Carbon monoxide poisoning caused by gas water heaters in Korea

Objective:
This study aimed at evaluating the characteristics and outcomes of patients who were diagnosed with carbon monoxide (CO) poisoning after using a gas water heater and to describe similar CO poisoning incidents involving gas water heaters in Korea.
Method:
We reviewed gas water heater-related CO poisoning affected patients who visited our emergency department (ED) from January 1, 2008, to December 31, 2019, and the CO poisoning incidents due to gas water heaters reported by the Korea Gas Safety Corporation (KGS) from January 1, 2000, to December 31, 2019.
Results:
During the study period, a total of eight patients visited our ED as a result of five incidents. All five incidents occurred while using a gas water heater in an enclosed space. Five patients were poisoned by CO while taking a shower, and the other three were poisoned by CO while washing their hair. Most patients complained of a transient loss of consciousness, headache, dizziness, and general weakness. The mean value of the initial CO-hemoglobin level was 27.2±14.2% with a range of 7.2-45.7%. All the patients admitted survived after being given hyperbaric oxygen therapy and subsequently discharged from hospital. A total of 32 incidents that involved 71 victims were identified from the KGS. Of these victims, 24 were already dead at the scene, with an estimated case-fatality rate of 33.8%. Most incidents occurred while the victims were showering using a gas water heater installed in a bathroom with poor ventilation.
Conclusion:
The present study showed that CO poisoning can occur even in a short time, such as taking a shower or shampooing hair, due to the use of a gas water heater installed in a closed space with poor ventilation. Also, it highlights the fact that the prehospital case-fatality rate of such CO poisoning is high.

Key words: Carbon monoxide; Poisoning; Gas water heater; Incident