The nurse is assessing a patient's active range of motion (ROM) and notices limited extension at the left elbow. What is the next step for the nurse to take?

A. A patient with chronic venous insufficiency and brownish discoloration of the lower legs: Hemosiderin staining results from red blood cell extravasation into the dermis. This represents a chronic, non-acute sequela of venous hypertension and valvular incompetence. While it requires management, it does not pose an immediate threat to systemic oxygenation.

B. A patient with a history of Raynaud's phenomenon and episodic cyanosis of the fingers: This condition involves vasospastic attacks of digital arteries, often triggered by cold or stress. The cyanosis is peripheral and typically transient rather than a sign of systemic hypoxia. It is a documented part of the patient's chronic history.

C. A patient with localized erythema around surgery site on the leg: Localized redness typically indicates an inflammatory response or localized infection at the incision. While it necessitates monitoring and wound care, it remains a focal issue. It is less urgent than conditions affecting the patient's central airway or circulation.

D. A patient with new onset of cyanosis around the lips: Circumoral cyanosis indicates central hypoxia and inadequate arterial oxygen saturation. This is a medical emergency requiring immediate respiratory or cardiac intervention to prevent tissue ischemia. It suggests a critical failure in the body's ability to oxygenate systemic blood.

A. Clenched fists: In patients with cognitive impairment, non-verbal cues such as motor tension or guarding are primary indicators of physical distress. Clenched fists often represent an involuntary response to acute or chronic pain when the patient cannot articulate their feelings. This behavior signals an increased sympathetic nervous system activation.

B. Shuffling gait: A shuffling gait is a common motor symptom of Parkinson's disease or normal aging and is not a specific indicator of pain. While pain can alter mobility, this particular gait pattern is usually related to neurological changes or balance deficits. It is a chronic physical characteristic rather than a behavioral clue for pain.

C. Flat affect: A flat affect is characterized by a lack of emotional expression and is often associated with depression or the progression of dementia itself. Pain more frequently causes an increase in facial activity rather than a decrease. It is not a reliable sign for identifying an acute painful stimulus.

D. Moaning: Vocalizations such as moaning, groaning, or whimpering are significant behavioral indicators of pain in non-verbal patients. These sounds often increase during movement or repositioning, suggesting localized or systemic discomfort. The nurse should use these cues to initiate a thorough pain assessment and intervention.

E. Grimacing: Facial expressions, including grimacing, furrowed brows, or distorted features, are the most common non-verbal manifestations of pain. These involuntary muscle contractions occur as a direct response to noxious stimuli. They provide clear evidence that the patient is experiencing a level of physiological or psychological distress.