Cystic fibrosis: pathophysiology and clinical management

Cystic Fibrosis: The Facts is a comprehensive, informative, and well-written book about the disease and its treatments. Ann Harris and Maurice Super address the book to a general audience, making the book extremely accessible to laypeople. Cystic Fibrosis: The Facts is an ideal source for people suffering from cystic fibrosis or for people who have loved ones suffering from the disease. Harris and Super divide the 129-page book into several well-defined chapters. The first chapter addresses the fundamentals of the disease, introducing the audience to the terminology, treatment modalities, and demographics of the disease. The opening pages of the book serve as both summary and introduction. A brief personal account is provided in Chapter 2: Living with Cystic Fibrosis. The author of the account is only 14 years old, adding weight and sentimentality to the story. The following three chapters are dedicated to the technical physiology of cystic fibrosis. While these chapters are filled with medical terminology and examinations of the human anatomy especially affected by the disease, the authors take care not to bog down their text with jargon. Every word is well-defined and only pertinent information is provided. Extraneous facts, data, or statistics do not clutter the pages of Cystic Fibrosis: The Facts, probably because it is published as a trade paperback. Chapter 6 is devoted to the psychology of cystic fibrosis, Chapter 7 to genetics, and Chapter 8 elucidates new treatment modalities. The authors present a summary of organizations concerned with cystic fibrosis in Chapter 9, which is supplemented by an appendix about the International Cystic Fibrosis Association. A thorough glossary is also provided, which is further testimony to the usability of this book.

Cystic fibrosis is a congenital disease that mainly affects the digestive and respiratory systems. Common symptoms include chest infections and steatorrhoea, a condition resulting in particularly malodorous stools. However, symptoms vary from person to person. Because it is a genetic illness and because symptoms often appear in newborns, cystic fibrosis is usually diagnosed soon after birth. While there is no cure for cystic fibrosis, there is a plethora of treatment modalities to ease symptoms and extend life expectancy. The average life expectancy of a person suffering from cystic fibrosis is only 40 years. The disease mainly affects Caucasians: between 1 in 1500 and 1 in 2500 births per year. The authors estimate that four to five births per day in the United States are affected.

Until the early 20th century, cystic fibrosis was not recognized as a distinct malady because its symptoms seemed unrelated. However, the coexistence of gastrointestinal and respiratory problems was recognized as a unique disease by the middle of the 20th century. The term cystic fibrosis refers to cysts, or fluid-filled scar tissue, that interferes with proper pancreatic functioning. The cysts cause excess mucous buildup in the lungs and digestive system, which leads to a multitude of problems People suffering from the disease cannot absorb nutrients from food properly, and are subject to chest infections. Cystic fibrosis also affects the sweat glands. Moreover, most men with cystic fibrosis will be infertile. The same effect is not shared by women, who can successfully give birth. The severity of the disease varies from person to person, as do the symptoms. Cystic fibrosis is caused by abnormal recessive genes on chromosome 7.

Both the upper and lower parts of the respiratory "tree" are affected by cystic fibrosis. The upper part of the respiratory tract includes the sinuses, the nasal passages, and the trachea, or windpipe. Cystic fibrosis may cause a condition called nasal polyps, which are growths in the mucous membranes of the nose that require surgery for removal.

Cystic fibrosis can lead to emphysema, a condition characterized by reduced lung elasticity and caused by excess mucous buildup in the lungs.

Weakening of the walls of the bronchial tubes, or bronchiestasis, is another severe problem associated with cystic fibrosis that can lead to permanent infections and "clubbing" of the extremities. People who suffer from cystic fibrosis commonly contract bacterial infections of the lungs, of which the most common is staphylococcus. Patients can also acquire fungal infections in the respiratory tract. Most of the complications caused by cystic fibrosis that affect the respiratory system are caused by mucous.

The digestive tract is another major victim of cystic fibrosis and is noticeable even before birth, as the fibrous scar tissue replaces normal pancreatic cells. This process is part of the degenerative process of cystic fibrosis. A decrease in the pancreatic juices severely and detrimentally affects digestion. Malabsorption of food and nutrients results in a myriad of symptoms, including steatorrhoea, the excretion of abnormal levels of fat through the feces. If left untreated, steatorrhoea can be a major problem, causing severe deficiencies of vitamins, minerals, proteins, carbohydrates, and water. Furthermore, poor fat metabolism leads to bowel irritations and increased frequency and rate of passage. Proteins will not be sufficiently broken down into their constituent amino acids in persons with cystic fibrosis, and large amounts of amino acids are found in patients. Together with the undigested fats in the bowel movements, the presence of the excess amino acids causes excessively foul-smelling feces. Treatment for this set of digestive issues is usually in the form of enzyme supplements.

Newborn babies diagnosed with cystic fibrosis exhibit meconium ileus, a blockage of the lower intestine that causes abdominal swelling and bilious vomit. Surgery is necessary to correct meconium ileus. Children past the newborn stage who have cystic fibrosis will have symptoms like abdominal distension, loose and malodorous stool, and rectal prolapse. All these problems are associated with an improper functioning of the small intestine. In some cases, children with cystic fibrosis will develop a mild form of diabetes. In about 10% of cystic fibrosis cases, no gastrointestinal symptoms will be present. However, GI symptoms are usually detected far before respiratory ones are. The sweat glands are also affected by cystic fibrosis, as the disease causes increased electrolyte presence in the sweat. In fact, using sweat as a diagnostic measure is one of the safest and most reliable tests for cystic fibrosis.

Children tested with the sweat test show two to five times the normal amount of salt in their sweat. This test provides a non-invasive measure to test young children; unfortunately it is not as effective in testing adults who develop symptoms later in life. Occasionally cystic fibrosis does remain diagnosed for years. If the results of the sweat test are inconclusive, then pancreatic secretions can be measured through a urine sample. Unfortunately, certain methods of testing newborns for cystic fibrosis result in false positive results: as many as 20 false positives for every 1 correctly diagnosed case of cystic fibrosis.

Treatment for cystic fibrosis is often approached in a multi-disciplinary manner. Clinics have been established to provide a safe haven for those who suffer. These Cystic fibrosis clinics promise a supportive atmosphere and usually result in improvements in health and life expectancy. The only disadvantages noticed by Harris and Super are the increased exposures to the negative consequences of the disease in fellow patients. However, the authors seem generally supportive of these clinics.

Diligent, daily treatments must be provided to stay symptoms of cystic fibrosis. Chest X-rays and lung-function tests are essential, as are immunizations against organisms that cause respiratory illnesses like whooping cough and measles. Antibiotics for staphylococcus are helpful as well. Draining infected material from the lungs is a significant aspect of recovery, achieved with physiotherapy like breathing exercises and physical activity. These actions help loosen phlegm and mucous from the lungs.