Three cases of clinically significant inaccurate carboxyhemoglobin measurement.
Undersea Hyperb Med
; 49(2): 171-177, 2022.
Article
em En
| MEDLINE
| ID: mdl-35580484
ABSTRACT
Background:
Clinicians often rely on measurement of carboxyhemoglobin (COHb) to confirm or rule out a diagnosis of carbon monoxide (CO) poisoning.Methods:
We report two cases of false negative COHb in patients with CO poisoning and one case of false positive COHb in a patient without CO poisoning.Results:
In the first case, a 20-year-old male developed headache, confusion, and near-syncope while operating a gasoline-powered pressure washer in an enclosed space. In the emergency department (ED), his COHb was 1.8%, but this level was disregarded, and he was referred for hyperbaric oxygen. His COHb just before hyperbaric oxygen was 4.1%, and later analysis of his blood collected at ED arrival revealed a COHb of 20.1%. The referral ED blood gas machine calibration and controls were within specification. In the second case, a 45-year-old male presented with several others to the ED with symptoms of CO poisoning after exposure at a conference. All others had elevated COHb levels, but his COHb was 2%. He was discharged but returned shortly with continued symptoms and requested his COHb be repeated. The repeat COHb was 17% (84 minutes after the first). After three hours of oxygen, his COHb was 7%. In the final case, an 83-year-old non-smoking male presented to an ED with breathlessness and tachypnea and was diagnosed with COVID-19 pneumonia. His COHb was 7.1%, but he reported living in an all-electric home. Another adult who lived with him and rode with him to the ED was asymptomatic and had a COHb of 3%. Later, COHb of 1.9% was measured from blood collected at ED arrival, and gas chromatography/mass spectrometry confirmed this result (2%).Conclusions:
COHb levels are not always accurate. Clinicians should use clinical judgment to manage their patients, including rejecting laboratory values that do not fit the clinical situation.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Intoxicação por Monóxido de Carbono
/
COVID-19
Tipo de estudo:
Diagnostic_studies
Limite:
Adult
/
Aged80
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article