A nurse is monitoring a client following a thoracentesis. The nurse should identify which of the following manifestations as a complication and contact the provider immediately?

A. An increase in the CMV rate:
Increasing the continuous mandatory volume (CMV) rate would provide more mandatory breaths, which may not address the patient's respiratory acidosis. It could potentially worsen the situation by causing respiratory alkalosis.

B. Change to SIMV (Synchronized Intermittent Mandatory Ventilation) MODE
The patient's arterial blood gas results indicate respiratory acidosis with an elevated PaCO2 (50 mmHg) and a low pH (7.30). The nurse would recommend changing to SIMV mode to allow for spontaneous breaths in addition to the set mandatory breaths. This change helps the patient to have more control over their respiratory efforts and may assist in lowering the PaCO2.

C. A decrease in the PaO2:
Decreasing the partial pressure of oxygen (PaO2) is not an appropriate response, especially when the patient is already on mechanical ventilation and has a moderate PaO2 level. The primary concern is the elevated PaCO2 and respiratory acidosis.

D. A decrease in the CMV rate:

Decreasing the CMV rate would reduce the number of mandatory breaths, potentially allowing the patient to hypoventilate further and retain more carbon dioxide. This is not the appropriate intervention for a patient with respiratory acidosis.

A. PEEP decreases the peak respiratory pressures:
PEEP may increase peak respiratory pressures, especially during inspiration, but its primary purpose is to prevent alveolar collapse and improve oxygenation.

B. “PEEP increases the number of breaths the patient takes on his own.”:
PEEP does not increase the number of breaths the patient takes. It primarily affects the quality of ventilation by preventing alveolar collapse.

C. “PEEP augments the patient’s overall tidal volumes.”:
PEEP does not necessarily increase overall tidal volumes. It focuses on maintaining positive pressure at the end of expiration to prevent alveolar collapse.

D. “PEEP improves oxygenation by keeping alveoli open after exhalation.”
Positive end-expiratory pressure (PEEP) is used in mechanical ventilation to maintain positive pressure in the airways and alveoli at the end of the respiratory cycle (expiration). This helps prevent alveolar collapse and improves oxygenation by keeping the alveoli open, particularly in patients with conditions like acute respiratory distress syndrome (ARDS). PEEP is commonly used to increase functional residual capacity (FRC) and improve oxygenation.