CARBON DIOXIDE ABSORPTION

Different anesthesia systems eliminate carbon dioxide with various degrees of efficiency. The closed and semiclosed circle systems require carbon dioxide absorption. Desirable features of carbon dioxide absorbents include lack of toxicity with common anesthetics, low resistance to airflow, low cost, ease of handling, and efficiency.

Absorber Canister

On modern anesthesia machines, the absorber canister (see Fig. 9-22 ) is composed of two clear plastic canisters arranged in series. The canisters can be filled with bulk absorbent or with absorbent supplied by the factory in prefilled plastic disposable cartridges called prepacks. Free granules from bulk absorbent can create a clinically significant leak if they lodge between the clear plastic canister and the O-ring gasket of the absorber. Leaks have also been caused by defective prepacks that were larger than factory specifications. ^[112] Prepacks can also cause total obstruction of the circle system if the clear plastic shipping wrapper is not removed before use.^[113]