Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNK) Management

Initial Assessment

The American Diabetes Association recommends that patients with blood glucose levels of 600 mg/dl should be evaluated immediately to rule out HHNK and treated promptly with fluid and insulin therapy 1, 2
Initial assessment should include evaluation of clinical status, such as degree of dehydration, level of consciousness, vital signs, and respiratory status 3
Laboratory tests that should be performed immediately include arterial blood gas, complete blood count, electrolyte panel, blood glucose, urea, creatinine, and urinalysis for ketones 3
Effective osmolality should be calculated using the formula: 2[Na+ (mEq/l)] + glucose (mg/dl)/18 3
Identifying precipitating factors such as infection, non-compliance with medication, trauma, myocardial infarction, or stroke is crucial 3, 4

The American Diabetes Association recommends starting fluid replacement with 0.9% NaCl at a rate of 15-20 ml/kg/hour in the first hour 3
The goal is to replace the estimated fluid deficit over 24 hours, with a decrease in osmolality of no more than 3 mOsm/kg/hour 3
Insulin therapy should be started with a continuous intravenous infusion of regular insulin at a dose of 0.1 units/kg/hour after excluding hypokalemia (K+ <3.3 mEq/l) 3
If blood glucose does not decrease by at least 50 mg/dl in the first hour, the insulin dose can be doubled every hour until a decrease in blood glucose of 50-75 mg/dl/hour is achieved 3

Blood glucose should be monitored every hour during the acute phase 3, 1
Electrolytes, renal function, and level of consciousness should be monitored every 2-4 hours 3, 4
The goal is to achieve a blood glucose level of 180-270 mg/dl within 24 hours 3

When the patient is able to eat, intravenous insulin can be switched to subcutaneous insulin 3, 2
The initial dose of subcutaneous insulin should be 60-80% of the total daily dose of intravenous insulin 5
For newly diagnosed patients with type 2 diabetes, metformin can be started when the acute condition has stabilized 2, 6

Watch for signs of cerebral edema if glucose falls too rapidly, as recommended by The Lancet Diabetes and Endocrinology 7
Transition from IV to subcutaneous insulin once the patient is stable with blood glucose <300 mg/dL and able to eat, as suggested by The Lancet Diabetes and Endocrinology 7, 8
Implement a basal-bolus insulin regimen with once-daily basal insulin and rapid-acting insulin with each meal at a total dose of 0.3-0.5 units/kg, split 50/50 between basal and bolus insulin, as recommended by The Lancet Diabetes and Endocrinology and Journal for ImmunoTherapy of Cancer 7, 9
For critically ill patients, maintain blood glucose between 140-180 mg/dL once insulin therapy is initiated, as recommended by Diabetes Care 10
Ensure follow-up with endocrinology or primary care within 1-2 weeks of discharge, as suggested by The Lancet Diabetes and Endocrinology 7
Emphasize that persistent blood glucose readings above 300 mg/dL require immediate medical attention, as recommended by Journal for ImmunoTherapy of Cancer 9