Dexamethasone for treatment of patients mechanically ventilated for lower respiratory tract infection caused by respiratory syncytial virus

Drugs targeting CMPK2 inhibit pyroptosis to alleviate severe pneumonia caused by multiple respiratory viruses

Severe pneumonia caused by respiratory viruses has become a major threat to humans, especially with the SARS-CoV-2 outbreak and epidemic. The aim of this study was to investigate the universal molecular mechanism of severe pneumonia induced by multiple respiratory viruses and to search for therapeutic strategies targeting this universal molecular mechanism. The common differential genes of four respiratory viruses, including respiratory syncytial virus (RSV), rhinovirus, influenza, and SARS-CoV-2, were screened by GEO database, and the hub gene was obtained by Sytohubba in Cytoscape. Then, the effect of hub genes on inflammasome and pyrodeath was investigated in the model of RSV infection in vitro and in vivo. Finally, through virtual screening, drugs targeting the hub gene were obtained, which could alleviate severe viral pneumonia in vitro and in vivo. The results showed that CMPK2 is one of the hub genes after infection by four respiratory viruses. CMPK2 activates the inflammasome by activating NLRP3, and promotes the releases of inflammatory factors interleukin (IL)-1β and IL-18 to induce severe viral pneumonia. Z25 and Z08 can reduce the expression level of CMPK2 mRNA and protein, thereby inhibiting NLRP3 and alleviating the development of severe viral pneumonia. In conclusion, the inflammatory response mediated by CMPK2 is the common molecular mechanism of severe pneumonia induced by viral infection, and Z25 and Z08 can effectively alleviate viral infection and severe pneumonia through this mechanism.

Corticosteroid in non-COVID-19 induced community-acquired pneumonia, a meta-analysis

BACKGROUND

Corticosteroid treatment in non-COVID-19 induced Community-acquired pneumonia (CAP) remains inconclusive.

OBJECTIVES

We aimed to assess the role of corticosteroid treatment in CAP.

METHODS

We conducted a comprehensive search of online databases, including PubMed, Embase, and Cochrane, to identify articles published from January 1, 2000, to May 5, 2023. Double-blind RCTs were selected. Two authors screened studies and extracted data. The evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

We analyzed data from 12 RCTs, involving 2446 patients. Corticosteroids therapy may reduce short-term mortality in patients with severe CAP (sCAP) and shorten the hospital length of stay in patients with CAP. Furthermore, corticosteroids treatment can decrease the risk of requiring mechanical ventilation, developing septic shock and multiple organ dysfunction syndrome (MODS). There were no significant differences between the corticosteroid and control groups concerning gastrointestinal bleeding and nosocomial infection. The use of corticosteroids could increase the risk of hyperglycemia.

CONCLUSION

Corticosteroid treatment for sCAP has the potential to provide benefits in reducing short-term mortality, but this conclusion necessitates more evidence. Besides, we found no evidence that strongly prevents us from using corticosteroids in patients with sCAP or those at risk of progressing to sCAP.

Management of parapneumonic pleural effusion in children: Is there a role for corticosteroids when conventional nonsurgical management fails? A single-center 15-year experience

OBJECTIVE

Description of the use of corticosteroids for the management of parapneumonic pleural effusion in children.

METHODS

Retrospective single-center observational study of all children hospitalized with a diagnosis of parapneumonic pleural effusion during a 15-year period.

RESULTS

We documented 97 cases of parapneumonic effusion during the study period, with a median age (interquartile range [IQR]) of 43 (33-61) months. Most of the children benefited from an evacuation of the pleural effusion (89/97, 91.8%): 21 patients (21.6%) were treated with needle thoracocentesis only, while a chest tube was inserted in 68 children (70.1%). Thirty-two patients (33%) were treated with intrapleural fibrinolysis. Fifty-five children (56.7%) received corticosteroids for persistent fever. The median time (IQR) between hospital admission and initiation of corticosteroids was 5.5 (4-7) days. When corticosteroids were initiated, children had been febrile for 9 (IQR: 8-11) days. The fever ceased in a median (IQR) of 0 (0-1) day after corticosteroids initiation. Only one patient required a video-assisted thoracoscopy that was necessary for morphological reasons (morbid obesity). No children treated with corticosteroids required surgery. All children were discharged from hospital. The median (IQR) hospital length of stay was 11 (8-14) days, with no difference between children with and those without corticosteroids.

CONCLUSION

Our findings indicate that corticosteroids may be a part of the therapeutic armamentarium for children with parapneumonic effusion when conventional nonsurgical management fails.

Angiotensin-converting Enzyme 2 roles in the Pathogenesis of COVID-19

The new pandemic Coronavirus Disease 2019 (COVID-19) causes a wide range of clinical consequences, from asymptomatic infection to acute respiratory failure and it is very heterogeneous. The renin-angiotensin system (RAS) is well recognized as a key regulating system in circulatory homeostasis that play prominent roles in pathophysiological processes in abnormal activation for instance renal and cardiovascular diseases, obesity, and stroke. Angiotensin converting enzyme 2(ACE2) as a component of the RAS system. However, unlike the ACE, its activity is not inhibited by the ACE inhibitors. The major product of ACE2 is Ang1-7, known as a vasodilator peptide and part of the depressant arm of the RAS. There are two form of ACE2. Coronavirus cover with some proteins in order to help viral attachment to the cell membrane ACE2 as a receptor and then fuse and enter the cells. ACE2 was expressed in oral Cavity, salivary glands of the mouth, esophagus, myocardial cells, kidney, and enterocytes, along all the respiratory tract, intestine, and blood vessels. In this article, we explain the renin-angiotensin system and its components. Also, we shortly explain the organs involved in COVID-19 disease and we will talk about the possible causes of damage to these organs. We also reviewed the probable mechanism of using ACE2 in viral attachment and the probable treatment processes will also be discussed based on the surface proteins of the virus and ACE2. In addition, we briefly discuss the anti-angiotensin drugs and why patients with chronic disease are more susceptible to COVID-19 infection and show worse progression.

Corticosteroids for treating sepsis in children and adults

BACKGROUND

Sepsis occurs when an infection is complicated by organ failure. Sepsis may be complicated by impaired corticosteroid metabolism. Thus, providing corticosteroids may benefit patients. The original review was published in 2004 and was updated in 2010 and 2015 prior to this update.

OBJECTIVES

To examine the effects of corticosteroids on death in children and adults with sepsis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, ClinicalTrials.gov, ISRCTN, and the WHO Clinical Trials Search Portal, on 25 July 2019. In addition, we conducted reference checking and citation searching, and contacted study authors, to identify additional studies as needed.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of corticosteroids versus placebo or usual care (antimicrobials, fluid replacement, and vasopressor therapy as needed) in children and adults with sepsis. We also included RCTs of continuous infusion versus intermittent bolus of corticosteroids.

DATA COLLECTION AND ANALYSIS

All review authors screened and selected studies for inclusion. One review author extracted data, which was checked by the others, and by the lead author of the primary study when possible. We obtained unpublished data from the authors of some trials. We assessed the methodological quality of trials and applied GRADE to assess the certainty of evidence. Review authors did not contribute to assessment of eligibility and risk of bias, nor to data extraction, for trials they had participated in.

MAIN RESULTS

We included 61 trials (12,192 participants), of which six included only children, two included children and adults, and the remaining trials included only adults. Nine studies are ongoing and will be considered in future versions of this review. We judged 19 trials as being at low risk of bias. Corticosteroids versus placebo or usual care Compared to placebo or usual care, corticosteroids probably slightly reduce 28-day mortality (risk ratio (RR) 0.91, 95% confidence interval (CI) 0.84 to 0.99; 11,233 participants; 50 studies; moderate-certainty evidence). Corticosteroids may result in little to no difference in long-term mortality (RR 0.97, 95% CI 0.91 to 1.03; 6236 participants; 7 studies; low-certainty evidence) and probably slightly reduce hospital mortality (RR 0.90, 95% CI 0.82 to 0.99; 8183 participants; 26 trials; moderate-certainty evidence). Corticosteroids reduced length of intensive care unit (ICU) stay for all participants (mean difference (MD) -1.07 days, 95% CI -1.95 to -0.19; 7612 participants; 21 studies; high-certainty evidence) and resulted in a large reduction in length of hospital stay for all participants (MD -1.63 days, 95% CI -2.93 to -0.33; 8795 participants; 22 studies; high-certainty evidence). Corticosteroids increase the risk of muscle weakness (RR 1.21, 95% CI 1.01 to 1.44; 6145 participants; 6 studies; high-certainty evidence). Corticosteroids probably do not increase the risk of superinfection (RR 1.06, 95% CI 0.95 to 1.19; 5356 participants; 25 studies; moderate-certainty evidence). Corticosteroids increase the risk of hypernatraemia (high-certainty evidence) and probably increase the risk of hyperglycaemia (moderate-certainty evidence). Moderate-certainty evidence shows that there is probably little or no difference in gastroduodenal bleeding, stroke, or cardiac events, and low-certainty evidence suggests that corticosteroids may result in little to no difference in neuropsychiatric events. Continuous infusion of corticosteroids versus intermittent bolus We are uncertain about the effects of continuous infusion of corticosteroids compared with intermittent bolus administration. Three studies reported data for this comparison, and the certainty of evidence for all outcomes was very low.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence indicates that corticosteroids probably reduce 28-day and hospital mortality among patients with sepsis. Corticosteroids result in large reductions in ICU and hospital length of stay (high-certainty evidence). There may be little or no difference in the risk of major complications; however, corticosteroids increase the risk of muscle weakness and hypernatraemia, and probably increase the risk of hyperglycaemia. The effects of continuous versus intermittent bolus administration of corticosteroids are uncertain.

Emerging problems in the treatment of pediatric community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) remains one of the most common reasons for paediatric morbidity and accounts for about 16% of all the deaths occurring in children less than 5 years of age. Areas covered: The main aim of this paper is to discuss the emerging problems for CAP treatment in paediatric age. Expert commentary: Official recommendations for therapeutic approaches to paediatric CAP, despite being not very recent, seem still to be the best solution to assure the highest probabilities of cure for children with this disease living in industrialized countries. Amoxicillin remains the drug of choice and use of macrolides alone or in combination does not seem supported by solid evidence. Corticosteroids can be useful in CAP associated with bronco-obstruction, whereas their effectiveness in cases with a severe inflammatory response, although plausible, is not supported by data collected through randomized, placebo-controlled trials. Finally, for the administration of vitamin C and vitamin D, the available data are not adequate to draw firm conclusions regarding the real importance of supplementation. Further studies are needed to evaluate which modifications of presently available recommendations for paediatric CAP treatment can improve final prognosis of this still common disease.

Bayesian sample size re-estimation using power priors

The sample size of a randomized controlled trial is typically chosen in order for frequentist operational characteristics to be retained. For normally distributed outcomes, an assumption for the variance needs to be made which is usually based on limited prior information. Especially in the case of small populations, the prior information might consist of only one small pilot study. A Bayesian approach formalizes the aggregation of prior information on the variance with newly collected data. The uncertainty surrounding prior estimates can be appropriately modelled by means of prior distributions. Furthermore, within the Bayesian paradigm, quantities such as the probability of a conclusive trial are directly calculated. However, if the postulated prior is not in accordance with the true variance, such calculations are not trustworthy. In this work we adapt previously suggested methodology to facilitate sample size re-estimation. In addition, we suggest the employment of power priors in order for operational characteristics to be controlled.

Corticosteroids for pneumonia

BACKGROUND

Pneumonia is a common and potentially serious illness. Corticosteroids have been suggested for the treatment of different types of infection, however their role in the treatment of pneumonia remains unclear. This is an update of a review published in 2011.

OBJECTIVES

To assess the efficacy and safety of corticosteroids in the treatment of pneumonia.

SEARCH METHODS

We searched the Cochrane Acute Respiratory Infections Group's Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS on 3 March 2017, together with relevant conference proceedings and references of identified trials. We also searched three trials registers for ongoing and unpublished trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that assessed systemic corticosteroid therapy, given as adjunct to antibiotic treatment, versus placebo or no corticosteroids for adults and children with pneumonia.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently assessed risk of bias and extracted data. We contacted study authors for additional information. We estimated risk ratios (RR) with 95% confidence intervals (CI) and pooled data using the Mantel-Haenszel fixed-effect model when possible.

MAIN RESULTS

We included 17 RCTs comprising a total of 2264 participants; 13 RCTs included 1954 adult participants, and four RCTs included 310 children. This update included 12 new studies, excluded one previously included study, and excluded five new trials. One trial awaits classification.All trials limited inclusion to inpatients with community-acquired pneumonia (CAP), with or without healthcare-associated pneumonia (HCAP). We assessed the risk of selection bias and attrition bias as low or unclear overall. We assessed performance bias risk as low for nine trials, unclear for one trial, and high for seven trials. We assessed reporting bias risk as low for three trials and high for the remaining 14 trials.Corticosteroids significantly reduced mortality in adults with severe pneumonia (RR 0.58, 95% CI 0.40 to 0.84; moderate-quality evidence), but not in adults with non-severe pneumonia (RR 0.95, 95% CI 0.45 to 2.00). Early clinical failure rates (defined as death from any cause, radiographic progression, or clinical instability at day 5 to 8) were significantly reduced with corticosteroids in people with severe and non-severe pneumonia (RR 0.32, 95% CI 0.15 to 0.7; and RR 0.68, 95% CI 0.56 to 0.83, respectively; high-quality evidence). Corstocosteroids reduced time to clinical cure, length of hospital and intensive care unit stays, development of respiratory failure or shock not present at pneumonia onset, and rates of pneumonia complications.Among children with bacterial pneumonia, corticosteroids reduced early clinical failure rates (defined as for adults, RR 0.41, 95% CI 0.24 to 0.70; high-quality evidence) based on two small, clinically heterogeneous trials, and reduced time to clinical cure.Hyperglycaemia was significantly more common in adults treated with corticosteroids (RR 1.72, 95% CI 1.38 to 2.14). There were no significant differences between corticosteroid-treated people and controls for other adverse events or secondary infections (RR 1.19, 95% CI 0.73 to 1.93).

AUTHORS' CONCLUSIONS

Corticosteroid therapy reduced mortality and morbidity in adults with severe CAP; the number needed to treat for an additional beneficial outcome was 18 patients (95% CI 12 to 49) to prevent one death. Corticosteroid therapy reduced morbidity, but not mortality, for adults and children with non-severe CAP. Corticosteroid therapy was associated with more adverse events, especially hyperglycaemia, but the harms did not seem to outweigh the benefits.

Identification of IFN-γ and IL-27 as Critical Regulators of Respiratory Syncytial Virus-Induced Exacerbation of Allergic Airways Disease in a Mouse Model

Respiratory syncytial virus (RSV) infection induces asthma exacerbations, which leads to worsening of clinical symptoms and may result in a sustained decline in lung function. Exacerbations are the main cause of morbidity and mortality associated with asthma, and significantly contribute to asthma-associated healthcare costs. Although glucocorticoids are used to manage exacerbations, some patients respond to them poorly. The underlying mechanisms associated with steroid-resistant exacerbations remain largely unknown. We have previously established a mouse model of RSV-induced exacerbation of allergic airways disease, which mimics hallmark clinical features of asthma. In this study, we have identified key roles for macrophage IFN-γ and IL-27 in the regulation of RSV-induced exacerbation of allergic airways disease. Production of IFN-γ and IL-27 was steroid-resistant, and neutralization of IFN-γ or IL-27 significantly suppressed RSV-induced steroid-resistant airway hyperresponsiveness and airway inflammation. We have previously implicated activation of pulmonary macrophage by TNF-α and/or MCP-1 in the mechanisms of RSV-induced exacerbation. Stimulation of pulmonary macrophages with TNF-α and/or MCP-1 induced expression of both IFN-γ and IL-27. Our findings highlight critical roles for IFN-γ and IL-27, downstream of TNF-α and MCP-1, in the mechanism of RSV-induced exacerbation. Thus, targeting the pathways that these factors activate may be a potential therapeutic approach for virus-induced asthma exacerbations.

Nonantibiotic Adjunctive Therapies for Community-Acquired Pneumonia (Corticosteroids and Beyond): Where Are We with Them?

Community-acquired pneumonia (CAP) is a leading cause of hospitalization, morbidity, and mortality. Despite advances in antibiotic treatments, mortality among patients with CAP is still high. For this reason, interest has been focused on nonantibiotic therapeutic measures directed to the host response rather than the microorganism. The development of an efficacious adjunctive treatment has important implications for reducing mortality in CAP. Some clinical studies performed in the last decade have shown a clinically beneficial effect of corticosteroids, possibly by diminishing local and systemic inflammatory host response. Recent meta-analyses showed faster resolution of symptoms, shorter time to clinically stability, reduction of mechanical ventilation needed, and reduction of mortality in the most severe population, although some methodological limitations must be taken into account. In addition, some studies using statins also suggested improved outcomes due to its anti-inflammatory effect in CAP, although this requires further research. Other adjunctive therapies such as immunoglobulins and stem cells are being explored, but are not yet in the stage of clinical trials. In summary, the use of corticosteroids and other adjuvant treatments are promising in CAP, but more studies are needed to determine their impact on mortality.

Pathogen- and antibiotic-specific effects of prednisone in community-acquired pneumonia

In a double-blind, randomised, placebo-controlled trial of hospitalised patients with community-acquired pneumonia (CAP), we demonstrated shorter time to clinical stability (TTCS) with adjunct corticosteroid therapy compared with placebo.

We did a pre-planned, exploratory analysis of any association between microbiological diagnosis, antibiotic treatment and procalcitonin level and effect of prednisone on TTCS, mortality, and CAP complications (n=726 participants, enrolled between December 2009 and May 2014). Multiplex viral real time PCR was systematically performed in nasopharyngeal swabs beginning November 2011 (n=489). Other investigations and treatments were at the discretion of the physician. Effect modification was tested with inclusion of interaction terms in the statistical models.

Reduced TTCS with prednisone was seen in all microbiological, antibiotic, procalcitonin and afebrile patient subgroups. We found evidence for a different prednisone response in patients with pneumococcal pneumonia in whom intravenous antibiotic duration was not shorter (interaction p=0.01) with prednisone, as was observed in the remaining study population. In patients without macrolide treatment, rehospitalisations were not lower with prednisone (interaction p=0.04). After adjustment for multiple testing, these subgroup effects were no longer significant.

Prednisone was associated with shorter TTCS independent of CAP aetiology. In pneumococcal pneumonia, prednisone effects on secondary endpoints may be less favourable.

TNF-α and Macrophages Are Critical for Respiratory Syncytial Virus-Induced Exacerbations in a Mouse Model of Allergic Airways Disease

Viral respiratory infections trigger severe exacerbations of asthma, worsen disease symptoms, and impair lung function. To investigate the mechanisms underlying viral exacerbation, we established a mouse model of respiratory syncytial virus (RSV)-induced exacerbation after allergen sensitization and challenge. RSV infection of OVA-sensitized/challenged BALB/c mice resulted in significantly increased airway hyperresponsiveness (AHR) and macrophage and neutrophil lung infiltration. Exacerbation was accompanied by increased levels of inflammatory cytokines (including TNF-α, MCP-1, and keratinocyte-derived protein chemokine [KC]) compared with uninfected OVA-treated mice or OVA-treated mice exposed to UV-inactivated RSV. Dexamethasone treatment completely inhibited all features of allergic disease, including AHR and eosinophil infiltration, in uninfected OVA-sensitized/challenged mice. Conversely, dexamethasone treatment following RSV-induced exacerbation only partially suppressed AHR and failed to dampen macrophage and neutrophil infiltration or inflammatory cytokine production (TNF-α, MCP-1, and KC). This mimics clinical observations in patients with exacerbations, which is associated with increased neutrophils and often poorly responds to corticosteroid therapy. Interestingly, we also observed increased TNF-α levels in sputum samples from patients with neutrophilic asthma. Although RSV-induced exacerbation was resistant to steroid treatment, inhibition of TNF-α and MCP-1 function or depletion of macrophages suppressed features of disease, including AHR and macrophage and neutrophil infiltration. Our findings highlight critical roles for macrophages and inflammatory cytokines (including TNF-α and MCP-1) in viral-induced exacerbation of asthma and suggest examination of these pathways as novel therapeutic approaches for disease management.

Recent advances in the management of acute bronchiolitis

Acute bronchiolitis is characterized by acute wheezing in infants or children and is associated with signs or symptoms of respiratory infection; it is rarely symptomatic in adults and the most common etiologic agent is respiratory syncytial virus (RSV). Usually it does not require investigation, treatment is merely supportive and a conservative approach seems adequate in the majority of children, especially for the youngest ones (<3 months); however, clinical scoring systems have been proposed and admission in hospital should be arranged in case of severe disease or a very young age or important comorbidities. Apnea is a very important aspect of the management of young infants with bronchiolitis. This review focuses on the clinical, radiographic, and pathologic characteristics, as well as the recent advances in management of acute bronchiolitis.

The effect of TIP on pneumovirus-induced pulmonary edema in mice

Background

Pulmonary edema plays a pivotal role in the pathophysiology of respiratory syncytial virus (RSV)-induced respiratory failure. In this study we determined whether treatment with TIP (AP301), a synthetic cyclic peptide that mimics the lectin-like domain of human TNF, decreases pulmonary edema in a mouse model of severe human RSV infection. TIP is currently undergoing clinical trials as a therapy for pulmonary permeability edema and has been shown to decrease pulmonary edema in different lung injury models.

Methods

C57BL/6 mice were infected with pneumonia virus of mice (PVM) and received TIP or saline (control group) by intratracheal instillation on day five (early administration) or day seven (late administration) after infection. In a separate set of experiments the effect of multiple dose administration of TIP versus saline was tested. Pulmonary edema was determined by the lung wet-to-dry (W/D) weight ratio and was assessed at different time-points after the administration of TIP. Secondary outcomes included clinical scores and lung cellular response.

Results

TIP did not have an effect on pulmonary edema in different dose regimens at different time points during PVM infection. In addition, TIP administration did not affect clinical severity scores or lung cellular response.

Conclusion

In this murine model of severe RSV infection TIP did not affect pulmonary edema nor course of disease.

Corticosteroids in the treatment of severe community-acquired pneumonia

Controversy surrounds the use of adjunctive corticosteroids in severe community acquired pneumonia (CAP) as current guidelines either do not address or discourage their use. Double-blind, placebo-controlled, randomized controlled trials examining systemic corticosteroids in the treatment of severe CAP were summarized and their impacts on patient-important outcomes assessed. Four trials describing systemic corticosteroid use in adults with severe CAP were identified. One trial had a significant mortality difference favoring corticosteroids. However, this may be the result of a CAP severity imbalance within the trial and the mortality benefit was not confirmed in a larger trial conducted in a similar critical care setting. Pneumonia severity, mortality assessment timing, comorbidities, corticosteroid and antibiotic choice and timing in the CAP disease course, and bias risks varied across the four trials. Because of the clinical heterogeneity of available studies and the unknowns pertaining to clinical efficacy and safety, we do not recommend the use of adjunctive corticosteroids in severe CAP.

Acute bronchiolitis in infants, a review

Acute viral bronchiolitis is one of the most common medical emergency situations in infancy, and physicians caring for acutely ill children will regularly be faced with this condition. In this article we present a summary of the epidemiology, pathophysiology and diagnosis, and focus on guidelines for the treatment of bronchiolitis in infants. The cornerstones of the management of viral bronchiolitis are the administration of oxygen and appropriate fluid therapy, and overall a “minimal handling approach” is recommended. Inhaled adrenaline is commonly used in some countries, but the evidences are sparse. Recently, inhalation with hypertonic saline has been suggested as an optional treatment. When medical treatment fails to stabilize the infants, non-invasive and invasive ventilation may be necessary to prevent and support respiratory failure. It is important that relevant treatment algorithms exist, applicable to all levels of the treatment chain and reflecting local considerations and circumstances.

In search of a small-molecule inhibitor for respiratory syncytial virus

Respiratory syncytial virus has been an ongoing health problem for 50 years. Hospitalization rates due to virus-induced respiratory illness continue to be substantial for infants, small children, the elderly and the immunocompromised. The only currently available treatments are a broad-spectrum antiviral and two immunoprophylactic antibodies, all of which are reserved for high-risk patients. The combination of this limited therapeutic repertoire and the lack of a vaccine clearly demonstrates the need to continue the search for more efficacious and safe agents against respiratory syncytial virus. The following is a review on the current progress of that search.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.

OBJECTIVES

To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 12), MEDLINE (1950 to January week 2, 2013), EMBASE (1980 to January 2013), LILACS (1982 to January 2013), Scopus® (1823 to January 2013) and IRAN MedEx (1998 to November 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children under 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. We meta-analysed inpatient and outpatient results separately using random-effects models. We pre-specified subgroup analyses, including the combined use of bronchodilators used in a protocol.

MAIN RESULTS

We included 17 trials (2596 participants); three had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% confidence interval (CI) 0.78 to 1.08 and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65; 95% CI 0.44 to 0.95; number needed to treat 11; 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.

AUTHORS' CONCLUSIONS

Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalisation. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.

Is prolonged low-dose glucocorticoid treatment beneficial in community-acquired pneumonia?

Community-acquired pneumonia (CAP) has a significant impact on public health in terms of short-term and long-term morbidity and mortality. Irrespective of microbiological etiology, the host's inability to fully downregulate systemic inflammation is the dominant pathogenetic process contributing to acute and long-term morbidity and mortality in CAP. Glucocorticoids are the natural regulators of inflammation, and their production increases during infection. There is consistent evidence that downregulation of systemic inflammation with prolonged low-dose glucocorticoid treatment in patients with severe sepsis and acute respiratory distress syndrome improves cardiovascular and pulmonary organ physiology. A recent meta-analysis of pooled controlled small trials (n = 970) of patients admitted with CAP found improved short-term mortality in the subgroup with severe CAP and/or receiving >5 days of glucocorticoid treatment. We have expanded on this meta-analysis by including patients with CAP recruited in trials investigating prolonged low-dose glucocorticoid treatment in septic shock and/or early acute respiratory distress syndrome (n = 1,206). Our findings confirm a survival advantage for severe CAP (RR 0.66, 95% confidence interval 0.51-0.84; p = .001). A large randomized trial is in progress to confirm the aggregate findings of these small trials and to evaluate the long-term effect of this low-cost treatment.

Resveratrol Inhibits respiratory syncytial virus-induced IL-6 production, decreases viral replication, and downregulates TRIF expression in airway epithelial cells

Respiratory syncytial virus (RSV) is the most common pathogen responsible for lower respiratory diseases in children. So far, there is no effective treatment or preventative vaccine available for RSV infection, although ribavirin and dexamethasone are commonly prescribed. Resveratrol has been shown to inhibit the replication of several other viruses, thus the effect of resveratrol on RSV-induced inflammatory mediators in 9HTEo cell cultures was evaluated, and possible mechanisms of action were explored and compared with dexamethasone and ribavirin. Incubation with resveratrol resulted in decreased IL-6 production and partial inhibition of RSV replication. Resveratrol treatment also inhibited virus-induced TIR-domain-containing adapter-inducing interferon-β (TRIF) and TANK binding kinase 1 (TBK1) protein expression. These data demonstrate the ability of resveratrol to inhibit cytokine production by RSV in airway epithelial cells, indicating that it might be a therapeutic agent with both anti-inflammatory and antiviral potential for the treatment of RSV infection.

The Pneumonia Virus of Mice (PVM) model of acute respiratory infection

Pneumonia Virus of Mice (PVM) is related to the human and bovine respiratory syncytial virus (RSV) pathogens, and has been used to study respiratory virus replication and the ensuing inflammatory response as a component of a natural host—pathogen relationship. As such, PVM infection in mice reproduces many of the clinical and pathologic features of the more severe forms of RSV infection in human infants. Here we review some of the most recent findings on the basic biology of PVM infection and its use as a model of disease, most notably for explorations of virus infection and allergic airways disease, for vaccine evaluation, and for the development of immunomodulatory strategies for acute respiratory virus infection.

Inflammatory responses to respiratory syncytial virus (RSV) infection and the development of immunomodulatory pharmacotherapeutics

Respiratory syncytial virus (RSV; Family Paramyxoviridae, Genus Pneumovirus) is a major respiratory pathogen of infants and children and an emerging pathogen of the elderly. Current management of RSV disease includes monoclonal antibody prophylaxis for infants identified as high risk and supportive care for those with active infection; there is no vaccine, although several are under study. In this manuscript, we review published findings from human autopsy studies, as well as experiments that focus on human clinical samples and mouse models of acute pneumovirus infection that elucidate basic principles of disease pathogenesis. Consideration of these data suggests that the inflammatory responses to RSV and related pneumoviral pathogens can be strong, persistent, and beyond the control of conventional antiviral and anti-inflammatory therapies, and can have profound negative consequences to the host. From this perspective, we consider the case for specific immunomodulatory strategies that may have the potential to alleviate some of the more serious sequelae of this disease.

Corticosteroids in respiratory diseases in children

We review recent advances in the use of corticosteroids (CS) in pediatric lung disease. CS are frequently used, systemically or by inhalation. Their mechanisms of action in pulmonary diseases are ill defined. CS exert direct inhibitory effects on many inflammatory cells through genomic mechanisms. There is a time lag before clinical response, and the washout of effects is also prolonged. Prompt relief in some conditions, such as croup, may be related to airway mucosal vasoconstriction through a nongenomic mechanism. CS have proven beneficial roles in the treatment of asthma, croup, allergic bronchopulmonary aspergillosis, and subglottic hemangioma. In some conditions, such as bronchiolitis, cystic fibrosis, and bronchopulmonary dysplasia, their use is controversial and is not recommended routinely. In other conditions, such as tuberculosis, interstitial lung disease, acute lung aspiration, and acute respiratory distress syndrome, CS are often used empirically despite the lack of clear evidence of their benefit. New drug regimens, including the more flexible use of inhaled corticosteroids and long-acting β-agonists in asthma, the lack of efficacy of oral corticosteroids in preschool children with acute wheeze, the severe complications of systemic dexamethasone used to prevent bronchopulmonary dysplasia and thus more restricted use, and the beneficial effect of pulse high-dose intravenous methylprednisolone in patients with allergic bronchopulmonary aspergillosis or cystic fibrosis are among the major recent developments. There is concern about adverse effects, especially growth and adrenal suppression, induced by systemic CS in children. These have been reduced, but not eliminated, with the use of the inhaled route. The benefits must be weighed against the potential detrimental effects.

Dexamethasone in children mechanically ventilated for lower respiratory tract infection caused by respiratory syncytial virus: a randomized controlled trial

OBJECTIVE

To determine the efficacy of dexamethasone in the treatment of mechanically ventilated children with respiratory syncytial virus-severe lower respiratory tract infection.

DESIGN

International, multicenter, randomized, double-blind, placebo-controlled trial.

SETTING

Twelve pediatric intensive care units.

SUBJECTS

Children (<2 yrs) mechanically ventilated for respiratory syncytial virus lower respiratory tract infection. Children were prestratified for severity of oxygen abnormalities on admission.

INTERVENTION

Intravenous dexamethasone (0.6 mg/kg/day, 48 hrs) or placebo.

MEASUREMENTS AND MAIN RESULTS

A superiority approach was used in the subgroup of patients with mild oxygen abnormalities (arterial partial pressure of oxygen/fractional inspired oxygen concentration [PaO(2)/FIO(2)] >200 mm Hg and/or mean arterial pressure ≤10 cm H(2)O) and a noninferiority approach in those with severe oxygen abnormalities (PaO(2)/FIO(2) ≤200 mm Hg and mean arterial pressure >10 cm H(2)O). Primary outcome was the duration of mechanical ventilation. In the subgroup with mild oxygenation abnormalities, 45 of the 89 included patients received dexamethasone and 44 placebo; in the subgroup with severe oxygenation abnormalities, 28 of the 56 included patients received dexamethasone and 28 placebo. Baseline characteristics in both treatment arms were similar for both subgroups. After the third interim analysis, the trial was stopped early for futility taking the slow enrollment into account. At that time, the median duration (interquartile range) of mechanical ventilation was 137 (91-195) hrs in the dexamethasone- and 139 (117-188) hrs in the placebo-treated patients in the subgroup with mild oxygenation abnormalities (p = .6). In the subgroup with severe oxygenation abnormalities, it was 171 (136-212) hrs in the dexamethasone- and 170 (125-201) hrs in the placebo-treated patients (p = .6).

CONCLUSION

In this prematurely ended trial in children mechanically ventilated for severe respiratory syncytial virus-lower respiratory tract infection, we found no evidence of a beneficial effect of dexamethasone in children with mild oxygenation abnormalities. Neither was evidence found that dexamethasone may prolong mechanical ventilation in those with severe oxygenation abnormalities.

Corticosteroids for pneumonia

BACKGROUND

Pneumonia is an acute inflammation of the lungs and treatments differ depending on the type and severity. Corticosteroids can influence immune regulation, carbohydrate metabolism, protein catabolism, electrolyte balance and stress response. However, the benefits of corticosteroids for patients with pneumonia remains unclear.

OBJECTIVES

To assess the efficacy and safety of corticosteroids in the treatment of pneumonia.

SEARCH STRATEGY

We searched Cochrane Central Register of Controlled Clinical Trials (CENTRAL) (The Cochrane Library 2010, Issue 11) which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to December week 4, 2010), EMBASE (1974 to December 2010), the China National Knowledge Infrastructure (CNKI) (1978 to December 2010) and VIP (1986 to December 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the effectiveness of corticosteroids for pneumonia.

DATA COLLECTION AND ANALYSIS

Three review authors selected studies. We telephoned the trial authors to confirm the randomisation method used. We extracted and analysed the methodological details and data from the included studies.

MAIN RESULTS

We included six studies including 437 participants in the review. Two studies were of high methodological quality and three were of poor quality. All studies involved small numbers of participants. Two small studies provided weak evidence that corticosteroids did not significantly reduce mortality (Peto odds ratio (OR) 0.26; 95% CI 0.05 to 1.37), but accelerated the resolution of symptoms or time to clinical stability, and decreased the rate of relapse of the disease. Steroids can improve the oxygenation and reduce the need for mechanical ventilation in severe pneumonia. There was no significant difference between treatment groups with regards to the time to discharge from the intensive care unit (ICU). There were insufficient data to report the time to pneumonia resolution and admission to ICU. Typical adverse events associated with corticosteroid therapy were infrequent.

AUTHORS' CONCLUSIONS

In most patients with pneumonia, corticosteroids are generally beneficial for accelerating the time to resolution of symptoms. However, evidence from the included studies was not strong enough to make any recommendations.

Small sample approach, and statistical and epidemiological aspects

In this chapter, the design of pharmacokinetic studies and phase III trials in children is discussed. Classical approaches and relatively novel approaches, which may be more useful in the context of drug research in children, are discussed. The burden of repeated blood sampling in pediatric pharmacokinetic studies may be overcome by the population pharmacokinetics approach using nonlinear mixed effect modeling as the statistical solution to sparse data. Indications and contraindications for phase III trials are discussed: only when there is true "equipoise" in the medical scientific community, it is ethical to conduct a randomized clinical trial. The many reasons why a pediatric trial may fail are illustrated with examples. Inadequate sample sizes lead to inconclusive results. Twelve classical strategies to minimize sample sizes are discussed followed by an introduction to group sequential design, boundaries design, and adaptive design. The evidence that these designs reduce sample sized between 35 and 70% is reviewed. The advantages and disadvantages of the different approaches are highlighted to give the reader a broad idea of the design types that can be considered. Finally, working with DMCs during the conduct of trials is introduced. The evidence regarding DMC activities, interim analysis results, and early termination of pediatric trials is presented. So far reporting is incomplete and heterogeneous, and users of trial reports may be misled by the results. A proposal for a checklist for the reporting of DMC issues, interim analyses, and early stopping is presented.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.

OBJECTIVES

To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, issue 4); MEDLINE (1950 to November 2009); EMBASE (1980 to Week 47 2009); LILACS (1982 to November 2009); Scopus® (1823 to November 2009); and IRAN MedEx (1998 to November 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children < 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. Inpatient and outpatient results were meta-analysed separately using random-effects models. We pre-specified subgroup analyses, including the combined use of protocolised bronchodilators.

MAIN RESULTS

We included 17 trials (2596 participants); only two had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% CI 0.78 to 1.08; and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65, 95% CI 0.44 to 0.95; number needed to treat 11, 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.

AUTHORS' CONCLUSIONS

Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalization. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.

Respiratory syncytial virus infections: characteristics and treatment

In this review, we describe the history, epidemiology and clinical manifestations of infections attributed to respiratory syncytial virus (RSV) in children. At present, no cure exists for RSV infection but commonly employed palliative treatments include oxygen and inhaled β2-adrenoceptor agonists, such as salbutamol, to relieve the wheezing and increased bronchiolar smooth muscle constriction. Adrenaline (epinephrine) has been found to be superior to the selective β2-adrenoceptor agonists. Oral or inhaled corticosteroids should counteract the inflammatory response to RSV infection but their effectiveness is controversial. Inhaled ribavirin is the only licensed antiviral product approved for the treatment of RSV lower respiratory-tract infection in hospitalized children, although its use is now restricted to high-risk infants. Other treatments considered are nasopharyngeal suctioning, surfactant therapy, recombinant human deoxyribonuclease I, heliox (helium:oxygen) and inhaled nitric oxide. Prevention of infection by RSV antibodies is another strategy and, currently, palivizumab is the only safe, effective and convenient preventative treatment for RSV disease in high-risk populations of infants and young children. Its cost-effectiveness, however, has been questioned. Both live attenuated and subunit vaccines against RSV infection have been developed but so far there is no safe and effective vaccine available. Finding effective treatments and prophylactic measures remains a major challenge for the future.

Antenatal and postnatal corticosteroid and resuscitation induced lung injury in preterm sheep

Background

Initiation of ventilation using high tidal volumes in preterm lambs causes lung injury and inflammation. Antenatal corticosteroids mature the lungs of preterm infants and postnatal corticosteroids are used to treat bronchopulmonary dysplasia.

Objective

To test if antenatal or postnatal corticosteroids would decrease resuscitation induced lung injury.

Methods

129 d gestational age lambs (n = 5-8/gp; term = 150 d) were operatively delivered and ventilated after exposure to either 1) no medication, 2) antenatal maternal IM Betamethasone 0.5 mg/kg 24 h prior to delivery, 3) 0.5 mg/kg Dexamethasone IV at delivery or 4) Cortisol 2 mg/kg IV at delivery. Lambs then were ventilated with no PEEP and escalating tidal volumes (V_T) to 15 mL/kg for 15 min and then given surfactant. The lambs were ventilated with V_T 8 mL/kg and PEEP 5 cmH₂0 for 2 h 45 min.

Results

High V_T ventilation caused a deterioration of lung physiology, lung inflammation and injury. Antenatal betamethasone improved ventilation, decreased inflammatory cytokine mRNA expression and alveolar protein leak, but did not prevent neutrophil influx. Postnatal dexamethasone decreased pro-inflammatory cytokine expression, but had no beneficial effect on ventilation, and postnatal cortisol had no effect. Ventilation increased liver serum amyloid mRNA expression, which was unaffected by corticosteroids.

Conclusions

Antenatal betamethasone decreased lung injury without decreasing lung inflammatory cells or systemic acute phase responses. Postnatal dexamethasone or cortisol, at the doses tested, did not have important effects on lung function or injury, suggesting that corticosteroids given at birth will not decrease resuscitation mediated injury.

Effect of dexamethasone on respiratory syncytial virus-induced lung inflammation in children: results of a randomized, placebo controlled clinical trial

Inflammatory mediators play a major role in the pathogenesis of respiratory syncytial virus (RSV) infection. The objective of this study was to evaluate the effect of i.v. dexamethasone on cytokine concentrations in tracheal aspirates (TA) of children with severe RSV disease and to correlate them with disease severity. Twenty-five cytokines were measured in TA obtained from children <2 yr old intubated for severe RSV disease, and enrolled in a double-blind study of i.v. dexamethasone (0.5 mg/kg; n = 22) vs. placebo (n = 19). Cytokine concentrations, measured at baseline and days 1 and 5 post-randomization using a multiplex assay, were compared within both treatment groups and correlated with: (i) tracheal white blood cell counts, (ii) tracheal RSV loads by culture and (iii) parameters of disease severity, including number of days of requirement for mechanical ventilation, intensive care unit (ICU), and hospitalization. At baseline interleukin (IL)-13 and IL-15 concentrations were significantly higher in the dexamethasone treatment group. On day 1 post-treatment, only MCP-1, eotaxin and IL-6 concentrations were significantly different but higher in the placebo group. On day 5: IL-13, IL-7, IL-8 and MIP-1alpha concentrations were higher in dexamethasone-treated patients. In both groups MIP-1beta inversely correlated with the days of ventilator support; MIP-1alpha, MIP-1beta and eotaxin inversely correlated with ICU days; and IL-6 inversely correlated with hospitalization regardless of the treatment assigned. Systemic administration of dexamethasone did not have a consistent effect on TA concentrations of pro-inflammatory cytokines. This may help explain, at least in part, the lack of clinical benefit of steroid treatment in children with severe RSV bronchiolitis.

Antiviral therapy for respiratory tract infections

Viruses are important pathogens causing respiratory tract infections both in the community and health‐care facility settings. They are extremely common causes of morbidity in the competent hosts and some are associated with significant mortality in the compromised individuals. With wider application of molecular techniques, novel viruses are being described and old viruses are found to have new significance in different epidemiological and clinical settings. Some of these emerging pathogens may have the potential to cause pandemics or global spread of a severe disease, as exemplified by severe acute respiratory syndrome and avian influenza. Antiviral therapy of viral respiratory infections is often unnecessary in the competent hosts because most of them are self‐limiting and effective agents are not always available. In the immunocompromised individuals or for infections caused by highly pathogenic viruses, such as avian influenza viruses (AIV), antiviral treatment is highly desirable, despite the fact that many of the agents may not have undergone stringent clinical trials. In immunocompetent hosts, antiviral therapy can be stopped early because adaptive immune response can usually be mounted within 5–14 days. However, the duration of antiviral therapy in immunosuppressed hosts depends on clinical and radiological resolution, the degree and duration of immunosuppression, and therefore maintenance therapy is sometimes needed after the initial response. Immunotherapy and immunoprophylaxis appear to be promising directions for future research. Appropriate and targeted immunomodulation may play an important adjunctive role in some of these infections by limiting the extent of end‐organ damage and multi‐organ failure in some fulminant infections.

Pitfalls in the design and analysis of paediatric clinical trials: a case of a 'failed' multi-centre study, and potential solutions

Aim: To increase awareness of possible pitfalls in the design and analysis of a multi-centre randomized clinical trial and to give an overview of alternative study designs and their consequences for power analyses in case of limited availability of trial participants.

Methods: Investigation of the assumptions in the power calculation and re-analysis of the original data of a ‘failed’ trial on the effect of dexamethasone on the duration of mechanical ventilation in young children with respiratory syncytial virus infection. Use of ‘boundaries approach’ is explored using the data from this trial. A comprehensive overview of the various modern solutions for the design of a subsequent trial in this field is given.

Results: Two frequent major deficiencies of trial design and data analysis are reviewed in depth, i.e. too optimistic assumptions for the sample size calculation and failure to adjust for centre effects.

Conclusion: Critical review of trial assumptions and if necessary sample size recalculation based on an internal pilot by a data monitoring committee is recommended to maximize the probability of obtaining conclusive results.

WITHDRAWN: Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Systemic glucocorticoids have been widely prescribed for use in infants and young children with acute viral bronchiolitis but the actual benefit of this intervention requires clarification.

OBJECTIVES

To systematically review the evidence on the effectiveness of systemic glucocorticoids for the treatment of infants and young children with acute viral bronchiolitis.

SEARCH STRATEGY

Multiple strategies were incorporated to maximize identification of suitable studies. The following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003); MEDLINE (January 1966 to September 2003); Current Contents (1998 to 2000); EMBASE (January 1990 to September 2003); and Sci Search. Handsearches through cited references and contacts with experts were also used.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were eligible for inclusion. Studies were included if participants were diagnosed with acute viral bronchiolitis and treated with systemic (oral, intramuscular or intravenous) corticosteroids. Three reviewers independently selected potentially relevant articles. Four reviewers evaluated these studies, determined eligibility and assessed the methodological quality of each RCT.

DATA COLLECTION AND ANALYSIS

The primary outcome of interest was length of hospital stay (LOS). Secondary outcomes were: respiratory rate, haemoglobin oxygen saturation, and hospital admission and revisit rates. Data were extracted independently by the four reviewers and the results compiled and compared. Two reviewers reassessed studies to clarify points of discrepancy in the data extraction and database entry processes. Missing data were requested from the authors or calculated from other data presented in the study report.

MAIN RESULTS

There was complete agreement on the inclusion of 13 trials and the exclusion of five studies. Two main study recruitment groups were identified: a) infants and young children within the first 48 hours of hospitalisation (10 trials), and b) outpatient infants and young children who were randomised from the emergency department and who may nor may not have required hospital admission (three trials).A total of 1,198 children aged 0 to 30 months were treated with the equivalent of 0.5 to 10 mg/kg of systemic prednisone for two to seven days. Outcomes of interest were not measured in each RCT. In the pooled analysis of seven trials, there was a decrease in LOS in treated children of 0.38 days (95% confidence interval (CI) -0.81 to 0.05), indicating no significant difference between treatment groups. In the pooled analysis of eight trials, the day three clinical score measured: a standard mean difference (SMD) of -0.20 (95% CI -0.73 to 0.32), indicating no difference between treatment groups. Subgroup analyses for base LOS and clinical score outcomes were performed on infants who were a) less than 12 months of age, b) all respiratory syncytial virus (RSV) positive, c) treated with less than 6 mg/kg of prednisone equivalent throughout the illness and d) first-time wheezers. These were limited by the small number of studies in each subgroup. Hospital admission rates were examined in three trials and no difference was seen between treatment groups (odds ratio (OR) 1.05 (95% CI 0.23 to 4.87). Readmission rates were reported in six studies; with no significant differences between treatment groups. Hospital revisit rates were reported in three studies, with a significant difference between treatment groups reported in one study only. The respiratory rate and haemoglobin oxygen saturation were reported descriptively in six RCTs; no differences were found between groups. Co-interventions (oxygen, supportive fluids and bronchodilators) were used similarly between treatment groups in all RCTs.

AUTHORS' CONCLUSIONS

No benefits were found in either LOS or clinical score in infants and young children treated with systemic glucocorticoids as compared to placebo. There were no differences in these outcomes between treatment groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, haemoglobin oxygen saturation, hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Marked study heterogeneity and occasionally conflicting direction of benefit between trials suggests that these results should be interpreted with caution. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.

Efficacy of prednisolone in children hospitalized for recurrent wheezing

Data on the efficacy of corticosteroids on respiratory picornavirus-induced wheezing are limited. To determine whether prednisolone is effective in rhinovirus- or enterovirus-induced recurrent wheezing, we conducted a controlled trial comparing oral prednisolone (2 mg/kg/day in three divided doses for 3 days) with placebo in hospitalized wheezing children and studied post hoc virus-specific efficacy in early wheezing (<3 episodes, reported elsewhere) and in recurrent wheezing (>or=3 episodes). Virus-negative children where excluded. Our primary endpoint was the time until children were ready for discharge. Secondary endpoints included oxygen saturation and exhaled nitric oxide during hospitalization, duration of symptoms, blood eosinophil count, and impulse oscillometry 2 wk after discharge, and occurrence of relapses during the following 2 months. Virus-specific effects were analyzed with interaction analysis in a multivariate regression model. During the study period, 661 patients were hospitalized, 293 randomized, and 59 were accepted in this analysis (mean age 2.6 yr, s.d. 1.3). Prednisolone did not significantly decrease the time until ready for discharge in all patients (prednisolone vs. placebo, medians, 18 vs. 24 h, p = 0.11). However, prednisolone decreased the time until ready for discharge in children with picornavirus infection (respectively, 12 vs. 24 h, p = 0.0022) and more specifically, in children with enterovirus infection (6 vs. 35 h, p = 0.0007). In the secondary endpoints, prednisolone decreased the duration of cough and dyspnea in rhinovirus-affected children (p = 0.033 for both). Prospectively designed clinical trial is needed to test the hypothesis that prednisolone reduces symptoms in picornavirus-affected wheezing children.

Effects of anti-inflammatory therapies on recurrent and low-grade respiratory syncytial virus infections in a murine model of asthma

BACKGROUND

Recurrent and subclinical viral respiratory tract infections could immunologically exacerbate allergic airway inflammation. However, the most appropriate treatment for virus-induced asthma exacerbation is yet to be established. The effects of glucocorticoids in virus-induced acute asthma are controversial.

OBJECTIVE

To determine the effects of representative anti-inflammatory therapies for asthma--glucocorticoids and leukotriene receptor antagonists (LTRAs)--in mite allergen-sensitized and repeatedly low-grade respiratory syncytial virus (RSV)--infected mice.

METHODS

Dermatophagoides farinae-sensitized mice were inoculated twice with low-grade RSV and subcutaneously injected with either a glucocorticoid or an LTRA for 4 consecutive days. Lung inflammation, cytokine profiles, LT production, and viral RNA in lung tissues were compared in 5 groups of 8 mice each: controls, D farinae allergen sensitized, D farinae sensitized and RSV infected, D farinae sensitized and RSV infected with dexamethasone, and D farinae sensitized and RSV infected with pranlukast, an LTRA.

RESULTS

Allergic airway inflammation in D farinae mice was significantly enhanced by recurrent and low-grade RSV infections (RLRIs). The glucocorticoid attenuated allergic airway inflammation, which was associated with interleukin 5 (IL-5) and interferon-gamma (IFN-gamma) suppression in lung-draining lymph nodes without affecting viral quantity. The LTRA also attenuated allergic airway inflammation in D farinae-RSV mice with concomitant inhibition of IL-5 but not IFN-gamma. Dermatophagoides farinae allergen sensitization significantly increased LTs in the airway, whereas RLRIs did not further enhance LT production.

CONCLUSIONS

Glucocorticoids and LTRAs significantly inhibit RLRI-induced exacerbation of allergic airway inflammation by distinct pathways. Dexamethasone suppressed nonspecific cytokines, whereas viral RNA did not increase via suppression of immunity. In contrast, pranlukast specifically inhibited IL-5 but not IFN-gamma.

Prospects of antiviral and anti-inflammatory therapy for respiratory syncytial virus infection

Respiratory syncytial virus is the leading viral cause of death in children less than 2 years of age, and is an increasing cause of morbidity and mortality in transplant patients and the elderly. Respiratory syncytial virus causes upper and lower respiratory tract infections, which can lead to severe bronchiolitis and pneumonia. High-risk groups for severe respiratory syncytial virus infection include infants with a history of premature birth with or without chronic lung disease, children with congenital heart disease, children with cystic fibrosis or chronic lung diseases, and immunosuppressed patients or patients with immunodeficiency. However, the majority of infants who have severe respiratory syncytial virus disease are born at full term and are otherwise healthy. It is unclear why children, the elderly and the immunosuppressed are at much higher risk for severe disease; however, a respiratory syncytial virus-induced immune pathologic mechanism has long been suspected. Attempts to develop a safe and effective vaccine against respiratory syncytial virus have failed. Antirespiratory syncytial virus immunotherapy, although effective prophylactically, does not provide any beneficial clinical outcome when administered therapeutically, indicating that respiratory syncytial virus-induced pathology is most likely the result of the inflammatory response to infection, rather than a direct viral cytopathic effect. Thus, a combined antiviral and anti-inflammatory therapy may represent the safest and most efficient treatment for acute respiratory syncytial virus infection. In this review, the current knowledge that has set the rationale for the development of such therapy is summarized.

Bronchiolitis

Bronchiolitis is a distressing, potentially life-threatening respiratory condition that affects young babies. Around 2-3% of all infants younger than 1 year are admitted to hospital with bronchiolitis, usually during the seasonal epidemic. The majority of these infants are infected with respiratory syncytial virus and all have an intense inflammatory response in their airways. Although most infants recover, they have an increased risk of recurrent wheezing. Although bronchiolitis is common, little is known about what causes infants to be susceptible. Diagnostic interventions have little effect on clinical outcome, and apart from supportive measures, there is no specific treatment. Bronchiolitis therefore presents an intriguing clinical conundrum and a major challenge to researchers. High quality clinical studies are needed to clarify assessment of disease severity and criteria for hospital admission, particularly the use of pulse oximetry and chest radiography. Careful mapping of the inflammatory pathways in the pathogenesis of bronchiolitis should lead to development of new therapies to alleviate symptoms.

Evaluation of the efficacy of prednisolone in early wheezing induced by rhinovirus or respiratory syncytial virus

BACKGROUND

The role of systemic corticosteroids in the treatment of early childhood wheezing in children is not clear.

OBJECTIVE

We sought to determine whether prednisolone is effective in rhinovirus-induced early wheezing.

METHODS

We conducted a controlled trial comparing oral prednisolone (2 mg/kg per day in three divided doses for 3 days) with placebo in 78 hospitalized children (mean age, 1.1 year; standard deviation, 0.7) experiencing their first or second episode of wheezing induced by rhinovirus or respiratory syncytial virus. Mixed viral infections were excluded. Our primary end point was the time until the patient was ready for discharge; secondary end points included oxygen saturation during hospitalization, duration of symptoms, occurrence of relapses during the next 2 months and blood eosinophil counts at discharge and 2 weeks later.

RESULTS

In multivariate regression analysis, prednisolone did not influence the time until ready for discharge, but it decreased relapses during the subsequent 2-month period in rhinovirus-affected children (prednisolone versus placebo, 22% versus 56%; odds ratio, 19.06; 95% confidence interval, 2.52-144.03; P = 0.004) and in children with blood eosinophils > or = 0.2 x 10/L (respectively, 24% versus 71%; odds ratio, 10.57; 95% confidence interval, 1.99-56.22; P = 0.006). Rhinovirus-affected children had more blood eosinophils on admission (mean, 0.44 versus 0.086 x 10/L), had a higher prevalence of atopy (44% versus 8%) and were older (mean, 1.4 versus 0.9 years, P < 0.001 for all) than respiratory syncytial virus-infected children.

CONCLUSION

Prednisolone reduced relapses during a 2-month period after first episodes of wheezing associated with rhinovirus infection or blood eosinophils > or = 0.2 x 10/L.

Bronchiolitis: in-patient focus

Bronchiolitis is among the most common and serious lower respiratory tract syndromes that affects young children. In developed countries, the case fatality rate among previously healthy children remains low; in contrast, infants with underlying medical conditions, such as immunodeficiency or chronic lung disease, are at risk of prolonged illness and death. Bronchiolitis is associated with significant morbidity among healthy young children. During the winter season, bronchiolitis is the most common cause of hospitalization among infants. Each year in the United States, approximately 2 per 100,000 infants die as a result of complications associated with bronchiolitis.

Dexamethasone inhalations in RSV bronchiolitis: a double-blind, placebo-controlled study

OBJECTIVE

To evaluate the effect of inhaled dexamethasone on hospitalization for respiratory syncytial virus (RSV) bronchiolitis.

STUDY DESIGN

A double-blind, placebo-controlled study compared nebulization of dexamethasone versus nebulization of 0.9% saline. Both groups were treated with epinephrine nebulizations. Follow-up continued for 3 mo.

PATIENTS AND METHODS

Sixty-one infants with bronchiolitis aged 3 to 12 mo were included. They were randomly allocated to nebulizations with 0.25 mg dexamethasone every 6 h (group 1) or an equivalent amount of normal saline (group 2).

RESULTS

No statistically significant differences with respect to clinical score, oxygen saturation, or IV fluid requirement between the groups were noted. Using Kaplan-Meyer's method, the cumulative proportion of in-hospital stay was significantly lower in group 1 compared with group 2, mainly in days 5 and 6 post-hospitalization (p<0.038). A subgroup of prematurely born children in group 1 had a shorter hospitalization period (6.5+/-1.7 d) compared with group 2 children (9.1+/-1.9) (p<0.018). Follow-up revealed similar wheeze and hospitalization rates in the two groups.

CONCLUSION

Inhaled dexamethasone may reduce the length of hospitalization among infants with acute viral bronchiolitis, especially among those born prematurely.

Variation in inpatient diagnostic testing and management of bronchiolitis

OBJECTIVES

We know little about the variation in diagnosis and management of bronchiolitis. The objectives of this study were (1) to document variations in treatment and diagnostic approaches, lengths of stay (LOSs), and readmission rates and (2) to determine which potentially modifiable process of care measures are associated with longer LOSs and antibiotic usage.

METHODS

We used the Pediatric Health Information System, which includes demographic, diagnostic, and detailed patient-level data on 30 large children's hospitals. We examined infants who were younger than 1 year and hospitalized for bronchiolitis (October 2001-September 2003). Multivariate analysis of variance was used to determine whether the variance in the outcomes was hospital related after controlling for other covariates. Linear regression was used to model predictors of increased LOS. Logistic regression was used to model antibiotic usage. Analyses were stratified by age group (<3 months and 3-11 months).

RESULTS

A total of 17397 patients were included in the analysis. The mean LOS was 2.97 days; 72% of patients received chest radiographs, 45% received antibiotics, and 25% received systemic steroids. The mean LOS varied considerably across hospitals (range: 2.40-3.90 days), and hospital remained a significant contributor to LOS variation after controlling for our covariates. Variations in the use of diagnostic tests and medications as well as readmission rates also existed and also remained significant after controlling for covariates. The factors associated with the greatest increases in LOS in the regression analyses included higher severity scores and use of antibiotics, bronchodilators, and corticosteroids. The strongest predictors of antibiotic use in the logistic regression analyses were higher severity scores and receipt of a blood or cerebrospinal fluid culture. Receiving a chest radiograph was a significant predictor of antibiotic use in older but not younger infants.

CONCLUSIONS

Considerable, unexplained variation exists in the inpatient management of bronchiolitis. The development of national guidelines and controlled trials of new therapies and different management approaches are indicated.

Efficacy of interventions for bronchiolitis in critically ill infants: a systematic review and meta-analysis

BACKGROUND

Viral bronchiolitis is the leading cause of respiratory failure among infants in the United States. Currently, the mainstay of treatment is supportive care. The effectiveness of treatments used for mechanically ventilated infants with bronchiolitis is unclear.

OBJECTIVE

To evaluate the strength of the evidence supporting the use of currently available treatments for critically ill infants with bronchiolitis.

DATA SOURCE

We searched PubMed, citations of relevant articles, personal files, and conference proceedings, and we contacted experts in the field.

STUDY SELECTION

Randomized, controlled trials evaluating any therapy for bronchiolitis that included children in an intensive care unit.

DATA EXTRACTION

Two reviewers independently extracted data and assessed methodologic quality.

DATA SYNTHESIS

A total of 2,319 citations were screened, and 16 randomized, controlled trials were included. There were three trials of surfactant, three of ribavirin, three of immune globulin, three of systemic corticosteroids, and one each of vitamin A, interferon, erythropoietin, and heliox. A meta-analysis of the three surfactant studies showed a strong trend toward a decrease in duration of mechanical ventilation of 2.58 days (95% confidence interval, -5.34 to 0.18 days; p =.07) and a significant decrease of 3.3 intensive care unit days (95% confidence interval, -6.38 to -0.23 days; p =.04). A meta-analysis of the three systemic corticosteroid studies showed no overall effect on duration of mechanical ventilation when all three trials were combined (-0.62 day; 95% confidence interval, -2.78 to 1.53 days; p =.57). We identified one published meta-analysis of three ribavirin studies showing a significant decrease in ventilator days with ribavirin (-1.2 days; 95% confidence interval, -0.2 to -3.4 days; p =.2).

CONCLUSIONS

Currently, there are no clearly effective interventions available to improve the outcome of critically ill infants with bronchiolitis. Surfactant seems to be a promising intervention, and corticosteroids or ribavirin may also be beneficial.