Comert 2016.

Study characteristics
Methods	Study design: randomised placebo‐controlled trial of parallel design Number of study centres: single centre Study location: Turkey University hospital Study setting: ambulatory care unit, Department of Pulmonology, School of Medicine, Istanbul University Date of study: December 2004 to September 2005 Withdrawals: none
Participants	Number randomised: 20 Numbers in treatment group: 10 Number in placebo group: 10 Numbers of withdrawals: 0 Numbers completing trial: 20 Mean age (years): 62.1 (SD 12) (magnesium); 71.3 (SD 5) (placebo) Gender (male/female): 8/2 (magnesium); 10/0 (placebo) Diagnostic criteria: clinical diagnosis Mean duration of COPD (years): 11.4 (magnesium); 13.5 (placebo) History of hospitalisation in recent year, n (%): 3(30) (magnesium); 4(40) (placebo) History of ICU in recent year, n (%): 0 (magnesium); 0 (placebo) Long‐term oxygen use, n (%): 2 (20) (magnesium); 6 (60) (placebo) Corticosteroid use in last 6 months, n (%): 3 (30) (magnesium); 4(40) (placebo) Inclusion criteria diagnosis of COPD (shortness of breath, chronic cough, sputum, exposure to known COPD risk factors, and FEV1/FVC < 70% measured after bronchodilator administration at a stable disease period) symptoms compatible with infectious COPD exacerbation according to Anthonisen criteria (increase in 2 of the following: shortness of breath, sputum purulence and sputum amount) – hospitalisation criteria (RR > 25/min, HR > 110 bpm, cyanosis, use of accessory respiratory muscles, drowsiness, PEFR < 100 L/min, FEV1 < 1 L, in arterial blood gas analysis PaO2 < 60 mmHg, PaCO2 ≥ 45 mmHg, SaO2 < 90%) Exclusion criteria presence of ICU indication presence of NIMV indication suspicion of pneumonia, pulmonary embolism, or pneumothorax known history of severe heart failure, renal, or hepatic disease suspicion of a mass lesion on CXR history of systemic corticosteroid use uncooperative patients severe loss of sight did not consent to participate
Interventions	Intervention: 2.5 mL isotonic magnesium sulfate (250 mmol/L, 151 mg/dose) by nebuliser + standard care Comparator: 2.5 mL isotonic saline solution by nebuliser + standard care Concomitant medications Nasal oxygen to increase SO2 > 90% Methyl prednisolone 32 mg PO Sulbactam/ampicillin 4g/day IV or cefuroxime 1.5 g/day 500 μg ipratropium bromide
Outcomes	At 24 and 48 hours: FEV1, ABG (PaO2, PaCO2, pH, SaO2), VAS dyspnoea score (0 ‐ 100), serum magnesium level 10, 30, 60 and 120 mins after each nebule treatment: PEFR 10, 30, and 120 mins after each nebule treatment: BP and HR
Notes	Funding: researcher Full text article in Turkish; translation done by Cochrane Airways.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: "1:1 randomisation in two groups" with no further information.
Allocation concealment (selection bias)	Unclear risk	Comment: no details reported.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: authors stated that all measurements were made by a single researcher; participants and the researcher who made the measurements did not know in which group the participant was.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: blinding of participants and researcher who made the measurements.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: all participants completed the study with no withdrawals.
Selective reporting (reporting bias)	Unclear risk	Comment: trial protocol was not available, unclear if outcomes were reported as planned.
Other bias	Low risk	Comment: no other apparent biases identified.