Applying ice water to the face may be a simple and quick method for first responders to temporarily prevent cardiovascular shutdown in casualties who have lost a lot of blood. Such a tool could be an effective way to buy time until the patient – whether in a civilian or combat setting – receives proper medical care.
The researchers explain that blood loss causes central hypovolemia – a condition in which there is a drop in blood volume in the heart and in the blood vessels of the lungs.
In severe instances, blood loss can also decrease blood pressure and result in cardiovascular decompensation – a condition that is caused by a sudden and steep drop in blood pressure and results in insufficient oxygen supply to the brain, heart, and other vital organs.
Even when the bleeding has stopped, there may still be a significant risk of cardiovascular decompensation.
The researchers urge that the new study should be regarded as a preliminary investigation of how effective the method might be.
10 healthy volunteers aged 22 years on average underwent a simulation of blood loss. The volunteers were placed in a chamber that lowers blood pressure by 30 millimeters of mercury and simulates 6 minutes of blood loss.
Such an experimental setup mimics what happens in a person’s circulation when they lose around 1.5 liters of blood and then the application of a tourniquet stops them losing any more blood.
The results showed that there was a marked increase in blood pressure during treatment with ice water but there was no change during the control treatment.
There was also a sustained increase in peripheral resistance during the ice water treatment, while there was no change in this measure in the control treatment.
The researchers concluded, “Face cooling during simulated moderate blood loss increases blood pressure through an increase in total peripheral resistance.”
However, they are keen to point out that the technique should not be used until after active bleeding has stopped such as after a tourniquet is applied. Blood loss will worsen, not reduce, if blood pressure increases during active bleeding.
They suggest that further studies should now be done to find out the types of emergency cases and situations in which face cooling is likely to be effective. They also wish to carry out a clinical trial.
First author Professor Blair Johnson said, “We believe that cooling the face could potentially be used as a quick and temporary method to prevent cardiovascular decompensation after blood loss, once active bleeding has stopped. We think that this technique could be used by first responders or combat medics on the battlefield to give additional time for transportation or evacuation.”
