Clinical Assessment and Risk Stratification

With lower-level or chronic CO poisoning, the person has no abnormal physical signs and has mild symptoms, including [1]:

Higher-level CO poisoning

There are 4 key questions to help diagnose domestic carbon monoxide poisoning. They follow the COMA acronym [8]:

C – Co-habitees and co-occupants: Is anyone else (including pets) in the house affected?

O – Outdoors : Do your symptoms improve outside of the house?

M – Maintenance: Are boilers and cooking appliances properly maintained?

A – Alarm: Do you have a functioning CO alarm

With higher-level CO poisoning, the above symptoms are more severe and are associated with the following symptoms and signs:

The appearance of intoxication or a personality change
Impaired mini mental-state examination
Vertigo and ataxia
Breathlessness and tachycardia
Chest pain (due to angina or myocardial infarction)
Loss of consciousness (with very high levels of carbon monoxide, this may be followed by death within a few minutes)
Seizure or multiple seizures
Abnormal neurological signs including blindness, deafness, and extrapyramidal effects. The onset of neurological deterioration may be delayed by several days. Memory impairment and changes in personality may persist long term
High risk features include chest pain, history of unconsciousness, any continuing neurological symptoms or signs (especially cerebellar features) and pregnancy due to the effects on the foetus

Learning bite

The classic description of cherry pink or red complexion is very rare and associated with the most severe and fatal cases.