Badawy 2014.

Methods	Randomised controlled trial. Outpatient department and Emergency department from 1 hospital, Egypt.
Participants	Inclusion criteria: pregnancy, acute exacerbation of asthma partially or not completely controlled on routine acute asthma therapy. Exclusion criteria: congestive heart failure, history of angina, renal problems, history suggestive of pulmonary oedema, very severe asthma (altered consciousness, respiratory acidosis, needing intubation, arrest), any associated medical illness e.g. diabetes/hypertension, fever > 38°C, inability to perform PEF. Number randomised: 60. All participants female. Intervention: 30 randomised. Mean age (years): 25.7 (3.8). Control: 30 randomised. Mean age (years): 25.9 (4.0).
Interventions	Intervention: 500 mg (1 mL) MgSO₄ with 1 mL salbutamol solution and 8 mL 0.9% NaCl. Control: 1 mL salbutamol solution with 9 mL 0.9% NaCl. Treatments given over 8 minutes; max 3 sets of nebulisation 20 minutes apart.
Outcomes	PEF, FEV1, FVC, FEV1/FVC ratio, FEF 25‐75%, arterial blood pCO2, pO2 and pH, oxygen saturations, serum potassium. Recorded at end of therapy ‒ assumed to be 2 h from baseline.
Notes	Funding: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Participants were randomly classified into groups comparable in socio‐demographic criteria, but no indication is given of random sequence generation. Baseline clinical characteristics are given, and there is no indication that the groups were balanced with regard to clinical criteria.
Allocation concealment (selection bias)	Unclear risk	Participants were randomized into 2 groups through sealed opaque envelopes, but no indication is given whether participants or research personnel were aware of group allocation.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were randomized into 2 groups through sealed opaque envelopes, but no mention of procedures to blind personnel.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No mention of procedures to blind personnel.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	On further correspondence, appropriate exclusion criteria were applied but no indication given whether excluded participants were balanced across groups, and no dropout data were given.
Selective reporting (reporting bias)	High risk	No prospective trial registration identified. Primary outcome on which this trial was powered is not stated. On further correspondence, adverse event data were given but no clinical baseline characteristics are given.