The patient is being supported with mechanical ventilation and is requiring very high levels of inspired oxygen to maintain his arterial blood gases at acceptable levels. In an attempt to reduce the amount of oxygen required, positive end-expiratory pressure (PEEP) at 5 cm H2O is added to the ventilator settings. What is the most important effect of PEEP?

Rationale:
A. Assure the patient that everything will be all right and that remaining calm is the best strategy is incorrect because while reassurance is supportive, it does not address the patient’s immediate communication needs, which are causing frustration.

B. Ask a family member to interpret what the patient is trying to communicate is incorrect because family members may not understand the patient’s intended message accurately, which can lead to miscommunication or frustration.

C. Ask the physician to wean the patient off the mechanical ventilator to allow the patient to speak freely is incorrect because weaning must be based on clinical readiness, not solely on communication needs. Premature weaning could compromise patient safety.

D. Express empathy and then encourage the patient to write, use a picture board, or spell words with an alphabet board is correct. These are alternative communication strategies for patients who are intubated or mechanically ventilated. By validating the patient’s feelings and providing tools for nonverbal communication, the nurse reduces frustration and supports patient autonomy and safety. This is considered best practice for facilitating communication in ventilated patients.

Rationale:
A. Cardiac output of 6 L/min is incorrect because a cardiac output in this range is generally adequate for tissue perfusion. Normal adult cardiac output is roughly 4–8 L/min, so this value alone would not impair the ability to wean from a ventilator.

B. Hemoglobin of 8 g/dL is correct. Low hemoglobin (normal 13.5–17.5 g/dL in males, 12–15.5 g/dL in females) reduces the oxygen-carrying capacity of the blood, meaning tissues—including respiratory muscles—receive less oxygen. This can lead to fatigue of the respiratory muscles and difficulty weaning from mechanical ventilation. Patients with anemia may require transfusion or optimization of oxygen delivery before successful weaning.

C. Sputum culture and sensitivity are negative is incorrect because the absence of infection does not contribute to weaning difficulty. In fact, a negative culture suggests no ongoing pulmonary infection, which would favor weaning.

D. White blood cell count of 8000 is incorrect because this is within the normal range (approximately 4,000–11,000/mm³). A normal WBC count does not indicate infection or inflammation that would interfere with ventilator weaning.