Ultrasound measurement of patients undergoing venesection
Research type
Research Study
Full title
Observational study of changes in ultrasound measurements of the vasculature of haemochromatosis patients before and after undergoing venesection
IRAS ID
143632
Contact name
Tim Harris
Contact email
Sponsor organisation
Barts Health NHS Trust
Research summary
Assessing the extent of blood loss from patients presenting to hospital is difficult. It is important to have some idea on how much blood loss has occurred to guide fluid replacement: insufficient fluid can lead to organ failure; surplus fluid can cause fluid to accumulate within the lungs and cause breathing problems.
Measures such as blood pressure, heart rate and respiratory rate are typically used to estimate fluid loss. However, in healthy young patients, it is possible to lose up to 30% of the patient's blood volume with minimal changes to these parameters. Additionally, alternative factors such as pain or illness can cause these parameters to be altered.
Accurate measurement of the extent of blood loss requires the use of invasive techniques: insertion of lines into the patient’s arteries, with potential associated risks including infection and bleeding.
Previous studies on healthy volunteers and patients undergoing venesection (blood removal) used non-invasive ultrasound methods to assess dehydration levels, measuring the inferior vena cava diameter (a large vein returning blood to the heart) and its change with rapid intake of breath. This has been shown to correlate with fluid loss in a previous study by Professor Tim Harris and Dr Chloe Baker.
The size and speed of the rapid inspiration can cause varying levels of inferior vena cava collapse. This study will attempt to standardise the rapid inhalation by using an incentive spirometer, which measures the speed of inhalation. The inferior vena cava size when breathing through incentive spirometer will be measured before and after blood removal. Stroke volume (blood pumped per heartbeat) will be measured using ultrasound. The stroke volume and size decrease of the inferior vena cava will be correlated with the blood loss to attempt to investigate whether inferior vena cava collapse on incentive spirometry is a useful predictor of fluid loss.
REC name
East Midlands - Derby Research Ethics Committee
REC reference
14/EM/1051
Date of REC Opinion
4 Nov 2014
REC opinion
Further Information Favourable Opinion