Altintas 2011.

Methods	RCT, single‐centre, 2‐arm, parallel design
Participants	Total number of randomized participants: 71 Inclusion criteria Needed invasive mechanical ventilation in the ICU Exclusion criteria Informed consent could not be obtained Participant received > 48 hours of mechanical ventilation in another unit Participant required < 72 hours of mechanical ventilation in the ICU or died within the first 72 hours Randomized route of nutrition support was medically contraindicated Nutrition support could not be started because of severe metabolic/haemodynamic instability during the first 48 hours of ventilation, or the participant was already receiving nutrition support at the time of intubation Primary diagnoses Acute respiratory failure Acute neurological pathology Severe metabolic/renal disease Intoxication Postoperative complications, or other diagnoses Baseline characteristics EN group Age, mean (SD): 57.77 (± 19.88) years Gender M/F: 15/15 APACHE II, mean (SD): 20.03 (± 7.43) PN group Age, mean (SD): 57.95 (± 18.00) years Gender M/F: 23/18 APACHE II, mean: 22.66 (± 7.47) Country: Turkey Setting: university hospital, medical ICU
Interventions	EN group n = 30; 0 losses; ITT analysis Details: preference for postpyloric tube placement, otherwise gastric feeding, feeding initiated within 48 hours, at target rate of 25 to 30 kcal/kg/day using ideal bodyweight, formula with proteins, carbohydrates, and lipids. 20 mL/hour of standard solution, increased every 4 to 6 hours by 20 mL/hour if GRV < 150 mL. Continuous infusion of insulin as needed with target level of 100‐140 mg/kL. Caloric intake received, reported as mean (SD) percentage of target calories given: 46.48 (± 19.34) PN group n = 41; 0 losses; deviations from protocol for 3 participants who were changed to EN feeding due to clinical needs; ITT analysis Details: preference for central or venous route, according to participant condition and contraindications to central venous line insertion, otherwise peripheral route. Target rate of delivery and glycaemic management same as EN group. Feeding started at full dose, unless participant at risk of refeeding syndrome, or severely malnourished and already had electrolyte disturbance. Caloric intake received, reported as mean (SD) percentage of target calories given: percentage of target calories given 66.78 (SD ± 18.85)
Outcomes	Mortality (in hospital and ICU) Pneumonia (diagnosed according to ACCP consensus statement) Sepsis Catheter infections Diarrhoea (diagnosed by an increase in stool amount > 1 L and frequency > 3/day with loss of consistency) Vomiting Hypervolaemia Severe shock Length of ICU stay Length of mechanical ventilation Achievement of feeding goals Interruption of feeding
Notes	Funding/declarations of interest: no details Study dates: February 2004 to January 2006
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quasi‐randomized method of sequence generation. Quote: "Patients were randomized to receive either EN or PN according to the last digit of their assigned hospital record number: odd numbers received PN, and even numbers received EN"
Allocation concealment (selection bias)	Low risk	Adequate concealment despite inadequate sequence generation. Hospital record numbers were assigned by staff independent of the ICU team
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 assessment of outcomes for mortality
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses but deviations from protocol in 3 participants in PN group. ITT analysis used
Selective reporting (reporting bias)	Unclear risk	Clinical trials registration not reported. Not possible to make assessment of selective outcome reporting bias
Baseline characteristics	Unclear risk	More sepsis and acute pathology in PN group; not reported as statistically significant. Unclear if these differences could influence outcome data. Also, we noted that number of participants in each group was not equivalent (41 in PN group; 30 in EN group) and this was not explained
Other bias	Low risk	Glycaemic controls equivalent between groups. Nutritional goals appeared to be equivalent. No other sources of bias identified