FOCUS Study
Research type
Research Study
Full title
Fluid Overload assessment in critically ill children using Chest UltraSound (FOCUS Study)
IRAS ID
311601
Contact name
Padmanabhan Ramnarayan
Contact email
Sponsor organisation
Imperial College Healthcare NHS Trust
Duration of Study in the UK
1 years, 5 months, 29 days
Research summary
Summary of Research
Intravenous fluid administration, either as a rapid push (bolus) and/or as slow continuous drip (maintenance), is a common treatment in sick children. Despite the belief that large amounts of fluid are beneficial, there is emerging evidence from paediatric intensive care units (PICUs) that too much fluid (fluid overload) may in fact flood children’s lungs and prolong the time spent on a ventilator. Therefore, regular assessment of fluid status, and early steps to decrease fluid overload (such as diuretic medication), may improve children’s health outcomes. Accurate assessment of fluid status, especially in children’s lungs, however, is challenging.Over the past decade, bedside point-of-care lung ultrasound (POCUS) has been increasingly used to assess fluid status in the lungs of adult patients. The advantage of lung POCUS is that it is non-invasive, quick and easy to perform; however, there is limited experience of using it for regular fluid assessment in sick children. In this study, following written informed consent from parents/guardians, we will perform daily lung POCUS in all ventilated children in a PICU, systematically measure POCUS markers of fluid overload (number of B-lines), and correlate these markers with daily measured fluid balance (calculated by measuring the fluid input and output), markers of oxygenation and ventilation (how much support the child is needing from the ventilator), and patient outcomes (such as length of ventilation).
We do not anticipate any risks to patients since lung POCUS is a safe procedure that takes under 10 minutes to perform. There is little change to current practice since POCUS is already being performed sporadically in the PICU; we simply intend to perform the POCUS once every day. No personal data will be collected in the study – each patient will be assigned a unique study number which will be used to match up with their clinical details.
Summary of Results
Excessive intravenous (IV) fluid administration can prolong mechanical ventilation in critically ill children. However, conducting accurate daily fluid assessment can be a complex task. In adult practice, the emergence of lung point-of-care ultrasound (POCUS) has aided this process. In this study, we aimed to assess the correlation between daily B-lines measured using lung POCUS in ventilated children compared to markers of oxygenation/ventilation and cumulative fluid balance.This was a prospective observational cohort study conducted at a general PICU in London, UK, with doctors and physiotherapists utilising POCUS to assess B-lines scores with an eight-zone protocol. Daily scans were conducted until ventilation liberation or day 7 of MV. Contemporaneous markers regarding oxygenation, ventilation and fluid balance were extracted from the electronic records. Mixed effects linear regression was used to assess the association between B-line scores and oxygen, ventilation, fluid and outcome parameters.
37 children were included who received a total of 78 scans. Median age was 18 months (interquartile range (IQR) 9-44 months). The most common reason for admission was due to respiratory causes (for 76%, n=28). Median duration of mechanical ventilation was 92.5 hours (54-132). Scan duration was short (median 10 minutes (5-10 minutes). Median average B-line score was 0.5 (0.25-1.125). There was no statistically significant trend over time in either the total or average B-line score (p=0.16) although scan numbers were lower at later stages.
This is the first paediatric study to show that serial lung POCUS is useful as an adjunct tool in complex post-resuscitation fluid management and to prognosticate ongoing ventilation support required.
REC name
London - Chelsea Research Ethics Committee
REC reference
22/PR/1633
Date of REC Opinion
31 Jan 2023
REC opinion
Further Information Favourable Opinion