FREQUENTLY ASKED QUESTIONS
1) What does the term "thermal shock" mean?
It is the response of the body to intense and powerful cold, through the transmission of messages to the brain from skin receptors.
2) Will this technique not freeze burn the skin surface? No. Although the stream of CO2 hits the skin surface at -78oC, the surface temperature is only lowered to a temperature of 4oC.
3) How does it compare to traditional ice treatments?
a) When ice packs are placed on the skin, the temperature of the ice immediately begins to rise due to the heat being released from the trauma site. With cryotherapy, the CO2 temperature remains stable, therefore the skin cooling is more effective.
b) Crushed ice is widely used, however, prolonged application is necessary to obtain effects e.g. 10mins to reduce skin temperature to 15oC and 30mins to reduce to 12oC. The applied cold is wet and treatments, which last more than 20mins, would not only be uncomfotable, but may also cause tissue damage.
Comparison of Blood Flow Properties
| ICE | LIQUID CO2 | |
| Vasoconstriction peak | 38% | 38% |
| Time of onset | 30 secs | 7 secs |
| Vasodilation peak | 80% | 117% |
| Time of onset | 20 mins | 20 secs |
4) How soon will the effects of cryotherapy be observed?
There will be a noted difference after a few minutes. Pain, through palpation, will immediately be removed, however this is due to the anaesthetic properties of the therapy. Palpation must therefore be carried out at a later stage. Muscles surrounding the trauma site will appear relaxed and any lameness will disappear. After 3 hours, signs may reappear although diminished. If this occurs, further treatment is recommended.
