Which of the following does the nurse understand are the cardinal features of acute kidney injury?

Rationale:

A. Rapid breathing (tachypnea) alone does not significantly prevent oxygenation. While it may cause fatigue over time, it is not the primary reason oxygen saturation remains low in pulmonary embolism.

B. Acute respiratory distress syndrome (ARDS) is a different condition. While ARDS also impairs oxygenation, the patient has a pulmonary embolism, so the cause of hypoxemia is different.

C. Immediate intubation is not automatically indicated for every patient with pulmonary embolism. Many patients can maintain adequate oxygenation with supplemental oxygen unless they develop severe respiratory failure.

D. A pulmonary embolism obstructs blood flow in the pulmonary arteries, causing a ventilation-perfusion (V/Q) mismatch. Oxygen can reach the alveoli, but blood flow is blocked, so oxygen cannot be effectively transferred into the circulation, resulting in persistent hypoxemia despite supplemental oxygen.

Rationale:

A. A kink or obstruction in the ventilator tubing increases resistance to airflow. The ventilator is pressure-triggered and senses that it must generate higher pressure than normal to deliver the set tidal volume. This triggers the high-pressure alarm. Nurses should inspect the tubing immediately, straighten any kinks, and ensure the circuit is free from obstruction.

B. A leak causes a loss of delivered volume or pressure, which usually triggers a low-pressure alarm rather than a high-pressure alarm. Leaks allow air to escape, so the ventilator cannot build the necessary pressure to deliver a full breath.

C. Secretions or mucus plugs obstruct airflow in the endotracheal or tracheostomy tube, making it harder for the ventilator to push air into the lungs. This obstruction increases airway pressure, resulting in a high-pressure alarm. Nurses should assess lung sounds, suction the airway if needed, and ensure proper humidification to prevent thick secretions.

D. Changing the circuit may temporarily trigger an alarm, but this is usually brief and procedural, not a physiologic cause of a high-pressure alarm. Once the circuit is connected properly, the alarm should resolve.

E. In modes that rely on spontaneous breathing, apnea or lack of patient effort usually triggers an apnea or low tidal volume alarm, not a high-pressure alarm. The high-pressure alarm reflects resistance or obstruction, not absence of breathing effort.