View Abstract

A3338 - Comparison of Gas Distribution in Patients by Electrical Impedance Tomography Undergoing Different Cardiac Surgery Study
Author Block: T. Yuan1, Y. Liu1, M. Bien2, H. Chang3, M. Chang1, J. Huang4, Y. Yang2; 1Chest Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan, 2School of Respiratory Therapy, Taipei Medical University, Taipei City, Taiwan, 3Department of Critical Care Medicine, Far Eastern Memorial Hosp, New Taipei City, Taiwan, 4Cardiac Surgery, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
Rationale: Heart disease is the top second leading cause of death in Taiwan. Most of these critically ill patients eventually have to undergo cardiac surgeries. Pulmonary complications, such as atelectasis and pneumonia, following cardiac surgeries are associated with high ICU stay and cost as well as high mortality. Therefore, it becomes an important issue if we can early monitor and prevent the poor lung ventilation. The common surgical procedures include the full sternotomy and the minimally invasive thoracotomy; the former adopts two-lung ventilation (TLV) while the latter adopts one-lung ventilation (OLV). This study is to comparison of lung gas distribution between the two types of surgical procedures. Methods: We used the electrical impedance tomography (EIT) to observe the patients’ lung gas distribution. Our study enrolled 39 patients, divided into two groups, underwent cardiac surgery. One group of 19 patients underwent full sternotomy with TLV and the other group consisted of 20 patients received minimally invasive thoracotomy with OLV. All patients received three times of EIT to monitor the lung gas distribution. The first time was done before surgery and taken as a baseline (preoperative period), and the second time was done within 24 hours after surgery under mechanical ventilation without extubation (postoperative period), then the third time was done within 24 hours after extubation (post-extubation period). Results: Our study found that patients’ lung gas distribution (mean ± sd : 47.7 ± 10.9%) of TLV group got worse in the dorsal lung regions during the postoperative period (34.9 ± 9.2%), but it reduced in the ventral lung regions during the postextubation period. In addition, we found that the patients’ lung gas distribution (52.2 ± 7.7%) of OLV group reduced in the non-dependent lung during the postoperative period (42.3 ± 11.5%) and postextubation period (44.3 ± 10.2%). Conclusion: We confirmed that patients underwent cardiac surgery, no matter full sternotomy or minimally invasive thoracotomy, most of them would suffer from lung atelectasis in different areas as well as other pulmonary complications. The finding of the study indicates that in the TLV group, patients’ collapsed lung was in the dorsal lung area, while in the OLV group patients’ collapsed lung area was in the non-dependent side. Finally, we hope that our study could help clinical medical staffs to design optimal breathing exercises by EIT.