- What is the process demonstrated in these sections? How does this differ in pattern from what you saw in Case 3?
These images show a lobar pneumonia. There is a diffuse infiltrate of acute polymorphonuclear cells in the consolidated lobe. In case 3, the infiltrate showed a patchy pattern. However, the distinction between bronchopneumonia and lobar pneumonia is often not clear, as some organisms cause one pattern in some patients, and another pattern in other patients. Also, treatment with antibiotics can alter the pattern as well. In image 5.2, in addition to the left upper lobar pneumonia, there is centrilobular emphysema.
- What organism(s) might have been cultured from her blood, had blood cultures been ordered?
Streptococcus pneumoniae causes 95% of the lobar pneumonias, although Klebsiella, Staphylococci, Hemophilus influenze, and some gram negative enteric bacteria (E. Coli, Klebsiella) may also cause it. S. pneumoniae characteristically produces a septic phase within the first 24 to 48 hours during which the organism can readily be cultured from the blood.
- Does the disease process in these sections look severe enough to result in a respiratory death? What else might have contributed to her death?
Although this looks like a relatively early pneumonia, the patient also was septic, which causes vascular collapse and hypotension. She likely died due to a combination of susceptibility due to old age, shock of trauma, septic shock and pneumonia.
