Differential Diagnosis for Residence over the Longs upon Percussion

• Single most likely diagnosis
  • Pneumothorax: This condition is the most likely diagnosis because a resonant or hyper-resonant sound upon percussion over the lung fields can indicate the presence of air in the pleural space, which is a hallmark of pneumothorax.
• Other Likely diagnoses
  • Pulmonary embolism: While not as directly related to percussion findings, pulmonary embolism can lead to areas of lung that are not functioning properly, potentially altering percussion sounds.
  • Chronic obstructive pulmonary disease (COPD): COPD can lead to hyperinflation of the lungs, which might result in a more resonant sound upon percussion due to the increased air trapping.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Tension pneumothorax: This is a life-threatening condition that requires immediate recognition and treatment. It can present with shifted trachea, decreased breath sounds on the affected side, and hyper-resonance to percussion.
  • Asthma exacerbation: In severe cases, asthma can lead to significant air trapping and hyperinflation, potentially mimicking the percussion findings of other conditions.
• Rare diagnoses
  • Cystic fibrosis: This chronic condition can lead to bronchiectasis and hyperinflation of the lungs, potentially altering percussion sounds, but it's less likely to present acutely with changes in percussion over the longs.
  • Congenital bullous emphysema: A rare condition that could potentially cause localized hyper-resonance due to large bullae, but it's much less common and typically presents in infancy or early childhood.