Effects of tidal volume and PEEP on arterial blood gases and pulmonary mechanics during one-lung ventilation.

PURPOSE

The main problem of one-lung ventilation (OLV) is hypoxemia. The use of a high tidal volume for preventing hypoxemia during OLV is controversial. We compared the effects of a high tidal volume versus a low tidal volume with or without PEEP on arterial oxygen tension (PaO(2)) and pulmonary mechanics during OLV.

METHODS

Sixty patients (age range, 16-65 years; ASA I, II) who underwent wedge resection with video-assisted thoracostomy during OLV were assigned to three groups: group I received a high tidal volume (10 ml/kg) (n = 20), group II received a low tidal volume (6 ml/kg) (n = 20), and group III received a low tidal volume (6 ml/kg) with PEEP (5 cmH(2)O) (n = 20). Patient hemodynamics, pulmonary mechanics, and arterial blood gases were measured before (T(0)) OLV and 5 (T(1)), 15 (T(2)), 30 (T(3)), and 45 min (T(4)) after OLV.

RESULTS

The PaO(2)/FiO(2) ratios of group II and III were significantly decreased and the incidence of hypoxemia was significantly higher in groups II and III than in group I (P < 0.05).

CONCLUSION

During OLV, mechanical ventilation with a low tidal volume with or without PEEP increased hypoxemia as compared to that when performing OLV with a high tidal volume.