Respiratory Case History 5:

 Fighting for Every Breath *

 

Jason, a 10-year-old boy, had had a mild cold for several days when he suddenly developed a fever of 103 degrees. The next day he said the right side of his chest hurt. Coughing or taking a deep breath caused sharp pain, and his breathing had become labored, rapid, and shallow. He looked anxious and much sicker than he did the day before.

 

His mother realized that he needed immediate attention, so she took him to a hospital emergency room. The examining physician tapped on his chest. Instead of the normal hollow thump, she heard a dull note over his lower right chest. The sound suggested that this area was not air-filled. She used a stethoscope to examine it further. Instead of hearing the normal soft flow of air entering and leaving the lungs, she heard no breath sounds at all in some places, and wet crackling sounds called rales in others. An x-ray of Jason‰s chest showed a relatively black left lung. That's the normal appearance, indicating that the x-rays are traveling mainly through air. But the lower lobe of his right lung was white, the characteristic appearance of x-rays passing through more dense material, in this case, fluid. He continued to complain of severe chest pain. A sample of blood was drawn and sent to the laboratory for a complete blood count and a microbiology culture. The hematology lab immediately reported an unusually high number of neutrophils, many of which looked immature.

 

Based on Jason's history, physical examination, and the hematology report, his physician felt confident in diagnosing pneumonia. She decided to admit him to the hospital and treat him with antibiotics. By the next day, his temperature had returned to normal and he was feeling much better. The microbiological culture confirmed a bacterial cause, Streptococcus pneumoniae, a common cause of pneumonia. Within a few days, Jason was feeling back to normal.

 

QUESTIONS:

  1. Describe the mechanics of breathing. Include the relationship between pressure and volume. How are oxygen and carbon dioxide transported in the blood? 
  2. What areas of the respiratory system does pneumonia affect? How does this compare to areas affected by a common cold or bronchitis?
  3. What structural features of normal lungs are necessary for good gas exchange? How were these impaired by the pneumonia infection?
  4. What protective mechanisms are normally in the upper airways to prevent lower respiratory tract infections?
  5. What reflex accounts for Jason's rapid breathing?

 

* from Human Physiology 5th ed., Lauralee Sherwood