Predictors of oxygenation impairment in medical treatment for type B acute aortic dissection.

Lung oxygenation impairment often occurs in patients with type B acute aortic dissection (AAD), necessitating mechanical ventilation. Patients receiving mechanical ventilation are at risk of complications, so a low-oxygen condition requiring mechanical ventilation should be avoided. We explored the predictors of oxygenation impairment. We enrolled 46 patients with type B AAD who had been medically treated and underwent computed tomography. Blood was sampled to measure markers of inflammation, such as the C-reactive protein (CRP) levels and white blood cell count. The arterial partial pressure of oxygen/fraction of inspired oxygen ratio (PaO2 /FiO2 ) was calculated to quantify the severity of respiratory failure. Spearman's rank correlation analysis revealed that the minimum PaO2 /FiO2 ratio was significantly correlated with gender, age, and current smoker, and the peak CRP, body temperature, and D-dimer values. A multivariate regression analysis revealed that younger age, male sex, and the peak CRP level were significant predictors of the minimum PaO2 /FiO2 ratio (P = 0.01, 0.035 and 0.005, respectively). A covariance structure analysis showed that a younger age and the peak CRP level were significant predictors of oxygenation impairment in type B AAD. Oxygenation impairment in type B AAD is correlated with younger age and a higher peak CRP level. This will enable the identification of patients whose respiratory condition is susceptible to worsening and help prevent mechanical ventilation, leading to the provision of appropriate therapy.