['To describe the outcome of intensive care unit (ICU) patients admitted with a hyperglycaemic hyperosmolar non-ketotic syndrome (HHNS), with a specific analysis of precipitating conditions and complications including lower limb ischemia.', 'Retrospective review of patients admitted in a university-hospital ICU for HHNS.', 'Seventeen consecutive patients (9F/8M, age: 75 years [57-81] (median [25-75% percentiles], Glasgow Coma score: 13 [12-14]) were admitted for HHNS over an 8-year period (1998-2005). On admission, the blood glucose level was 40.0 mmol/l [26.3-60.8], the corrected serum sodium concentration 167 mmol/l [158-174], and the calculated plasma osmolarity 384 mosmol/l [365-405]. All the patients presented with renal failure due to severe dehydration. An infection was identified as the precipitating factor in 8/17 cases. Three (18%) patients died in the ICU. Non-survivors were significantly older than survivors (P=0.02). Using univariate analysis, no other parameter measured on admission was related to mortality. Four patients (24%) presented with lower limb ischemia. They had a significantly more elevated blood urea nitrogen (P=0.03), creatinine phosphokinase level (P=0.04), and leukocyte count (P=0.02). The bilateral, symmetrical, and distal extremity involvement suggested diminished blood flow due to hyperviscosity, hypotension, vasoconstrictors, or cholesterol emboli rather than a proximal arterial obstruction as causative mechanisms. No patient was treated surgically. Ischemia reversed with fluid loading and resulted in toe dry digital necrosis.'] Is acute lower limb ischemia a frequent complication of severe diabetic hyperosmolarity?