Definitions, predictors and outcomes of feeding intolerance in critically ill children: A systematic review

Clinicians and researchers often use feeding intolerance (FI) as main cause for insufficient enteral nutrition (EN). However, there is no uniform definition for FI. A uniform definition is essential for future studies focusing on predictors and outcomes of FI and enteral nutrition. A systematic review was performed to investigate the definitions, prevalence, predictors and outcomes of FI in critically ill children.The databases Medline, Embase, Cochrane CENTRAL, Web of Science were searched. Inclusion criteria were interventional, observational or case-control studies (>10 patients) in which a definition of FI was reported in critically ill children (0-21 years).FI was defined in 31 unique studies performed in 2973 critically ill children. FI was most commonly defined as presence of gastrointestinal (GI) symptoms and/or large gastric residual volume (GRV) (n = 21), followed by discontinuation of EN due to GI symptoms (n = 7) and inadequate delivery of EN (n = 3). Median prevalence of FI was 20.0% [IQR 7.4%-33.0%]. Large GRV, abdominal distention, diarrhoea and vomiting/emesis, were the predominantly reported GI symptoms to define FI. FI was associated with severity of illness, mortality and nosocomial infections.Feeding intolerance is inconsistently defined in the current literature, but appears to be a prevalent concern in critically ill children. FI is most frequently defined by the presence of GI symptoms. A standardized definition is needed for both clinical and research purpose to determine the consequences of FI in relation to short-term and long-term outcomes. The new proposed definition for FI entails the inability to achieve enteral nutrition target intakes in combination with the presence of GI symptoms indicating GI dysfunction.PROSPERO registration number: CRD42018092967. Registered on 07 June 2018.