Effect of dexmedetomidine on intrapulmonary shunt in patients with sevoflurane maintained during one-lung...

The effects of dexmedetomidine on the circulatory system are complex. It is difficult to predict its effects on intrapulmonary shunts and hypoxic pulmonary vasoconstriction in patients with one-lung ventilation. This study aimed to investigate the effect of dexmedetomidine on intrapulmonary shunt in patients with sevoflurane during one-lung ventilation.

Forty patients requiring thoracoscopic lobectomy were randomly divided into the dexmedetomidine group (Group D, n = 20) and the normal saline group (Group N, n = 20). The arterial partial pressure of oxygen (PaO2), pulmonary shunt fraction (Qs/Qt), mean end-tidal sevoflurane concentration, mean arterial pressure, and heart rate were compared between the 2 groups at 3 time points: (i) after 5 minutes of two-lung ventilation (T0), (ii) after 30 minutes of one-lung ventilation (OLV) (T1), and (iii) after 45 minutes of OLV (T2). The dosage of sevoflurane from the beginning of OLV to T2 was calculated.

There were no significant differences in age, body mass index, and FEV1/FVC between Groups D and N (P > .05). At T0, T1, and T2, the PaO2 levels of Group D and Group N were similar (P > .05), and the PaO2 levels of Group D and Group N decreased after OLV. The Qs/Qt level of Groups D and N were similar at T0 (P > .05), and the level of Groups D and N at T1 and T2 was higher than that at T0. The Qs/Qt of Group D was statistically significantly lower than that of Group N at T1 and T2 (P < .05).

Compared with the control group, we found that dexmedetomidine can reduce the intrapulmonary shunt fraction and improve the body's status during OLV.