Engel 1997.

Methods	RCT, single‐centre, 3‐arm, parallel design
Participants	Number of randomized participants: 20 Inclusion criteria APACHE II score > 10, requiring ≥ 7 days of nutritional support, 18 to 65 years of age Exclusion criteria Abdominal injury Gastrointestinal stenosis Liver or renal insufficiency High catecholamine requirement Acute or severe pancreatitis Post‐transplantation surgery Taking cortisone medication Immunosuppressant therapy and autoimmune illnesses Primary diagnoses Multiple trauma Baseline characteristics EN group (standard) Age, mean (SD): 41 (± 16) years Gender, M/F: 10/0 APACHE II, mean (SD): 16.3 (± 4.5) EN group (supplemented) Age, mean (SD): 33 (± 13) years Gender M/F: 8/2 APACHE II, mean (SD): 15.7 (± 4.4) PN group Mean age: 32 (SD ± 10) years Gender M/F: 7/3 Mean APACHE II: 16.3 (SD ± 3.1) Country: Germany Setting: ICU
Interventions	EN group (standard) n = 10; 0 losses Details: nasojejunal tube with feeding pump, feeding started within 24 hours of trauma, "Oligopeptide standard diet" (Survimed OPD, Frensenius). Target energy of 25 kcal/kg/day. Initial rate of 25 mL/hour. Infusion rate increased at rate of 25 mL/hour up to the 4th day and a minimum of 75 mL/hour. Caloric intake received: not reported EN group (supplemented) n = 10; 0 losses Details: nasojejunal tube with feeding pump, feeding started within 24 hours of trauma. Formula consisted of Impact (Fa. Sandoz), supplemented with arginine, omega‐3 fatty acids, nucleotide, and selenium. Target energy of 25 kcal/kg/day. Initial rate of 25 mL/hour. Infusion rate increased at rate of 25 mL/hour up to the 4th day and a minimum of 75 mL/hour. Caloric intake received: not reported PN group n = 10; 0 losses Details: isocaloric and isonitrogenous total PN Caloric intake received: not reported
Outcomes	Septic complications (diagnosed according to the ACCP/SCCM definitions) Immunological measurements
Notes	Funding/declarations of interest: not reported Study dates: not reported Note: for the purpose of review analysis, we combined data for the 2 EN groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomized but no additional details
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias) All outcomes	High risk	No details and we assumed investigators made no attempts to blind personnel
Blinding of outcome assessment (detection bias) All outcomes (except mortality)	Unclear risk	No details
Blinding of outcome assessment (detection bias) Mortality	Low risk	No details. Lack of blinding unlikely to influence outcome data for mortality
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses
Selective reporting (reporting bias)	Unclear risk	Clinical trials registration of prospectively published protocol not reported; not feasible to assess risk of reporting bias
Baseline characteristics	Low risk	Appear comparable
Other bias	Low risk	No other sources of bias identified