A male patient has a sucking stab wound to the chest. Which action should the nurse take first?
The nurse immediately should apply a dressing over the stab wound and tape it on three sides to allow air to escape and to prevent tension pneumothorax (which is more life-threatening than an open chest wound). 
Only after covering and taping the wound should the nurse draw blood for laboratory tests, assist with chest tube insertion, and start an I.V. line.
Drawing blood for a hematocrit and hemoglobin level
Applying a dressing over the wound and taping it on three sides
preparing a chest tube insertion tray
Preparing to start an I.V. line