A nurse assesses an audible grating sound (crepitus) when a client with osteoarthritis moves his knees. What is the cause of this sound?

Choice A reason: This is not the correct answer because opioids are a class of medications that act on the opioid receptors in the brain and spinal cord to reduce pain perception and emotional response. Opioids do not have a direct effect on tissue inflammation or bone healing, but they can cause side effects such as constipation, nausea, sedation, respiratory depression, and addiction.

Choice B reason: This is not the correct answer because anticoagulants are a class of medications that prevent or reduce the formation of blood clots by interfering with the clotting factors or platelets. Anticoagulants do not have a direct effect on tissue inflammation or bone healing, but they can increase the risk of bleeding and hematoma formation, which can impair the blood supply and oxygen delivery to the injured tissues.

Choice C reason: This is the correct answer because NSAIDs are a class of medications that inhibit the enzyme cyclooxygenase (COX), which is involved in the synthesis of prostaglandins, which are inflammatory mediators that cause pain, swelling, and fever. NSAIDs can decrease tissue inflammation and pain, but they can also delay bone healing by reducing the formation of osteoblasts, which are cells that build new bone tissue.

Choice D reason: This is not the correct answer because narcotics are another term for opioids, which are a class of medications that act on the opioid receptors in the brain and spinal cord to reduce pain perception and emotional response. Narcotics do not have a direct effect on tissue inflammation or bone healing, but they can cause side effects such as constipation, nausea, sedation, respiratory depression, and addiction.

Choice A reason: Heberden's nodes are not a symptom of lupus. Heberden's nodes are bony swellings that form on the distal interphalangeal joints of the fingers. They are a sign of osteoarthritis, which is a degenerative joint disease that causes pain, stiffness, and reduced mobility.

Choice B reason: Chvostek's sign is not a symptom of lupus. Chvostek's sign is a facial twitch that occurs when the facial nerve is tapped near the ear. It is a sign of hypocalcemia, which is a low level of calcium in the blood. Hypocalcemia may be caused by various conditions, such as hypoparathyroidism, vitamin D deficiency, or renal failure.

Choice C reason: OsgoodSchlatter's disease is not a symptom of lupus. OsgoodSchlatter's disease is a condition that affects the growth plate of the tibia, which is the shin bone. It causes pain, swelling, and tenderness below the knee. It is common in adolescents who are active in sports that involve running, jumping, or bending the knee.

Choice D reason: Butterfly rash is a classic symptom of lupus. Butterfly rash is a malar rash that appears across the cheeks and the bridge of the nose. It is a common sign of systemic lupus erythematosus (SLE), which is an autoimmune disease that causes inflammation and damage to various organs and tissues. The rash may flare up or fade depending on the disease activity and exposure to sunlight.