Lung perfusion, shunt fraction, and oxygenation during one-lung ventilation in pigs: the effects of desflurane, isoflurane, and propofol.

ABSTRACT

OBJECTIVE: To study how desflurane, isoflurane, and propofol affect pulmonary perfusion, shunt fraction, and systemic oxygenation during one-lung ventilation (OLV) in vivo. DESIGN: Prospective animal study with a crossover design. SETTING: Animal laboratory of a university hospital. PARTICIPANTS: Twelve female pigs. INTERVENTIONS: The pigs were anesthetized, tracheally intubated, and mechanically ventilated. After placement of femoral arterial and thermodilution pulmonary artery catheters, a left-sided, double-lumen tube (DLT) was placed via tracheotomy. After DLT placement, F(I)O(2) was adjusted at 0.8, and anesthesia was continued in random order with 1 minimal alveolar concentration of desflurane, 1 minimal alveolar concentration of isoflurane, or propofol. MEASUREMENTS AND MAIN RESULTS: Measurements of respiratory and hemodynamic parameters were made after stabilization at each anesthetic. During OLV, perfusion of the nonventilated lung and shunt fraction were comparable during all 3 anesthetics. PaO(2) was lower during desflurane and isoflurane anesthesia as compared with propofol anesthesia. Mixed venous PO(2) and cardiac output were lower with desflurane and isoflurane as compared with propofol. CONCLUSIONS: In a clinically relevant model of OLV cardiac output, PaO(2) and mixed venous PO(2) decreased during desflurane and isoflurane as compared with propofol, whereas perfusion of the nonventilated lung and shunt fraction remained comparable.