Poster Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

Hyperosmolar hyperglycaemic state (HHS) is a life-threatening endocrine emergency. HHS occurs less frequently than diabetic ketoacidosis (DKA) (1), but has a higher mortality (2), with reported mortality rates of 10-50% (3-7). HHS management is largely varied in clinical practice due to a lack of high-quality evidence. This systematic review aims to compare international guidelines and their underlying evidence base in HHS management. MEDLINE, Embase and Emcare databases were searched, and references of relevant papers were reviewed, identifying 363 papers, of which 7 met the inclusion criteria.

The hallmark features of HHS include profound hypovolaemia, extreme hyperglycaemia, and hyperosmolality (7, 8), although specific diagnostic criteria vary among guidelines from glucose ≥33.3mmol/L and osmolality ≥320mOsm/kg (American Diabetes Association [ADA] and Diabetes Canada [DC]) (7, 9) to glucose ≥30.0mmol/L with osmolality ≥320mOsm/kg (Joint British Diabetes Society [JBDS]) (10) (Table 1). There is also significant heterogeneity in HHS management (Figure 1). The ADA and DC guidelines recommend correction of serum osmolality <3mOsm/kg/hr (7, 9), whereas the JBDS accept osmolality change of 3-8mOsm/kg/hr (10). ADA guidelines suggest 0.9% normal saline at 15-20mL/kg/hr or 1-1.5L/hr (7), whereas JBDS guidelines suggest replacing ~50% of the estimated fluid loss within the first 12 hours (10). The ADA and DC guidelines recommend a fixed rate insulin infusion of 0.1units/kg/hr (7, 9). The JBDS guidelines recommend 0.05units/kg/hr, increasing by 1.0units/hr as required (10).

Current HHS guidelines are consensus-based rather than evidence-based because no randomised controlled trials exist. HHS management is largely driven by evidence derived from small studies in patients with DKA, rather than specific HHS trials. Further high-quality prospective studies specific to HHS are required to standardise diagnosis and optimise management.