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Patients with COPD are easy prey for other predatory illnesses for two reasons.
One, COPD patients are primarily older, 60-and-up; and, two, smoking has predisposed them to other bodily breakdowns that can follow decades of inhaling the witch's brew of toxins woven into cigarettes.
Teasing out COPD's symptoms from those of its comorbidities can test the acumen of even seasoned pulmonologists or respiratory therapists.
"The same things that cause lung problems can cause heart problems," said Alan Plummer, MD, professor of medicine at the Emory University School of Medicine, Atlanta. "Smoking can cause arteriosclerosis. But it's sometimes difficult to know if you're dealing with the heart component or the lung component. They may go into pulmonary edema, but testing is required to determine if that's an exacerbation of the COPD or not, because edema can be brought on without having lung disease."
Researchers recently compared 75 COPD patients with 42 disease-free control subjects who were either smokers or ex-smokers.1The COPD patients exhibited greater arterial stiffness, a precursor to arteriosclerosis possibly due to increased inflammation.
In a double whammy, the investigators also found COPD patients had lower bone mineral density than controls, placing osteoporosis on the list of the disease's comorbidities, particularly for older women, a growing COPD population.
Depression
Clinical depression is common in patients whose disease prevents them from participating in normal activities and, in some cases, ravages them with guilt for having smoked.
However, a 2008 study found evidence that depression can exacerbate COPD.2 Researchers tested 491 COPD patients for depression and anxiety using various scales before following them for a year. "Probable" depression coincided with an increased risk of exacerbations and hospitalization, they found. Moreover, the duration of exacerbations was longer for anxious patients.
Many COPD patients reach a point "where they're not getting out any more, closing themselves in, feeling they're a burden on their families and caregivers," said Adrian Knight, RRT, who has 20 years experience in acute and home care. "You see their will to live start to fail."
That's where pulmonary rehab comes in.
"Rehab enables them to do more than they thought they could possibly do," Plummer said. "That affects their mental outlook."
COPD patients faithfully engaged in rehab are "vivacious" people with terrific attitudes, agreed Knight, a national clinical manager for an oxygen concentrator manufacturer. "They know their disease process isn't going to get better, but they want to do the best they can."
Obstructive Sleep Apnea
Evidence for another comorbidity of airway disease, obstructive sleep apnea (OSA), "has really come on in the last five years," Knight continued. "When COPD patients sleep, their respiration is shallow, placing a strain on the heart to expel the CO2."
OSA may affect up to a third of COPD patients, Plummer said. "It's long been known these people may hypoventilate at night."
Treating COPD patients in the sleep lab presents challenges "especially if they have severe COPD and chronic hypercapnia, which can worsen during REM sleep when they naturally lose muscle tone in the accessory muscles of ventilation," said Paul Selecky, MD, medical director of the pulmonary department and sleep disorders center, Hoag Hospital, Newport Beach, CA.
"The puzzle has always been: What do we do when their oxygen saturation levels drop [to worrisome levels]?" he said. If it drops into the low 80s, "then we often treat the two separately: sleep apnea with CPAP (continuous positive airway pressure) and the drop in O2sat[uration] with oxygen therapy."
Moderate to severe COPD patients also have a higher risk of aspiration pneumonia, and a just-published study suggests a disordered breathing-swallowing pattern may account for it.3
Plus, one especially grave threat haunts COPD patients.
"There is always the chance they might develop lung cancer," Plummer said. "You always have that in the back of your mind."
Michael Gibbons is senior associate editor at ADVANCE.
Researchers Look To Improve COPD Outcomes
Even if everyone in the world stopped smoking today, lung experts would continue to treat people with COPD for decades. The disease's legacy makes finding ways to improve outcomes and quality of life for patients vital.
Recently, several large, multinational studies like TORCH (Towards a Revolution in COPD Health) have begun to probe for answers. While that trial in 2006 failed to tease survival benefits, a second study in 2008 gave new insights.
INSPIRE (Investigating New Standards for Prophylaxis in Reduction of Exacerbations) offered the first large prospective study to compare the impact of salmeterol/fluticasone propionate (SFC) and tiotropium bromide. It included 1,300 patients with severe or very severe COPD.4
SFC demonstrated a 52 percent mortality reduction and improvement in quality of life over two years.
"These results suggest the treatments work in different ways," said Wisia Wedzicha, MD, professor of respiratory medicine at University College, London.
Additionally, a new medical device that could one day provide an alternative to invasive treatments for COPD patients debuted at the 2008 European Respiratory Society Congress. Made of super elastic memory metal, the Lung Volume Reduction Coil is implanted in the lung from the working channel of the bronchoscope. It aims to compress the lung tissue, restore elasticity and reduce excessive hyperinflation. After implantation, the device can be repositioned or removed.
"With more than 20 treatments, we know the safety parameters now," said Erin McGurk, MS, president and CEO of PneumRx Inc., makers of the coil. "We're still optimizing the treatment and identifying patient populations that will respond best."
The procedure, during which several devices are implanted, can be accomplished in less than a half hour in humans.
On average, patients who received the device walked an additional 38 meters in the six-minute walk test (19 percent improvement).
Shawn Proctor
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