Final answer:
The nurse manager should take action by educating the nurse and aide about the seriousness of pain reports and the subjective nature of pain, and the necessity of using pain assessment tools without prejudice.
Step-by-step explanation:
The appropriate action for the nurse manager upon overhearing a nurse expressing disbelief about a client's reported level of pain after a Caesarean birth is to address the situation promptly and professionally. The nurse manager should remind the nurse and nurse aide of the importance of taking all reports of pain seriously, considering pain as a subjective experience that should be assessed with empathy and without judgment. The nurse manager needs to reinforce the importance of using appropriate pain assessment tools and ensuring that the client's pain management needs are addressed according to best practices.
Moreover, the nurse manager should educate the staff on the potential for biased attitudes toward pain perception and the dangers of labeling patients as 'drug-seeking' without evidence. It's crucial to foster a respectful and caring environment for all patients and to ensure that prejudices do not interfere with the provision of high-quality care. In-service training or a refresher course on pain management could also be considered to improve staff understanding and practice.