Cambonie 2006.
| Methods | Prospective, randomised, double‐blind study | |
| Participants | 20 infants (all < 3 months old) admitted to the PICU with moderate‐to‐severe RSV bronchiolitis Criteria for inclusion: bronchiolitis RSV+, m‐WCAS > 5, PaCO2 > 42 mmHg Group characteristics after randomisation, mean ± SD: Age, d 29 ± 5 versus 34 ± 9 Weight, kg 3.5 ± 0.46 versus 3.83 ± 0.24 Clinical score, (m‐WCAS, maximum score of 10): 5.4 ± 0.2 versus 5.6 ± 0.2 Respiratory rate, breaths/min 59.4 ± 6.4 versus 64.9 ± 5.7 FiO2, % 31.4 ± 4.0 versus 34.0 ± 2.6 PCO2, mmHg 56.5 ± 4.9 versus 53.6 ± 2.3 | |
| Interventions | Inhalation of either heliox OR air‐oxygen, for 1 hour under a 7 L/min oxy hood | |
| Outcomes | Primary goal: to assess the effect on respiratory distress evaluated using the modified Wood Clinical Asthma Score (m‐WCAS) at H1 Secondary endpoints: need for mechanical ventilation, rate of intubation, length of mechanical ventilation, length of stay in PICU, mortality, wheezing score evaluated at H1 and H24, pCO2 at H1, respiratory rate at H1 | |
| Notes | — | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Computerised random listing |
| Allocation concealment (selection bias) | Low risk | Sealed envelopes |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | 1 investigator was not blinded: the physiologist The labelling of intervention gases as cylinder A and B potentially exposed the study to assessment bias |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | All patients completed the study and there were no losses to follow‐up, no treatment withdrawals 31 infants with the diagnosis of respiratory distress attributable to RSV bronchiolitis were admitted to the PICU during the study period. Among them, 11 were excluded for clinical scores below 5. 20 infants were thus randomised into the 2 groups, with 10 in each group. One infant randomised into the control group was excluded for an oxygen haemoglobin saturation < 90% that persisted under the maximum 40% Fio2 authorised by the protocol |
| Selective reporting (reporting bias) | Low risk | All results for outcomes were reported |
| Other bias | Low risk | |