Abstract 15730: High Frequency Ventilation: A New Strategy in Off Pump Coronary Artery Bypass
Introduction Accessing the back wall during off pump coronary artery bypass (OPCAB) surgery is a cause hemodynamic instability especially with enlarge heart. Positive pressure ventilation creates an up and down movement exacerbating the sewing difficulty and reduces the surgeon working space as well. High frequency ventilation with low tidal volumes decreases movement of the intrathoracic content and improve the surgical field for the surgeons. It can also reduce the risk of oxygen desaturation during myocardial mobilisation and provide better hemodynamic.
Methods To test this hypothesis we design a prospective randomized study. Patients were randomized into 2 groups. Group 1 had the regular ventilation (RV) (apnea periods according to surgeon’s need). Group 2 had high frequency ventilation (HFV) during the time of anastomosis. Pulse oxymetry and cerebral saturation were measured in all patients. Significant decrease in cerebral saturation was defined as a decrease of > 20% of baseline. Hemodynamic parameters were monitored during the surgery.
Results Twenty eight patients were studied, 13 in the RV groups and 15 in the HFV group. Ninety (90) anastomosis were performed, 49 with regular ventilation and 41 with the HFV. The surgeon noted a more stable surgical field and a better surgical environment during HFV. Drops in cerebral saturation were more frequent in the RV group (19/49) compared to the HFV group (1/41) with a relative risk of 2.2 (1.1661-2.958, p<0.0001). Systemic oxygen desaturation was also more frequent in the RV group (8/49) compared to the HVF group (0/41) with a relative risk of 2.0 (1.611-2.483, p= 0.0071). Changes in systolic pressure during grafting was more important in RV group than in the HFV group (-13.5 mmHG vs +4mmHg respectively, 0<0.0001).
Conclusions High frequency ventilation during anastomosis in OPCAB surgery results in better hemodynamic conditions and more stable cerebral and systemic oxygen saturation. HFV could help to flatten the learning curve for OPCAB for surgeons and make this technique more available for selected patients
- © 2012 by American Heart Association, Inc.