Winter is coming… Think CO toxicity!

Much has been written on the topic of Carbon Monoxide Toxicity. I will not reiterate that CO is a colorless, tasteless, odorless gas, nor will I restate that it is among the top killers of toxins worldwide. I may tell you, however, that whenever a carbon based material undergoes incomplete combustion, CO is generated. Another tidbit commonly discussed in this context is that dichloromethane (CH2Cl2) ingestion will lead to high serum CO concentrations from metabolic conversion in the liver. There have been countless laboratory, animal and human studies which elucidate aspects of the multifactorial pathophysiology of CO toxicity which show effects from displacement of oxygen, causing hypoxic injury, binding to cytochrome, myoglobin and other proteins causing disruption in cellular respiration or function, lipid peroxidation and inflammatory effects with oxygen free radical generation, etc. most commonly manifesting in neurological, neuropsychiatric and cardiac dysfunction1. I am going to cut to the chase, as this is a blog and not a stuffy scientific manuscript, and discuss the presentation, diagnosis, treatment and outcome of patients with CO exposure and toxicity. Be warned, there is much controversy, a lot of data- some of which is contradictory- and even more anecdotal case studies. There are also medical-legal overtones and regional differences in preferred treatment modalities.

CO 1
Figure 1: Electron Transport Chain and the Effect of CO. https://www.boundless.com/biology/textbooks/boundless-biology-textbook/cellular-respiration-7/oxidative-phosphorylation-76/chemiosmosis-and-oxidative-phosphorylation-363-11589/

Case: 54 yo woman presenting with headache, nausea and blurred vision for 7-10 days. She stated that her contractor hired to re-work a botched job on her boiler advised her to go the emergency department because the CO level in her house was “sky-high”. After seeing another physician and hours after leaving her house, she presented to the emergency department. The boiler was faulty for about 2 weeks. Her examination was normal. Her labs and ECG were normal. Her COHgb concentration was 4.

Continue reading