A patient from a natural gas explosion shows symptoms of diminished hearing and dyspnea. What mechanism is likely responsible?

In the context of a natural gas explosion, if a patient presents with diminished hearing and dyspnea, primary blast injury is the most likely mechanism at play. Primary blast injuries are specifically caused by the over-pressurization wave generated by an explosion, which can lead to barotrauma. This type of injury often affects air-filled structures in the body, such as the ears and lungs.

Diminished hearing can occur due to damage to the tympanic membrane (eardrum) or other structures of the inner ear caused by the sudden increase and decrease in pressure. Similarly, dyspnea or difficulty in breathing can result from pulmonary barotrauma where the explosive force leads to damage in the lung tissue, causing airway obstruction or other respiratory issues.

While toxic inhalation of natural gas could also lead to respiratory symptoms, the contextual clues in the scenario emphasize the blast effects rather than chemical poisoning. Other blast injury types such as secondary or tertiary blast injuries typically involve projectiles or displacement forces impacting the body, leading to different patterns of injury that are not specifically linked to the symptoms described in this case.