Emergent cardiopulmonary bypass in canines with penetrating cardiac wounds caused by gunshot.
BACKGROUND
Most patients with penetrating cardiac wounds die within minutes of injury from uncontrolled haemorrhage and acute cardiac dysfunction. Thus, sustaining sufficient circulation rapidly is crucial to saving lives. Emergent cardiopulmonary bypass (CPB) is a potential intervention to maintain circulation after penetrating cardiac wounds from a gunshot.


METHODS
Canines were wounded with a bullet and randomly split into one of three treatment groups. Animals in group 1 (Gp1) were treated with conventional methods. Animals in group 2 (Gp2) received emergent CPB for 180 min and autologous blood transfusion. Animals in group 3 (Gp3) received emergent CPB for 30 min followed by surgical repair. Animal survival, haemodynamics and blood chemistry were measured, and lung water content was evaluated at the end of the experiment.


RESULTS
The right ventricle was the most severely wounded cardiac chamber. In Gp1, mean arterial pressure and central venous pressure were dramatically decreased 8 min after injury, and all animals died within 18 min. In Gp2 and Gp3, mean arterial pressure ranged from 60-90 mm Hg during CPB. 60 min after terminating CPB in Gp2, mean arterial pressure and heart rate were decreased compared to Gp3. In Gp3, most animals maintained haemodynamic stability. 60 min after CPB, free haemoglobin in circulating blood was elevated compared to pre-trauma levels. Pulmonary water content was significantly higher in Gp2 and Gp3 than in Gp1.


CONCLUSIONS
Emergent CPB in the field can maintain haemodynamic stability and supply vital organs with sufficient blood flow, but surgery following CPB is essential to rescue patients with penetrating cardiac wounds.
Zhang
Jinzhou
J
Department of Cardiovascular Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, People's Republic of China. jinzhouzhang2006@yahoo.com
Wang
Wen
W
Chen
Wensheng
W
Zhu
Hailong
H
Liu
Jincheng
J
Sun
Guocheng
G
Cui
Qin
Q
Liu
Weiyong
W
Yi
Dinghua
D
D000704:Analysis of Variance; D000818:Animals; D001784:Blood Gas Analysis; D001803:Blood Transfusion; D002302:Cardiac Output; D002315:Cardiopulmonary Bypass; D003402:Creatine Kinase / Q000032:analysis; D004285:Dogs; D006335:Heart Injuries / Q000601:surgery*; D006454:Hemoglobins / Q000032:analysis; D011669:Pulmonary Wedge Pressure; D011897:Random Allocation; D014948:Wounds, Gunshot / Q000601:surgery*
D006454:Hemoglobins; D003402:Creatine Kinase