MEDICAL JOURNAL OF BAKIRKOY, vol.17, no.3, pp.227-232, 2021 (ESCI)
Objective: We routinely calculate the pulmonary to systemic (Qp/Qs) ratio to avoid missing any left-to-right shunts in patients with precapillary pulmonary hypertension (PH). However, the pulmonary artery oxygen saturation (SpaO(2)) was lower than the mixed venous oxygen saturation (SmvO(2)) calculated using the formula; hence, the Qp/Qs ratio was calculated as less than "1" in some patients despite the absence of any detectable shunt. We hypothesized that this observation might have prognostic significance; however, to the best of our knowledge, it has not been investigated yet. Therefore, we aimed to examine the prognostic value of the Qp/Qs ratio in precapillary PH without left-to-right shunts.