Assess the patient's chest and respiratory function. Administer oxygen at 12 L/min by mask. Identify the 2nd intercostal space in the midclavicular line on the side of the pneumothorax. If patient is conscious and time permits, add a little of L.A. Insert the needle of a 20 mL syringe attached. Aspiration of air confirms the diagnosis. The syringe is remmoved and a hissing sound is usually heard as air is expelled rapidly. If you place your hand close to the needle, you can detect this rush of air. Doing this urgent procedure will convert a tension pneumothorax into an ordinary one. A wide-bore intercostal rube is then introduced laterally and directed to the apex of the pleural cavity. A second drain may be introduced basally to drain blood. The site of insertion is in the triangle of safety which is defined as the anterior border of the latissimus dorsi, the posterior border of the pectoralis major and the superior border of the fifth rib. The area chosen...