%0 Journal Article
%T Preliminary report of a gas conditioner to improve operational reliability of cryotherapy in developing countries
%A Yancy Seamans
%A John Sellors
%A Fredrik Broekhuizen
%A Michelle Howard
%J BMC Women's Health
%D 2006
%I BioMed Central
%R 10.1186/1472-6874-6-2
%X The prototype conditioner device consists of an expansion chamber that filters and dries the refrigerant gas. Users in Peru and Kenya reported on their experience with the prototype conditioner. In Ghana, simulated cryotherapy procedures were used to test the effects of the prototype conditioner, as well as the commonly used "cough technique."Anecdotal reports from field use of the device were favorable. During simulated cryotherapy, the prevalence of blockage during freezing were 0% (0/25) with the device alone, 23.3% (7/30) with the cough technique alone, 5.9% (1/17) with both, and 55.2% (16/29) with neither (Pearson's Chi square = 26.6, df = 3, p < 0.001 (comparison amongst all groups)).This prototype design of a cryotherapy gas conditioner is a potential solution for low-resource settings that are experiencing cryotherapy device malfunction.Cryotherapy to treat precancerous cervical lesions in low-resource settings has been shown to be both clinically effective and logistically possible [1-4]. However, experience in developing country clinics has indicated that cryotherapy units fail due to blockage (i.e. complete stoppage of the gas flow), and that preventive measures are advisable [5,6]. This problem arises when there is an interruption in gas flow during the procedure, and results in service disruption for several minutes while the unit thaws and the blockage clears. It can be argued that such interruptions might threaten the effectiveness of cryotherapy, since the procedure usually entails two 3-minute freezes, separated by a 5-minute interval to allow thawing of the tissue [7]. Typically, failures have been attributed to gas supply line blockages caused by gas impurities, condensation and freezing of water vapor, or formation of dry ice in the gas supply lines.JHPIEGO currently advocates a "freeze-clear-freeze technique (also known as the "cough" technique) to alleviate blockages [5]. The cough technique involves briefly interrupting freezing every 15 secon
%U http://www.biomedcentral.com/1472-6874/6/2