Carbon Monoxide Background

Carbon monoxide exposure is one of the most common poisonings in the United States.  Although we often think of CO is a “winter time” problem, carbon monoxide exposure and poisonings can take place at any time of the year. Carbon monoxide exposure incidents tend to increase during the winter months we can also see an increase in these events at any time when a population uses auxiliary heating or power generating equipment; such as seen during major power failures or other natural events.

Carbon monoxide is known as the “Great Imitator” and can mimic a variety of other medical problems such as cold and flu. In fact a study done in 2006 indicated that one in four patients presenting to a hospital with cold and flu symptoms actually had carbon monoxide exposure. Carbon monoxide has also been linked to cardiac events after chronic exposure. Failure to recognize the potential of carbon monoxide exposure can lead to a deadly missed diagnosis. In some cases, carbon monoxide exposure and poisoning has been mistaken for substance abuse.

Common signs and symptoms of carbon monoxide exposure include headache, drowsiness, confusion, tachycardia. Continued exposure to carbon monoxide also lead to impaired thinking and sensory perception.  These effects of carbon monoxide reduce the ability of a person to recognize a hazard or self rescue from an environment.

Symptoms of carbon monoxide differ from person to person and level of exposure. Mild exposures (15 to 20% COHb) symptoms may include headache, nausea, vomiting, dizziness, and blurred vision. Moderate exposure is defined as 21 to 40% COHb and may present as confusion, syncope, chest pain, dyspnea, and general weakness. The severe exposure (41 to 59% COHb) may result in myocardial ischemia, rhythm disturbances seizures, and respiratory as well as cardiac arrest. Exposures to levels of carbon monoxide greater than 60% are usually considered fatal. It's important to note that CO exposure and COHb  levels do not have the same symptoms with all patients.

 Carbon monoxide alarm technology is reliable and found in many residential and commercial structures. In general, there are two types of carbon monoxide detection equipment. The first type is known is a biomimetic style detector. This type of detector uses a synthetic hemoglobin that reacts to acute and chronic carbon monoxide. Biomimetic style detectors are very common and usually resemble smoke alarms or are manufactured in combination with a smoke alarm.  These units typically have a module sensor built-in the battery compartment. Some of the most common manufacturers estimate a module life of two years and a total unit life of 10 years. This type of carbon monoxide detector can be influenced greatly by exposure to cooking products.
Another style of carbon monoxide alarm is the semiconductor style. this style of alarm uses an electronic sensor to measure carbon monoxide  and is typically plugged into a power outlet or other power supply. The general recommendation is that the unit be replaced every 5 to 10 years. Most carbon monoxide alarms activate at an estimated 10% of carboxylhemoglobin or 100 ppm of carbon monoxide.