Respiratory system mechanics in patients receiving aerosolized ribavirin during mechanical ventilation for suspected respiratory syncytial viral infection

WITHDRAWN: Ribavirin for respiratory syncytial virus infection of the lower respiratory tract in infants and young children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in infants and is responsible for many hospitalizations annually. Ribavirin is approved for treatment of these infections, but its use is controversial because of questions about its efficacy, concerns about occupational exposure, and its high cost.

OBJECTIVES

The objective of this review is to assess the efficacy of aerosolized ribavirin for infants and children with lower respiratory tract infection due to RSV.

SEARCH STRATEGY

We performed an updated electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database (EED) (The Cochrane Library 2006, issue 3) which contains the Acute Respiratory Infections Group's specialized register; MEDLINE (Ovid) (2004 to September Week 3 2006); and EMBASE (WebSpirs) (2004 to June 2006).

SELECTION CRITERIA

Randomized trials comparing ribavirin with placebo in infants and children with lower respiratory tract infection attributable to RSV.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Unpublished data were requested from trial authors when necessary.

MAIN RESULTS

Twelve trials were included. All trials enrolled infants below the age of six months. In four trials with 158 participants, mortality with ribavirin was 5.8% compared with 9.7% with placebo (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.18 to 1.85). In three trials with 116 participants the probability of respiratory deterioration with ribavirin was 7.1% compared with 18.3% with placebo (OR 0.37; 95% CI 0.12 to 1.18). In three studies with 104 ventilated participants, the mean difference in days of hospitalization was 1.9 fewer days with ribavirin (95% CI -4.6 to +0.9) and the mean difference in days of ventilation was 1.8 fewer days with ribavirin (95% CI -3.4 to -0.2). No statistically significant differences in long-term pulmonary function or in incidence of recurrent wheezing following RSV infection were associated with the use of ribavirin.

AUTHORS' CONCLUSIONS

Trials of ribavirin for RSV lack sufficient power to provide reliable estimates of the effects. The cumulative results of three small trials show that ribavirin may reduce the duration of mechanical ventilation and may reduce days of hospitalization. In addition, use of ribavirin may be associated with a decrease in the long-term incidence of recurrent wheezing following RSV disease. A large randomized controlled trial of ribavirin for ventilated and other high-risk participants is indicated.

Heliox reduces respiratory system resistance in respiratory syncytial virus induced respiratory failure

INTRODUCTION

Respiratory syncytial virus (RSV) lower respiratory tract disease is characterised by narrowing of the airways resulting in increased airway resistance, air-trapping and respiratory acidosis. These problems might be overcome using helium-oxygen gas mixture. However, the effect of mechanical ventilation with heliox in these patients is unclear. The objective of this prospective cross-over study was to determine the effects of mechanical ventilation with heliox 60/40 versus conventional gas on respiratory system resistance, air-trapping and CO2 removal.

METHODS

Mechanically ventilated, sedated and paralyzed infants with proven RSV were enrolled within 24 hours after paediatric intensive care unit (PICU)admission. At T = 0, respiratory system mechanics including respiratory system compliance and resistance, and peak expiratory flow rate were measured with the AVEA ventilator. The measurements were repeated at each interval (after 30 minutes of ventilation with heliox, after 30 minutes of ventilation with nitrox and again after 30 minutes of ventilation with heliox). Indices of gas exchange (ventilation and oxygenation index) were calculated at each interval. Air-trapping (defined by relative change in end-expiratory lung volume) was determined by electrical impedance tomography (EIT) at each interval.

RESULTS

Thirteen infants were enrolled. In nine, EIT measurements were performed. Mechanical ventilation with heliox significantly decreased respiratory system resistance. This was not accompanied by an improved CO2 elimination, decreased peak expiratory flow rate or decreased end-expiratory lung volume. Importantly, oxygenation remained unaltered throughout the experimental protocol.

CONCLUSIONS

Respiratory system resistance is significantly decreased by mechanical ventilation with heliox (ISCRTN98152468).

Ribavirin for respiratory syncytial virus infection of the lower respiratory tract in infants and young children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in infants and is responsible for many hospitalizations annually. Ribavirin is approved for treatment of these infections, but its use is controversial because of questions about its efficacy, concerns about occupational exposure, and its high cost.

OBJECTIVES

The objective of this review is to assess the efficacy of aerosolized ribavirin for infants and children with lower respiratory tract infection due to RSV.

SEARCH STRATEGY

We performed an updated electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database (EED) (The Cochrane Library Issue 3, 2006); MEDLINE (Ovid) (2004 to September Week 3 2006); and EMBASE (WebSpirs) (2004 to June 2006).

SELECTION CRITERIA

Randomized trials comparing ribavirin with placebo in infants and children with lower respiratory tract infection attributable to RSV.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Unpublished data were requested from trial authors when necessary.

MAIN RESULTS

Twelve trials were included. All trials enrolled infants below the age of six months. In four trials with 158 participants, mortality with ribavirin was 5.8% compared with 9.7% with placebo (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.18 to 1.85). In three trials with 116 participants the probability of respiratory deterioration with ribavirin was 7.1% compared with 18.3% with placebo (OR 0.37; 95% CI 0.12 to 1.18). In three studies with 104 ventilated participants, the mean difference in days of hospitalization was 1.9 fewer days with ribavirin (95% CI -4.6 to +0.9) and the mean difference in days of ventilation was 1.8 fewer days with ribavirin (95% CI -3.4 to -0.2). No statistically significant differences in long-term pulmonary function or in incidence of recurrent wheezing following RSV infection were associated with the use of ribavirin.

AUTHORS' CONCLUSIONS

Trials of ribavirin for RSV lack sufficient power to provide reliable estimates of the effects. The cumulative results of three small trials show that ribavirin may reduce the duration of mechanical ventilation and may reduce days of hospitalization. In addition, use of ribavirin may be associated with a decrease in the long-term incidence of recurrent wheezing following RSV disease. A large randomized controlled trial of ribavirin for ventilated and other high-risk participants is indicated.

Serious and lethal respiratory tract infections of viral etiology in children

Viruses may lead to serious and lethal pulmonary infections in immunocompetent and immunocompromised children. Series of children with acute respiratory distress syndrome and series of children requiring extracorporeal membrane oxygenation, as well as reported series of nosocomial viral illness, offer an insight into the extent of serious viral disease documented in the medical literature. Series of children with specific viral respiratory illness also will be reviewed, as will the means of diagnosis in these groups of patients. Copyright © 2000 by W.B. Saunders Company

Ribavirin for respiratory syncytial virus infection of the lower respiratory tract in infants and young children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in infants and is responsible for 100,000 hospitalizations annually. Ribavirin is approved for treatment of these infections, but its use is controversial because of questions about its efficacy, concerns about occupational exposure, and its high cost.

OBJECTIVES

The objective of this review is to assess the efficacy of aerosolized ribavirin for infants and children with lower respiratory tract infection due to RSV.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2004), MEDLINE (January 1975 to January week 3, 2004) and EMBASE (January 1990 to December 2003). We scanned reference lists of articles and contacted experts in the field.

SELECTION CRITERIA

Randomized trials comparing ribavirin with placebo in infants and children with RSV infection and lower respiratory tract infection.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. Unpublished data were requested from authors when necessary.

MAIN RESULTS

Twelve trials were included. All trials enrolled infants below the age of six months. In four trials with 158 patients, mortality with ribavirin was 5.8% compared with 9.7% with placebo (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.18 to 1.85). In three trials with 116 patients the probability of respiratory deterioration with ribavirin was 7.1% compared with 18.3% with placebo (OR 0.37; 95% CI 0.12 to 1.18). In three studies with 104 ventilated patients, the weighted mean difference in days of hospitalization was 1.9 fewer days with ribavirin (95% CI -4.6 to +0.9) and the weighted mean difference in days of ventilation was 1.8 fewer days with ribavirin (95% CI -3.4 to -0.2). No statistically significant differences in long-term pulmonary function or in incidence of recurrent wheezing following RSV infection were associated with the use of ribavirin.

REVIEWERS' CONCLUSIONS

Trials of ribavirin for RSV lack sufficient power to provide reliable estimates of the effects. The cumulative results of three small trials show that ribavirin may reduce the duration of mechanical ventilation and may reduce days of hospitalization. In addition, use of ribavirin may be associated with a decrease in the long-term incidence of recurrent wheezing following RSV disease. A large randomized controlled trial of ribavirin for ventilated and other high-risk patients is indicated.

Mechanical ventilatory support in infants with respiratory syncytial virus infection

OBJECTIVE: To present a review of current knowledge of the use of mechanical ventilatory support in the management of infants with respiratory failure secondary to infection with respiratory syncytial virus (RSV). DATA SOURCES: MEDLINE and manual search for case reports and clinical trials that address management strategies for respiratory support of infants with RSV infection. Data Extraction and Synthesis: Critical appraisal of reported epidemiologic and clinical data regarding risk factors, pathophysiology, and efficacy of respiratory therapy. There is an increasing number of hospital admissions for RSV infection with a variable proportion of infants who need mechanical ventilatory support. The mortality rate is estimated to be <1% in infants without preexisting respiratory or cardiac disorders vs. <5% in those with preexisting respiratory or cardiac disorders. Optimal ventilator settings need to be refined according to the dominant obstructive or restrictive pattern with the aim to avoid barovolutrauma. The role of noninvasive ventilation and additional therapies (heliox, beta(2) agonists, surfactant) is not conclusively established. The indications for high-frequency oscillatory ventilation with the possible adjunction of inhaled nitric oxide deserve further study. Extracorporeal membrane oxygenation plays a minor role in severe cases that are refractory to conventional treatment. CONCLUSIONS: Conventional ventilation strategies are usually adequate for treating infants with severe RSV infection. Particular attention must be paid to the dominant pathophysiologic mechanism in a given condition. Prospective trials are needed to validate alternative therapeutic options and to improve the outcome of the rare but most severe cases that are difficult to control.

Antiviral agents in the critically ill child

The treatment for most viral infections in children primarily is supportive. Severe viral illnesses and significant secondary complications that require treatment in the intensive care unit may occur in immunocompromised patients and also in infants and children who were previously healthy. Antiviral agents with specific activity against certain respiratory viruses, herpesviruses, and enteric viruses are available. New drugs are under development, and their use in pediatric patients is a subject of active research. The clinician's knowledge of the mechanisms of action, spectrum of activity, and side effects of these drugs is an important tool for their judicious use in the treatment of the critically ill child. Copyright © 2000 by W.B. Saunders Company