Hi dillion215.
Voltaren Gel is a nonsteroidal anti-inflammatory drug, commonly known as NSAIDs. It works by reducing hormones that cause inflammation and pain in the body. Voltaren Topical Gel is used to treat joint pain in the hands, wrists, elbows, knees, ankles, or feet caused by osteoarthritis. This medication is for pain. I do not see why a patient with respiratory condition, specifically COPD cannot be safe using the drug for musculo-skeletal pain relief, unless otherwise contraindicated or advised by the physician. Please consult your doctor for further advise.
Voltaren gell is a topical transdermal anti-inflammatory. The actions should not interfere with respiratory status.