difference in mortality at day 28 between the 4 groups (HR no indication, no prone vs. no indication, prone vs. indication, no prone vs. indication, prone: 1.05 (0.76-1.45) vs. 0.88 (0.62-1.26) vs. 1.15 (0.80-1.54) vs. 0.96 (0.73-1.26) (p = 0.08)). Factors associated with the use of prone positioning were ARDS severity and FiO₂. The findings of this study are that prone positioning is often used in COVID-19 patients, even in patients that have no indication for this intervention. Sessions of prone positioning lasted long. Use of prone positioning may affect outcomes.

Variation in Early Management Practices in Moderate-to-Severe ARDS in the United States: The Severe ARDS: Generating Evidence Study

BACKGROUND

Although specific interventions previously demonstrated benefit in patients with ARDS, use of these interventions is inconsistent, and patient mortality remains high. The impact of variability in center management practices on ARDS mortality rates remains unknown.

RESEARCH QUESTION

What is the impact of treatment variability on mortality in patients with moderate to severe ARDS in the United States?

STUDY DESIGN AND METHODS

We conducted a multicenter, observational cohort study of mechanically ventilated adults with ARDS and Pao2 to Fio2 ratio of ≤ 150 with positive end-expiratory pressure of ≥ 5 cm H2O, who were admitted to 29 US centers between October 1, 2016, and April 30, 2017. The primary outcome was 28-day in-hospital mortality. Center variation in ventilator management, adjunctive therapy use, and mortality also were assessed.

RESULTS

A total of 2,466 patients were enrolled. Median baseline Pao2 to Fio2 ratio was 105 (interquartile range, 78.0-129.0). In-hospital 28-day mortality was 40.7%. Initial adherence to lung protective ventilation (LPV; tidal volume, ≤ 6.5 mL/kg predicted body weight; plateau pressure, or when unavailable, peak inspiratory pressure, ≤ 30 mm H2O) was 31.4% and varied between centers (0%-65%), as did rates of adjunctive therapy use (27.1%-96.4%), methods used (neuromuscular blockade, prone positioning, systemic steroids, pulmonary vasodilators, and extracorporeal support), and mortality (16.7%-73.3%). Center standardized mortality ratios (SMRs), calculated using baseline patient-level characteristics to derive expected mortality rate, ranged from 0.33 to 1.98. Of the treatment-level factors explored, only center adherence to early LPV was correlated with SMR.

INTERPRETATION

Substantial center-to-center variability exists in ARDS management, suggesting that further opportunities for improving ARDS outcomes exist. Early adherence to LPV was associated with lower center mortality and may be a surrogate for overall quality of care processes. Future collaboration is needed to identify additional treatment-level factors influencing center-level outcomes.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03021824; URL: www.clinicaltrials.gov.

Natural history, trajectory, and management of mechanically ventilated COVID-19 patients in the United Kingdom

PURPOSE

The trajectory of mechanically ventilated patients with coronavirus disease 2019 (COVID-19) is essential for clinical decisions, yet the focus so far has been on admission characteristics without consideration of the dynamic course of the disease in the context of applied therapeutic interventions.

METHODS

We included adult patients undergoing invasive mechanical ventilation (IMV) within 48 h of intensive care unit (ICU) admission with complete clinical data until ICU death or discharge. We examined the importance of factors associated with disease progression over the first week, implementation and responsiveness to interventions used in acute respiratory distress syndrome (ARDS), and ICU outcome. We used machine learning (ML) and Explainable Artificial Intelligence (XAI) methods to characterise the evolution of clinical parameters and our ICU data visualisation tool is available as a web-based widget ( https://www.CovidUK.ICU ).

RESULTS

Data for 633 adults with COVID-19 who underwent IMV between 01 March 2020 and 31 August 2020 were analysed. Overall mortality was 43.3% and highest with non-resolution of hypoxaemia [60.4% vs17.6%; P < 0.001; median PaO2/FiO2 on the day of death was 12.3(8.9-18.4) kPa] and non-response to proning (69.5% vs.31.1%; P < 0.001). Two ML models using weeklong data demonstrated an increased predictive accuracy for mortality compared to admission data (74.5% and 76.3% vs 60%, respectively). XAI models highlighted the increasing importance, over the first week, of PaO2/FiO2 in predicting mortality. Prone positioning improved oxygenation only in 45% of patients. A higher peak pressure (OR 1.42[1.06-1.91]; P < 0.05), raised respiratory component (OR 1.71[ 1.17-2.5]; P < 0.01) and cardiovascular component (OR 1.36 [1.04-1.75]; P < 0.05) of the sequential organ failure assessment (SOFA) score and raised lactate (OR 1.33 [0.99-1.79]; P = 0.057) immediately prior to application of prone positioning were associated with lack of oxygenation response. Prone positioning was not applied to 76% of patients with moderate hypoxemia and 45% of those with severe hypoxemia and patients who died without receiving proning interventions had more missed opportunities for prone intervention [7 (3-15.5) versus 2 (0-6); P < 0.001]. Despite the severity of gas exchange deficit, most patients received lung-protective ventilation with tidal volumes less than 8 mL/kg and plateau pressures less than 30cmH2O. This was despite systematic errors in measurement of height and derived ideal body weight.

CONCLUSIONS

Refractory hypoxaemia remains a major association with mortality, yet evidence based ARDS interventions, in particular prone positioning, were not implemented and had delayed application with an associated reduced responsiveness. Real-time service evaluation techniques offer opportunities to assess the delivery of care and improve protocolised implementation of evidence-based ARDS interventions, which might be associated with improvements in survival.

Prone position in intubated, mechanically ventilated patients with COVID-19: a multi-centric study of more than 1000 patients

Background

Limited data are available on the use of prone position in intubated, invasively ventilated patients with Coronavirus disease-19 (COVID-19). Aim of this study is to investigate the use and effect of prone position in this population during the first 2020 pandemic wave.

Methods

Retrospective, multicentre, national cohort study conducted between February 24 and June 14, 2020, in 24 Italian Intensive Care Units (ICU) on adult patients needing invasive mechanical ventilation for respiratory failure caused by COVID-19. Clinical data were collected on the day of ICU admission. Information regarding the use of prone position was collected daily. Follow-up for patient outcomes was performed on July 15, 2020. The respiratory effects of the first prone position were studied in a subset of 78 patients. Patients were classified as Oxygen Responders if the PaO₂/FiO₂ ratio increased ≥ 20 mmHg during prone position and as Carbon Dioxide Responders if the ventilatory ratio was reduced during prone position.

Results

Of 1057 included patients, mild, moderate and severe ARDS was present in 15, 50 and 35% of patients, respectively, and had a resulting mortality of 25, 33 and 41%. Prone position was applied in 61% of the patients. Patients placed prone had a more severe disease and died significantly more (45% vs. 33%, p < 0.001). Overall, prone position induced a significant increase in PaO₂/FiO₂ ratio, while no change in respiratory system compliance or ventilatory ratio was observed. Seventy-eight % of the subset of 78 patients were Oxygen Responders. Non-Responders had a more severe respiratory failure and died more often in the ICU (65% vs. 38%, p = 0.047). Forty-seven % of patients were defined as Carbon Dioxide Responders. These patients were older and had more comorbidities; however, no difference in terms of ICU mortality was observed (51% vs. 37%, p = 0.189 for Carbon Dioxide Responders and Non-Responders, respectively).

Conclusions

During the COVID-19 pandemic, prone position has been widely adopted to treat mechanically ventilated patients with respiratory failure. The majority of patients improved their oxygenation during prone position, most likely due to a better ventilation perfusion matching.

Trial registration: clinicaltrials.gov number: NCT04388670

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03552-2.

A Case-Control Study of Prone Positioning in Awake and Nonintubated Hospitalized Coronavirus Disease 2019 Patients

Supplemental Digital Content is available in the text.

To determine the association between prone positioning in nonintubated patients with coronavirus disease 2019 and frequency of invasive mechanical ventilation or inhospital mortality.

Enteral Nutrition Safety With Advanced Treatments: Extracorporeal Membrane Oxygenation, Prone Positioning, and Infusion of Neuromuscular Blockers

This review aims at assessing the safety and efficacy of enteral nutrition in critically ill patients receiving extracorporeal membrane oxygenation, prone positioning, and infusion of neuromuscular blockers. Existing data from randomized controlled trials demonstrate the survival benefit of early enteral nutrition in critically ill patients. Observational data have demonstrated that enteral nutrition in patients receiving extracorporeal membrane oxygenation, prone positioning, and infusion of neuromuscular blockers is generally safe. However, these patients are at increased risk for gastrointestinal complications from enteral nutrition because of critical illness-induced gastrointestinal dysfunction; associated shock; the concomitant use of vasopressor agents, sedatives, and narcotics; possibly mesenteric circulatory compromise; and regurgitation associated with prone positioning. Therefore, early enteral nutrition is generally recommended in these patients in the absence of severe gastrointestinal dysfunction or shock. To reduce the complications, early nutrition should be advanced gradually (trophic feeding or permissive underfeeding), the bed should be tilted to a maximum of 30°, and concentrated nutritional formulae and the use of prokinetics may be considered to treat enteral feeding intolerance. Physicians should be vigilant about monitoring for early signs of acute mesenteric ischemia, which should lead to holding enteral feeding. Parenteral nutrition may be utilized in patients who cannot receive enteral nutrition or are unable to reach their nutrition goals by the end of the first week.

Identification of a Circulating miRNA Signature to Stratify Acute Respiratory Distress Syndrome Patients

There is a need to improve acute respiratory distress syndrome (ARDS) diagnosis and management, particularly with extracorporeal membrane oxygenation (ECMO), and different biomarkers have been tested to implement a precision-focused approach. We included ARDS patients on veno-venous (V-V) ECMO in a prospective observational pilot study. Blood samples were obtained before cannulation, and screened for the expression of 754 circulating microRNA (miRNAs) using high-throughput qPCR and hierarchical cluster analysis. The miRNet database was used to predict target genes of deregulated miRNAs, and the DIANA tool was used to identify significant enrichment pathways. A hierarchical cluster of 229 miRNAs (identified after quality control screening) produced a clear separation of 11 patients into two groups: considering the baseline SAPS II, SOFA, and RESP score cluster A (n = 6) showed higher severity compared to cluster B (n = 5); p values < 0.05. After analysis of differentially expressed miRNAs between the two clusters, 95 deregulated miRNAs were identified, and reduced to 13 by in silico analysis. These miRNAs target genes implicated in tissue remodeling, immune system, and blood coagulation pathways. The blood levels of 13 miRNAs are altered in severe ARDS. Further investigations will have to match miRNA results with inflammatory biomarkers and clinical data.

Obesity and smoking as risk factors for invasive mechanical ventilation in COVID-19: A retrospective, observational cohort study

PURPOSE

To describe the trajectory of respiratory failure in COVID-19 and explore factors associated with risk of invasive mechanical ventilation (IMV).

MATERIALS AND METHODS

A retrospective, observational cohort study of 112 inpatient adults diagnosed with COVID-19 between March 12 and April 16, 2020. Data were manually extracted from electronic medical records. Multivariable and Univariable regression were used to evaluate association between baseline characteristics, initial serum markers and the outcome of IMV.

RESULTS

Our cohort had median age of 61 (IQR 45-74) and was 66% male. In-hospital mortality was 6% (7/112). ICU mortality was 12.8% (6/47), and 18% (5/28) for those requiring IMV. Obesity (OR 5.82, CI 1.74-19.48), former (OR 8.06, CI 1.51-43.06) and current smoking status (OR 10.33, CI 1.43-74.67) were associated with IMV after adjusting for age, sex, and high prevalence comorbidities by multivariable analysis. Initial absolute lymphocyte count (OR 0.33, CI 0.11-0.96), procalcitonin (OR 1.27, CI 1.02-1.57), IL-6 (OR 1.17, CI 1.03-1.33), ferritin (OR 1.05, CI 1.005-1.11), LDH (OR 1.57, 95% CI 1.13-2.17) and CRP (OR 1.13, CI 1.06-1.21), were associated with IMV by univariate analysis.

CONCLUSIONS

Obesity, smoking history, and elevated inflammatory markers were associated with increased need for IMV in patients with COVID-19.

Obesity and Smoking as Risk Factors for Invasive Mechanical Ventilation in COVID-19: a Retrospective, Observational Cohort Study

Purpose:

To describe the trajectory of respiratory failure in COVID-19 and explore factors associated with risk of invasive mechanical ventilation (IMV).

Materials and Methods:

A retrospective, observational cohort study of 112 inpatient adults diagnosed with COVID-19 between March 12 and April 16, 2020. Data were manually extracted from electronic medical records. Multivariable and Univariable regression were used to evaluate association between baseline characteristics, initial serum markers and the outcome of IMV.

Results:

Our cohort had median age of 61 (IQR 45–74) and was 66% male. In-hospital mortality was 6% (7/112). ICU mortality was 12.8% (6/47), and 18% (5/28) for those requiring IMV. Obesity (OR 5.82, CI 1.74–19.48), former (OR 8.06, CI 1.51–43.06) and current smoking status (OR 10.33, CI 1.43–74.67) were associated with IMV after adjusting for age, sex, and high prevalence comorbidities by multivariable analysis. Initial absolute lymphocyte count (OR 0.33, CI 0.11–0.96), procalcitonin (OR 1.27, CI 1.02–1.57), IL-6 (OR 1.17, CI 1.03–1.33), ferritin (OR 1.05, CI 1.005–1.11), LDH (OR 1.57, 95% CI 1.13–2.17) and CRP (OR 1.13, CI 1.06–1.21), were associated with IMV by univariate analysis.

Conclusions:

Obesity, smoking history, and elevated inflammatory markers were associated with increased need for IMV in patients with COVID-19.