Critical illness often disrupts gut function, metabolism, and immune function, leading to malnutrition. Enteral nutrition (EN) is preferred for critically ill patients, but up to 75% face feeding intolerance, resulting in poor nutrient delivery and GI symptoms. Dietary fibre (DF) has health benefits, including supporting gut integrity and immune responses, which may help EN tolerance in critical care.
Despite some promising results, studies on DF in EN show inconsistent outcomes and high-quality evidence is limited. ASPEN and SCCM recommend fermentable soluble DF supplements in stable ICU patients but advise against mixed DFs due to risks, while ESPEN lacks guidance. Previous reviews included non-RCTs and none applied trial sequential analysis (TSA), a method to improve error assessment.
A recent study conducted a systematic review and meta-analysis (SRMA) of RCTs, using TSA and GRADE assessment to provide more reliable conclusions on DF-supplemented EN for critically ill patients. This analysis investigated the effects of fibre-supplemented EN in adult critically ill patients. Trials comparing fibre-supplemented EN to placebo or standard care were selected. Two independent reviewers extracted data and assessed study bias. Random-effect meta-analysis and trial sequential analysis (TSA) were used, focusing on overall mortality as the primary outcome and diarrhoea incidence as a secondary outcome. Subgroup analyses were conducted for both outcomes.
The review included 20 studies with 1,405 critically ill patients and found that fibre-supplemented EN significantly reduced both overall mortality and diarrhoea incidence. However, both outcomes showed a very serious risk of bias, and TSA indicated a potential type-1 error. No differences were observed in subgroup analyses for mortality.
Four studies on gastrointestinal (GI) complications found no significant difference between groups. No significant differences were observed for abdominal distension, vomiting, regurgitation, or GI bleeding. However, six studies showed that fibre-supplemented EN significantly reduced the incidence of constipation. It was also associated with a significant reduction in both ICU length of stay (LOS) and hospital LOS.
Fibre-supplemented EN showed no significant association with the overall incidence of infectious complications. There was no significant effect on the incidence of pneumonia, urinary tract infections, intra-abdominal infections, sepsis, vascular infections, wound infections, or bacteraemia. In three studies on the duration of mechanical ventilation (MV), no significant difference was found between the groups.
One study reported episodes of hypoglycaemia, showing a significant benefit of fibre-supplemented EN. Two studies provided blood glucose data, and one study reported serum triglyceride levels. However, due to differences in timing and measurement units, the data were not suitable for a pooled meta-analysis.
Three studies on gastric residual volume found no significant differences at various time points. Five studies on caloric intake showed that fibre supplementation benefited overall energy intake in one study and intake on specific days in another. Tolerated feeding volumes were assessed in five studies, with one showing greater volumes for the intervention group on specific days and another showing a higher mean daily volume ratio. However, due to differences in timing and measurement units, data could not be aggregated for these outcomes. A meta-analysis of the time to reach energy targets from two studies showed a beneficial effect of fibre-supplemented EN.
Three studies reported the incidence of adverse events, but data were not pooled due to inconsistent definitions. One study on GI adverse events found no significant difference between groups. Another study reported no differences in the incidence or severity of adverse health events between groups. A third study found no adverse events related to fibre supplementation, but it did not define the events specifically or compare them to the control group.
The evidence, rated as very low certainty, suggests that fibre-supplemented EN may offer clinical benefits for critically ill patients. However, high-quality, large-scale multicentre RCTs are needed before recommending its routine use.
Source: Critical Care
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