Final answer:
A patient with the symptoms described is likely suffering from a pneumothorax, a condition where air enters the space between the lung and chest wall. The contraction of external intercostal muscles usually assists in inhalation by expanding the rib cage. Intubation is indicated for injuries in the respiratory system, possibly at the pharynx or lower.
Step-by-step explanation:
A patient with blunt trauma who is holding the lateral side of his chest and has rapid and shallow respirations is most likely suffering from a pneumothorax. A pneumothorax, also known as a collapsed lung, occurs when air leaks into the space between the lung and chest wall, often related to subtle abnormalities in connective tissue or trauma. This condition can cause the feeling of chest pain and lead to difficulty breathing, hence the rapid and shallow respirations observed in the patient.
The contraction of the external intercostal muscles typically causes the rib cage to expand, not compress, which facilitates inhalation. When the diaphragm moves downward, it increases the volume of the thoracic cavity, allowing air to enter the lungs.
The respiratory system is a complex network involving the pharynx, bifurcating into primary bronchi, which further divide into secondary and tertiary bronchi, and finally into bronchioles. If a patient has been surgically intubated, the injury requiring such a procedure likely occurred in a part of the respiratory system that is crucial for ensuring the passage of air into the lungs—potentially at the level of the pharynx or below, depending on the specifics of the case.