Heat generation as an index of exhaustion of soda lime.
The wall temperatures of the absorptive chambers of a divided soda lime canister were measured in 70 patients to determine the relationship between the difference in temperature of the two chambers and CO2 passage through the first chamber. CO2 passage through the first chamber was detected when the temperature of the second chamber became equal to that of the first. A significant correlation (R = 0.94; P less than 0.001) was found between the magnitude of CO2 passage through the first chamber and the difference in temperature between the chambers. When the maximal absorptive capacity of soda lime was reached, the pH of the surface of soda lime granules was still too high to change the indicator color. Exhaustion of soda lime is more reliably recognized by measuring wall temperatures of the chambers than by observing color change of the soda lime granules.
Tsuchiya
M
M
Department of Anesthesiology, Kochi Medical School, Japan.
Ueda
W
W
D000327:Adsorption; D000328:Adult; D000776:Anesthesiology / Q000295:instrumentation*; D017610:Calcium Compounds; D002245:Carbon Dioxide; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008875:Middle Aged; D010087:Oxides; D012972:Sodium Hydroxide
D017610:Calcium Compounds; D010087:Oxides; D002245:Carbon Dioxide; C004569:soda lime; D012972:Sodium Hydroxide