Restricted fluid bolus versus current practice in children with septic shock: the FiSh feasibility study and pilot RCT
Authors: Inwald David , Canter Ruth R , Woolfall Kerry , O’Hara Caitlin B , Mouncey Paul R , Zenasni Zohra , Hudson Nicholas , Saunders Steven , Carter Anjali , Jones Nicola , Lyttle Mark D , Nadel Simon , Peters Mark J , Harrison David A , Rowan Kathryn M 
Published: September 2018

Background
There has been no randomised controlled trial (RCT) of fluid bolus therapy in paediatric sepsis in the developed world despite evidence that excess fluid may be associated with harm.

Objectives
To determine the feasibility of the Fluids in Shock (FiSh) trial – a RCT comparing restricted fluid bolus (10 ml/kg) with current practice (20 ml/kg) in children with septic shock in the UK.

Design
(1) Qualitative feasibility study exploring parents’ views about the pilot RCT. (2) Pilot RCT over a 9-month period, including integrated parental and staff perspectives study.

Setting
(1) Recruitment took place across four NHS hospitals in England and on social media. (2) Recruitment took place across 13 NHS hospitals in England.

Participants
(1) Parents of children admitted to a UK hospital with presumed septic shock in the previous 3 years. (2) Children presenting to an emergency department with clinical suspicion of infection and shock after 20 ml/kg of fluid. Exclusion criteria were receipt of > 20 ml/kg of fluid, conditions requiring fluid restriction and the patient not for full active treatment (i.e. palliative care plan in place). Site staff and parents of children in the pilot were recruited to the perspectives study.

Interventions
(1) None. (2) Children were randomly allocated (1 : 1) to 10- or 20-ml/kg fluid boluses every 15 minutes for 4 hours if in shock.

Main outcome measures
(1) Acceptability of FiSh trial, proposed consent model and potential outcome measures. (2) Outcomes were based on progression criteria, including recruitment and retention rates, protocol adherence and separation between the groups, and collection and distribution of potential outcome measures.

Results
(1) Twenty-one parents were interviewed. All would have consented for the pilot study. (2) Seventy-five children were randomised, 40 to the 10-ml/kg fluid bolus group and 35 to the 20-ml/kg fluid bolus group. Two children were withdrawn. Although the anticipated recruitment rate was achieved, there was variability across the sites. Fifty-nine per cent of children in the 10-ml/kg fluid bolus group and 74% in the 20-ml/kg fluid bolus group required only a single trial bolus before shock resolved. The volume of fluid (in ml/kg) was 35% lower in the first hour and 44% lower over the 4-hour period in the 10-ml/kg fluid bolus group. Fluid boluses were delivered per protocol (volume and timing) for 79% of participants in the 10-ml/kg fluid bolus group and for 55% in the 20-ml/kg fluid bolus group, mainly as a result of delivery not being completed within 15 minutes. There were no deaths. Length of hospital stay, paediatric intensive care unit (PICU) transfers, and days alive and PICU free did not differ significantly between the groups. Two adverse events were reported in each group. A questionnaire was completed by 45 parents, 20 families and seven staff were interviewed and 20 staff participated in focus groups. Although a minority of site staff lacked equipoise in favour of more restricted boluses, all supported the trial.

Conclusions
Even though a successful feasibility and pilot RCT were conducted, participants were not as unwell as expected. A larger trial is not feasible in its current design in the UK.

Future work
Further observational work is required to determine the epidemiology of severe childhood infection in the UK in the postvaccine era.

Trial registration
Current Controlled Trials ISRCTN15244462.

Funding
This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 51. See the NIHR Journals Library website for further project information.