Fifteen studies (n=1,352 including 935 patients who received early feeding) were included: 5 RCTs (n=598), 2 non-randomised CCTs (n=68) and 8 observational or descriptive studies.
Two of the 5 RCTs reported adequate randomisation methods. None of the RCTs reported blinding. Three RCTs reported withdrawals and gave reasons and two reported no drop-outs. All RCTs analysed data on an intention-to-treat basis. Both CCTs showed baseline differences between the treatment groups but reported reasons for withdrawals.
The studies used different definitions of complication rates and measured them over different time periods (from initial hospital stay to 30-day out-patient follow-up). Eight studies (including all 5 RCTs and both CCTs) reported no difference in overall complication rates between patients receiving early compared with traditional feeding. Complications were experienced by 12.5% of all patients (117 out of 935; the rates ranged from 0 to 25%) and included pneumonia (7 cases), anastomotic dehiscence (8 cases), intestinal obstruction (11 cases), prolonged ileus (2 cases) and death unrelated to early feeding (2 patients).
Six studies reported no difference in nausea or vomiting between patients receiving early compared with traditional feeding; 2 RCTs reported a significant increase in nausea and vomiting associated with early feeding. The overall incidence of persistent nausea or vomiting was 14%. Rates of toleration of early feeding (defined variably) ranged from 73 to 100%.
Duration of post-operative ileus.
The duration of post-operative ileus ranged from 1 to 4 days among patients receiving early feeding. Three studies (all using multi-modal approaches) reported a significant decrease in the time to first bowel movement for patients receiving early compared with traditional feeding, while 3 studies (all using conventional peri-operative approaches) reported no difference.
LOS in the hospital.
Five studies (all using multi-modal approaches but only one was an RCT) reported a significant decrease in the duration of hospitalisation among patients receiving early feeding; the LOS ranged from 2 days (4 studies) to 12 days (1 study) for early feeding groups and from 12 to 25 days for traditional feeding groups.