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In minimally invasive surgical ablation for atrial fibrillation during video-assisted thoracoscopy surgery, one-lung ventilation (OLV) with a double- lumen tube is commonly employed. In contrast with the majority of thoracic procedures, the patient lies supine; thus, the protective effect of gravity is lost and intrapulmonary shunt remains high. To decrease intrapulmonary shunt and to increase oxygenation, many strategies are utilized: high inspiratory fraction of oxygen (F I O 2), positive end-expiratory pressure on the ventilated lung, and continuous positive airway pressure (CPAP) on the deflated lung. The authors performed a prospective, single- center, randomized study to evaluate the effect of additional CPAP in the nonventilated lung on oxygen delivery during surgical ablation for atrial fibrillation via video-assisted thoracoscopy in the supine position. University hospital Centro Cardiologico Monzino IRCCS, Milano, Italy. Twenty-two patients scheduled for minimally invasive surgical ablation for atrial fibrillation. The patients underwent pressure-controlled ventilation, adjusting inspiratory pressure to obtain a tidal volume of 7 mL/kg while keeping F I O 2 constantly 1.0, a respiratory rate to maintain arterial partial pressure of carbon dioxide (PaCO 2) between 35 and 40 mmHg, and positive end-expiratory pressure of 5 cmH 2 O. During OLV, inspiratory pressure was reduced to obtain a tidal volume of 5 mL/kg, maintaining F I O 2 of 1.0, a respiratory rate to maintain PaCO 2 between 35 and 40 mmHg with capnothorax of 10 cmH 2 O. The patients were then randomized into the CPAP group (CPAP 10 cmH 2 0 on deflated lung) and NO CPAP group. Inotropic agents (dopamine or dobutamine) were used if cardiac index fell below 1.5 L/min/m2. Twenty-two patients were enrolled, randomized, and completed the study. Median age was 62 years. The difference in arterial partial pressure of oxygen between the 2 groups was shy of significance, p = 0.16. Cardiac index progressively increased during OLV until the end of the procedure in both groups (p < 0.01) and was maintained above 1.5 mL/min/m2 during the whole study time. Arterial oxygen content remained stable during the entire procedure in both groups (p = 0.27). Oxygen delivery index (DO 2 I) increased significantly during the procedure (p < 0.01); nevertheless, the difference in DO 2 I between the CPAP and NO CPAP group was nonsignificant (p = 0.61). Intrapulmonary shunt (Q s /Q t) increased during OLV (p < 0.01 for the time effect) and remained high until total lung ventilation was reintroduced. No difference in Q s /Q t was observed between the CPAP and NO CPAP groups (p = 0.98). Similarly, mean pulmonary artery pressure increased significantly during OLV and remained high at the end of the procedure in both groups (time effect p < 0.01). During OLV for atrial fibrillation surgical ablation in the supine position, CPAP on the deflated lung seemed to be ineffective to reduce Q s /Q t or to increase arterial partial pressure of oxygen and DO 2 I, provided cardiac output was maintained above 1.5 L/min/m2. [ABSTRACT FROM AUTHOR]

Background: Propofol (2,6-diisopropylphenol) is an anesthetic drug with antioxidant and antiinflammatory properties, documented both in vitro and in experimental models of ischemia-reperfusion injury and septic shock. These properties have been related to the similarity of its chemical structure to that of endogenous tocopherols, which are phenol-containing radical scavengers. This study evaluated the effects of propofol on alpha- and gamma-tocopherol (alpha- and gamma-T) levels and on selected markers of oxidant-antioxidant and inflammatory status in patients undergoing cardiac surgery., Methods: Patients were randomly assigned for anesthesia with either propofol (propofol group, n = 22) or sevoflurane (control group, n = 21). Plasma levels of alpha- and gamma-T, individual antioxidant capacity, malondialdehyde, and interleukin 10 were measured before, during, and after anesthesia. In addition, levels of the proinflammatory prostaglandin E2 as a marker of cyclooxygenase-2 activity and those of interleukin 10 were measured in whole blood cultured with bacterial lipopolysaccharide., Results: Gamma-T levels increased significantly during surgery in propofol group (P < 0.0001 vs. control group). By contrast, alpha-T similarly decreased in both groups. Malondialdehyde and interleukin 10 increased markedly and individual antioxidant capacity decreased, without differences between groups. Prostaglandin E2 levels measured 24 h after anesthesia induction were significantly lower in the propofol than in the control group. In vitro studies highlighted the different capacity of gamma- and alpha-T to impair prostaglandin E2 synthesis by human monocytes challenged with bacterial lipopolysaccharide., Conclusions: The antiinflammatory properties of propofol that may be linked to its effect on gamma-T levels could be relevant in controlling the inflammatory response that accompanies tissue injury during reperfusion.