Rationale for Prolonged Glucocorticoid Use in Pediatric ARDS: What the Adults Can Teach Us

Taraxasterol Inhibits Hyperactivation of Macrophages to Alleviate the Sepsis-induced Inflammatory Response of ARDS Rats

To explore the effect and mechanism of taraxasterol on sepsis-induced acute respiratory distress syndrome (ARDS). Twenty-four male SD rats were randomly divided into four groups: the control group, model (lipopolysaccharide, LPS) group, lipopolysaccharide+taraxasterol (LPS + TXL) group, and lipopolysaccharide+ulinastatin (LPS + UTI) group. The model of sepsis-induced ARDS was established by intraperitoneal injection of LPS. The lung water content of the rats in each group was determined by the dry/wet ratio. Pathology of rat lung tissue was observed through H&E staining. Wright staining was applied to count the number of neutrophils, macrophages, and total cells. ELISA was utilized to measure the levels of the inflammatory factors TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF). Biochemical detection was adopted to check the levels of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) in lung tissue. Western blotting was performed to check the protein expression of IL-12, iNOS, Arg-1, and Mrc1 in lung tissue. Compared with the LPS group, both taraxasterol and ulinastatin significantly decreased lung tissue water content, improved lung tissue injury, reduced the number of neutrophils, macrophages and total cells, and decreased the level of inflammatory factors. In addition, taraxasterol and ulinastatin also reduced the content of MPO and the expression of IL-12 and iNOS and increased the activity of SOD and CAT as well as the protein expression of Arg-1 and Mrc1. Taraxasterol can suppress macrophage M1 polarization to alleviate the inflammatory response and oxidative stress, thereby treating sepsis-induced ARDS.

Advances in the Pharmacological Management of Pediatric Acute Respiratory Distress Syndrome

INTRODUCTION

Noninvasive mechanical ventilation is the main supportive measure used in patients with pediatric ARDS (PARDS), but adjunctive pharmacological therapies (corticosteroids, inhaled nitric oxide [iNO], surfactant replacement therapy and neuromuscular blocking drugs) are also used, although limited data exists to inform of this practice.

AREAS COVERED

The authors review the current challenges in the pharmacological management of PARDS and highlight the few certainties currently available.

EXPERT OPINION

Children with PARDS must not be treated as young adults with ARDS, essentially because children's lungs differ substantially from those of adults and PARDS occurs in children differently than ARDS in adults. Pharmacological treatments available for PARDS are relatively few and, since there is great uncertainty about their effectiveness also because of the extreme heterogeneity of this syndrome, it is necessary to conduct large clinical trials using currently available definitions and considering recent pathobiological knowledge. The aim is to identify homogeneous subgroups or phenotypes of children with PARDS that may benefit from the specific pharmaceutical approach examined. It will be then necessary to link endotypes and outcomes to appropriately target therapies in future trials, but this will be possible only after it will be possible to identify the different PARDS endotypes.

Short-Course of Methylprednisolone Improves Respiratory Functional Parameters After 120 Days in Hospitalized COVID-19 Patients (Metcovid Trial): A Randomized Clinical Trial

Background: The use of corticosteroids may help control the cytokine storm occurring in acute respiratory failure due to the severe form of COVID-19. We evaluated the postacute effect of corticosteroids used during the acute phase, such as impairment in pulmonary function parameters, on day 120 (D120)-follow-up, in participants who survived over 28 days. Methods: This is a parallel, double-blind, randomized, placebo-controlled phase IIb clinical trial carried out between April 18 and October 9, 2020, conducted in hospitalized patients with clinical-radiological suspicion of COVID-19, aged 18 years or older, with SpO2 ≤ 94% on room air or requiring supplementary oxygen, or under invasive mechanical ventilation (IMV) in a referral center in Manaus, Western Brazilian Amazon. Intravenous methylprednisolone (MP) (0.5 mg/kg) was given two times daily for 5 days to these patients. The primary outcome used for this study was pulmonary function testing at day 120 follow-up visit. Results: Out of the total of surviving patients at day 28 (n = 246) from the Metcovid study, a total of 118 underwent satisfactory pulmonary function testing (62 in the placebo arm and 56 in the MP arm). The supportive treatment was similar between the placebo and MP groups (seven [11%] vs. four [7%]; P = 0.45). At hospital admission, IL-6 levels were higher in the MP group (P < 0.01). Also, the need for ICU (P = 0.06), need for IMV (P = 0.07), and creatine kinase (P = 0.05) on admission also tended to be higher in this group. In the univariate analysis, forced expiratory volume on 1st second of exhalation (FEV1) and forced vital capacity (FVC) at D120 follow-up were significantly higher in patients in the MP arm, being this last parameter also significantly higher in the multivariate analysis independently of IMV and IL-6 levels on admission. Conclusion: The use of steroids for at least 5 days in severe COVID-19 was associated with a higher FVC, which suggests that hospitalized COVID-19 patients might benefit from the use of MP in its use in the long-term, with less pulmonary restrictive functions, attributed to fibrosis. Trial Registration: ClinicalTrials.gov, Identifier: NCT04343729.

Effectiveness of Glucocorticoids in Acute Respiratory Distress Syndrome: An Umbrella Review

Objectives. Acute respiratory distress syndrome is a very challenging condition that is associated with high morbidity and mortality. This review was intended to evaluate evidence on the effectiveness of glucocorticoid treatment for acute respiratory distress syndrome. Method. A comprehensive search strategy was conducted on PubMed/Medline, Cochrane Library, Science Direct, and LILACS. Data extraction was carried out by two independent reviewers using a customized checklist. The quality of each systematic review was assessed by two independent reviewers using an AMSTAR tool, and the overall quality of evidence was generated with online GRADEpro GDT software for primary and secondary outcomes. Results. The umbrella review included nine systematic reviews and meta-analysis and one narrative review with 8491 participants. The methodological quality of the included studies was moderate-to-high quality. The overall quality of evidence and recommendations varied form high to very low. Conclusion. There is high-to-moderate quality evidence that early low-dose prolonged glucocorticoid therapy reduces mortality in ARDS. However, randomized controlled trials with large sample sizes to address ventilator-free days, the incidence of infection, and other glucocorticoid-associated adverse events are required as the quality of evidence for these secondary outcomes which were low to very low. Registration. This umbrella review was registered in PROSPERO, the International Prospective Register of Systematic Reviews (CRD42019130539).

Preventing the development of severe COVID-19 by modifying immunothrombosis

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) is associated with significant morbidity and high levels of mortality. This paper describes the processes involved in the pathophysiology of COVID-19 from the initial infection and subsequent destruction of type II alveolar epithelial cells by SARS-CoV-2 and culminating in the development of ARDS.

MAIN BODY

The activation of alveolar cells and alveolar macrophages leads to the release of large quantities of proinflammatory cytokines and chemokines and their translocation into the pulmonary vasculature. The presence of these inflammatory mediators in the vascular compartment leads to the activation of vascular endothelial cells platelets and neutrophils and the subsequent formation of platelet neutrophil complexes. These complexes in concert with activated endothelial cells interact to create a state of immunothrombosis. The consequence of immunothrombosis include hypercoagulation, accelerating inflammation, fibrin deposition, migration of neutrophil extracellular traps (NETs) producing neutrophils into the alveolar apace, activation of the NLRP3 inflammazome, increased alveolar macrophage destruction and massive tissue damage by pyroptosis and necroptosis Therapeutic combinations aimed at ameliorating immunothrombosis and preventing the development of severe COVID-19 are discussed in detail.

Mortality in COVID-19 patients with acute respiratory distress syndrome and corticosteroids use: a systematic review and meta-analysis

OBJECTIVES

The acute respiratory distress syndrome (ARDS) secondary to viral pneumonitis is one of the main causes of high mortality in patients with COVID-19 (novel coronavirus disease 2019). We systematically reviewed mortality in COVID-19 patients with ARDS and the potential role of systemic corticosteroids in COVID-19 patients.

METHODS

Electronic databases and country-specific healthcare databases were searched to identify relevant studies/reports. The quality assessment of individual studies was conducted using the Newcastle-Ottawa Scale. Country-specific proportion of individuals with COVID-19 who developed ARDS and reported death were combined in a random-effect meta-analysis to give a pooled mortality estimate of ARDS.

RESULTS

The overall pooled mortality estimate among 10,815 ARDS cases in COVID-19 patients was 39% (95% CI: 23-56%). The pooled mortality estimate for China was 69% (95% CI: 67-72%). In Europe, the highest mortality estimate among COVID-19 patients with ARDS was reported in Poland (73%; 95% CI: 58-86%) while Germany had the lowest mortality estimate (13%; 95% CI: 2-29%) among COVID-19 patients with ARDS. The median crude mortality rate of COVID-19 patients with reported corticosteroid use was 28.0% (lower quartile: 13.9%; upper quartile: 53.6%).

CONCLUSIONS

The high mortality in COVID-19 associated ARDS necessitates a prompt and aggressive treatment strategy which includes corticosteroids. Most of the studies included no information on the dosing regimen of corticosteroid therapy, however, low-dose corticosteroid therapy or pulse corticosteroid therapy appears to have a beneficial role in the management of severely ill COVID-19 patients.

Successful use of extracorporeal membrane oxygenation in acute respiratory distress syndrome following accidental chlorine gas inhalation at a swimming pool

While there is evidence to support the use of extracorporeal membrane oxygenation in acute respiratory distress syndrome due to a variety of causes, its use in chlorine gas-induced acute respiratory distress syndrome has not been described in the English medical literature. We present a young girl who had severe acute respiratory distress syndrome following exposure to chlorine gas during the disinfection process at a swimming pool. She failed conventional management and underwent venovenous extracorporeal membrane oxygenation. Despite multiple infections and a pneumothorax, she eventually recovered. Chlorine gas was the first agent of chemical warfare which caused a massive death toll during the First World War. Even today, the chemical is produced in large quantities and the threat of a large-scale leak is ever-present from industrial accidents or terrorist attacks. The criteria to assess and manage chlorine gas-induced acute respiratory distress syndrome are likely to be the same as for other causes of acute respiratory distress syndrome and extracorporeal membrane oxygenation can be used successfully.

Steroids in pediatric acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a complex entity with high potential for harm and healthcare resource utilization. Despite multiple clinical advances in its ventilatory management, ARDS continues to be one of the most challenging disease processes for intensivists. It continues to lack a direct, proven and desperately needed effective therapeutic intervention. Given their biologic rationale, corticosteroids have been widely used by clinicians and considered useful by many in the management of ARDS since its first description. Adult data is abundant, yet contradictory. Controversy remains regarding the routine use of corticosteroids in ARDS. Therefore, widespread evidence-based recommendations for this heterogeneous disease process have not been made. In this article, our aim was to provide a summary of available evidence for the role of steroids in the treatment of ARDS, while giving special focus on pediatric ARDS (PARDS).

Corticosteroids in Acute Lung Injury: The Dilemma Continues

Acute lung injury (ALI) represents a serious heterogenous pulmonary disorder with high mortality. Despite improved understanding of the pathophysiology, the efficacy of standard therapies such as lung-protective mechanical ventilation, prone positioning and administration of neuromuscular blocking agents is limited. Recent studies have shown some benefits of corticosteroids (CS). Prolonged use of CS can shorten duration of mechanical ventilation, duration of hospitalization or improve oxygenation, probably because of a wide spectrum of potentially desired actions including anti-inflammatory, antioxidant, pulmonary vasodilator and anti-oedematous effects. However, the results from experimental vs. clinical studies as well as among the clinical trials are often controversial, probably due to differences in the designs of the trials. Thus, before the use of CS in ARDS can be definitively confirmed or refused, the additional studies should be carried on to determine the most appropriate dosing, timing and choice of CS and to analyse the potential risks of CS administration in various groups of patients with ARDS.

Pathophysiology and Management of Acute Respiratory Distress Syndrome in Children

Acute respiratory distress syndrome (ARDS) is a syndrome of noncardiogenic pulmonary edema and hypoxia that accompanies up to 30% of deaths in pediatric intensive care units. Pediatric ARDS (PARDS) is diagnosed by the presence of hypoxia, defined by oxygenation index or Pao₂/Fio₂ ratio cutoffs, and new chest infiltrate occurring within 7 days of a known insult. Hallmarks of ARDS include hypoxemia and decreased lung compliance, increased work of breathing, and impaired gas exchange. Mortality is often accompanied by multiple organ failure. Although many modalities to treat PARDS have been investigated, supportive therapies and lung protective ventilator support remain the mainstay.

[Acute respiratory distress syndrome in childhood: Changing definition and news from the Pediatric Consensus Conference]

Acute respiratory distress syndrome (ARDS) is a rapidly progressive hypoxemic respiratory insufficiency induced by alveolar filling mainly caused by alveolocapillary wall disruption, following direct or indirect pulmonary injury. Much less frequent in children than in adults, pediatric intensivists had long applied adult guidelines to their daily practice. In 2015, experts from the Pediatric Acute Lung Injury Consensus Conference (PALICC) published the first international guidelines specifically dedicated to pediatric ARDS. After a short summary of the history of the ARDS definition since its first report in 1967, we describe the main diagnostic and therapeutic guidelines for PALICC.

Hydrocortisone treatment in early sepsis-associated acute respiratory distress syndrome: results of a randomized controlled trial

Background

Authors of recent meta-analyses have reported that prolonged glucocorticoid treatment is associated with significant improvements in patients with severe pneumonia or acute respiratory distress syndrome (ARDS) of multifactorial etiology. A prospective randomized trial limited to patients with sepsis-associated ARDS is lacking. The objective of our study was to evaluate the efficacy of hydrocortisone treatment in sepsis-associated ARDS.

Methods

In this double-blind, single-center (Siriraj Hospital, Bangkok), randomized, placebo-controlled trial, we recruited adult patients with severe sepsis within 12 h of their meeting ARDS criteria. Patients were randomly assigned (1:1 ratio) to receive either hydrocortisone 50 mg every 6 h or placebo. The primary endpoint was 28-day all-cause mortality; secondary endpoints included survival without organ support on day 28.

Results

Over the course of 4 years, 197 patients were randomized to either hydrocortisone (n = 98) or placebo (n = 99) and were included in this intention-to-treat analysis. The treatment group had significant improvement in the ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen and lung injury score (p = 0.01), and similar timing to removal of vital organ support (HR 0.74, 95 % CI 0.51–1.07; p = 0.107). After adjustment for significant covariates, day 28 survival was similar for the whole group (HR 0.80, 95 % CI 0.46–1.41; p = 0.44) and for the larger subgroup (n = 126) with Acute Physiology and Chronic Health Evaluation II score <25 (HR 0.57, 95 % CI 0.24–1.36; p = 0.20). With the exception of hyperglycemia (80.6 % vs. 67.7 %; p = 0.04), the rate of adverse events was similar. Hyperglycemia had no impact on outcome.

Conclusions

In sepsis-associated ARDS, hydrocortisone treatment was associated with a significant improvement in pulmonary physiology, but without a significant survival benefit.

Trial registration

ClinicalTrials.gov identifier NCT01284452. Registered on 18 January 2011.