Psychological reasons:
(1) lack of cooperation with outpatient treatment
(2) poor motivation or insight into seriousness of condition
(3) unable to eat independently
(4) need for nasogastric feeding
(5) marked suicidal ideation or suicidal plan
(6) severe coexisting psychiatric disorder
(7) antitherapeutic or abusive home environment
Metabolic reasons:
(1) bradycardia (pediatric < 50 beats per minute; adult < 40 beats per minute)
(2) hypotension (pediatric < 80/50 mm Hg; adult < 90/60 mm Hg)
(3) symptomatic hypoglycemia (pediatric fasting glucose < 3.0 mmol/L or < 54 mg/dL)
(4) hypokalemia (adult < 3 mmol/L)
(5) rapid weight loss (pediatric any; adult if > several kilograms within a week)
(6) dehydration
(7) failure of outpatient management (lack of improvement or worsening condition)
Additional reasons for adult:
(1) weight < 75% of the expected weight
(2) hypothermia (< 36.1°C or < 97°F)
(3) cardiovascular abnormality other than bradycardia or hypotension
Additional reasons in a pediatric patient:
(1) hypophosphatemia
(2) significant orthostatic hypotension (increase in heart rate > 20 beats per minute or drop in blood pressure > 20 mm Hg)
