A single-blinded randomised clinical trial of permissive underfeeding in patients requiring parenteral nutrition

Summary Background & aims The importance of adequate nutritional support is well established, but characterising what ‘adequate nutrition’ represents remains contentious. In recent years there has been increasing interest in the concept of ‘permissive underfeeding’ where patients are intentionally prescribed less nutrition than their calculated requirements. The aim of this study was to evaluate the effect of permissive underfeeding on septic and nutrition related morbidity in patients requiring short term parenteral nutrition (PN). Methods This was a single-blinded randomised clinical trial of 50 consecutive patients requiring parenteral nutritional support. Patients were randomized to receive either normocaloric or hypocaloric feeding (respectively 100% vs. 60% of estimated requirements). The primary end point was septic complications. Secondary end points included the metabolic, physiological and clinical outcomes to the two feeding protocols. Results Permissive underfeeding was associated with fewer septic complications (3 vs. 12 patients; p  = 0.003), and a lower incidence of the systemic inflammatory response syndrome (9 vs. 16 patients; p  = 0.017). Permissively underfed patients had fewer feed related complications (2 vs. 9 patients; p  = 0.016). Conclusion Permissive underfeeding in patients requiring short term PN appears to be safe and may results in reduced septic and feed-related complications. Trial registration: NCT01154179 Trial registry: http://clinicaltrials.gov/ct2/show/NCT01154179 .