Protective ventilation and outcomes of critically ill patients with COVID-19: a cohort study

Epidemiology, Ventilation Management, and Outcomes in Invasively Ventilated Coronavirus Disease 2019 Patients: An Analysis of Four Observational Studies in Four Countries on Two Continents

Epidemiology, ventilator management, and outcomes in patients with acute respiratory distress syndrome (ARDS) because of coronavirus disease 2019 (COVID-19) have been described extensively but have never been compared between countries. We performed an individual patient data analysis of four observational studies to compare epidemiology, ventilator management, and outcomes. We used propensity score weighting to control for confounding factors. The analysis included 6,702 patients: 1,500 from Argentina, 844 from Brazil, 975 from the Netherlands, and 3,383 from Spain. There were substantial differences in baseline characteristics between countries. There were small differences in ventilation management. Intensive care unit mortality was higher in Argentina and Brazil compared with the Netherlands and Spain (59.6% and 56.6% versus 32.1% and 34.7%; P <0.001). The median number of days free from ventilation and alive at day 28 was equally low (0 [0-7], 0 [0-18], 1 [0-16], and 0 [0-16] days, respectively; P = 0.03), and the median number of days free from ventilation and alive at day 60 was higher in the Netherlands and Spain (0 [0-37], 0 [0-50], 33 [0-48], and 26 [0-48] days, respectively; P <0.001). Propensity score matching confirmed the outcome differences. Thus, the outcome of COVID-19 ARDS patients in Argentina and Brazil was substantially worse compared with that of patients in the Netherlands and Spain. It is unlikely that this results from differences in case mix or ventilation management.

Epidemiology, ventilation management and outcomes of COVID-19 ARDS patients versus patients with ARDS due to pneumonia in the Pre-COVID era

BACKGROUND

Ventilation management may differ between COVID-19 ARDS (COVID-ARDS) patients and patients with pre-COVID ARDS (CLASSIC-ARDS); it is uncertain whether associations of ventilation management with outcomes for CLASSIC-ARDS also exist in COVID-ARDS.

METHODS

Individual patient data analysis of COVID-ARDS and CLASSIC-ARDS patients in six observational studies of ventilation, four in the COVID-19 pandemic and two pre-pandemic. Descriptive statistics were used to compare epidemiology and ventilation characteristics. The primary endpoint were key ventilation parameters; other outcomes included mortality and ventilator-free days and alive (VFD-60) at day 60.

RESULTS

This analysis included 6702 COVID-ARDS patients and 1415 CLASSIC-ARDS patients. COVID-ARDS patients received lower median VT (6.6 [6.0 to 7.4] vs 7.3 [6.4 to 8.5] ml/kg PBW; p < 0.001) and higher median PEEP (12.0 [10.0 to 14.0] vs 8.0 [6.0 to 10.0] cm H2O; p < 0.001), at lower median ΔP (13.0 [10.0 to 15.0] vs 16.0 [IQR 12.0 to 20.0] cm H2O; p < 0.001) and higher median Crs (33.5 [26.6 to 42.1] vs 28.1 [21.6 to 38.4] mL/cm H2O; p < 0.001). Following multivariable adjustment, higher ΔP had an independent association with higher 60-day mortality and less VFD-60 in both groups. Higher PEEP had an association with less VFD-60, but only in COVID-ARDS patients.

CONCLUSIONS

Our findings show important differences in key ventilation parameters and associations thereof with outcomes between COVID-ARDS and CLASSIC-ARDS.

TRIAL REGISTRATION

Clinicaltrials.gov (identifier NCT05650957), December 14, 2022.

Adherence to low tidal volume in the transition to spontaneous ventilation in patients with acute respiratory failure in intensive care units in Latin America (SPIRAL): a study protocol

OBJECTIVE

Patients with acute respiratory failure often require mechanical ventilation to reduce the work of breathing and improve gas exchange; however, this may exacerbate lung injury. Protective ventilation strategies, characterized by low tidal volumes (≤ 8mL/kg of predicted body weight) and limited plateau pressure below 30cmH2O, have shown improved outcomes in patients with acute respiratory distress syndrome. However, in the transition to spontaneous ventilation, it can be challenging to maintain tidal volume within protective levels, and it is unclear whether low tidal volumes during spontaneous ventilation impact patient outcomes. We developed a study protocol to estimate the prevalence of low tidal volume ventilation in the first 24 hours of spontaneous ventilation in patients with hypoxemic acute respiratory failure and its association with ventilator-free days and survival.

METHODS

We designed a multicenter, multinational, cohort study with a 28-day follow-up that will include patients with acute respiratory failure, defined as a partial oxygen pressure/fraction of inspired oxygen ratio < 300mmHg, in transition to spontaneous ventilation in intensive care units in Latin America.

RESULTS

We plan to include 422 patients in ten countries. The primary outcomes are the prevalence of low tidal volume in the first 24 hours of spontaneous ventilation and ventilator-free days on day 28. The secondary outcomes are intensive care unit and hospital mortality, incidence of asynchrony and return to controlled ventilation and sedation.

CONCLUSION

In this study, we will assess the prevalence of low tidal volume during spontaneous ventilation and its association with clinical outcomes, which can inform clinical practice and future clinical trials.

Data-driven, cross-disciplinary collaboration: lessons learned at the largest academic health center in Latin America during the COVID-19 pandemic

Introduction

The COVID-19 pandemic has prompted global research efforts to reduce infection impact, highlighting the potential of cross-disciplinary collaboration to enhance research quality and efficiency.

Methods

At the FMUSP-HC academic health system, we implemented innovative flow management routines for collecting, organizing and analyzing demographic data, COVID-related data and biological materials from over 4,500 patients with confirmed SARS-CoV-2 infection hospitalized from 2020 to 2022. This strategy was mainly planned in three areas: organizing a database with data from the hospitalizations; setting-up a multidisciplinary taskforce to conduct follow-up assessments after discharge; and organizing a biobank. Additionally, a COVID-19 curated collection was created within the institutional digital library of academic papers to map the research output.

Results

Over the course of the experience, the possible benefits and challenges of this type of research support approach were identified and discussed, leading to a set of recommended strategies to enhance collaboration within the research institution. Demographic and clinical data from COVID-19 hospitalizations were compiled in a database including adults and a minority of children and adolescents with laboratory confirmed COVID-19, covering 2020-2022, with approximately 350 fields per patient. To date, this database has been used in 16 published studies. Additionally, we assessed 700 adults 6 to 11 months after hospitalization through comprehensive, multidisciplinary in-person evaluations; this database, comprising around 2000 fields per subject, was used in 15 publications. Furthermore, thousands of blood samples collected during the acute phase and follow-up assessments remain stored for future investigations. To date, more than 3,700 aliquots have been used in ongoing research investigating various aspects of COVID-19. Lastly, the mapping of the overall research output revealed that between 2020 and 2022 our academic system produced 1,394 scientific articles on COVID-19.

Discussion

Research is a crucial component of an effective epidemic response, and the preparation process should include a well-defined plan for organizing and sharing resources. The initiatives described in the present paper were successful in our aim to foster large-scale research in our institution. Although a single model may not be appropriate for all contexts, cross-disciplinary collaboration and open data sharing should make health research systems more efficient to generate the best evidence.

COVID-19 death risk predictors in Brazil using survival tree analysis: a retrospective cohort from 2020 to 2022

PURPOSE

This study analyses the survival of hospitalized patients with Severe Acute Respiratory Syndrome (SARS) due to COVID-19 and identifies the risk groups for death due to COVID-19 from the identification of potential interactions between its predictors.

METHODS

This was a retrospective longitudinal study with data from 1,756,917 patients reported in the Influenza Epidemiological Surveillance Information System from 26 February 2020 to 31 December 2022. In this study, all adult and older (≥ 20 years) patients were hospitalized with SARS due to COVID-19, with death as the outcome. Survival tree analysis was used to identify potential interactions between the predictors. A model was built for each year of study.

RESULTS

Hospital lethalitywas 33.2%. The worst survival curve was observed among those who underwent invasive mechanical ventilation and were aged 80 years or older in the three years of the pandemic. Black and brown race/color were predictors of deaths in the years 2020 and 2021 when there was greater demand from the health system due to the greater number of cases.

CONCLUSION

By applying survival tree analysis we identified several numbers of homogeneous subgroups with different risks for mortality from COVID-19. These findings show the effects of wide inequalities of access by the population, requiring effective policies for the reduction and adequate management of the disease.

Effects of driving pressure-guided ventilation on postoperative pulmonary complications in patients with COVID-19 undergoing abdominal surgery: A post-hoc propensity score-matched analysis

Background

Application of individualized positive end-expiratory pressure (PEEP) based on minimum driving pressure facilitates to prevent from postoperative pulmonary complications (PPCs). Whether lung protective ventilation strategy can reduce the risk of PPCs in COVID-19 patients remains unclear. In this study, we compared the effects of driving pressure-guided ventilation with conventional mechanical ventilation on PPCs in patients with COVID-19.

Methods

Patients infected COVID-19 within 30-day before surgery were retrospectively enrolled consecutively. Patients were divided into two group: driving pressure-guided lung protective ventilation strategy group (LPVS group) and conventional mechanical ventilation group (Control group). Propensity score matching for variables selected was used by logistic regression with the nearest-neighbor method. The outcomes were the incidence of PPCs and hypoxemia in post-anesthesia care unit.

Results

There was no significant difference in the baseline data between both groups (P > 0.05). The incidence of PPCs (12.73 % vs 36.36 %, χ2 = 7.068, P = 0.008) and hypoxemia [18.18 % vs 38.18 %, χ2 = 4.492, P = 0.034], and lung ultrasound scores [4.68 ± 1.60 vs 8.39 ± 1.87, t = 8.383, P < 0.001] in LPVS group were lower than control group. The PEEP, airway pressure and plateau pressure in LPVS group were higher than control group, but driving pressure and tidal volume was lower than control group, the difference was statistically significant (P < 0.05).

Conclusion

Individualized PEEP ventilation strategy guided by minimum driving pressure could improve oxygenation and reduce the incidence of PPCs in surgical patients with COVID-19.

[Driving pressure-guided lung protective ventilation strategy reduces postoperative pulmonary complications in patients recovered from COVID-19]

OBJECTIVE

To investigate the value of lung protective ventilation strategy (LPVS) guided by driving pressure for preventing postoperative pulmonary complications (PPCs) in patients recovered from COVID-19 and optimize intraoperative respiratory management.

METHODS

From December, 2022 to February, 2023, a total of 118 patients recovered from COVID-19 within a month (ASA Ⅰ~Ⅲ, aged ≥18 years) undergoing elective non-cardiac surgeries under general anesthesia in our hospital were randomized equally into LPVS group and control group.The patients in LPVS group received a tidal volume of 6 mL/kg with an individualized PEEP guided by minimum driving pressure and lung re-expansion every 30 min, and those in the control group received conventional mechanical ventilation.The incidence of PPCs and hypoxemia and pulmonary ultrasound score of the patients were compared between the two groups.

RESULTS

There was no significant difference in the baseline data between LPVS group and the control group (P>0.05).Compared with the control group, LPVS group showed significantly lower incidences of PPCs (16.95%vs 35.59%, χ2=5.294, P=0.021) and hypoxemia (15.25%vs 30.51%, χ2=3.890, P=0.049) with also lower pulmonary ultrasound scores (5.31±1.07 vs 8.32±2.34, t=8.986, P<0.001).The PEEP value, airway pressure and plateau pressure in LPVS group were significantly higher, but the driving pressure and the tidal volume were lower than those in the control group (P<0.05).

CONCLUSION

LPVS guided by driving pressure can improve oxygenation and reduce the risk of PPCs in patients recently recovered from COVID-19.

Positive end-expiratory pressure induced changes in airway driving pressure in mechanically ventilated COVID-19 Acute Respiratory Distress Syndrome patients

BACKGROUND

The profile of changes in airway driving pressure (dP_aw) induced by positive-end expiratory pressure (PEEP) might aid for individualized protective ventilation. Our aim was to describe the dP_aw versus PEEP curves behavior in ARDS from COVID-19 patients.

METHODS

Patients admitted in three hospitals were ventilated with fraction of inspired oxygen (FiO₂) and PEEP initially adjusted by oxygenation-based table. Thereafter, PEEP was reduced from 20 until 6 cmH₂O while dP_aw was stepwise recorded and the lowest PEEP that minimized dP_aw (PEEPmin_dP_aw) was assessed. Each dP_aw vs PEEP curve was classified as J-shaped, inverted-J-shaped, or U-shaped according to the difference between the minimum dP_aw and the dP_aw at the lowest and highest PEEP. In one hospital, hyperdistention and collapse at each PEEP were assessed by electrical impedance tomography (EIT).

RESULTS

184 patients (41 including EIT) were studied. 126 patients (68%) exhibited a J-shaped dP_aw vs PEEP profile (PEEPmin_dP_aw of 7.5 ± 1.9 cmH₂O). 40 patients (22%) presented a U (PEEPmin_dP_aw of 12.2 ± 2.6 cmH₂O) and 18 (10%) an inverted-J profile (PEEPmin_dP_aw of 14,6 ± 2.3 cmH₂O). Patients with inverted-J profiles had significant higher body mass index (BMI) and lower baseline partial pressure of arterial oxygen/FiO₂ ratio. PEEPmin_dP_aw was associated with lower fractions of both alveolar collapse and hyperinflation.

CONCLUSIONS

A PEEP adjustment procedure based on PEEP-induced changes in dP_aw is feasible and may aid in individualized PEEP for protective ventilation. The PEEP required to minimize driving pressure was influenced by BMI and was low in the majority of patients.

Morphological and functional findings in COVID-19 lung disease as compared to Pneumonia, ARDS, and High-Altitude Pulmonary Edema

Coronavirus disease-2019 (COVID-19) may severely affect respiratory function and evolve to life-threatening hypoxia. The clinical experience led to the implementation of standardized protocols assuming similarity to severe acute respiratory syndrome (SARS-CoV-2). Understanding the histopathological and functional patterns is essential to better understand the pathophysiology of COVID-19 and then develop new therapeutic strategies. Epithelial and endothelial cell damage can result from the virus attack, thus leading to immune-mediated response. Pulmonary histopathological findings show the presence of Mallory bodies, alveolar coating cells with nuclear atypia, reactive pneumocytes, reparative fibrosis, intra-alveolar hemorrhage, moderate inflammatory infiltrates, micro-abscesses, microthrombus, hyaline membrane fragments, and emphysema-like lung areas. COVID-19 patients may present different respiratory stages from silent to critical hypoxemia, are associated with the degree of pulmonary parenchymal involvement, thus yielding alteration of ventilation and perfusion relationships. This review aims to: discuss the morphological (histopathological and radiological) and functional findings of COVID-19 compared to acute interstitial pneumonia, acute respiratory distress syndrome (ARDS), and high-altitude pulmonary edema (HAPE), four entities that share common clinical traits, but have peculiar pathophysiological features with potential implications to their clinical management.

Calculating Route: Functional Trajectories and Long-Term Outcomes in Survivors of Severe COVID-19

OBJECTIVES

We investigated functional trajectories after severe COVID-19 and estimated their associations with adverse outcomes (falls, rehospitalizations, institutionalization, or death), cognition and post COVID-19 condition within 1-year of hospital discharge.

DESIGN

Prospective cohort study.

SETTING

A large academic medical center in Sao Paulo, Brazil.

PARTICIPANTS

Survivors of COVID-19 admissions to an intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS

We evaluated participants' disability status before hospital admission and three, six, nine, and twelve months after discharge using 15 activities of daily living. During follow-up, cognition and post COVID-19 condition (defined as persistent symptoms with duration ≥2 months) were assessed. A latent class growth analysis was performed to investigate functional trajectories after discharge.

RESULTS

We included 422 participants (median age 63 years, 13.5% were frail before COVID-19). Four distinct functional trajectories could be identified: "minimal disability trajectory" (37.4% of participants), "mild disability trajectory" (37.9%), "moderate disability trajectory" (16.8%), and "severe disability trajectory" (7.8%). Compared with minimal disability trajectory, the odds ratios (95% confidence interval) for 1-year adverse outcomes were 2.28 (1.38-3.76) for minor disability trajectory; 4.21 (2.10-8.42) for moderate disability trajectory; and 4.16 (1.51-11.46) for severe disability trajectory, even after adjustments. The occurrence of post COVID-19 condition was 67.5% and associated with functional trajectories (p=0.004). Cognition was also associated with functional trajectories.

CONCLUSION

Severe COVID-19 survivors can experience diverse functional trajectories, with those presenting higher levels of disability at increased risk for long-term adverse outcomes. Further investigations are essential to confirm our findings and assess the effectiveness of rehabilitation interventions, aiming to improve health outcomes in those who survived severe COVID-19 and other causes of sepsis.

Prediction of intensive care admission and hospital mortality in COVID-19 patients using demographics and baseline laboratory data

INTRODUCTION

Optimized allocation of medical resources to patients with COVID-19 has been a critical concern since the onset of the pandemic.

METHODS

In this retrospective cohort study, the authors used data from a Brazilian tertiary university hospital to explore predictors of Intensive Care Unit (ICU) admission and hospital mortality in patients admitted for COVID-19. Our primary aim was to create and validate prediction scores for use in hospitals and emergency departments to aid clinical decisions and resource allocation.

RESULTS

The study cohort included 3,022 participants, of whom 2,485 were admitted to the ICU; 1968 survived, and 1054 died in the hospital. From the complete cohort, 1,496 patients were randomly assigned to the derivation sample and 1,526 to the validation sample. The final scores included age, comorbidities, and baseline laboratory data. The areas under the receiver operating characteristic curves were very similar for the derivation and validation samples. Scores for ICU admission had a 75% accuracy in the validation sample, whereas scores for death had a 77% accuracy in the validation sample. The authors found that including baseline flu-like symptoms in the scores added no significant benefit to their accuracy. Furthermore, our scores were more accurate than the previously published NEWS-2 and 4C Mortality Scores.

DISCUSSION AND CONCLUSIONS

The authors developed and validated prognostic scores that use readily available clinical and laboratory information to predict ICU admission and mortality in COVID-19. These scores can become valuable tools to support clinical decisions and improve the allocation of limited health resources.

Respiratory system mechanics, gas exchange, and outcomes in mechanically ventilated patients with COVID-19-related acute respiratory distress syndrome: a systematic review and meta-analysis

The association of respiratory mechanics, particularly respiratory system static compliance (C_RS), with severity of hypoxaemia in patients with COVID-19-related acute respiratory distress syndrome (ARDS) has been widely debated, with some studies reporting distinct ARDS phenotypes based on C_RS. Ascertaining whether such phenotypes exist is important, because they might indicate the need for ventilation strategies that differ from those used in patients with ARDS due to other causes. In a systematic review and meta-analysis of studies published between Dec 1, 2019, and March 14, 2022, we evaluated respiratory system mechanics, ventilator parameters, gas exchange parameters, and clinical outcomes in patients with COVID-19-related ARDS. Among 11 356 patients in 37 studies, mean reported C_RS, measured close to the time of endotracheal intubation, was 35·8 mL/cm H₂O (95% CI 33·9-37·8; I²=96·9%, τ²=32·6). Pooled mean C_RS was normally distributed. Increasing ARDS severity (assessed by PaO₂/FiO₂ ratio as mild, moderate, or severe) was associated with decreasing C_RS. We found no evidence for distinct C_RS-based clinical phenotypes in patients with COVID-19-related ARDS, and we therefore conclude that no change in conventional lung-protective ventilation strategies is warranted. Future studies should explore the personalisation of mechanical ventilation strategies according to factors including respiratory system mechanics and haemodynamic status in patients with ARDS.

Clinical, sociodemographic and environmental factors impact post-COVID-19 syndrome

Background

Sociodemographic and environmental factors are associated with incidence, severity, and mortality of COVID-19. However, little is known about the role of such factors in persisting symptoms among recovering patients. We designed a cohort study of hospitalized COVID-19 survivors to describe persistent symptoms and identify factors associated with post-COVID-19 syndrome.

Methods

We included patients hospitalized between March to August 2020 who were alive six months after hospitalization. We collected individual and clinical characteristics during hospitalization and at follow-up assessed ten symptoms with standardized scales, 19 yes/no symptoms, a functional status and a quality-of-life scale and performed four clinical tests. We examined individual exposure to greenspace and air pollution and considered neighbourhood´s population density and socioeconomic conditions as contextual factors in multilevel regression analysis.

Results

We included 749 patients with a median follow-up of 200 (IQR = 185-235) days, and 618 (83%) had at least one of the ten symptoms measured with scales. Pain (41%), fatigue (38%) and posttraumatic stress disorder (35%) were the most frequent. COVID-19 severity, comorbidities, BMI, female sex, younger age, and low socioeconomic position were associated with different symptoms. Exposure to ambient air pollution was associated with higher dyspnoea and fatigue scores and lower functional status.

Conclusions

We identified a high frequency of persistent symptoms among COVID-19 survivors that were associated with clinical, sociodemographic, and environmental variables. These findings indicate that most patients recovering from COVID-19 will need post-discharge care, and an additional burden to health care systems, especially in LMICs, should be expected.

Development and Internal Validation of a New Prognostic Model Powered to Predict 28-Day All-Cause Mortality in ICU COVID-19 Patients-The COVID-SOFA Score

Background: The sequential organ failure assessment (SOFA) score has poor discriminative ability for death in severely or critically ill patients with Coronavirus disease 2019 (COVID-19) requiring intensive care unit (ICU) admission. Our aim was to create a new score powered to predict 28-day mortality. Methods: Retrospective, observational, bicentric cohort study including 425 patients with COVID-19 pneumonia, acute respiratory failure and SOFA score ≥ 2 requiring ICU admission for ≥72 h. Factors with independent predictive value for 28-day mortality were identified after stepwise Cox proportional hazards (PH) regression. Based on the regression coefficients, an equation was computed representing the COVID-SOFA score. Discriminative ability was tested using receiver operating characteristic (ROC) analysis, concordance statistics and precision-recall curves. This score was internally validated. Results: Median (Q1−Q3) age for the whole sample was 64 [55−72], with 290 (68.2%) of patients being male. The 28-day mortality was 54.58%. After stepwise Cox PH regression, age, neutrophil-to-lymphocyte ratio (NLR) and SOFA score remained in the final model. The following equation was computed: COVID-SOFA score = 10 × [0.037 × Age + 0.347 × ln(NLR) + 0.16 × SOFA]. Harrell’s C-index for the COVID-SOFA score was higher than the SOFA score alone for 28-day mortality (0.697 [95% CI; 0.662−0.731] versus 0.639 [95% CI: 0.605−0.672]). Subsequently, the prediction error rate was improved up to 16.06%. Area under the ROC (AUROC) was significantly higher for the COVID-SOFA score compared with the SOFA score for 28-day mortality: 0.796 [95% CI: 0.755−0.833] versus 0.699 [95% CI: 0.653−0.742, p < 0.001]. Better predictive value was observed with repeated measurement at 48 h after ICU admission. Conclusions: The COVID-SOFA score is better than the SOFA score alone for 28-day mortality prediction. Improvement in predictive value seen with measurements at 48 h after ICU admission suggests that the COVID-SOFA score can be used in a repetitive manner. External validation is required to support these results.

Predictors of Poor Outcome among Critically Ill COVID-19 Patients: A Nationally Representative Sample of the Saudi Arabian Population

The outbreak and continuing impact of COVID-19 have significantly increased the rates of hospitalization and admissions to intensive care units (ICU). This study evaluates clinical outcomes in critically ill patients and investigates variables tied to poor prognosis. A secondary database analysis was conducted to investigate the predictors of poor outcome among critically ill COVID-19 patients in Saudi Arabia. Multivariable logistic regression analysis was used to assess the association between various demographic characteristics, comorbidities, and COVID-19 symptoms and patients’ poor prognosis, as a composite outcome. A total of 2257 critically ill patients were identified (male (71.8%), and elderly (37.3%)). The mortality rate was 50.0%, and the composite poor outcome was 68.4%. The predictors of poor outcome were being elderly (OR = 4.79, 95%CI 3.19−7.18), obesity (OR = 1.43, 95%CI 1.1−1.87), having a severe or critical case at admission (OR = 6.46, 95%CI 2.34−17.8; OR = 22.3, 95%CI 11.0−45, respectively), and some signs and symptoms of COVID-19 such as shortness of breath, feeling fatigued or headache, respiratory rate ≥ 30/min, PaO2/FiO2 ratio < 300, and altered consciousness. In conclusion, identifying high-risk populations that are expected to have a poor prognosis based on their criteria upon admission helps policymakers and practitioners better triage patients when faced with limited healthcare resources.

Low tidal volume ventilation is associated with mortality in COVID-19 patients-Insights from the PRoVENT-COVID study

Purpose

Low tidal volume ventilation (LTVV) is associated with mortality in patients with acute respiratory distress syndrome. We investigated the association of LTVV with mortality in COVID-19 patients.

Methods

Secondary analysis of a national observational study in COVID-19 patients in the first wave of the pandemic. We compared COVID-19 patients that received LTVV, defined as controlled ventilation with a median tidal volume ≤ 6 mL/kg predicted body weight over the first 4 calendar days of ventilation, with patients that did not receive LTVV. The primary endpoint was 28-day mortality. In addition, we identified factors associated with use of LTVV.

Results

Of 903 patients, 294 (32.5%) received LTVV. Disease severity scores and ARDS classification was not different between the two patient groups. The primary endpoint, 28-day mortality, was met in 68 out of 294 patients (23.1%) that received LTVV versus in 193 out of 609 patients (31.7%) that did not receive LTVV (P < 0.001). LTVV was independently associated with 28-day mortality (HR, 0.68 (0.45 to 0.95); P = 0.025). Age, height, the initial tidal volume and continuous muscle paralysis was independently associated with use of LTVV.

Conclusions

In this cohort of invasively ventilated COVID-19 patients, approximately a third of patients received LTVV. Use of LTVV was independently associated with reduced 28-day mortality. The initial tidal volume and continuous muscle paralysis were potentially modifiable factors associated with use of LTVV. These findings are important as they could help clinicians to recognize patients who are at risk of not receiving LTVV.

Sex Differences in Use of Low Tidal Volume Ventilation in COVID-19-Insights From the PRoVENT-COVID Study

The purpose of this study was to compare and understand differences in the use of low tidal volume ventilation (LTVV) between females and males with acute respiratory distress syndrome (ARDS) related to coronavirus disease 2019 (COVID-19). This is a post-hoc analysis of an observational study in invasively ventilated patients with ARDS related to COVID-19 in 22 ICUs in the Netherlands. The primary endpoint was the use of LTVV, defined as having received a median tidal volume (V_T) ≤6 ml/kg predicted body weight (PBW) during controlled ventilation. A mediation analysis was used to investigate the impact of anthropometric factors, next to the impact of sex per se. The analysis included 934 patients, 251 females and 683 males. All the patients had ARDS, and there were no differences in ARDS severity between the sexes. On the first day of ventilation, females received ventilation with a higher median V_T compared with males [6.8 (interquartile range (IQR) 6.0–7.6 vs. 6.3 (IQR 5.8–6.9) ml/kg PBW; p < 0.001]. Consequently, females received LTVV less often than males (23 vs. 34%; p = 0.003). The difference in the use of LTVV became smaller but persisted over the next days (27 vs. 36%; p = 0.046 at day 2 and 28 vs. 38%; p = 0.030 at day 3). The difference in the use LTVV was significantly mediated by sex per se [average direct effect of the female sex, 7.5% (95% CI, 1.7–13.3%); p = 0.011] and by differences in the body height [average causal mediation effect, −17.5% (−21.5 to −13.5%); p < 0.001], but not by the differences in actual body weight [average causal mediation effect, 0.2% (−0.8 to 1.2%); p = 0.715]. In conclusion, in this cohort of patients with ARDS related to COVID-19, females received LTVV less often than males in the first days of invasive ventilation. The difference in the use of LTVV was mainly driven by an anthropometric factor, namely, body height. Use of LTVV may improve by paying attention to correct titration of V_T, which should be based on PBW, which is a function of body height.

Differential mortality with COVID-19 and invasive mechanical ventilation between high-income and low-and middle-income countries: a systematic review, meta-analysis, and meta-regression

The COVID-19 pandemic has markedly affected the health care of patients in low- and middle-income countries (LMICs), but no systematic study to corroborate this effect has been undertaken. In addition, the survival outcomes of patients with COVID-19 who received invasive mechanical ventilation (IMV) have not been well established. We pooled evidence from all available studies and did a systematic review and meta-analysis to assess and compare mortality outcomes between LMICs and high-income countries (HICs). We searched MEDLINE and the University of Michigan Library according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from December 1, 2019, to July 15, 2021, for case-control studies, cohort studies, and brief reports that discussed mortality ratios and survival outcomes among patients with SARS-CoV-2 who received IMV. We excluded studies and case reports without comparison groups, narrative reviews, and preprints. A random-effects estimate of the arcsine square root transformation (PAS) of each outcome was generated with the DerSimonian-Laird method. Seven eligible studies, consisting of 243,835 patients with COVID-19, were included. We identified a significantly higher mortality rate (i.e., a larger PAS) among the patients receiving IMV in LMICs (PAS, 0.754; 95% CI, 0.569-0.900; P<.001) compared to patients in HICs (PAS, 0.588; 95% CI, 0.263-0.876; P<.001). Considerable heterogeneity was present within the individual subgroups possibly because of the extent of the included studies, which had data from specific countries and states but not from individual hospitals or health care centers. Moreover, the sample population in each study was diverse. Meta-regression showed that a higher mortality rate among patients with COVID-19 who received IMV in both HICs (P<.001) and LMICs (P=.04) was associated with chronic pulmonary disease. Our study suggests that chronic pulmonary diseases and poor demographics lead to a worse prognosis among patients with COVID-19 who received IMV. Moreover, the survival outcome is worse in LMICs, where health care systems are usually understaffed and poorly financed.

Protective ventilation in patients with acute respiratory distress syndrome related to COVID-19: always, sometimes or never?

PURPOSE OF REVIEW

To review current evidence on the pathophysiology of COVID-19-related acute respiratory distress syndrome (ARDS) and on the implementation of lung protective ventilation.

RECENT FINDINGS

Although multiple observations and physiological studies seem to show a different pathophysiological behaviour in COVID-19-ARDS compared with 'classical' ARDS, numerous studies on thousands of patients do not confirm these findings and COVID-19-ARDS indeed shares similar characteristics and interindividual heterogeneity with ARDS from other causes. Although still scarce, present evidence on the application of lung protective ventilation in COVID-19-ARDS shows that it is indeed consistently applied in ICUs worldwide with a possible signal towards better survival at least in one study. The levels of positive end-expiratory pressure (PEEP) usually applied in these patients are higher than in 'classical' ARDS, proposing once again the issue of PEEP personalization in hypoxemic patients. In the absence of robust evidence, careful evaluation of the patient is needed, and empiric settings should be oriented towards lower levels of PEEP.

SUMMARY

According to the present evidence, a lung protective strategy based on low tidal volume and plateau pressures is indicated in COVID-19-ARDS as in ARDS from other causes; however, there are still uncertainties on the appropriate levels of PEEP.

Sildenafil for treating patients with COVID-19 and perfusion mismatch: a pilot randomized trial

BACKGROUND

SARS-CoV-2 seems to affect the regulation of pulmonary perfusion. Hypoperfusion in areas of well-aerated lung parenchyma results in a ventilation-perfusion mismatch that can be characterized using subtraction computed tomography angiography (sCTA). This study aims to evaluate the efficacy of oral sildenafil in treating COVID-19 inpatients showing perfusion abnormalities in sCTA.

METHODS

Triple-blinded, randomized, placebo-controlled trial was conducted in Chile in a tertiary-care hospital able to provide on-site sCTA scans and ventilatory support when needed between August 2020 and March 2021. In total, 82 eligible adults were admitted to the ED with RT-PCR-confirmed or highly probable SARS-COV-2 infection and sCTA performed within 24 h of admission showing perfusion abnormalities in areas of well-aerated lung parenchyma; 42 were excluded and 40 participants were enrolled and randomized (1:1 ratio) once hospitalized. The active intervention group received sildenafil (25 mg orally three times a day for seven days), and the control group received identical placebo capsules in the same way. Primary outcomes were differences in oxygenation parameters measured daily during follow-up (PaO₂/FiO₂ ratio and A-a gradient). Secondary outcomes included admission to the ICU, requirement of non-invasive ventilation, invasive mechanical ventilation (IMV), and mortality rates. Analysis was performed on an intention-to-treat basis.

RESULTS

Totally, 40 participants were enrolled (20 in the placebo group and 20 in the sildenafil group); 33 [82.5%] were male; and median age was 57 [IQR 41-68] years. No significant differences in mean PaO₂/FiO₂ ratios and A-a gradients were found between groups (repeated-measures ANOVA p = 0.67 and p = 0.69). IMV was required in 4 patients who received placebo and none in the sildenafil arm (logrank p = 0.04). Patients in the sildenafil arm showed a significantly shorter median length of hospital stay than the placebo group (9 IQR 7-12 days vs. 12 IQR 9-21 days, p = 0.04).

CONCLUSIONS

No statistically significant differences were found in the oxygenation parameters. Sildenafil treatment could have a potential therapeutic role regarding the need for IMV in COVID-19 patients with specific perfusion patterns in sCTA. A large-scale study is needed to confirm these results.

TRIAL REGISTRATION

Sildenafil for treating patients with COVID-19 and perfusion mismatch: a pilot randomized trial, NCT04489446, Registered 28 July 2020, https://clinicaltrials.gov/ct2/show/NCT04489446 .

COVID-19-Associated Pulmonary Aspergillosis in Russia

We studied the risk factors, etiology, clinical features and the effectiveness of therapy of COVID-19-associated pulmonary aspergillosis (CAPA) in adult patients. In this retrospective study, we included 45 patients with proven (7%) and probable (93%) CAPA. The ECMM/ISHAM, 2020 criteria were used to diagnose CAPA. A case-control study was conducted to study the risk factors of CAPA; the control group included 90 adult COVID-19 patients without IA. In CAPA patients, the main underlying diseases were diabetes mellitus (33%), and hematological and oncological diseases (31%). The probability of CAPA developing significantly increased with lymphocytopenia >10 days (OR = 8.156 (3.056–21.771), p = 0.001), decompensated diabetes mellitus (29% vs. 7%, (OR = 5.688 (1.991–16.246), p = 0.001)), use of glucocorticosteroids (GCS) in prednisolone-equivalent dose > 60 mg/day (OR = 4.493 (1.896–10.647), p = 0.001) and monoclonal antibodies to IL-1ß and IL-6 (OR = 2.880 (1.272–6.518), p = 0.01). The main area of localization of CAPA was the lungs (100%). The clinical features of CAPA were fever (98% vs. 85%, p = 0.007), cough (89% vs. 72%, p = 0.002) and hemoptysis (36% vs. 3%, p = 0.0001). Overall, 71% of patients were in intensive care units (ICU) (median—15.5 (5–60) days), mechanical ventilation was used in 52% of cases, and acute respiratory distress syndrome (ARDS) occurred at a rate of 31%. The lung CT scan features of CAPA were bilateral (93%) lung tissue consolidation (89% vs. 59%, p = 0.004) and destruction (47% vs. 1%, p = 0.00001), and hydrothorax (26% vs. 11%, p = 0.03). The main pathogens were A. fumigatus (44%) and A. niger (31%). The overall survival rate after 12 weeks was 47.2%.

Corticosteroid treatment and mortality in mechanically ventilated COVID-19-associated acute respiratory distress syndrome (ARDS) patients: a multicentre cohort study

BACKGROUND

Some unanswered questions persist regarding the effectiveness of corticosteroids for severe coronavirus disease 2019 (COVID-19) patients. We aimed to assess the clinical effect of corticosteroids on intensive care unit (ICU) mortality among mechanically ventilated COVID-19-associated acute respiratory distress syndrome (ARDS) patients.

METHODS

This was a retrospective study of prospectively collected data conducted in 70 ICUs (68 Spanish, one Andorran, one Irish), including mechanically ventilated COVID-19-associated ARDS patients admitted between February 6 and September 20, 2020. Individuals who received corticosteroids for refractory shock were excluded. Patients exposed to corticosteroids at admission were matched with patients without corticosteroids through propensity score matching. Primary outcome was all-cause ICU mortality. Secondary outcomes were to compare in-hospital mortality, ventilator-free days at 28 days, respiratory superinfection and length of stay between patients with corticosteroids and those without corticosteroids. We performed survival analysis accounting for competing risks and subgroup sensitivity analysis.

RESULTS

We included 1835 mechanically ventilated COVID-19-associated ARDS, of whom 1117 (60.9%) received corticosteroids. After propensity score matching, ICU mortality did not differ between patients treated with corticosteroids and untreated patients (33.8% vs. 30.9%; p = 0.28). In survival analysis, corticosteroid treatment at ICU admission was associated with short-term survival benefit (HR 0.53; 95% CI 0.39-0.72), although beyond the 17th day of admission, this effect switched and there was an increased ICU mortality (long-term HR 1.68; 95% CI 1.16-2.45). The sensitivity analysis reinforced the results. Subgroups of age < 60 years, severe ARDS and corticosteroids plus tocilizumab could have greatest benefit from corticosteroids as short-term decreased ICU mortality without long-term negative effects were observed. Larger length of stay was observed with corticosteroids among non-survivors both in the ICU and in hospital. There were no significant differences for the remaining secondary outcomes.

CONCLUSIONS

Our results suggest that corticosteroid treatment for mechanically ventilated COVID-19-associated ARDS had a biphasic time-dependent effect on ICU mortality. Specific subgroups showed clear effect on improving survival with corticosteroid use. Therefore, further research is required to identify treatment-responsive subgroups among the mechanically ventilated COVID-19-associated ARDS patients.

Management of COVID-19 Patients in the Emergency Department

COVID-19 is an emerging disease of global public health concern. As the pandemic overwhelmed emergency departments (EDs), a restructuring of emergency care delivery became necessary in many hospitals. Furthermore, with more than 2000 papers being published each week, keeping up with ever-changing information has proven to be difficult for emergency physicians. The aim of the present review is to provide emergency physician with a summary of the current literature regarding the management of COVID-19 patients in the emergency department.

Use and misuse of biomarkers and the role of D-dimer and C-reactive protein in the management of COVID-19: A post-hoc analysis of a prospective cohort study

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is associated with high mortality among hospitalized patients and incurs high costs. Severe acute respiratory syndrome coronavirus 2 infection can trigger both inflammatory and thrombotic processes, and these complications can lead to a poorer prognosis. This study aimed to evaluate the association and temporal trends of D-dimer and C-reactive protein (CRP) levels with the incidence of venous thromboembolism (VTE), hospital mortality, and costs among inpatients with COVID-19.

METHODS

Data were extracted from electronic patient records and laboratory databases. Crude and adjusted associations for age, sex, number of comorbidities, Sequential Organ Failure Assessment score at admission, and D-dimer or CRP logistic regression models were used to evaluate associations.

RESULTS

Between March and June 2020, COVID-19 was documented in 3,254 inpatients. The D-dimer level ≥4,000 ng/mL fibrinogen equivalent unit (FEU) mortality odds ratio (OR) was 4.48 (adjusted OR: 1.97). The CRP level ≥220 mg/dL OR for death was 7.73 (adjusted OR: 3.93). The D-dimer level ≥4,000 ng/mL FEU VTE OR was 3.96 (adjusted OR: 3.26). The CRP level ≥220 mg/dL OR for VTE was 2.71 (adjusted OR: 1.92). All these analyses were statistically significant (p<0.001). Stratified hospital costs demonstrated a dose-response pattern. Adjusted D-dimer and CRP levels were associated with higher mortality and doubled hospital costs. In the first week, elevated D-dimer levels predicted VTE occurrence and systemic inflammatory harm, while CRP was a hospital mortality predictor.

CONCLUSION

D-dimer and CRP levels were associated with higher hospital mortality and a higher incidence of VTE. D-dimer was more strongly associated with VTE, although its discriminative ability was poor, while CRP was a stronger predictor of hospital mortality. Their use outside the usual indications should not be modified and should be discouraged.