Chapter 46: Chronic Lung Disease

INTRODUCTION

Chronic lung diseases are common in older adults and can significantly impact overall health, function, and quality of life. However, older adults often have other comorbidities and complicating factors that play a role in pulmonary disease processes and treatments. When assessing older adults, clinicians must consider and possibly differentiate between the normal physiologic changes of aging and disease pathology.

As people age, chest wall compliance and respiratory muscle strength both decrease. Age and diseases such as osteoporosis are associated with thoracic spine changes that structurally affect lung function. It has been shown that the forced expiratory volume in 1 second (FEV₁) decreases with advancing age, more quickly after 70 years of age. Within the lungs, the alveolar dead space increases, diffusing capacity for carbon monoxide (DLCO) decreases, and receptors become less sensitive to medications. The respiratory response to hypoxia and hypercapnia also decreases; this contributes to reduced awareness symptoms and leaves older patients at greater risk for respiratory decompensation. Because of pulmonary changes associated with aging, pulmonary function tests may need to be interpreted differently for older patients. When treating older adults with chronic lung disease, functional ability, cognitive status, and polypharmacy must all be taken into account.

CHRONIC OBSTRUCTIVE PULMONARY DISEASE

General Principles

Chronic obstructive pulmonary disease (COPD) is a common pulmonary condition characterized by persistent respiratory symptoms and airflow obstruction. COPD is a major cause of morbidity and mortality in the United States and worldwide. In the United States, COPD affects approximately 5% to 10% of the adult population, depending on the population studied. COPD is of special concern to older adults, as its prevalence rises steeply with age. Over the past 30 years, mortality from COPD has increased substantially in the United States, and the number of women dying from COPD has surpassed the number for men. COPD is now the fourth leading cause of death in the United States, accounting for >154,000 deaths in 2016. Worldwide, COPD is currently the fourth leading cause of death but is projected to be the third leading cause of death by 2020.

COPD represents a major public health challenge, as it is largely preventable and treatable, and, yet, it is the only common chronic illness where morbidity and mortality continue to climb. It is a significant cause of hospitalization, particularly in the older population. Rates of hospitalization for COPD increased >30% between 1992 and 2006. In 2010, COPD accounted for approximately 715,000 hospital discharges in the United States, up from 672,000 in 2006. Approximately 65% of discharges were in the population aged 65 years and older. The hospitalization rate for those 65 years of age and older was four times higher ...