Final answer:
The finding most consistent with an injury to the diaphragm following a trauma would be referred pain in the shoulder or neck, due to Kehr's sign, which is widespread in cases of diaphragmatic irritation. Difficulty in breathing due to compromised pressure changes, and potential complications like pneumonia or pneumothorax, should also be considered.
Step-by-step explanation:
When a patient is complaining of increased difficulty breathing and presents with a small penetrating wound to the sixth intercostal space in the left lateral chest, the findings consistent with an injury to the diaphragm can vary. If the diaphragm is damaged, individuals may experience referred pain, which is pain perceived at a location other than the site of the painful stimulus. This is observed in Kehr's sign, where irritation or damage to the diaphragm can feel like pain in the shoulder or neck because of the nerve pathways that the diaphragm shares with the shoulder.
The diaphragm's role in breathing involves contraction and relaxation, which affect pressure changes in the thoracic cavity, resulting in inspiration and expiration. If the diaphragm is injured, these pressure changes become less effective, thereby compromising the breathing process. Moreover, if airway resistance is increased, this will affect intrapleural pressure during inhalation, making it more challenging for the lungs to expand appropriately. A puncture to the thoracic cavity can similarly alter the ability to inhale by introducing air into the pleural space (pneumothorax), further inhibiting proper lung expansion and reducing respiratory efficiency.
In cases of chest trauma, clinicians will also be vigilant for other complications such as pneumonia, which can be identified by symptoms like crepitation in the lungs, chest radiographs showing opacities, and the presence of abnormal material in the lungs. A pneumothorax or the presence of fluid, as might be seen with a spleen rupture causing referred pain through Kehr's sign, would also be important to consider based on the described symptoms and presentation.