Tracheobronchial and pulmonary cytologic changes in shock.

Smears were made from tracheobronchial washings of patients undergoing general endotracheal anesthesia for surgery. Morphologically abnormal histiocytes were noticed in specimens obtained from subjects during hemorrhagic shock. These cells were overloaded with Papanicolaou stain (a greenish orange compound) which compressed the nucleus against the cell membrane. Cytochemical staining methods were undertaken to discover the composition of this substance. In secretions suctioned from ten patients in shock, large numbers of histiocytes were found to have ingested inorganic iron detectable by the Prussian blue method. Only two patients from a matched control group had smears in which this phenomenon was discovered. The maximum proportion of histiocytes containing Prussian blue granules was 40% for patients in shock and only 2% in normal controls. Histologic studies conducted on rats submitted to hemorrhagic shock were carried out to investigate this phenomenon. Iron-laden histiocytes were found in the kidneys, spleen, and lungs of both shocked and control animals. However, substantially more histiocytes containing Prussian blue positive granules were discovered in the lungs of rats in shock than in controls. It may, therefore, be that iron is deposited in the lungs in low flow states.