Martinón‐Torres 2008.
| Methods | Prospective, interventional, single‐centre, cross‐over study | |
| Participants | 12 infants (< 2 years old) admitted to the PICU with RSV bronchiolitis RSV+, m‐WCAS > 5, SpO2 < 92% or tcPCO2 > 50 mmHg despite optimised supportive therapy Criteria for inclusion: RSV + bronchiolitis with Modified Woods Clinical Asthma Score > 5, arterial oxygen saturation < 92%, or transcutaneous CO2 pressure > 50 mmHg Baseline, mean (SD): Age, mo 5 (2.9) versus 4.5 (2.2) m‐WCAS, maximum score of 10, mean standard deviation: 7.6 (1.2) versus 7.7 (1.0) | |
| Interventions | Inhalation in a random order of heliox AND air‐oxygen, by non‐invasive ventilation equipment (nasal continuous positive airway pressure with minimum level of 5 cmH2O) for 2 30‐minute study periods The heliox mixture was delivered to the patient, warmed, and humidified by means of a standard device | |
| Outcomes | Main outcome measures: modified Woods Clinical Asthma Score (m‐WCAS), and pCO2 at 30 minutes Secondary outcomes: rate of intubation, length of mechanical ventilation, length of stay in PICU, mortality, m‐WCAS at H24 and H48, pCO2 at H24 | |
| Notes | — | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Coin tossing only for the first infant; then alternately |
| Allocation concealment (selection bias) | High risk | |
| Blinding (performance bias and detection bias) All outcomes | High risk | Non‐blinded study: obvious changes in ventilator noise because of the expiratory branch of the flow generator |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | All patients completed the study and there were no losses to follow‐up and no treatment withdrawals During the study period, 40 infants with acute bronchiolitis were admitted to the PICU; 12 of them (7 boys and 5 girls) fulfilled the inclusion criteria and were enrolled in the study |
| Selective reporting (reporting bias) | Low risk | All results for outcomes were reported |
| Other bias | Low risk | |
ED: emergency department FiO2: fraction of inspired oxygen H1: first hour H24: twenty‐fourth hour IQR: interquartile range m‐WCAS: modified Wood Clinical Asthma Score min: minute mo: month nCPAP: nasal continuous positive airway pressure pCO2: carbon dioxide pressure PICU: paediatric intensive care unit RDAI: respiratory distress assessment instrument RSV: respiratory syncytial virus SD: standard deviation SEM: standard error of the mean SpO2: oxygen saturation on pulse oximetry wk: week