What should be done first for a sucking chest injury?

In the case of a sucking chest injury, the first and foremost action to take is to seal the wound with an airtight dressing. A sucking chest injury occurs when an open wound in the chest wall allows air to be drawn in and out during respiration, which can lead to a collapse of the lung on the affected side and result in a life-threatening condition known as tension pneumothorax.

By applying an airtight dressing, the priority is to prevent air from entering the chest cavity through the wound during inhalation, thereby stabilizing the patient's condition. The dressing should be secured on three sides to allow for some air to escape but not enter, thereby promoting lung inflation while providing a seal to the wound.

While calling for emergency help is crucial and providing oxygen may be necessary, these actions follow the immediate need to control the airflow into the chest cavity. Direct pressure is typically used for external bleeding management, not for dealing with a sucking chest injury, making sealing the wound the most critical priority in this scenario.