Effect of cough technique and cryogen gas on temperatures achieved during simulated cryotherapy

<p>Abstract</p> <p>Background</p> <p>Cryotherapy is often used to treat cervical precancer in developing countries. There are different methods and cryogen gases used for cryotherapy, including the freeze-flush-freeze (cough) technique employed to minimize gas blockage. However, there is limited information to compare their effectiveness.</p> <p>Methods</p> <p>Using a tissue model, we compared temperature-time curves for four cryotherapy methods: uninterrupted freezing with nitrous oxide (N₂O) and carbon dioxide (CO₂), and two methods using a standard and extended version of the cough technique with CO₂.</p> <p>Results</p> <p>Uninterrupted freezing with both N₂O and CO₂produced tissue temperatures less than -20°C (-40°C and -30°C respectively). CO₂cryotherapy procedures using the two cough techniques produced temperatures greater than -20°C in the model tissue.</p> <p>Conclusion</p> <p>CO₂cryotherapy using the cough technique may not achieve sufficiently low temperatures to produce the desired therapeutic effect. Other alternatives to the prevention of gas blockage should be developed.</p