A nurse is caring for a client who reports an area of redness, warmth, tenderness, and pain in the right calf. The nurse anticipates which of the following orders when notifying the provider of this finding?

Choice A reason: Impedance plethysmography is an older diagnostic method for detecting deep vein thrombosis (DVT) but is less commonly used today due to lower sensitivity and specificity compared to duplex ultrasound. It may be considered in certain settings but is not the first-line test. Choice B reason: Cold therapy is contraindicated in suspected DVT. It can cause vasoconstriction and worsen symptoms. Warm compresses may be used in some cases for comfort, but only after diagnosis and under provider direction. Choice C reason: Venous duplex ultrasound is the gold standard non-invasive diagnostic test for DVT. It combines traditional ultrasound with Doppler flow studies to visualize thrombus and assess blood flow, making it the most appropriate and widely used test in this scenario. Choice D reason: Homan's sign (pain in the calf upon dorsiflexion of the foot) is no longer considered a reliable or safe diagnostic tool for DVT. It lacks sensitivity and specificity and may even risk dislodging a clot. It is not recommended in current clinical practice.