Extensive pulmonary infections (e.g. caused by viruses, bacteria, fungi), aspiration of e.g. gastric juice or in people close to drowning, inhalation of toxins or irritants (e.g. chlorine gas, nitrogen oxides, smoke), direct or indirect trauma (e.g. multiple fractures or lung damage), systemic responses to inflammatory conditions present outside the lungs (e.g. acute pancreatic haemorrhage, sepsis caused by Gram-negative bacteria), transfusions of large blood volumes or, otherwise, after extracorporeal circulation.

https://patents.google.com/patent/PL190775B1/en

Pulmonary complications can be the result of direct chest trauma or can occur from indirect trauma outside of the thorax.
https://pubmed.ncbi.nlm.nih.gov/8055358/

First rib fractures in sports may also occur from indirect trauma as a result of forceful opposing muscle contraction [83] and have been reported in tennis players, surfers, windsurfers, rowers, dancers, gymnasts, and basketball players [84, 85, 86, 87, 88, 89, 90]. Fractures from indirect trauma occur with hyperabduction of the arm and falling on an outstretched arm, as well as sudden muscle contraction [83, 84, 91, 92].
https://link.springer.com/chapter/10.1007/978-3-319-56188-2_...


A significant amount of force is required to fracture this large bone. The fracture can be caused by direct or indirect trauma. Direct trauma involves a forceful blow to the thigh. Indirect trauma involves twisting the thigh or a violent muscle contraction
https://journals.lww.com/md-journal/fulltext/2019/05170/trea...