Song 1993.

Methods	Randomised clinical trial, China
Participants	25 hospitalised adults with COPD and infection, PaO2 < 8 kPa, or PaCO2 > 6.7 kPa, at nutritional risk due to trialist characterising them as malnourished. Male:Female = 23:2 Mean age = 60.3 years Exclusion criteria: diabetes, hyperthyroidism or other endocrine and metabolic diseases
Interventions	Experimental group: Received parenteral nutrition in the form of amino acids injection (5% Nutrisol‐S) 500 ml (Green Cross, Japan) and lipid emulsion (Intralipid: (1000 ml Intralipid contains rectification soybean oil 100 g, glycerinum 22.5 g rectification lecithin 12 g, PH 8.0, 4602.4 kJ/kg)) 500 ml (Sino‐Swed Pharmaceutical Corp. Ltd. China) for intravenous drip, once daily, for 10 to 20 days (10 of the participants were over 15 days). (n = 23) Control group: standard diet(n = 23) Co‐intervention: persistent low‐flow oxygen inspiration and anti‐infection, anti‐asthmatic and antitussive and standard diet
Outcomes	All‐cause mortality, NEFA, ABG, serum amino acid
Study dates	Not stated
Notes	We tried and failed to contact the authors by phone.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and personnel were not blinded.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	The number of participants with incomplete data was not reported.
Selective reporting (reporting bias)	Low risk	No protocol could be obtained but all‐cause mortality was reported.
For‐profit bias	Unclear risk	It was unclear how the trial was funded.
Other bias	Low risk	The trial appeared to be free of other components that could put it at risk of bias.