Evidence-Based Child Health Clinical Answer: Intervention

QUESTIONFor infants admitted to the intensive care unit (ICU) with severe bronchiolitis, which treatments are effective in reducing mortality, length of stay and need for ventilation?
ANSWERContinuous negative extrathoracic pressure (CNEP) and non-invasive continuous positive airway pressure (Ni-CPAP) did not reduce the need for ventilation, and heliox therapy (a helium-oxygen mixture) did not reduce mortality, length of ICU stay or need for ventilation.
IMPLICATIONS FOR PRACTICEDue to lack of available evidence, neither CNEP, Ni-CPAP nor heliox therapy can be recommended for patients with bronchiolitis who are admitted to the ICU.
BACKGROUND• Bronchiolitis describes a viral inflammation of the bronchioles in the lower respiratory tract that is typically caused by infection with respiratory syncytial virus. • Bronchiolitis is the most common acute infection of the lower respiratory tract during the first year of life, with an incidence rate of approximately 33% within the first year of life.
SEARCH STRATEGY• Issue 9, 2011 of the Cochrane Database of Systematic Reviews was searched using the term ‘bronchiolitis’ restricted to the title, abstract or keywords.
INCLUDED REVIEWS• Out of 17 potential reviews and two protocols, two reviews on CNEP, Ni-CPAP and heliox inhalation were included in this analysis. • The included reviews contained a total of seven paediatric trials and 167 infants. • Three relevant reviews were excluded from this analysis: one review on bronchodilators contained no relevant data, and two on immunoglobulin and surfactant had been withdrawn from the Cochrane Library. • Table1 presents characteristics of the included reviews.
RESULTS• The two included reviews examined CNEP or Ni-CPAP versus standard care and heliox inhalation versus air or oxygen inhalation. • Neither CNEP nor Ni-CPAP compared to standard care reduced the need for non-invasive or invasive ventilation. • Heliox inhalation versus air or oxygen inhalation did not significantly reduce mortality, length of ICU stay or need for non-invasive or invasive ventilation (Table2).
LIMITATIONS• Although five separate Cochrane reviews examined the treatment of bronchiolitis in an ICU setting, only two of these reviews could be included in this analysis. Therefore, this analysis could not examine the efficacy of using bronchodilators, immunoglobulin or surfactant to treat severe bronchiolitis in an ICU setting. • The two reviews included in this analysis included a very limited number of trials, which precluded any useful conclusions from being made. • The trials included in this analysis were mostly restricted to healthy infants, which makes it difficult to apply these findings to infants with chronic conditions or prematurity, although it is these infants who are at increased risk of developing bronchiolitis. • Data on length of stay are often influenced by factors aside from treatment (i.e. volume of patients per day).
Table I. Characteristics of included reviews
Review titleNumber of studiesPopulationInterventionComparisonOutcomes for which data were reported
Authors Definition of bronchiolitis   
Assessed as up-to- datePooled sample size (range)    
  1. AHRF: acute hypoxemic respiratory failure; CNEP: continuous negative extrathoracic pressure; ICU: intensive care unit; Ni-CPAP: non-invasive continuous positive airway pressure; PPV: positive pressure ventilation; RSV: respiratory syncytial virus.

CNEP or continuous positive airway pressure for AHRF in children2Children between one month and 18 years admitted to the ICUCNEP with or without assisted PPV or Ni-CPAP without assisted PPVStandard care (including PPV with endotracheal intubation)Improvement in oxygenation, failure (death or use of any additional form of assisted ventilation) and duration of oxygen therapy
Shah PS, Ohlsson A, Shah JPData were not combined for meta-analysis because of significant heterogeneity between the two trials with respect to interventionAHRF: alveolar arterial oxygenation gradient more than 100 or arterial oxygen tension (PaO2)/fraction of inspired oxygen (FiO2) ratio less than 200 in the presence of respiratory symptoms (or PaO2 less than 10 kPa with FiO2 more than 0.5, with bilateral diffuse infiltrates on chest X-ray in the absence of cardiogenic causes). The one included trial included infants with a clinical diagnosis of bronchiolitis   
October 2007CNEP: 33, Ni-CPAP: 37    
Heliox inhalation therapy for bronchiolitis in infants5Infants under two years of age admitted to the ICUInhaled helioxPlacebo (oxygen or air)Primary: in-hospital mortality, need for mechanical ventilation, rate of endotracheal intubation, length of ICU stay and adverse events
Liet JM, Ducruet T, Gupta V, Cambonie G.97 (12–39)Acute bronchiolitis: signs of respiratory distress secondary to RSV infection and/or patients with respiratory distress and symptoms that occur within RSV epidemic periods and are not due to other medical conditions  Secondary: gas exchange and clinical respiratory scores within first hour after starting heliox treatment
June 2009     
Table II. Mortality, length of ICU stay and need for ventilation in ICU patients with bronchiolitis
OutcomeComparisonNumber of subjects (studies)Measure of effect (95% CI)I2 (%)
  1. CI: confidence interval; ICU: intensive care unit; MD: mean difference; NE: not estimable; RR: risk ratio.

MortalityHeliox inhalation versus air or oxygen inhalation58 (2)MD: 3.47 (0.15, 80.35)NE
Length of ICU stayHeliox inhalation versus air or oxygen inhalation58 (2)MD: − 0.15 (−0.92, 0.61)0
Need for non-invasive or invasive ventilationHeliox inhalation versus air or oxygen inhalation58 (2)RR: 1.11 (0.36, 3.38)0
 Continuous negative extrathoracic pressure versus standard care33 (1)RR: 0.40 (0.02, 9.06)