A nurse is assisting a client with ambulation several hours after a hip replacement. Which of the following postoperative complications is the nurse trying to prevent?

Postoperative care focuses on mitigating risks associated with immobility and surgical trauma. Early ambulation is a primary intervention for vascular health. Knowledge of Virchow’s triad, including venous stasis and hypercoagulability, is necessary to prioritize nursing actions following major orthopedic surgery. Choice A rationale Postoperative delirium is an acute cognitive impairment often caused by anesthesia, electrolyte imbalances, or sensory deprivation. While mobility helps overall recovery, it is not the primary physiological mechanism used to prevent the cognitive fluctuations associated with delirium. Choice B rationale Malignant hyperthermia is a life-threatening pharmacogenetic reaction to volatile inhalational anesthetics or succinylcholine. It typically occurs in the operating room or PACU. Ambulation hours later does nothing to prevent this specific metabolic crisis involving calcium release. Choice C rationale Hip surgery increases the risk of venous thromboembolism due to vessel wall injury and immobility. Early ambulation promotes the skeletal muscle pump, increasing venous return and preventing blood stasis, which is a key component of Virchow's triad. Choice D rationale Malnutrition involves inadequate intake of proteins and calories required for wound healing. While mobility can stimulate appetite, it is not the direct clinical intervention used to prevent nutritional deficits, which require dietary assessment and oral or parenteral support.