Author, date and country | Patient group | Study type (level of evidence) | Outcomes | Key results | Study weaknesses |
---|---|---|---|---|---|
Rodrigo G et al, 2004 | Six RCTs including 369 patients with acute asthma (five studies involving adults, one study dealing only with children) | Meta-analysis | Spirometric measurements (PEF l/min, PEF % predicted, FEV1 L, FEV1 % predicted) | Use of heliox did not improve pulmonary function compared with standard care (SMD = 0.13; 95% CI: −0.09 to 0.34) | Surrogate end points |