Hyperglycemic hyperosmolar coma

Hyperglycemic hyperosmolar coma (HHC), also known as hyperosmolar nonketotic coma (HONK), is a serious and life-threatening complication of diabetes mellitus. It is characterized by extremely high blood sugar levels, extreme dehydration, and increased osmolarity of the blood, without significant ketoacidosis. HHC is most commonly seen in individuals with type 2 diabetes, especially older adults, but it can occur in type 1 diabetes under certain circumstances.

Causes and Risk Factors

The primary cause of HHC is a significant rise in blood sugar levels, which leads to a cascade of effects. Factors that can precipitate this condition include infections, medications that increase blood sugar (such as steroids), inadequate diabetes management, and certain medical conditions. Poor fluid intake plays a critical role in the development of dehydration and subsequent hyperosmolarity.

Symptoms

Symptoms of HHC include extreme thirst, frequent urination, confusion, drowsiness, and in severe cases, coma. Due to the insidious onset of symptoms, the condition may progress significantly before it is recognized.

Diagnosis

Diagnosis of HHC involves a combination of clinical assessment and laboratory tests. Key diagnostic criteria include very high blood glucose levels (often >600 mg/dL), increased serum osmolarity, and the absence of significant ketoacidosis. Blood tests will also reveal elevated levels of sodium and potassium due to dehydration.

Treatment

Treatment of HHC requires immediate medical attention and typically involves aggressive fluid replacement, insulin therapy to lower blood sugar levels, and correction of electrolyte imbalances. Monitoring and support of vital functions are also critical. The treatment aims to gradually normalize blood sugar levels to avoid the risk of cerebral edema, a potential complication of rapid changes in osmolarity.

Prevention

Prevention of HHC involves effective management of diabetes, including regular monitoring of blood sugar levels, proper medication management, and lifestyle modifications such as diet and exercise. Education on the importance of adequate fluid intake, especially during illnesses or conditions that increase the risk of dehydration, is also crucial.

Complications

If not treated promptly, HHC can lead to severe complications, including seizures, renal failure, myocardial infarction, and death. The condition requires careful management to avoid these outcomes.

Prognosis

The prognosis of HHC depends on the timeliness and effectiveness of treatment. With prompt and appropriate management, individuals can recover from HHC. However, delays in treatment can result in permanent damage or death.