There are no clear data on prognosis following carbon monoxide poisoning. Evidence from a Danish study showed an overall 30-day mortality of 9.2% following carbon monoxide poisoning, including patients who died at the scene.[29]Simonsen C, Thorsteinsson K, Mortensen RN, et al. Carbon monoxide poisoning in Denmark with focus on mortality and factors contributing to mortality. PLoS One. 2019;14(1):e0210767.
https://www.doi.org/10.1371/journal.pone.0210767
http://www.ncbi.nlm.nih.gov/pubmed/30653615?tool=bestpractice.com
However, 30-day mortality fell to 1.5% for patients who arrived at hospital.[29]Simonsen C, Thorsteinsson K, Mortensen RN, et al. Carbon monoxide poisoning in Denmark with focus on mortality and factors contributing to mortality. PLoS One. 2019;14(1):e0210767.
https://www.doi.org/10.1371/journal.pone.0210767
http://www.ncbi.nlm.nih.gov/pubmed/30653615?tool=bestpractice.com
Factors that are associated with increased mortality are advanced age, acidotic states, pre-existing cardiovascular disease, drug or alcohol misuse, psychiatric disease, cognitive impairment, and structural abnormalities on imaging studies such as lucencies in the basal ganglia, cerebral white matter and globus pallidus.[3]Varon J, Marik PE. Carbon monoxide poisoning. Internet J Emerg Intensive Care Med. 1997;1(2).[4]Tomaszewski C. Carbon monoxide poisoning: early awareness and intervention can save lives. Postgrad Med. 1999 Jan;105(1):39-40, 43-8, 50.
http://www.ncbi.nlm.nih.gov/pubmed/9924492?tool=bestpractice.com
[29]Simonsen C, Thorsteinsson K, Mortensen RN, et al. Carbon monoxide poisoning in Denmark with focus on mortality and factors contributing to mortality. PLoS One. 2019;14(1):e0210767.
https://www.doi.org/10.1371/journal.pone.0210767
http://www.ncbi.nlm.nih.gov/pubmed/30653615?tool=bestpractice.com
One third of patients may have subtle memory deficits or show personality changes after carbon monoxide poisoning.
MRI should be considered as a test of choice for evaluation of chronic changes and prognosis after carbon monoxide poisoning.[36]Beppu T. The role of MR imaging in assessment of brain damage from carbon monoxide poisoning: a review of the literature. AJNR Am J Neuroradiol. 2014 Apr;35(4):625-31.
http://www.ajnr.org/content/early/2013/04/18/ajnr.A3489.full.pdf
http://www.ncbi.nlm.nih.gov/pubmed/23598831?tool=bestpractice.com
Even mild symptoms in a pregnant woman can have devastating effects on the unborn child, such as fetal demise or congenital malformations. Fetal haemoglobin has a much greater affinity for carbon monoxide than adult haemoglobin.