Case Study
Chapter 22: The Respiratory System Case Story Summary Cari, a 47-year-old female with a 20-year history of pack-a-day smoking and chronic bronchitis, presents at the clinic complaining of a cold and potential sinus infection. She describes general muscle aches, fatigue, sore throat, hoarseness of voice, and has a temperature of 101.2 and a history of several weeks of flu-like symptoms. Upon examination it is found that her respiratory rate is elevated and she has a low oxygen saturation level. Her lung sounds are abnormal. A follow up chest x-ray reveals fluid infiltrate within the lungs. A Gram’s stain reveals the presence of bacteria, resulting in a diagnosis of pneumococcal pneumonia. Cari is initially unresponsive to the antibiotic therapy, but makes a full recovery after changing therapies. Like many smokers, Cari has a hard decision to make: Continue smoking and risk further infections, loss of respiratory function, emphysema, cancer, and chronic obstructive lung disease, or quit. Diagnostic Information Pneumonia may be caused by a variety of organisms including viruses, bacteria and even fungi. Pneumococcal pneumonia is caused by streptococcus pneumoniae, a type of bacteria. Typical symptoms include high fever, cough, shortness of breath, rapid breathing and chest pains. Sometimes, nausea headache, and general muscle soreness and fatigue may be present also. Pleural effusion may be seen on chest xrays and typically a culture of the patients sputum is obtained. See the DVD accompanying the textbook for more information on smoking. Treatment Information The mortality rate for this type of pneumonia is around 10%. Treatment may consist of penicillin for non-resistant bacterial strains. Many resistant strains do exist however. In these cases quinolone antibiotics may be administered (levofloxacin). Oxygen may be administered to improve blood oxygen saturation levels. Constant and regular monitoring of lung sounds is important and follow-up chest x-rays are usually advised after therapy. Chapter 22: The Respiratory System Answers to Case Questions 1. How could an infection in Cari’s nasal passages and pharynx spread into the sinuses? 2. What sinuses lie over Cari’s eyes? (Hint: see paranasal sinuses on page 837)? 3. Which cells found within Cari’s mucous membranes are producing excess amounts of mucus? 4. What is the cough reflex? . 5. How might Cari’s hoarse voice be related to the upper respiratory tract infection? Which structures found in the terminal bronchioles and alveoli normally would protect Cari’s lungs from infectious pathogens and particulate matter? 6. Where is the base of Cari’s lung that the nurse is listening to? 7. What accessory muscles of respiration must Cari use to forcefully inspire air? 8. How would Cari’s the resistance of Cari’s airways be affected by the excess mucus and fluid in her lung? 9. How would Cari’s lung compliance (the effort required to expand the lungs) be altered as her alveoli fill with fluid due to pneumonia? 10. Cari’s respiratory rate is elevated; how does this alter her minute ventilation? . 11. Cari has been given pure oxygen to breath; why would increasing the oxygen concentration in the air she is breathing help Cari? 12. Normal blood oxygen saturation levels are greater than 94%; Cari’s blood oxygen saturation level was 90% at the time of her exam and an initial arterial blood gas analysis done when she was admitted to the hospital revealed her arterial PO 2 was 54 mm Hg. How would these clinical findings relate to internal respiration in Cari’s body? The fluid in Cari’s lungs decreases her functional alveolar surface area; how is this affecting Cari’s external respiration? 13. Which of the symptoms that Cari has described are due to lack of oxygen and reduced oxygen exchange at her tissues?. 14. Why would Cari’s increased respiratory rate cause her to lose more CO2 than gain oxygen? 15. Cari has been put on an artificial ventilation machine and she is still receiving oxygen; how would increasing her PO2 assist hemoglobin in oxygen transport?. 16. As Cari’s PCO2 rose, how was the oxygen-carrying capacity of hemoglobin affected? 17. Cari’s fever is subsiding; how might her elevated body temperature have altered oxygen transport in her body? 18. How would you have expected Cari’s decreased PCO2 and alkaline blood pH to have affected her breathing?. 19. Why would a decrease in bicarbonate have caused Cari’s blood pH to rise? 20. How would administration of oxygen enhance Cari’s central drive to breath? Severe oxygen deficiency depresses the activity of central chemoreceptors in the inspiratory area. 21. What is another name for Cari’s low blood PCO2 ? Hypocapnia. 22. Which anatomic structures in Cari’s respiratory system were initially involved? 23. Why was Cari plagued with a chronic smoker’s cough? 24. Which damaging effects of tobacco smoke led to Cari’s impaired respiratory defense mechanisms? 25. How did pneumonia affect Cari’s lung function?
