When choosing a type of CO2 absorbent, it is important to understand the absorbents environmental impact, effect on patient safety, ease of use and the effect on the consumption of volatile anesthetics. Today we are going to review Amsorb vs. soda limes that contain traces of Sodium Hydroxide, NaOH, such as Medisorb, Sodasorb, Dragersorb and others.
Soda limes can have a pH of up to 14 and may require disposal as a hazardous waste according to U.S. Federal Code of Regulations. Soda limes contain sodium hydroxide and are considered corrosive.
Amsorb Plus has a pH of less than 12.5 and is safe for our water table and landfills where it will break down into harmless organic compounds. Amsorb Plus comes with certification of such (see Amsorb Plus disposal document). Kaiser Permanente independently tested all the types of CO2 absorbents readily available on the market and determined Amsorb Plus to be the only one that was safe for disposal in regular landfills. Other types of CO2 absorbents had higher pH and needed to be red bagged and incinerated at greater expense. Amsorb Plus is not harmful in disposal to the environment which translates into a cost savings for hospitals and surgery centers since red bagging is expensive and time consuming.
Soda limes are known to degrade volatile anesthetics to Carbon Monoxide, Compounds A – F, and Formaldehyde.
Amsorb Plus has no strong alkali and is incapable of producing any of these toxins. Clinical Anesthesia by Barash, 2012, recommends using Amsorb Plus by name and states doing so: (Amsorb Plus)
eliminates all of the potential complications related to anesthetic breakdown and therefore minimizes the possibility of additional costs from those complications, including additional laboratory tests, hospital days, and medical/legal expenses. Adoption of [Amsorb Plus] into routine clinical practice is consistent with the patient safety goals of our anesthesia society.
Ease of Use & Consumption of Volatile Anesthetic
Soda Lime users generally change absorbent based on color change and never know for sure when to change product. Users usually error on the side of caution and change soda lime more often (a wasteful and confusing practice) because if they don’t change soda lime it is possible to endanger the patient by producing toxins such as Compound A, Formaldehyde and Carbon Monoxide. Soda Lime includes a dye that changes color to indicate exhaustion. However, it does not retain color change for long before reverting back to looking fresh. The user can never be sure when product should be changed. Ask any clinician that has used a soda lime and they will verify it is not uncommon to begin a case with what they think is fresh absorbent only to immediately find out they have high levels of FiCO2 and rapid color change of their absorbent.
Soda Limes “adsorbs” (significant amounts of volatile anesthetic which means clinicians wait longer periods of time for their machines and vaporizers to equilibriate. They are less able to reach desired drug percentages without increasing vaporizer settings.
Amsorb Plus has permanent, consistent, and reliable color change. Thus allowing the user to easily tell the state of the absorbent at a glance. Amsorb Plus also adsorbs far less anesthetic vapor than soda limes so machines and vaporizers reach equilibriation faster and accurately reach desired drug percentages without needing to increase vaporizer settings above what is desired for patient inspiration. This saves time and money (utilizing less anesthetic vapor).
Amsorb vs. Soda Lime Review Summary
|Soda Lime||Amsorb Plus|
|Ease of Use & Consumption of Volatile Anesthetic|