In Reply:—

Dr. Lemmens voices several complaints about the only investigation that has evaluated, under clinically relevant conditions, carbon monoxide (CO) and carboxyhemoglobin formation by carbon dioxide absorbents that do not contain strong base. 1The first complaint refers to the initial results sentence in the abstract. The sentence is correct (i.e. , order of formation) as stated. And it contains no statements regarding significance. Dr. Lemmens appears to have found fault based on incorrect assumptions. Of necessity, the abstract is a summary, not a complete statement of results. The issue is fully presented in the Results section of the manuscript where the same sentence describing order refers to a figure that clearly depicts results and is followed by several sentences that explicitly describe statistical significance (i.e. , CO formation from isoflurane was significantly less with Amsorb®than sodalime). The analysis of variance was two-way repeated measures, or one-way, as appropriate, with Student Newman–Kuels post hoc  comparisons. Dr. Lemmens’ last complaint relates to the two sentences in the final paragraph of the manuscript. Again, this is a summary (as indicated by the words that start the paragraph, i.e. , “In summary”). The first sentence is true; Amsorb did cause minimal if any CO formation. The second sentence also is true; the findings seem relevant to patient safety. Finally, Dr. Lemmens appears disturbed that the investigation was supported by a pharmaceutical company (not withstanding that it was investigator-initiated, and the company neither designed the experiments, analyzed the data, contributed to the manuscript, nor currently markets the product).

Dr. Lemmens does not indicate whether he would rather be anesthetized with desflurane passing through desiccated sodalime, or through a carbon dioxide absorbent that does not contain strong base.


Kharasch ED, Powers KM, Artru AA: Comparison of Amsorb®, sodalime, and Baralyme®degradation of volatile anesthetics and formation of carbon monoxide and compound A in swine in vivo . A nesthesiology 2002; 96: 173–82