Final answer:
Medical records indicating a deteriorating condition in an anorexia nervosa patient include QT prolongation, hematemesis, temperature issues, laxative abuse, and decreasing BMI.
Step-by-step explanation:
Indicators from a client's medical record that suggest their condition of anorexia nervosa is deteriorating include QT prolongation, hematemesis, temperature abnormalities, excessive laxative use, and a declining Body Mass Index (BMI). QT prolongation is a sign of potential heart issues which can be exacerbated by malnutrition.
Hematemesis, the vomiting of blood, can indicate severe gastrointestinal damage due to anorexia or the excessive use of laxatives or vomiting to control weight. Abnormal body temperature may reflect the body's inability to regulate heat due to a lack of insulating body fat and muscle mass. Excessive laxative use is symptomatic of ongoing efforts to lose weight and can lead to severe electrolyte imbalances and dehydration. A declining BMI below already dangerous levels signifies continued weight loss and is directly related to the severity of anorexia nervosa.