The HyFin chest seals are designed to be used for penetrating trauma to the chest. In such a situation a condition called a tension pneumothorax may develop. A tension pneumothorax is a condition when air becomes trapped in the pleural space due to the formation of a one-way valve.
The HyFin Vent Compact Chest Seal Twin Pack is a 2x vented chest seals for the treatment of penetrating injuries to the chest. The 3-vented channels of the HyFin Vent allows air to escape the chest cavity during exhalation, while also preventing air from entering through the injury during inhalation.
Chest seals are manufactured as occlusive or ventilated (one-way valve) seals recommended for any patient who presents with penetrating inferior neck or thoracoabdominal trauma that could result in an open, pneumothorax or haemothorax.
A pneumothorax is a collection of air between the lung and chest wall due to an injury to the chest and/or lung. The lung then collapses as shown. Normally the lung fills up the entire chest cavity. With an injury to the lung or the chest wall, air may get between the chest wall and the lung and allow the elastic lung to collapse. Air is supposed to be INSIDE the lung. Here the air is inside the chest but OUTSIDE the lung – and this does not help get oxygen to the body.
A tension pneumothorax is worse. Injured lung tissue acts as a one-way valve, trapping more and more air between the lung and the chest wall. Pressure builds up and compresses both lungs and the heart. As a tension pneumothorax develops, every breath adds more air to the air space inside the rib cage and outside the lung. The air can’t be exhaled because it’s outside the lung – there’s no way for it to escape – so the pressure inside the chest builds up.
A developing tension pneumothorax generally follows these steps:
- Injury or insult causing an opening into the pleural space
- Air builds up in the pleural space, forcing the lung on the affected side to collapse.
- Increased intrathoracic pressure
- Occlusion of inferior vena cava and superior vena cava
- Which leads to:
- A decrease in venous return
- A decrease in cardiac output and blood pressure (BP)
- This decrease in BP is detected by baroreceptors In the carotid sinus and aortic arch
- The body mounts a compensatory response
- This eventually fails (assuming no intervention)
- The persons BP drops, conscious state drops and they eventually die.
Chest Seal Indication:
All open and/or sucking chest wounds should be treated by immediately applying a vented chest seal to cover the defect.
Apply the chest seal during expiration. At this point in the breathing cycle, there is relatively less air in the pleural space. If a vented chest seal is not available, use a non-vented chest seal. Monitor the casualty for respiratory distress. If it develops, you should suspect a tension pneumothorax. Once the wound has been occluded with a chest seal, air can no longer enter (or exit) the pleural space through the wound in the chest wall. The injured lung will remain partially collapsed, but the mechanics of respiration will be better.
After you apply the chest seal, you have to be alert for the possible development of tension pneumothorax because air can still leak into the pleural space from the injured lung. Monitor these patients for any future difficulty in breathing. Treat this by burping or temporarily removing the dressing. If that doesn’t relieve the respiratory distress, refer to a medic.
- Butler Frank K. et al, 2013, ‘Management of Open Pneumothorax in Tactical Combat Casualty Care’. Journal of Special Operations Medicine, 13(3):81-6.