Final answer:
The nurse failed to use effective communication by injecting her own negative attitudes and feelings into the Interview, potentially creating a barrier to open and trustful dialogue.
Step-by-step explanation:
The aspect of effective communication that the nurse has disregarded, which will most significantly impact the exchange of information during the interview with the child and his mother, is injecting her own attitudes and feelings into the interview. Making judgmental statements about the child being overweight and criticizing the diet and exercise plan as 'dreadful' and 'appalling' can create a defensive or on-guard environment. This can hamper open communication and trust between the healthcare provider and the patient. Instead, it is important to use respectful language and to be sensitive to the patient's feelings, especially when discussing issues related to health and lifestyle. An effective communication strategy would involve establishing rapport, assurance of privacy and confidentiality, and using a non-judgmental tone to discuss sensitive topics, such as a patient's weight.