Final answer:
The most effective nursing intervention to prevent dehiscence in a postoperative client is preventing vomiting. Vomiting increases abdominal pressure which can cause wound separation, especially after abdominal surgery.
Step-by-step explanation:
To prevent dehiscence in a postoperative client, the nursing intervention most effective is preventing vomiting. Vomiting can increase abdominal pressure, which can lead to wound disruption and dehiscence, particularly in abdominal surgeries. While helping a client lose weight and administering antibiotics can be beneficial for overall health and reducing infection risk, respectively, they do not directly prevent dehiscence. Keeping the wound dry is important, but preventing vomiting is a more direct intervention to avoid the mechanical stress that can lead to wound separation. In addition to preventing vomiting, the nurse should educate the client about proper wound care and the importance of avoiding activities that increase intra-abdominal pressure, such as straining during bowel movements or heavy lifting.