To study the effect of Tourniquets on tissue oxygenation using NIRS
Research type
Research Study
Full title
To study the effect of Tourniquet applications on tissue oxygenation measured using Near Infra Red Spectroscopy (NIRS): A feasibility study
IRAS ID
156425
Contact name
A Guleria
Contact email
Duration of Study in the UK
0 years, 6 months, 0 days
Research summary
Tourniquets are applied to reduce blood loss during surgery by preventing blood flow into the area over which they are applied. Oxygenated blood cannot get to the tissues which may cause ischemia. They can also cause damage by pressure effect if applied too long. Tourniquets are applied for a restricted period of time and inflated to agreed pressures to occlude blood flow to the limb. These values are taken from adult practice. However there is no evidence for what are safe values in children. Near infra-Red Spectroscopy (NIRS) uses different wavelengths of light to measure the oxygen content in the tissues. It is a non invasive monitor which is in clinical use in other areas eg cardiac practice and Intensive Care units.
We plan to look at the rate of fall of oxygen in the tissues when the tourniquet is applied to a limb for surgery and measure the recovery to normal values by comparing it to the oxygen levels in the opposite limb of the patient. This involves no change in the care of the patient except application of two additional NIRS probes similar to an ECG electrode. The data we obtain will help to establish what is happening under standard care, which is not evidence based. It will also enable us to undertake further research into how we can make the use of tourniquet's safer for patients, eg by reducing the inflation pressures, managing the time for which we should apply a tourniquet and also whether we can reduce the fall in tissue oxygen levels by increasing delivery of oxygen to tissues before the Tourniquet is applied. This has implications for a reduction in tourniquet complications and may extend the use of tourniquets in certain subsets of patients in whom they are contra-indicated like sickle cell patients.REC name
North West - Liverpool Central Research Ethics Committee
REC reference
15/NW/0390
Date of REC Opinion
30 Apr 2015
REC opinion
Further Information Favourable Opinion