Absorption of Carbon Dioxide by Dry Soda Lime Decreases Carbon Monoxide Formation from Isoflurane Degradation

2000 ◽  
Vol 91 (2) ◽  
pp. 446-451 ◽  
Author(s):  
Erich Knolle ◽  
Hermann Gilly
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Soda Lime ◽  
Carbon Monoxide Formation

Using Amsorb to Detect Dehydration of CO2Absorbents Containing Strong Base

2002 ◽  
Vol 97 (2) ◽  
pp. 454-459 ◽  
Author(s):  
Erich Knolle ◽  
Wolfgang Linert ◽  
Hermann Gilly
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Water Content ◽  
Color Change ◽  
Anesthesia Machine ◽  
Strong Base ◽  
Carbon Monoxide Formation ◽  
The Mean ◽  
Indicator Dye

Background Because Amsorb changes color when it dries, the authors investigated whether Amsorb combined with different strong base-containing carbon dioxide absorbents signals dehydration of such absorbents. Methods Five different carbon dioxide absorbents (1,330 g) each topped with 70 g of Amsorb were dried in an anesthesia machine (Modulus CD, Datex-Ohmeda, Madison, WI) with oxygen (Amsorb layer at the fresh gas inflow site). As soon as a color change was detected in the Amsorb, the authors tested the samples for a change in weight and carbon monoxide formation from 7.5% desflurane or 4% isoflurane. In a different experiment with the five absorbents, Amsorb was layered at the drying gas outflow site. In further experiments, the authors tested for a color change in Amsorb from drying and rehydrating and from drying with nitrogen. Finally, they dried a mixture of Amsorb and 1% NaOH and examined it for color change. Results In the experiments with Amsorb layered at the inflow, the Amsorb changed color when the water content of the samples was only marginally reduced (to a mean 13.6%), and no carbon monoxide formed. With Amsorb layered at the outflow, it changed color when the mean water content of the samples was reduced to 8.8%, and carbon monoxide formation was detected to varying degrees. The color change was independent of the drying gas and could be reversed by rehydrating. Adding NaOH to Amsorb prevented a color change. Conclusions Dehydration in strong base-containing absorbents can reliably be indicated before carbon monoxide is formed when Amsorb is layered at the fresh gas inflow. The authors assume that the indicator dye in Amsorb changes color on drying because of the absence of strong base in this absorbent.

Carbon Monoxide Formation in Dry Soda Lime is Prolonged at Low Gas Flow

2001 ◽  
Vol 93 (2) ◽  
pp. 488-493
Author(s):  
Erich Knolle ◽  
Georg Heinze ◽  
Hermann Gilly
Keyword(s):  
Carbon Monoxide ◽  
Gas Flow ◽  
Soda Lime ◽  
Carbon Monoxide Formation

Amsorb 

1999 ◽  
Vol 91 (5) ◽  
pp. 1342-1342 ◽  
Author(s):  
James M. Murray ◽  
Craig W. Renfrew ◽  
Amit Bedi ◽  
Conor B. McCrystal ◽  
David S. Jones ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Parent Drug ◽  
Soda Lime ◽  
Calcium Sulphate ◽  
Carbon Dioxide Absorption ◽  
Compound A ◽  
New Material ◽  
Carbon Dioxide Absorbent

Background This article describes a carbon dioxide absorbent for use in anesthesia. The absorbent consists of calcium hydroxide with a compatible humectant, namely, calcium chloride. The absorbent mixture does not contain sodium or potassium hydroxide but includes two setting agents (calcium sulphate and polyvinylpyrrolidine) to improve hardness and porosity. Methods The resultant mixture was formulated and subjected to standardized tests for hardness, porosity, and carbon dioxide absorption. Additionally, the new absorbent was exposed in vitro to sevoflurane, desflurane, isoflurane, and enflurane to determine whether these anesthetics were degraded to either compound A or carbon monoxide. The performance data and inertness of the absorbent were compared with two currently available brands of soda lime: Intersorb (Intersurgical Ltd., Berkshire, United Kingdom) and Dragersorb (Drager, Lubeck, Germany). Results The new carbon dioxide absorbent conformed to United States Pharmacopeia specifications in terms of carbon dioxide absorption, granule hardness, and porosity. When the new material was exposed to sevoflurane (2%) in oxygen at a flow rate of 1 l/min, concentrations of compound A did not increase above those found in the parent drug (1.3-3.3 ppm). In the same experiment, mean +/-SD concentrations of compound A (32.5 +/- 4.5 ppm) were observed when both traditional brands of soda lime were used. After dehydration of the traditional soda limes, immediate exposure to desflurane (60%), enflurane (2%), and isoflurane (2%) produced concentrations of carbon monoxide of 600.0 +/- 10.0 ppm, 580.0 +/- 9.8 ppm, and 620.0 +/-10.1 ppm, respectively. In contrast, concentrations of carbon monoxide were negligible (1-3 ppm) when the anhydrous new absorbent was exposed to the same anesthetics. Conclusions The new material is an effective carbon dioxide absorbent and is chemically unreactive with sevoflurane, enflurane, isoflurane, and desflurane.

Rehydration of Desiccated Baralyme Prevents Carbon Monoxide Formation from Desflurane in an Anesthesia Machine 

1997 ◽  
Vol 86 (5) ◽  
pp. 1061-1065 ◽  
Author(s):  
Pamela J. Baxter ◽  
Evan D. Kharasch
Keyword(s):  
Carbon Monoxide ◽  
Water Content ◽  
Effective Means ◽  
Soda Lime ◽  
Anesthesia Machine ◽  
Gas Chromatography Mass Spectrometry ◽  
Constant Weight ◽  
Normal Water ◽  
Carbon Monoxide Formation

Background Desiccated carbon dioxide absorbents degrade desflurane, enflurane, and isoflurane to carbon monoxide (CO) in vitro and in anesthesia machines, which can result in significant clinical CO exposure. Carbon monoxide formation is highest from desflurane, and greater with Baralyme than with soda lime. Degradation is inversely related to absorbent water content, and thus the greatest CO concentrations occur with desflurane and fully desiccated Baralyme. This investigation tested the hypothesis that rehydrating desiccated absorbent can diminish CO formation. Methods Baralyme was dried to constant weight. Carbon monoxide formation from desflurane and desiccated Baralyme was determined in sealed 20.7-ml vials without adding water, after adding 10% of the normal water content (1.3% water), and after adding 100% of the normal water content (13% water) to the dry absorbent. Similar measurements were made using an anesthesia machine and circle system. Carbon monoxide was measured by gas chromatography-mass spectrometry. Results Carbon monoxide formation from desflurane in vitro was decreased from 10,700 ppm with desiccated Baralyme to 715 ppm and less than 100 ppm, respectively, when 1.3% and 13% water were added. Complete rehydration also decreased CO formation from enflurane and isoflurane to undetectable concentrations. Desflurane degradation in an anesthesia machine produced 2,500 ppm CO in the circuit, which was reduced to less than 180 ppm when the full complement of water (13%) was added to the dried absorbent. Conclusions Desflurane is degraded by desiccated Baralyme in an anesthesia machine, resulting in CO formation. Adding water to dried Baralyme is an effective means of reducing CO formation and the risk of intraoperative CO poisoning. Although demonstrated specifically for desflurane and Baralyme, rehydration is also applicable to enflurane and isoflurane, and to soda lime.

The Source of Carbon Monoxide in the Float of the Portuguese Man-of-War, Physalia Physalis L

1960 ◽  
Vol 37 (4) ◽  
pp. 698-705
Author(s):  
JONATHAN B. WITTENBERG
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Folic Acid ◽  
Large Concentration ◽  
Carbon Monoxide Formation ◽  
Through Diffusion ◽  
Gas Gland ◽  
Physalia Physalis

1. Carbon monoxide, 0.5-13%, is found in the float gases of Physalia. Oxygen comprises 15-20% of the total gas. Carbon dioxide is present in negligible amounts. 2. The gas gland, pneumadena, is the site of carbon monoxide formation. 3. L-Serine is the substrate for carbon monoxide formation. 4. A strikingly large concentration of folic acid is found in the gas gland. 5. It is suggested that carbon monoxide secretion serves to inflate the float of Physalia and that carbon monoxide is later slowly replaced by air through diffusion and exchange.

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