Complications

Complications

In 2002, chronic obstructive lung disease was responsible for 120,000 deaths. COLD costs in the U.S. in 2004 reached $37.2 billion. It is the fourth leading cause of death in the U.S., and its death rates are increasing. Some evidence suggests that these death rates may be higher than current estimates, because COLD patients are at greater risk for life-threatening conditions, notably heart attack and pulmonary embolism.

Chronic obstructive lung disease is progressive; however, when patients stop smoking the disease often levels off.

• Outlook for Patients with Emphysema. If emphysema is detected before causing symptoms, there may be some chance of reversing it, although permanent changes in the alveoli usually occur, even in young smokers. Patients with the inherited form of early-onset emphysema are at risk for early death unless the disease is treated and its progression halted or slowed. Emphysema patients who experience severe involuntary weight loss (which indicates muscle wasting) have a poorer outlook, regardless of lung function.
• Outlook for Patients with Chronic Bronchitis. Chronic bronchitis does not cause as much lung damage as emphysema, although the airways become blocked by mucous plugs, and narrow due to inflammation. Thus poor air exchange causes reduced levels of oxygen, and high carbon dioxide levels. This state of poor gas exchange can lead to serious, life-threatening conditions that include severe breathing difficulty and heart failure.

Acute Exacerbations

Acute exacerbations are episodes that occur with both types of COLD. The airways suddenly become obstructed, and symptoms worsen. Such events are associated with inflammation in the airways and are triggered by infections about 80% of the time. They are not due to other complications of COLD, including pneumonia, heart failure, or a collapsed lung.

A new study found that 25% (one quarter) of people with COLD, who have an acute exacerbation with no known cause, actually suffer from pulmonary embolism (a blood clot in the lung). The risk for pulmonary embolism was higher in patients who had blood clot problems in the past and patients with cancer. The risk was also increased in patients whose carbon dioxide pressure in the alveoli was significantly reduced, compared to their usual levels.