Initial treatment generally consists of intravenous fluids to manage dehydration, intravenous insulin in those with significant ketones, low molecular weight heparin to decrease the risk of blood clotting, and antibiotics among those in whom there are concerns of infection.[3] The goal is a slow decline in blood sugar levels.[3]Potassium replacement is often required as the metabolic problems are corrected.[3] Efforts to prevent diabetic foot ulcers are also important.[3] It typically takes a few days for the person to return to baseline.[3]
While the exact frequency of the condition is unknown, it is relatively common.[2][4] Older people are most commonly affected.[4] The risk of death among those affected is about 15%.[4] It was first described in the 1880s.[4]
Cranial imaging is not used for diagnosis of this condition. However, if an MRI is performed, it may show cortical restricted diffusion with unusual characteristics of reversible T2 hypointensity in the subcortical white matter.[10]
Differential diagnosis
The major differential diagnosis is diabetic ketoacidosis (DKA). In contrast to DKA, serum glucose levels in HHS are extremely high, usually greater than 40-50 mmol/L (600 mg/dL).[6]Metabolic acidosis is absent or mild.[6]A temporary state of confusion (delirium) is also more common in HHS than DKA. HHS also tends to affect older people more. DKA may have fruity breath, and rapid and deep breathing.[6]
DKA often has serum glucose level greater than 300 mg/dL (HHS is >600 mg/dL).[6] DKA usually occurs in type 1 diabetics whereas HHS is more common in type 2 diabetics.[6] DKA is characterized by a rapid onset, and HHS occurs gradually over a few days.[6] DKA also is characterized by ketosis due to the breakdown of fat for energy.[6]
Both DKA and HHS may show symptoms of dehydration, increased thirst, increased urination, increased hunger, weight loss, nausea, vomiting, abdominal pain, blurred vision, headaches, weakness, and low blood pressure with standing.[6]
Management
Phases and timelines
The JBDS HHS care pathway[11] comprises 3 main themes to consider when managing a patient with HHS:
clinical assessment and monitoring
interventions
assessments and prevention of harm
To streamline management, there are 5 phases of therapy from the time of recognition of the condition to resolution:
Treatment of HHS begins with reestablishing tissue perfusion using intravenous fluids. People with HHS can be dehydrated by 8 to 12 liters. Attempts to correct this usually take place over 24 hours with initial rates of normal saline often in the range of 1 L/h for the first few hours or until the condition stabilizes.[12]
Electrolyte replacement
Potassium replacement is often required as the metabolic problems are corrected.[3] It is generally replaced at a rate 10 mEq per hour as long as there is adequate urinary output.[13]
Insulin
Insulin is given to reduce blood glucose concentration; however, as it also causes the movement of potassium into cells, serum potassium levels must be sufficiently high or dangerously low blood potassium levels may result. Once potassium levels have been verified to be greater than 3.3 mEq/L, then an insulin infusion of 0.1 units/kg/hr is started.[14] The goal for resolution is a blood glucose of less than 200 mg/dL.[6]