1. CPAP Effects on Oxygen Delivery in One-Lung Ventilation During Minimally Invasive Surgical Ablation for Atrial Fibrillation in The Supine Position.
- Author
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L'Acqua C, Meli A, Rondello N, Polvani G, and Salvi L
- Subjects
- Continuous Positive Airway Pressure, Humans, Italy, Middle Aged, Oxygen, Prospective Studies, Respiration, Artificial, Supine Position, Atrial Fibrillation surgery, One-Lung Ventilation
- Abstract
Objective: 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 O2 ), positive end-expiratory pressure on the ventilated lung, and continuous positive airway pressure (CPAP) on the deflated lung., Design: 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., Setting: University hospital Centro Cardiologico Monzino IRCCS, Milano, Italy., Participants: Twenty-two patients scheduled for minimally invasive surgical ablation for atrial fibrillation., Interventions: The patients underwent pressure-controlled ventilation, adjusting inspiratory pressure to obtain a tidal volume of 7 mL/kg while keeping FI O2 constantly 1.0, a respiratory rate to maintain arterial partial pressure of carbon dioxide (PaCO2 ) between 35 and 40 mmHg, and positive end-expiratory pressure of 5 cmH2 O. During OLV, inspiratory pressure was reduced to obtain a tidal volume of 5 mL/kg, maintaining FI O2 of 1.0, a respiratory rate to maintain PaCO2 between 35 and 40 mmHg with capnothorax of 10 cmH2 O. The patients were then randomized into the CPAP group (CPAP 10 cmH2 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 ., Measurements and Main Results: 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 (DO2 I) increased significantly during the procedure (p < 0.01); nevertheless, the difference in DO2 I between the CPAP and NO CPAP group was nonsignificant (p = 0.61). Intrapulmonary shunt (Qs /Qt ) increased during OLV (p < 0.01 for the time effect) and remained high until total lung ventilation was reintroduced. No difference in Qs /Qt 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)., Conclusions: During OLV for atrial fibrillation surgical ablation in the supine position, CPAP on the deflated lung seemed to be ineffective to reduce Qs /Qt or to increase arterial partial pressure of oxygen and DO2 I, provided cardiac output was maintained above 1.5 L/min/m2 ., Competing Interests: Conflict of Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2020
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