McKenna's Pharmacology for Nursing, 2e

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P A R T 1 0  Drugs acting on the respiratory system

Acute respiratory distress syndrome (ARDS) is char- acterised by progressive loss of lung compliance and increasing hypoxia. This syndrome typically results from a severe insult to the body, such as cardiovascular collapse, major burns, severe trauma or rapid depres- surisation. Treatment of ARDS involves reversal of the underlying cause of the problem combined with ventila- tory support. ■■ Inflammation of the lower respiratory tract can result in serious disorders that interfere with gas exchange, including bronchitis and pneumonia. ■■ Obstructive disorders interfere with the ability to deliver gases to the alveoli because of obstructions in the conducting airways and eventually in the respiratory airways. These disorders include asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis and respiratory distress syndrome (RDS). CHAPTER SUMMARY ■■ The respiratory system is composed of the upper respiratory tract, which includes the nose, pharynx, larynx and trachea, and the lower respiratory tract, which includes the bronchial tree and the alveoli. ■■ The respiratory system is essential for survival; it brings oxygen into the body, allows for the exchange of gases and expels carbon dioxide and other waste products. ■■ The upper airways have many features to protect the fragile alveoli: hairs filter the air; goblet cells produce mucus to trap foreign material; cilia move the trapped material towards the throat for swallowing; the blood supply close to the surface warms the air and adds humidity to improve gas movement and gas exchange; and the cough and sneeze reflexes clear the airways. ■■ The alveolar sac is where gas exchange occurs across the respiratory membrane. The alveoli produce surfactant to decrease surface tension within the sac and facilitate diffusion. ■■ Respiration is controlled through the medulla in the central nervous system and depends on a balance between the sympathetic and parasympathetic systems and a functioning muscular system. ■■ Inflammation of the upper respiratory tract is seen in many disorders, including the common cold, seasonal rhinitis, sinusitis, pharyngitis and laryngitis. KEY POINTS

■■ Inflammation of the lower respiratory tract can result in serious disorders that interfere with gas exchange, including bronchitis and pneumonia. ■■ Obstructive disorders interfere with the ability to deliver gases to the alveoli because of obstructions in the conducting airways and eventually in the respiratory airways. These disorders include asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis and respiratory distress syndrome (RDS). Knowing your strengths and weaknesses helps you to study more effectively. Take a PrepU Practice Quiz to find out how you measure up! ONLINE RESOURCES An extensive range of additional resources to enhance teaching and learning and to facilitate understanding of this chapter may be found online at the text’s accompanying website, located on thePoint at http://thepoint.lww.com. These include Watch and Learn videos, Concepts in Action animations, journal articles, review questions, case studies, discussion topics and quizzes. Barrett, K. E. & Ganong, W. F. (2010). Ganong’s Review of Medical Physiology (23rd edn). New York: McGraw-Hill. George, R. B., Light, R. W., Matthay, M. A. & Matthay, R. A. (Eds.). (2006). Chest Medicine: Essentials of Pulmonary and Critical Care Medicine . Philadelphia: Lippincott Williams & Wilkins. Goodman, L. S., Brunton, L. L., Chabner, B. & Knollmann, B. C. (2011). Goodman and Gilman’s Pharmacological Basis of Therapeutics (12th edn). New York: McGraw-Hill. Guyton, A. & Hall, J. (2011). Textbook of Medical Physiology (12th edn). Philadelphia: Saunders Elsevier. Levitzky, M. G. (2007). Pulmonary Physiology. New York: McGraw-Hill. Porth, C. M. (2011). Essentials of Pathophysiology: Concepts of Altered Health States (3rd edn). Philadelphia: Lippincott Williams & Wilkins. Porth, C. M. (2009). Pathophysiology: Concepts of Altered Health States (8th edn). Philadelphia: Lippincott Williams & Wilkins. Simon, S. (2007). Lungs: Your Respiratory System . New York: Collins. Weinberger, S. E., Cockrill, B. A. & Mandel, J. (2014). Principles of Pulmonary Medicine . Philadelphia: Elsevier Saunders. West, J. B. (2013). Pulmonary Physiology: The Essentials (8th edn). Philadelphia: Lippincott Williams & Wilkins. Zevitz, M. & Leonhardt, R. (2005). Pulmonary Medicine Review. New York: McGraw-Hill. BIBLIOGRAPHY