What Is a Hyperosmolar Coma?

Diabetic hypertonic coma (HNDC) is a rare serious acute complication of diabetes. It is more common in elderly patients with no history of diabetes or mild type 2 diabetes, but also in patients with type 1 diabetes. The patient's original insulin secretion was insufficient, and the blood sugar increased sharply under the influence of the inducement. The glucose metabolism disorder was aggravated, causing extracellular fluid to become hypertonic, hypovolemic hypertonic dehydration, and neurological abnormalities (25% -50%) often occurred. Coma).

Basic Information

Visiting department
Endocrinology
Multiple groups
Elderly people without a history of diabetes, mild type 2 diabetes, type 1 diabetes
Common causes
Stress and infection, insufficient water intake, excessive dehydration and dehydration, high sugar intake and input, drug effects, etc.
Common symptoms
Polyuria, polydipsia, thirst, weight loss; drowsiness, hallucinations, disorientation, symptoms of focal neurological impairment and / or epilepsy, etc., finally coma

Causes of hyperosmolar non-ketotic diabetic coma

Stress and infection
Such as cerebrovascular accident, acute myocardial infarction, acute pancreatitis, gastrointestinal bleeding, trauma, surgery, heat stroke or hypothermia. Infections, especially upper respiratory infections, urinary tract infections, etc. are most often induced.
2. Insufficient water intake
Sensitivity of the elderly has decreased central sensitivity to thirst, bedridden patients, patients with mental disorders or coma, and young children who cannot take water actively.
3. Excessive water loss and dehydration
Such as severe vomiting, diarrhea, large-area burn patients, neurological, surgical dehydration treatment and dialysis treatment.
4. High sugar intake and input
Such as a large intake of sugary beverages, high-sugar foods, intravenous infusion of large amounts of glucose when the diagnosis is unknown or missed, complete intravenous hypertrophy, and the use of sugary solutions for hemodialysis or peritoneal dialysis. Especially in patients with certain endocrine diseases combined with glucose metabolism disorders, such as hyperthyroidism, acromegaly, cortisol, and pheochromocytoma are more likely to be induced.
5. Drugs
Many drugs can be incentives, such as heavy use of diuretics such as glucocorticoids, thiazines or furosemide (fast urine), propranolol, phenytoin, chlorpromazine, cimetidine, glycerol, and thiazole Purines and other immunosuppressants can cause or aggravate the body's insulin resistance and increase blood glucose and dehydration. Some drugs, such as thiazide diuretics, can also inhibit insulin secretion and reduce insulin sensitivity, which can induce HNDC.
6. Other
Such as acute and chronic renal failure, diabetic nephropathy, etc., because the glomerular filtration rate is reduced, the clearance of blood glucose is also reduced, which can also be an incentive.

Clinical manifestations of hyperosmolar non-ketotic diabetic coma

Onset is more hidden, often polyuria, drink more, thirst, weight loss, but too much food is not obvious, or the appetite is reduced, so often overlooked. Dehydration gradually increased with the course of the disease, and neuropsychiatric symptoms appeared, including drowsiness, hallucinations, and disorientation. Some patients had focal neurological impairment (hemiplegic or blindness) and / or epilepsy, and finally fell into a coma. He often has significant dehydration and even shock when he comes to the clinic, and has a deep breath without acidosis.

Hypertonic non-ketogenic diabetes coma test

Blood sugar and urine sugar
This disease is characterized by markedly high blood sugar and high urine glucose. Blood glucose was more than 33mmol / L (600mg / dl), and urine glucose was strongly positive. If the patient is severely dehydrated or has renal impairment that raises the renal glucose threshold, urine glucose may not show a strong positive, but urine glucose negative is rare.
Blood electrolytes
In general, normal or elevated blood sodium can also be reduced; normal or decreased blood potassium can also be increased; overall sodium and potassium are reduced. Patients may also lose calcium, magnesium, and phosphorus. The level of blood sodium and potassium of a patient depends on the amount of loss and distribution inside and outside the cell, and the degree of water loss.
3. Blood urea nitrogen and creatinine
Often significantly increased, the extent of which reflects severe dehydration and renal insufficiency. Urea nitrogen (BUN) can reach 21 36mmol / L (60 100mg / dl), creatinine (Cr) can reach 163 600mol / L (1.7 7.5mg / dl), and BUN / Cr ratio can reach 30: 1 or more (Most normal people are between 10: 1 and 20: 1).
4. Plasma osmotic pressure
Significant elevation is an important feature and diagnostic basis of HNDC.
5. Acid-base imbalance
About half of patients have mild or moderate metabolic, high anion gap acidosis. The anion gap increased about 1 time, the blood HCO 3 was more than 15mmol / L, and the pH value was more than 7.3. The increased anions are mainly organic acid groups such as lactic acid and keto acid, but also contain a small amount of sulfuric acid and phosphate.
6. Blood Ketones and Urine Ketones
Serum ketones are usually normal or slightly elevated, and the quantitative determination is usually not more than 50 mg / dl. When measured by the dilution method, there are few people who have a positive reaction when the plasma is diluted to more than 1: 4. Urine ketones are mostly negative or weakly positive.
7. Blood white blood cell count
The white blood cell count of HNDC patients often increases, reaching 50 × 10 / L; the hematocrit increases, reflecting dehydration and blood concentration.
8. Imaging examination
Urine culture, chest X-rays and electrocardiogram were selected according to the condition.

Diagnosis of hypertonic non-ketogenic diabetic coma

1. Symptoms and signs
(1) Most patients with medical history are elderly, and 90% have kidney disease.
(2) The onset is relatively slow, and the symptoms of diabetes (polyuria, polydipsia, and fatigue) are often aggravated, reflecting the gradual increase in blood glucose and plasma osmotic pressure.
(3) Dehydration and peripheral circulation failure Hypertonic hyperglycemia syndrome (HHS) often has severe signs of dehydration, which are manifested by dry skin and mucous membranes, sunken eyes, and a rapid pulse. When severe, it shows a state of shock.
(4) Patients with neuropsychiatric symptoms often have varying degrees of neuropsychiatric symptoms and signs. Half of them are confused and one third are in a coma. The state of consciousness is related to the rate and extent of the increase in plasma osmotic pressure. When the effective plasma osmotic pressure exceeds 350 mmol / L, 40% of patients may have consciousness or coma. In addition to coma, various signs of the nervous system can occur, such as epilepsy, hemiplegia, visual impairment, positive pathological signs, or central fever.
Some patients have high blood glucose, but due to low blood sodium, the effective osmotic pressure does not reach 320mmol / L. Although these patients cannot be diagnosed as HNDC, they should still be treated as HNDC.
2. Laboratory inspection
(1) Hyperglycemia of blood glucose and urine glucose, blood glucose more than 33.3mmol / L, urine glucose is strongly positive.
(2) Blood ketone bodies and urine ketone bodies are mostly negative or weakly positive, but they can be positive when combined with diabetic ketoacidosis (DKA).
(3) The electrolyte blood sodium can be normal, increased or decreased, most of them are> 150mmol / L; the blood potassium can also be normal, increased or decreased. Both sodium and potassium are lost. It should be noted that the reabsorption of sodium by the hypertonic diuretic renal tubules is inhibited, and intracellular water is transferred to the outside of the cells, which reduces blood sodium, and each time blood glucose increases by 5.6mmol / L, blood sodium decreases by about 1.7mmol / L Chylous blood can also reduce the false blood sodium. But at the same time, if hypertonic diuretic dehydration is more than sodium loss, activation of the renin-angiotensin-aldosterone system (RAAS system) can cause sodium retention and possibly increase blood sodium.
(4) Effective plasma osmotic pressure Effective plasma osmotic pressure = 2 (Na + K) + blood glucose (mmol / L), effective plasma osmotic pressure 320mOsm / L is an important diagnostic criterion.
(5) Approximately half of patients with blood gas have AG metabolic metabolic acidosis, usually mild or moderate, pH is generally> 7.3, and blood HCO 3 is more than 15mmol / L.
(6) Blood urea and creatinine Blood urea often increases significantly due to dehydration, which is positively related to the degree of dehydration, and creatinine can also increase several times.

Differential diagnosis of hyperosmolar non-ketotic diabetic coma

Main and DKA differential diagnosis, see the table below for details.
DKA
HHS
blood sugar
More than 16.7mmol / L, generally between 16.7 and 33.3mmol / L
33.3mmol / L
Effective plasma osmotic pressure
Normal or slightly higher
320mOsm / L
Urine test
Urine glucose positive; urine ketone body positive
Urinary glucose-positive; urine ketone body negative
Vitality
Reduce, pH <7.3 or HCO 3 <15mmol / L
Normal or slightly lower, pH7.3 or HCO 3 15mmol / L
Blood sodium
Reduced or normal
Mostly normal or significantly elevated

Treatment of hypertonic non-ketogenic diabetic coma

Fluid replacement
Rehydration is a crucial step and plays a decisive role in prognosis. Patients have more severe fluid loss than DKA, which is estimated to reach one quarter of body fluids or more than one eighth of body weight.
(1) The total amount of fluid replacement is mostly 6-10L. One third of the total amount is replenished within 4 hours after admission, and the total amount is replenished within 24 hours after admission. Due to the large amount of fluid replacement, the gastrointestinal tract should be refilled as much as possible. The gastrointestinal fluid can be boiled water, which can replenish the volume on the one hand and reduce the osmotic pressure on the other. Because the patient's consciousness is usually poor, nasal feeding is usually a necessary method. This method is safe and effective.
(2) Types of fluid replacement In the early stage of treatment, it is recommended to use physiological saline. Although it is an isotonic fluid, it is hypotonic relative to the patient's blood. If combined with shock or insufficient blood volume, consider using colloid fluid to expand the volume while replenishing normal saline. The timing of the use of semi-osmotic solution (0.45% sodium chloride) is still controversial. It is generally believed that this solution can be used when the blood Na> 150mmol / L and no obvious hypotension. Once the blood sugar drops to 13.9mmol / L, use 5% glucose solution or sugar saline, and add insulin in proportion.
2.Insulin
Generally, a continuous low-dose insulin treatment regimen is used. The blood glucose drop rate should not be too fast, and the blood glucose drop too quickly can lead to cerebral edema. Patients can start subcutaneous insulin injection after eating, but should pay attention to check blood glucose after subcutaneous insulin injection. Generally speaking, after hypodermic insulin injection, the hypoglycemic effect of insulin can overlap with intravenous insulin by at least 1 to 2 hours. Those who metabolize quickly. It should be noted that patients with this disease are more sensitive to insulin than diabetic ketoacidosis and may have a higher chance of hypoglycemia.
3. Correct electrolyte disorders
The electrolyte disorders are mainly caused by the loss of sodium and potassium, and the loss of sodium can be corrected by supplementing the liquid containing NaCl. Therefore, the key to correcting the electrolyte disorders is potassium supplementation. At present, potassium chloride is still the main source in China.
4. Correct acidosis
Some patients have acidosis, and if the severity is not serious, the use of alkaline drugs is not considered.
5. Correct the predisposing factors

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