Hyperosmolar nonketotic diabetic coma in the elderly

Introduction to hyperosmolar nonketotic diabetic coma in the elderly Hyperosmotic nonketotic diabetic coma (hyperosmotic nonketotic diabetic syndrome), hyperosmolar nonketotic diabetic coma is a serious acute complication of diabetes, its clinical features are severe hyperglycemia Dehydration, elevated plasma osmotic pressure without obvious ketoacidosis, patients often have disturbance of consciousness or coma. The disease has a high mortality rate, and should be given sufficient vigilance, timely diagnosis and effective treatment. basic knowledge The proportion of the disease: the incidence of this disease in diabetic patients is about 0.04% -0.08% Susceptible people: the elderly Mode of infection: non-infectious Complications: coma shock

Hyperosmolar nonketotic diabetic coma in the elderly

(1) Causes of the disease

1. The cause of extreme high blood sugar

Mainly the result of the following factors working together.

(1) Insufficient insulin supply in the body: may be caused by the increase of the original diabetes or the use of thiazide diuretics or ethenic acid (diuretic acid); it may also be caused by the increase of endogenous catecholamine content, further reducing insulin secretion.

(2) Insulin hypoglycemic effect in the body is weakened: the secretion of insulin antagonistic hormones such as glucocorticoids, catecholamines, glucagon can be increased by infection, trauma, surgery and other stress, antagonizing or inhibiting the action of insulin, and Inhibition of glucose uptake by tissues, the use of glucocorticoids, phenytoin sodium immunosuppressants and other drugs can also weaken the role of insulin.

(3) Increased glucose load in the body: mainly due to increased secretion of cortisol such as cortisol, which leads to increased gluconeogenesis, which is an increase in endogenous glucose load. In addition, it can also be due to high-glucose diet or peritoneal dialysis. A large amount of glucose is introduced into the body, which is an increase in exogenous glucose load.

(4) Others: Due to severe dehydration, thirst central dysfunction, the ability of active drinking water to maintain water balance is reduced, the kidney mediates water, electrolyte balance function is reduced, blood glucose discharge is limited, and blood sugar is extremely elevated.

2. Hypernatremia

Part of hyperosmolar non-ketotic diabetic coma patients have high blood sodium, resulting in hyperosmotic state of extracellular fluid, and then the intracellular fluid is transferred to the extracellular fluid, causing intracellular dehydration, and severe dehydration may occur with hypovolemic shock. Severe intracellular dehydration and hypovolemic shock are the main causes of neurological disorders.

The main reasons for the formation of high blood sodium are:

1 blood volume reduction and stress can increase aldosterone and adrenocortical hormone secretion resulting in high blood sodium.

2 severe dehydration can cause secondary high blood sodium.

3. Severe dehydration and high osmotic pressure of plasma

It is generally believed that the degree of dehydration is directly proportional to the severity of the disease. The average water loss during ketoacidosis is about 7L, and the hyperosmolar non-ketotic diabetes coma can reach 12-14L. Extreme hyperglycemia leads to an increase in urine sugar. Severe hyperosmolar diuresis, hyperosmolar non-ketotic diabetic coma patients often accompanied by cerebrovascular disease and kidney disease, can lead to thirst center is not sensitive, slow response to dehydration caused by dehydration, resulting in reduced water intake and The kidney regulates the dysfunction of water and electrolytes, thereby further aggravating dehydration and causing electrolyte imbalance, resulting in oliguria or urinary closure.

At the same time, due to cerebral circulatory disturbances, the development of hyperosmolar dehydration and disturbance of consciousness is accelerated, and the intake of fluid is less when coma, especially in the case of insulin deficiency, glucose is abnormally slow through the brain cell membrane, thus increasing the osmotic pressure of extracellular fluid, resulting in water Intracellular extracellular transfer, with the development of hypertonic and low-capacity dehydration, plasma concentration, stasis of blood flow and promote cerebral thrombosis and brain softening on the basis of cerebral arteriosclerosis.

Due to osmotic diuresis, water, sodium, potassium and the like are largely lost from the kidneys, especially the loss of water is more than the loss of electrolytes, thus causing hypovolemia and hyperosmotic dehydration, forming dehydration of brain tissue cells, and insufficient blood supply to the brain. Psychotic symptoms further aggravate coma.

4. Mild ketosis or non-ketosis

Hyperosmolar ketosis Diabetes coma Why there are severe hyperglycemia without obvious ketosis, the mechanism may have the following aspects:

(1) Hyperosmolar non-ketotic diabetic coma patients are mostly non-insulin-dependent diabetes mellitus, plasma insulin levels are higher than those with diabetic ketoacidosis, and a certain amount of endogenous insulin cannot cope with sugar metabolism in certain causes such as infection. The need for load, but sufficient to inhibit lipolysis, reduces free fatty acids into the liver and produces ketone bodies, so blood ketones are not significantly elevated.

(2) Hyperglycemia itself has an antagonistic effect on ketone bodies.

(3) Obvious high plasma osmotic pressure can inhibit lipolysis of fat cells, reduce free fatty acids into the liver, and reduce ketone formation in the liver.

(4) Hyperosmolar non-ketotic diabetic coma patients with lower plasma growth hormone levels than diabetic ketoacidosis, lack of growth hormone mobilization of fat decomposition may also be associated with no obvious ketosis.

(5) Some patients with hyperosmolar nonketotic diabetic coma have high levels of plasma free fatty acids, but no ketosis, which may be due to gastrointestinal ketogenic effects in patients.

(two) pathogenesis

The main cause of hyperosmolar nonketotic diabetic coma is insulin deficiency and dehydration. The insulin in patients is absolutely or relatively insufficient. Under various inducements, blood sugar is significantly increased. Severe hyperglycemia and diabetes cause osmotic diuresis, resulting in water. And a large amount of electrolytes are lost from the kidneys. Because patients have active water-removing capacity disorders and varying degrees of renal dysfunction, hyperglycemia dehydration and high plasma osmotic pressure gradually increase, eventually leading to hyperosmolar non-ketotic diabetic coma.

As mentioned above, the basic cause of hyperosmolar nonketotic diabetic coma is absolute or relative deficiency of insulin. Various inducements can further reduce insulin secretion in patients, increase hormone levels against insulin, and significantly increase blood glucose concentration. Blood sugar and diabetes cause osmotic diuresis. At this time, about 50% of the osmotic pressure of urine is maintained by glucose in the urine. Therefore, patients often lose water much more than electrolytes. Hyperosmotic non-ketotic diabetic patients have active drinking water. In order to maintain the body's water balance and renal insufficiency, hyperglycemia and dehydration are severe. Dehydration and hypokalemia can cause the increase of cortisol, catecholamine and glucagon, and on the other hand. It can further inhibit the secretion of insulin, which in turn causes the hyperglycemia state to continue to increase, forming a vicious circle, which eventually leads to the occurrence of hyperosmolar nonketotic diabetic coma.

Hyperosmolar non-ketotic diabetic coma prevention in the elderly

1. Actively control the high blood sugar of diabetes.

2. Take care to avoid predisposing factors, especially various infections and a large amount of sweets and injection of glucose.

3. Always maintain water and electrolyte balance.

4. Protect heart and kidney function.

Hyperosmolar nonketotic diabetic coma complications in the elderly Complications, coma shock

Concurrent coma, shock, cardiovascular and infarction.

Hyperosmolar non-ketotic diabetic coma symptoms in the elderly Common symptoms Polyuria and polydipsia hypotension hyperosmotic coma loss of appetite, weakness, diabetes, facial expression, apathy, circulatory failure, apathy

Precursor period

Hyperosmolar non-ketotic diabetic coma usually begins slowly. In the process of neurological symptoms and coma, it is the prodromal phase. This period ranges from several days to several weeks. Half of the patients have no history of diabetes. Most of them have a history of decreased kidney function, due to fatigue, relaxed diet control, and increased chances of infection. The incidence rate is higher in winter, especially before and after the Spring Festival. The incidence of patients is slow, and the clinical manifestations of diabetes are often aggravated several days before the onset. Thirsty, polydipsia, polyuria, weakness, dizziness, loss of appetite, nausea, vomiting, abdominal pain, etc., unresponsiveness, indifferent expression, the basic cause of these symptoms is due to osmotic diuretic dehydration.

2. Typical period

If the prodromal period is not treated in time, the condition continues to develop. Due to severe water loss, plasma hyperosmosis and blood volume decrease. The patient is mainly characterized by severe dehydration and neurological symptoms.

(1) severe dehydration, often accompanied by circulatory failure: due to the age of the patient, the reserve of water in the body before the onset is poor, coupled with high sugar and diuresis, water intake dysfunction is obvious in patients with dehydration, physical examination shows weight Significantly decreased, dry skin, less sweat and decreased elasticity, eyeball depression, dry tongue and longitudinal cracks. Patients with severe disease may have peripheral circulatory failure, pulse is fine and fast, pulse compression is small, and jugular vein filling in lying position Incomplete, low blood pressure during standing position, even cold limbs, cyanosis in a state of shock, and some due to severe dehydration and oliguria, no urine.

(2) Consciousness and focal central nervous system dysfunction: patients often have different degrees of neurological and psychiatric symptoms, half of patients have conscious disturbances, and about 1/3 of patients are in a coma state. It is generally believed that the presence or absence of consciousness disorder in patients with this disease mainly depends on The rate and degree of increase in plasma osmotic pressure are also related to the level of blood sugar, but have little to do with acidosis. The degree of hypertonic state is serious or rapid, and it is prone to central nervous system dysfunction, except for disturbance of consciousness. In addition, patients often have a variety of focal neurological signs, from apathy, dizziness to coma, in addition to sensory nerves are suppressed and indifferent, dull and even stiff, motor nerves are more involved, common strokes, different Degree of hemiplegia, systemic and focal motor neuronal seizures, including aphasia, hemiplegia, nystagmus and strabismus, as well as focal or systemic seizures, reflexes often disappear or disappear, vestibular dysfunction sometimes has hallucinations, gibberish Language, restlessness, etc., sometimes with severe mental symptoms, sometimes body temperature can rise above 40 ° C, may be central Heat, can also be caused by various infections, often misdiagnosed as encephalitis or meningitis, due to extreme hyperglycemia and high plasma osmotic pressure, blood concentration, increased viscosity, easy to develop venous thrombosis, especially cerebral thrombosis is serious , leading to a higher mortality rate.

According to the clinical manifestations of hyperosmolar coma patients, and the possible predisposing factors, combined with blood glucose, blood sodium and plasma osmotic pressure, a correct diagnosis can be made in time.

Examination of hyperosmolar nonketotic diabetic coma in the elderly

Blood sugar

Extremely elevated, usually 33.3mmol / L (600mg / dl), or even 83.3 ~ 266.7mmol / L (1500 ~ 4800mg / dl).

2. Electrolyte

Serum sodium is often increased to >150mmol / L, but there is also a slight increase or normal, serum potassium can be elevated, normal or decreased, depending on the patient's dehydration and renal dysfunction, and blood volume is less Secondary aldosterone secretion, after insulin and fluid replacement treatment, even if there is hyperkalemia, significant hypokalemia can occur, blood chlorine can be slightly increased.

3. Plasma osmotic pressure 350mmol/L or effective osmotic pressure>320mmol/L (effective osmotic pressure does not include urea nitrogen fraction), calculated according to the formula:

Plasma osmotic pressure (mmol/L) = 2 (sodium + potassium) mmol / L + blood glucose (mmol / L) + urea nitrogen (mmol / L)

Normal range: 280 ~ 300mmol / L.

4. Blood urea nitrogen is usually moderately elevated, up to 28.56 ~ 32.13mmol / L (80 ~ 90mg / dl), serum creatinine is also high, up to 442 ~ 530.4mol / L (5 ~ 6mg / dl), mostly Prerenal (dehydration, circulatory failure), or associated with acute renal insufficiency.

5. Blood routine

White blood cells can also be significantly increased without infection, hematocrit is increased, hemoglobin can be increased, and some patients may have anemia. For example, most patients with normal hematocrit have anemia.

6. Urine routine

Heavier patients may have proteinuria, erythrocyte beta-tube type urine, strong urine sugar, negative or weak positive urine ketone body.

7. Blood carbon dioxide binding

The blood pH is mostly normal or slightly decreased. When combined with ketoacidosis or renal insufficiency, the blood pH is lowered.

8. Blood ketone body

Most of the normal or mild elevation, with ketoacidosis is higher.

9. Other

Plasma growth hormone, cortisol determination was slightly elevated, plasma C-peptide determination content can be reduced, but not as obvious as diabetic ketoacidosis.

Cerebrospinal fluid examination, osmotic pressure and grape content increased.

Diagnosis and diagnosis of hyperosmolar nonketotic diabetic coma in the elderly

Should pay attention to the identification and coexistence of other diseases:

1. Diabetic ketoacidosis

It can coexist with hyperosmolar coma. At this time, not only high blood sugar, high blood sodium and high plasma osmotic pressure, but also high blood ketone, blood pH and CO2 binding force, and strong urinary ketone body.

2. Diabetes lactic acidosis

Hyperosmolar coma is accompanied by 50% of lactic acidosis.

3. Cerebrovascular accident

Generally, diabetic patients with cerebral thrombosis are affected by small arteries, and may have limb dysfunction, but less conscious disturbance and coma.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.