Reference Manual - IARC Screening Group

Figure D-5. Removing Protector Tube from ProbeTechnical Overview of the Cryotherapy SystemFigure D-6. Installing CryotipChecking that • Press the freeze (left) trigger. After several seconds, the cryotipSystem Is Working should frost.Properly 5 If no gas flows when the freeze trigger is depressed, see Problem8 (Appendix E, page E-3).• Release the freeze (left) trigger and press the defrost (right) trigger.After several seconds, the frost should disappear. If no gas flows when the defrost trigger is depressed, seeProblem 9 (Appendix E, page E-3). If the triggers will not move, see Problem 10 (Appendix E,page E-3).THE FREEZE-CLEAR-FREEZE TECHNIQUEWhen using CO 2 cylinders, the cryotherapy unit may become blockedwith small ice particles, cutting off the gas flow in the system andcausing it to stop working. To prevent this from happening, it isimportant to use the freeze-clear-freeze (FCF) technique—according tothe guidelines shown in Figure D-7—throughout the entire freezingperiod in all cryosurgical treatment procedures. Application of the FCFtechnique prevents the cryotherapy unit from becoming blocked with ice5 This step should be performed at the beginning of the day and before each cryosurgical procedure.Cervical Cancer Prevention Guidelines for Low-Resource Settings D-5