National Poisons Information Service – Research into Medical Professional's Awareness of Carbon Monoxide Poisoning

This survey was undertaken by the National Poisons Information Service (NPIS) and sought to help gauge healthcare professionals’ awareness of carbon monoxide (CO) poisoning, following a pilot project.

The 2011 All Party Parliamentary Carbon Monoxide Group (APPCOG) report highlighted the challenges faced by healthcare professionals in diagnosis and treatment. According to the Department of Health, every year in the UK, over 200 people go to hospital with suspected CO poisoning, leading to around 40 deaths; however, relatively little is known about its epidemiology.

The NPIS Annual Report 2014/15 included data from 479 telephone enquiries (calls) that related to CO exposures involving a total of 682 patients. This study used the NPIS’s TOXBASE® online resource and its 24-hour telephone advice service to gather information from users. There was a follow-up questionnaire sent to gain further data, all of which was used to understand how a diagnosis was made and if cases were confirmed.

At the same time, healthcare professionals accessing the TOXBASE CO entry were presented with a simple pop-up box asking whether they were seeing a patient with suspected CO poisoning and for a contact address.

A questionnaire was then sent to these healthcare professionals for additional information. The results of this exercise were then analysed with the aim of improving how CO poisoning is diagnosed.


 

CO poisoning is a major public health concern in the UK. Unintentional non-fire related CO exposures pose a particular public health challenge as patients are often unaware of the presence of CO even after they begin to experience symptoms:

CO is a common and potentially serious source of unintentional poisoning in the UK. 

Twelve fatalities were recorded as a result of unintentional non-fire related CO  exposure during this 8-year study period. These were typically reported to the NPIS  as multiple presentations where poisoning did not result in death. 

The majority of unintentional exposures resulted in no symptoms or mild symptoms only.   

Symptoms most commonly involve the CNS, GI or CV systems but are often non-specific in nature and may often be mistaken for flu-like symptoms. 

Where blood COHb% measurements were available, the data suggest a correlation between these levels and poisoning severity, however this was not statistically significant. 

Faulty boilers, in the home, were the most reported source of CO causing unintentional poisoning. 

The NPIS was made aware of 21.0% of cases where the activation of a CO alarm prompted the patient to seek medical attention. The majority of these cases were associated with mild symptoms or no symptoms at all. 

Self-harm cases resulted in proportionally higher cases of serious poisoning. Vehicle  exhausts and BBQs were the predominant source of exposure in this cohort. 

The NPIS is uniquely placed to collect and act as a central repository for national data on CO exposures across the UK. 

Public health policy needs to continue to focus on raising awareness of this hidden danger while identifying and eliminating potential sources of CO. 

Further investigations into long-term outcomes and assessment of low-level chronic exposures should be included in future work.