Parenteral versus enteral fluid therapy for children hospitalised with bronchiolitis

The main focus of treatment for children hospitalised with bronchiolitis is supportive, including oxygen supplementation, respiratory support, and fluid therapy. Up to half of infants hospitalised with bronchiolitis require non-oral fluid therapy due to dehydration or concerns related to the safety of oral feeding. The two main modalities used for non-oral fluid therapy are parenteral (intravenous (IV)) and enteral tube (nasogastric (NG) or orogastric (OG)). However, it is not known which mode is optimal in young children.

To systematically review randomised clinical trials (RCTs) of the effectiveness and safety of parenteral and enteral tube fluid therapy for children under two years of age hospitalised with bronchiolitis.

We conducted a search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, Web of Science, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform on 8 March 2021. We handsearched conference proceedings, conducted forward and backward searching of citation lists of relevant articles, and contacted experts.

We included RCTs and quasi-RCTs of children aged up to two years admitted to hospital with a clinical diagnosis of bronchiolitis who required fluid therapy. The trials compared enteral tube fluid therapy with parenteral fluid therapy. The primary outcome was difference in length of hospital stay in hours after each non-oral fluid therapy modality. As actual time of discharge can be impacted by various factors, we also assessed theoretical length of stay (i.e. time when a patient is safe for discharge). We assessed several secondary outcomes.

We used standard methodological procedures expected by Cochrane.  MAIN RESULTS: The searches yielded 615 unique records, of which four articles underwent full-text screening. We included two trials (810 children). Oakley 2013 was an open, non-blinded RCT of infants aged two to 12 months admitted to hospitals in Australia and New Zealand with a clinical diagnosis of bronchiolitis during three bronchiolitis seasons. The trial enrolled 759 children, of which 381 were randomised to NG tube therapy and 378 to IV therapy. Risk of bias was low in most domains. Kugelman 2013 was an open, non-blinded RCT that enrolled infants aged less than six months with a clinical diagnosis of "moderate bronchiolitis" at a single hospital in Israel. The study enrolled 51 infants, of which 31 were assigned to NG or OG tube therapy and 20 to IV therapy. Risk of bias was unclear in most domains. The application of enteral tube fluid therapy compared to IV fluid therapy probably makes little to no difference for actual length of hospital stay (mean difference (MD) 6.8 hours, 95% confidence interval (CI) -4.7 to 18.4 hours; 2 studies, 810 children, moderate certainty evidence). There was also little to no difference for theoretical length of stay (MD 4.4 hours, 95% CI -3.6 to 12.4 hours; 2 studies, 810 children, moderate certainty evidence). For the secondary outcomes, enteral tube fluid therapy probably makes little to no difference for time to resume full oral feeding compared to IV fluid therapy (MD 2.8 hours, 95% CI -3.6 to 9.2 hours; 2 studies, 810 children, moderate certainty evidence). The use of enteral tube for fluid therapy probably results in a large increase in the success of insertion of fluid modality at first attempt (risk ratio (RR) 1.52, 95% CI 1.36 to 1.69; 1 study, 617 children, moderate certainty evidence), and probably largely reduces the chances of change in fluid therapy modality (RR 0.52, 95% CI 0.38 to 0.71; 1 study, 759 children, moderate certainty evidence) compared to IV fluid.  Oakley 2013 reported 47 local complication events after discharge in the IV fluid group compared to 30 events in the NG tube group. They also evaluated parental satisfaction, which was high with both modalities. Enteral tube fluid therapy makes little to no difference to the duration of oxygen supplementation (MD 2.2 hours, 95% CI -5.0 to 9.5 hours; 2 studies, 810 children, moderate certainty evidence). Compared with the IV fluid therapy group, there was a 17% relative reduction in the number of intensive care unit admissions (RR 0.83, 95% CI 0.47 to 1.46; 1 study, 759 children, moderate certainty evidence) and a 19% relative reduction in number of readmissions to hospital (RR 0.81, 95% CI 0.33 to 2.04; 1 study, 678 children, moderate certainty evidence) in the enteral tube fluid therapy group. Adverse events were uncommon in both trials, with likely little to no differences between groups.

Based on two RCTs, enteral tube feeding likely results in little to no difference in length of hospital stay compared with the IV fluid group. However, enteral tube fluid therapy likely results in a large increase in the success of insertion of fluid modality at first attempt, and a large reduction in change in modality of fluid therapy. It also probably reduces local complications compared to the IV fluid group. Despite bronchiolitis being one of the most prevalent childhood conditions, we identified only two studies with under 1000 participants in total, which highlights the need for multicentre trials. Future studies should explore type of fluid administered, parent-reported outcomes and preferences, and the role of shared decision-making.