Which of the following factors could contribute to a high pressure alarm on a mechanical ventilator? Select All that Apply.

A pulmonary embolism (PE) occurs when a blood clot, usually from the deep veins of the legs, travels to and obstructs the pulmonary arteries. Management priorities depend on the severity and stability of the client. In a low-risk, hemodynamically stable PE, the main goal is to prevent clot extension and new thrombus formation while allowing the body to gradually break down the existing clot. Anticoagulation therapy is the cornerstone of treatment in these cases.

Rationale:
A. Encouraging physical therapy to strengthen leg muscles is not a priority in the acute management of a pulmonary embolism. While mobility and rehabilitation are important in long-term prevention of venous thromboembolism, they do not address the existing clot or prevent immediate progression. The priority is anticoagulation to stabilize the condition before initiating strengthening or exercise programs.

B. Instructing the client to perform deep breathing exercises every hour may support lung expansion and oxygenation, but it does not treat the underlying clot or prevent further embolization. Respiratory exercises are supportive care and are secondary to pharmacologic management. They are useful for preventing atelectasis but are not the priority intervention in acute PE treatment.

C. Administering low molecular weight heparin as ordered is the priority intervention because it prevents further clot formation and propagation. Low molecular weight heparin works by inhibiting clotting factors in the coagulation cascade, reducing the risk of additional emboli. In a stable PE, anticoagulation is the first-line therapy to allow the body’s fibrinolytic system to gradually dissolve the existing clot.

D. Preparing the client for surgery to remove the embolus is not indicated in a low-risk, stable pulmonary embolism. Surgical or catheter-directed embolectomy is reserved for massive or life-threatening PE with hemodynamic instability. In stable patients, invasive procedures are unnecessary and expose the client to additional risks without clear benefit.

Cerebral edema involves increased intracranial pressure due to fluid accumulation within brain tissues, which can lead to decreased cerebral perfusion and neurological deterioration. Mannitol is an osmotic diuretic used to reduce intracranial pressure by drawing fluid from brain tissue into the intravascular space for renal excretion. Because mannitol can crystallize at room temperature, proper preparation and safety checks are essential before IV administration to prevent harm and ensure therapeutic effectiveness.

Rationale:
A. Checking for crystallization in the mannitol solution is essential before administration because mannitol can form crystals when stored at low temperatures. Infusing crystallized solution can cause catheter occlusion or embolization. If crystals are present, the solution should be warmed or filtered before use to ensure safe administration.

B. Administering mannitol rapidly over 10 minutes is unsafe unless specifically prescribed, as rapid infusion can cause sudden fluid shifts and cardiovascular overload. Mannitol should be administered at the prescribed controlled rate to prevent complications such as pulmonary edema, hypotension, or electrolyte imbalance. Proper infusion timing is critical to avoid adverse hemodynamic effects.

C. Ensuring systolic blood pressure is below 100 mm Hg is not a required pre-administration parameter for mannitol. While blood pressure monitoring is important due to the risk of fluid shifts and osmotic diuresis, the drug is not contraindicated based solely on systolic pressure thresholds. The focus is on intracranial pressure reduction rather than strict blood pressure limits.

D. Administering mannitol with food to improve absorption is incorrect because mannitol is given intravenously, not orally. Food intake has no effect on its absorption or pharmacologic action. Its therapeutic effect depends entirely on controlled IV infusion and its osmotic movement across the blood-brain barrier.