Postural tachycardia in psychiatric inpatient eating disorders treatment

Background: Postural tachycardia has been observed as a sign of malnutrition in eating disorders, including anorexia nervosa. However, there is limited information regarding other contributors to postural tachycardia in this population. Aim: This study aimed to determine the following among patients admitted to the Eating Disorders Unit (EDU) at a metropolitan tertiary hospital in Victoria, Australia: (a) the prevalence of postural tachycardia among eating disorder inpatients, and (b) the associated demographic and clinical features. Methods: Retrospective review of patient files was undertaken for inpatients aged 18-65 years with an eating disorder who resided within the Body Image & Eating Disorders Treatment & Recovery Service catchment area and were admitted to EDU between January 01, 2021 and October 30, 2023. Logistics regression was used for statistical analysis. Results: Among 177 admissions, 48 patients had postural tachycardia and this was at least partially attributed to malnutrition in 42 patients. Antipsychotics were significantly positively associated, and for every increase in one antipsychotic medication, there was an 89% increase in postural tachycardia diagnosis likelihood (B = 0.637) (Exp('B')) = 1.890). Higher admission body mass index/weight, emergency medical reviews, ≥ 10 prior psychiatric admissions, and 1-3 prior medical admissions showed significant positive associations. Conclusions: Postural tachycardia is a multifactorial issue which contributes to medical instability and is associated with antipsychotic medications and a history of multiple medical and psychiatric admissions.