Damage Control Techniques 14-18

1. The goals of damage control surgery, hemorrhage and contamination control, are the same regardless of location of injury. While hemorrhage control remains paramount in damage control thoracic surgery, contamination from the alimentary tract is infrequently encountered from esophageal injuries. Damage control surgery is a staged approach to life-threatening injury. As applied to thoracic surgery in the combat setting, damage control surgery consists of:
   - Rapid transport from point of injury to a higher level of care and recognition of need for DCS (Role 2,3).
   - Rapid control of hemorrhage and contamination (Role 2,3).
   - Resuscitation with restoration of physiology in intensive care setting (Role 2-4).
   - Return to surgery for completion of operative repairs (Role 3, 4).
   - Definitive chest closure (Role 3, 4).
2. Packing may be used as a complement to hemostatic efforts for hemorrhage from the chest wall, lung, and vascular structures that have been repaired. When packing, no pressure should be placed on the heart or major, low-pressure vasculature (i.e. superior vena cava, inferior vena cava, pulmonary artery).
3. There is a stepwise increase in mortality with more extensive resections when lung injuries are encountered. Tractotomy and limited wedge resection are associated with higher survival rates compared to lobectomy. Trauma pneumonectomy carries the worse prognosis with mortality rates ranging from 50-100%.
4. Pulmonary tractotomy is performed by opening a through-and-through injury tract with a gastrointestinal anastomosis (GIA) stapler (or between straight vascular clamps) followed by control of the bleeding edges and/or air leaks with additional staplers or a running suture repair using a non-cutting needle.
5. Damage control surgical techniques to temporarily control massive hilar hemorrhage include: the hilar twist maneuver, temporary hilar clamping, and intra-pericardial control of the ipsilateral main pulmonary artery with a Rommel tourniquet. These techniques should be prioritized in an effort to defer or avoid pneumonectomy.
6. A pneumonectomy may be warranted in unstable patients with massive parenchymal destruction, massive hilar hemorrhage, or extensive bronchial disruption beyond repair.
7. Acute right heart failure is the most common cause of death after trauma pneumonectomy. Rapid increases in pulmonary vascular resistance/pressure lead to increased right ventricular end diastolic pressure followed by shifting of the interventricular septum leftward, which ultimately leads to left ventricular dysfunction. Principles of treatment center on judicious volume resuscitation, inotropic support, and reduction in pulmonary vascular resistance and right ventricular afterload. Early ECMO team contact is indicated.
8. Medications
   - Dobutamine and milrinone provide positive inotropic effects and serve as moderate pulmonary vasodilators, lowering right ventricular afterload while improving function.
   - Inhaled nitric oxide (20-40 ppm through the ventilator) is a pure pulmonary vasodilator that also improves right ventricular function by lowering right ventricular afterload. These medications are typically only available in the Role 4 setting or higher.
9. Cardiac injury may be associated with intra-cardiac valve or septum injury. Maintain a high-index of suspicion for injury to more than one cardiac structure or hidden, intra-cardiac injuries.
10. Cardiac bleeding after penetrating injury can be controlled initially with a skin stapler or Foley balloon.
11. Open cardiac massage should be performed by compressing the heart between two flat hands from the apex towards the outflow tracts.
12. Temporary chest closure should be considered in the damage control setting or if there is concern for thoracic compartment syndrome (increased intrathoracic pressure causing decreased venous return and decreased cardiac output). It is performed in a manner similar to that of temporary abdominal closure. Thoracostomy tubes (or mediastinal drains) and sterile surgical towels or gauze are placed, followed by placement of an occlusive dressing. Negative pressure is then applied to the temporary closure. A wound vacuum system can also be utilized in this setting. When a vacuum sponge closure is used, direct contact between the sponge and lung tissue should be avoided.
13. Timing for return for definite chest closure is determined by adequacy of resuscitation and normalization of physiologic parameters, as evidenced by reversal of triad of hypothermia, acidosis, and coagulopathy.