Final answer:
The nurse should monitor for impaired venous return as an adverse effect of PEEP in a client on mechanical ventilation.
Step-by-step explanation:
A nurse caring for a client who is receiving positive end-expiratory pressure (PEEP) via mechanical ventilation should monitor the client for impairment of venous return as an adverse effect. PEEP can increase intrathoracic pressure, which might consequently reduce the return of blood to the heart, potentially leading to decreased cardiac output and other hemodynamic changes. This monitoring is essential to prevent complications such as hypotension and organ hypoperfusion associated with impaired venous return.