Signs and symptoms of peripheral arterial disease may include which one of the following?

A. First-degree (superficial) burns result in blister formation is incorrect because first-degree burns affect only the epidermis. They cause redness, mild pain, and swelling but do not form blisters. Blistering occurs in second-degree burns.

B. Fourth-degree (full-thickness) burns involve all skin layers and underlying tissue is correct because fourth-degree burns extend through the epidermis, dermis, subcutaneous tissue, and into underlying structures such as muscle, tendons, or bone. These burns are severe, often result in charring, and usually require surgical intervention or amputation due to extensive tissue loss.

C. Second-degree (partial thickness) burns are painless is incorrect because second-degree burns affect both the epidermis and part of the dermis, causing intense pain due to exposed nerve endings. They are typically characterized by redness, swelling, blistering, and significant discomfort.

D. Third-degree (full-thickness) burns do not extend beyond the dermis is incorrect because third-degree burns destroy the entire epidermis and dermis, potentially extending into subcutaneous tissue. Unlike second-degree burns, third-degree burns may appear white, brown, or charred and are often painless due to nerve destruction.

A. Diabetes is incorrect because diabetes mellitus is a chronic metabolic disorder caused by insufficient insulin production or insulin resistance. It is unrelated to the acute fluid shifts or volume depletion seen in burn injuries, so it is not a complication of burns.

B. Hypovolemic shock is correct because severe burns damage the skin, which acts as a protective barrier, allowing significant fluid, plasma, and protein loss through the injured tissue. This results in a decrease in circulating blood volume, leading to reduced tissue perfusion, hypotension, tachycardia, and potential organ dysfunction. Hypovolemic shock is a life-threatening complication in the acute phase of burn injury. Early recognition and prompt fluid resuscitation using formulas like the Parkland formula are critical to restore intravascular volume, maintain organ perfusion, and prevent multi-organ failure.

C. Pneumonia is incorrect because pneumonia is primarily a respiratory complication, often arising from inhalation injury, aspiration, or prolonged immobility, rather than from fluid loss. While burn patients are at increased risk for infections due to compromised skin integrity and immune suppression, pneumonia is not the direct result of hypovolemia.

D. Heart failure is incorrect because heart failure occurs when the heart is unable to pump blood effectively due to structural or functional problems. Although severe burns can stress the cardiovascular system, the immediate threat from fluid loss is hypovolemic shock, not intrinsic heart failure.