The Importance and Place of Methemoglobin and Carboxyhemoglobin Levels in the Diagnosis and Prognosis of Pulmonary Embolism

This is a retrospective study to investigate the effects of Carboxyhemoglobin (COHb) and Methemoglobin (MetHb) levels in the diagnosis and prognosis of Pulmonary Thromboembolism (PTE). Cases that were confirmed with PTE diagnosis using CT Pulmonary Angiography (CTPA) or Ventilation/Perfusion Scintigraphy were accepted as pulmonary embolism. And patients which were excluded using the same methods were accepted as the control group. Patients with carbon monoxide poisoning, Chronic Obstructive Pulmonary Disease (COPD), sepsis, pneumonia, asthma, idiopathic pulmonary fibrosis, bronchiectasis, decompensated cardiac failure or those who used drugs that cause methemoglobinemia (sulphanomides, dapson, phenacetin, primacine,benzocaine) were not included in the study. In our study, 462 patients were examined with an initial PTE diagnosis. Among these patients, 107 patients who met the inclusion criteria were included in the study. The mean age of all patients was 56.44 ±17.3 years (21-86) and the mean age of patients with PTE diagnosis was 55.3 years and the mean age of excluded patients was 59 years (p:0.27). When the blood gas parameters of both groups were compared, COHb levels in the groups with PTE diagnosis were statistically significantly higher (p=0.001), and the PO2 levels in the group excluded for PTE diagnosis were statistically significantly higher (p=0.028). In our study, six of our patients (8.1%) died in the early stages because of PTE. In our study, COHb level was found to be statistically significant in the group with PTE. However, this value was not higher than the normal COHb level in the blood. We found that MetHb and COHb levels were not statistically significant in the prognosis of PTE.