Carbon Monoxide Poisoning

Abstract

Carbon monoxide poisoning is a serious and life-threatening event. Educating workers and communities on exposure sources, symptoms, and prevention is an important role for occupational health nurses.

Carbon monoxide (CO), a leading cause of poisonings globally, causes an estimated 50,000 emergency department visits and 400 deaths in the United States annually (Agency for Toxic Substance and Disease Registry [ATSDR], 2012). Carbon monoxide binds with hemoglobin more readily than oxygen (O₂), affecting blood’s O₂ carrying ability and tissue hypoxia. Target organs are the respiratory, cardiovascular, and central nervous systems. Preexisting cardiovascular or respiratory disease and age extremes increases the risk for adverse outcomes (ATSDR, 2012).

Carbon monoxide is highly flammable and accumulates rapidly in enclosed spaces. Inhalation of this odorless, tasteless, colorless gas occurs during daily activities, hobbies, traveling, and tobacco smoke exposures. Improper ventilation increases workers’ CO risks during steel and carbon black production, coke oven use, petroleum refining, and furniture refinishing. In addition, “Forklifts powered with internal combustion engines can cause high levels of CO in enclosed work areas” (Occupational Safety and Health Administration [OSHA], n.d., carbon monoxide). Gasoline engines are the primary source of CO exposure, yet household gas appliances, furnaces, wood burning stoves, and fireplaces can leak CO (ATSDR, 2012; OSHA, 2002).

Occupational fatalities from CO poisoning (flue gas) are less common in the United States because of increased medical surveillance and industrial monitoring; 374 deaths occurred between 1992 and 2008 (Henn, Bell, Sussell, & Konda, 2013). Workers involved directly with vehicle driving, maintenance, and parking are at greatest risk (ATSDR, 2012). Others include firefighters; warehouse forklift operators; welders; restaurant, bar, and longshore workers; and crane deck operators (ATSDR, 2012; National Institute for Occupational Safety and Health [NIOSH], 2016; OSHA, 2002). Some industries use liquid CO, which requires personal protective equipment for skin and eye protection to prevent frostbite (NIOSH, 2016). NIOSH (2016) and OSHA (2002) give recommendations for occupational exposure limits and medical surveillance.

Mild CO poisoning includes flu like symptoms and occasionally cherry red lips. Moderate poisoning leads to confusion, tachypnea, tachycardia, syncope, chest pain, and rhabdomyolysis. Severe poisoning causes hypotension, seizures, arrhythmias, myocardial ischemia, pulmonary edema, and death. Delayed impaired judgment, poor concentration, memory loss, cognitive and personality changes, psychosis, and Parkinson disease may appear days to weeks post exposure and continue for months (ATSDR, 2012). Elevated carboxyhemoglobin (COHb) levels are diagnostic: 1% is normal, except smokers’ COHb can be 3% to 10% normally (Centers for Disease Control and Prevention [CDC], 2017). Neurobehavioral and cognitive effects start between 5% and 20%; levels above 60% are often fatal (ATSDR, 2012). Carbon monoxide crosses the placenta and accumulates more rapidly in fetal than maternal tissue. Elevated CO, primarily with loss of consciousness, damages the developing fetal nervous system and may cause spontaneous abortion or fetal death (NIOSH, 2017).

Occupational health nurses should provide workplace and community education about prevention strategies and CO exposure risks and symptoms, particularly during pregnancy, cold weather preparations, or after power disruptions. Improperly vented generators and gas or charcoal grills used indoors cause dangerous CO levels. Prevention includes proper maintenance and ventilation for gas-powered engines, home cooking appliances, furnaces, and generators; installing home and worksite CO monitors with audible alarms; and providing at-risk workers with respirators and personal CO monitors (ATSDR, 2012; CDC, 2017). Caution pregnant workers that weight gain affects respirator fit. Promptly remove exposed victims to fresh air, activate emergency medical response, give 100% O₂ by mask, and warn rescuers of suspected CO poisoning (OSHA, 2002). Prevention at home and in the workplace is vital to protect against CO exposure and death.