Positive end-expiratory pressure during one-lung ventilation improves oxygenation in patients with low arterial oxygen tensions.

Objective: The application of 10 cm H2O of positive end-expiratory pressure (PEEP10) to the ventilated lung during one-lung ventilation (OLV) has an unpredictable effect on PaO2. It was hypothesized that patients with a low PaO2 (< 80 mmHg) during OLV may benefit from application of PEEP.

Design: Prospective, open.

Setting: A university medical center.

Participants: Eighteen patients were studied who were undergoing OLV for pulmonary resection. All were anesthetized with thiamylal, N2O/O2 (50%/50%), isoflurane, and pancuronium.

Interventions: Application of PEEP10 during one-lung ventilation.

Measurements And Main Results: Hemodynamics and oxygenation were measured during two-lung ventilation in the lateral position, OLV, and OLV plus application of PEEP10. Overall, PEEP10 during OLV failed to produce significant changes in PaO2, Qs/Qt%, cardiac output (CO), SvO2, or mean arterial pressure. However, in 11 patients whose PaO2 was less than 80 mmHg during OLV, application of PEEP10 significantly increased PaO2, decreased Qs/Qt%, and decreased CO (p < 0.05). In the 7 patients whose PaO2 was greater than 80 mmHg on OLV, the authors did not find a significant effect of PEEP10 on the hemodynamic or oxygenation parameters measured.

Conclusions: In patients with a low PaO2 (< 80 mmHg) during OLV with F1O2 = 0.5, PaO2 is increased by the application of PEEP10. This maneuver may be useful in situations in which application of continuous positive airway pressure (CPAP) to the nonventilated lung is not possible.