Correction to: Factors influencing liberation from mechanical ventilation in coronavirus disease 2019: multicenter observational study in fifteen Italian ICUs

Using risk factors and markers to predict bacterial respiratory co-/superinfections in COVID-19 patients: is the antibiotic steward's toolbox full or empty?

BACKGROUND

Adequate diagnosis of bacterial respiratory tract co-/superinfection (bRTI) in coronavirus disease (COVID-19) patients is challenging, as there is insufficient knowledge about the role of risk factors and (para)clinical parameters in the identification of bacterial co-/superinfection in the COVID-19 setting. Empirical antibiotic therapy is mainly based on COVID-19 severity and expert opinion, rather than on scientific evidence generated since the start of the pandemic.

PURPOSE

We report the best available evidence regarding the predictive value of risk factors and (para)clinical markers in the diagnosis of bRTI in COVID-19 patients.

METHODS

A multidisciplinary team identified different potential risk factors and (para)clinical predictors of bRTI in COVID-19 and formulated one or two research questions per topic. After a thorough literature search, research gaps were identified, and suggestions concerning further research were formulated. The quality of this narrative review was ensured by following the Scale for the Assessment of Narrative Review Articles.

RESULTS

Taking into account the scarcity of scientific evidence for markers and risk factors of bRTI in COVID-19 patients, to date, COVID-19 severity is the only parameter which can be associated with higher risk of developing bRTI.

CONCLUSIONS

Evidence on the usefulness of risk factors and (para)clinical factors as predictors of bRTI in COVID-19 patients is scarce. Robust studies are needed to optimise antibiotic prescribing and stewardship activities in the context of COVID-19.

Factors Affecting Mechanical Ventilator Weaning Success and 28-Day Survival Among Patients With Acute Respiratory Distress Syndrome Secondary to COVID-19

Introduction

The process of weaning patients off mechanical ventilation (MV) is difficult and complex. Critical care nurses must maintain continuity of care for patients undergoing MV weaning, assess patients' overall condition, and meet patients' needs.

Objectives

The study aimed to explore clinical factors of MV weaning success and 28-day survival among patients with acute respiratory distress syndrome secondary to COVID-19.

Methods

This prospective observational study was conducted on 90 newly admitted patients in the general intensive care unit Assiut Univeristy Main Hospital in Egypt from October 2021 to March 2022. The researchers applied a standard weaning protocol for all of the patients in this study and then assessed the outcome variables: success or failure of weaning trials from a mechanical ventilator, and 28-day survival.

Results

In total, 50 (55.6%) patients were successfully weaned from MV, and 45 (50%) patients survived at 28 days. In a multivariate regression analysis, dynamic compliance (OR, 1.115; 95% CI, 1.010-1.230, p = .031*), lymphocyte count (OR, 3.025; 95% CI, 1.322-6.923, p = .009*), urine output (OR, 1.002; 95% CI, 1.001-1.004, p = .002*), and alanine aminotransferase (ALT; OR, 0.993; 95% CI, 0.988-0.999, p = .017*) were significantly associated with weaning success. In addition, age (OR, 1.058; 95% CI, 1.015-1.102; p = .007*), lymphocyte count (OR, 3.304; 95% CI, 1.348-8.100; p = .009*), urine output (OR, 1.003; 95% CI, 1.001-1.004; p = .001*), and ALT (OR, 0.994; 95% CI, 0.989-0.99, p = .015*) were significantly associated with survival at 28 days.

Conclusion

Dynamic lung compliance, lymphocyte count, urine output, and ALT were found to be predictive parameters that may affect the success of weaning off MV. Additionally, it was found that age, lymphocyte count, urine output, and ALT are predictors of survival at 28 days. We recommend further studies with larger, more systematic samples and complete follow-up, focusing on pulmonary function and quality of life in postweaning patients with acute respiratory distress syndrome.

Clinical implications of microvascular CT scan signs in COVID-19 patients requiring invasive mechanical ventilation

Purpose

COVID-19-related acute respiratory distress syndrome (ARDS) is characterized by the presence of signs of microvascular involvement at the CT scan, such as the vascular tree in bud (TIB) and the vascular enlargement pattern (VEP). Recent evidence suggests that TIB could be associated with an increased duration of invasive mechanical ventilation (IMV) and intensive care unit (ICU) stay. The primary objective of this study was to evaluate whether microvascular involvement signs could have a prognostic significance concerning liberation from IMV.

Material and methods

All the COVID-19 patients requiring IMV admitted to 16 Italian ICUs and having a lung CT scan recorded within 3 days from intubation were enrolled in this secondary analysis. Radiologic, clinical and biochemical data were collected.

Results

A total of 139 patients affected by COVID-19 related ARDS were enrolled. After grouping based on TIB or VEP detection, we found no differences in terms of duration of IMV and mortality. Extension of VEP and TIB was significantly correlated with ground-glass opacities (GGOs) and crazy paving pattern extension. A parenchymal extent over 50% of GGO and crazy paving pattern was more frequently observed among non-survivors, while a VEP and TIB extent involving 3 or more lobes was significantly more frequent in non-responders to prone positioning.

Conclusions

The presence of early CT scan signs of microvascular involvement in COVID-19 patients does not appear to be associated with differences in duration of IMV and mortality. However, patients with a high extension of VEP and TIB may have a reduced oxygenation response to prone positioning.

Trial Registration: NCT04411459

Supplementary Information

The online version contains supplementary material available at 10.1007/s11547-021-01444-7.

Comparative evaluation of ventilator-associated pneumonia in critically ill COVID- 19 and patients infected with other corona viruses: a systematic review and meta-analysis

The Coronavirus disease 19 (COVID-19) pandemic is associated with an unprecedented requirement for intensive care unit (ICU) admission, invasive mechanical ventilation, and thereby significantly increasing the risk of secondary nosocomial pneumonia, Ventilator-Associated Pneumonia (VAP). Our study aims to identify the overall incidence of VAP, common organisms associated with it, and outcome in COVID-19 patients in comparison to the non-SARS-CoV-2 infected critically ill ventilated COVID-19 patients. A comprehensive screening was conducted using major electronic databases), from January 1st 2020 to May 31st 2021, as per the PRISMA statement. In our rapid review, we included a total of 34 studies (involving 8901 cases. Overall VAP was reported in 48.15 % (95% CI 42.3%-54%) mechanically ventilated COVID-19 patients and the mortality rate was 51.4% (95% CI 42.5%-60%). COVID-19 patients had increased risk of VAP and mortality in comparison to other non-SARS-CoV-2 viral pneumonia (OR=2.33; 95%CI 1.75-3.11; I2=15%, and OR=1.46; 95%CI 1.15-1.86; I2=0% respectively). Critically ill COVID-19 patients are prone to develop VAP, which worsens the outcome.

Mortality and Clinical Interventions in Critically ill Patient With Coronavirus Disease 2019: A Systematic Review and Meta-Analysis

Objective: The aims of this systematic review and meta-analysis were to summarize the current existing evidence on the outcome of critically ill patients with COVID-19 as well as to evaluate the effectiveness of clinical interventions.

Data Sources: We searched MEDLINE, the Cochrane library, Web of Science, the China Biology Medicine disc, China National Knowledge Infrastructure, and Wanfang Data from their inception to May 15, 2021. The search strings consisted of various search terms related to the concepts of mortality of critically ill patients and clinical interventions.

Study Selection: After eliminating duplicates, two reviewers independently screened all titles and abstracts first, and then the full texts of potentially relevant articles were reviewed to identify cohort studies and case series that focus on the mortality of critically ill patients and clinical interventions.

Main Outcomes and Measures: The primary outcome was the mortality of critically ill patients with COVID-19. The secondary outcomes included all sorts of supportive care.

Results: There were 27 cohort studies and six case series involving 42,219 participants that met our inclusion criteria. All-cause mortality in the intensive care unit (ICU) was 35% and mortality in hospital was 32% in critically ill patients with COVID-19 for the year 2020, with very high between-study heterogeneity (I² = 97%; p < 0.01). In a subgroup analysis, the mortality during ICU hospitalization in China was 39%, in Asia—except for China—it was 48%, in Europe it was 34%, in America it was 15%, and in the Middle East it was 39%. Non-surviving patients who had an older age [−8.10, 95% CI (−9.31 to −6.90)], a higher APACHE II score [−4.90, 95% CI (−6.54 to −3.27)], a higher SOFA score [−2.27, 95% CI (−2.95 to −1.59)], and a lower PaO₂/FiO₂ ratio [34.77, 95% CI (14.68 to 54.85)] than those who survived. Among clinical interventions, invasive mechanical ventilation [risk ratio (RR) 0.49, 95% CI (0.39–0.61)], kidney replacement therapy [RR 0.34, 95% CI (0.26–0.43)], and vasopressor [RR 0.54, 95% CI (0.34–0.88)] were used more in surviving patients.

Conclusions: Mortality was high in critically ill patients with COVID-19 based on low-quality evidence and regional difference that existed. The early identification of critical characteristics and the use of support care help to indicate the outcome of critically ill patients.

Distinctive features of severe SARS-CoV-2 pneumonia

The coronavirus disease 2019 (COVID-19) pandemic is among the most important public health crises of our generation. Despite the promise of prevention offered by effective vaccines, patients with severe COVID-19 will continue to populate hospitals and intensive care units for the foreseeable future. The most common clinical presentation of severe COVID-19 is hypoxemia and respiratory failure, typical of the acute respiratory distress syndrome (ARDS). Whether the clinical features and pathobiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia differ from those of pneumonia secondary to other pathogens is unclear. This uncertainty has created variability in the application of historically proven therapies for ARDS to patients with COVID-19. We review the available literature and find many similarities between patients with ARDS from pneumonia attributable to SARS-CoV-2 versus other respiratory pathogens. A notable exception is the long duration of illness among patients with COVID-19, which could result from its unique pathobiology. Available data support the use of care pathways and therapies proven effective for patients with ARDS, while pointing to unique features that might be therapeutically targeted for patients with severe SARS-CoV-2 pneumonia.

Fatal COVID-19 ARDS associated with incomplete AEC1 differentiation from the transitional state without senescence or fibrosis

COVID-19 ARDS is associated with prolonged respiratory failure and high mortality, but the underlying mechanisms are unknown. ARDS results from injury to the alveolar epithelial cell (AEC) barrier; clinical recovery requires epithelial regeneration. During physiologic regeneration, AEC2s proliferate, exit the cell cycle, and transiently assume a transitional state before differentiating into AEC1s; transitional cells persist with ineffectual AEC1 differentiation in pulmonary fibrosis. It is unknown why transitional cells differentiate into AEC1s during physiologic regeneration but persist with ensuing scar in fibrosis and whether incomplete AEC1 differentiation from transitional cells without fibrosis may underlie prolonged respiratory failure in COVID-19 ARDS. Immunostaining of postmortem COVID-19 ARDS lungs revealed abundant transitional cells. They were typically cuboidal or partially spread, occasionally flat, but rarely expressed AEC1 markers. They formed organized monolayers on alveolar septa without fibrosis. Immunostaining and/or meta-analysis of scRNAseq datasets revealed that transitional cells in two mouse models of physiologic regeneration, COVID-19 ARDS, and fibrosis express markers of cell cycle exit but only in fibrosis express a specific senescence marker. These data suggest that in COVID-19 ARDS, physiologic AEC1 differentiation from transitional cells is incomplete, thus underlying prolonged barrier permeability and respiratory failure, but as in physiologic regeneration, is ongoing without fibrosis.

Markers of endothelial and epithelial pulmonary injury in mechanically ventilated COVID-19 ICU patients

Background

Biomarkers can be used to detect the presence of endothelial and/or alveolar epithelial injuries in case of ARDS. Angiopoietin-2 (Ang-2), soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein-1 (VCAM-1), P-selectin and E-selectin are biomarkers of endothelial injury, whereas the receptor for advanced glycation end-products (RAGE) reflects alveolar epithelial injury. The aims of this study were to evaluate whether the plasma concentration of the above-mentioned biomarkers was different 1) in survivors and non-survivors of COVID-19-related ARDS and 2) in COVID-19-related and classical ARDS.

Methods

This prospective study was performed in two COVID-19-dedicated Intensive Care Units (ICU) and one non-COVID-19 ICU at Ferrara University Hospital. A cohort of 31 mechanically ventilated patients with COVID-19 ARDS and a cohort of 11 patients with classical ARDS were enrolled. Ang-2, ICAM-1, VCAM-1, P-selectin, E-selectin and RAGE were determined with a bead-based multiplex immunoassay at three time points: inclusion in the study (T1), after 7 ± 2 days (T2) and 14 ± 2 days (T3). The primary outcome was to evaluate the plasma trend of the biomarker levels in survivors and non-survivors. The secondary outcome was to evaluate the differences in respiratory mechanics variables and gas exchanges between survivors and non-survivors. Furthermore, we compared the plasma levels of the biomarkers at T1 in patients with COVID-19-related ARDS and classical ARDS.

Results

In COVID-19-related ARDS, the plasma levels of Ang-2 and ICAM-1 at T1 were statistically higher in non-survivors than survivors, (p = 0.04 and p = 0.03, respectively), whereas those of P-selectin, E-selectin and RAGE did not differ. Ang-2 and ICAM-1 at T1 were predictors of mortality (AUROC 0.650 and 0.717, respectively). At T1, RAGE and P-selectin levels were higher in classical ARDS than in COVID-19-related ARDS. Ang-2, ICAM-1 and E-selectin were lower in classical ARDS than in COVID-19-related ARDS (all p < 0.001).

Conclusions

COVID-19 ARDS is characterized by an early pulmonary endothelial injury, as detected by Ang-2 and ICAM-1. COVID-19 ARDS and classical ARDS exhibited a different expression of biomarkers, suggesting different pathological pathways.

Trial registration

NCT04343053, Date of registration: April 13, 2020