A 24-year-old man attends the emergency department with sudden onset pleuritic chest pain and shortness of breath. He is tall and thin with no significant past medical history. On examination he is not distressed, respiratory rate is 18 breaths per minute, oxygen saturation 98 percent on room air and there is decreased air entry on the right. A chest X-ray confirms a 2 cm rim of air at the right apex with no mediastinal shift. What is the most appropriate initial management