Hypoglycemia: classification, causes and mechanism of development, symptoms, methods of diagnosis, treatment and prevention
Hypoglycemia is a pathological condition characterized by a decrease in plasma glucose concentration below 2.8 mmol / l, occurring with certain clinical symptoms, or less than 2.2 mmol / l, regardless of the presence or absence of clinical signs. A condition in which hypoglycemia is accompanied by loss of consciousness is called hypoglycemic coma .
Classification of hypoglycemia
It is customary to distinguish two forms of hypoglycemia , differing from each other in the severity of the condition.
1. Mild hypoglycemia – in this condition, the patient, regardless of the severity of clinical symptoms, can correct the hypoglycemic state on his own by ingesting carbohydrate foods.
2. Severe hypoglycemia is accompanied by impaired consciousness, including loss of consciousness. In this case, the patient needs outside help.
Causes and mechanism of hypoglycemia development
Experts associate the occurrence of a hypoglycemic state with a number of reasons, for example, with a failure in the conduct of therapy that normalizes sugar levels, with dietary habits, as well as with an increase in muscle loads.
Hypoglycemia associated with glucose-normalizing therapy can occur in the following situations.
Overdose of insulin and medications that lower blood glucose levels. This can happen as a result of a doctor’s mistake, if he selected an overestimated dose of drugs, or because of a patient’s mistake, which may consist in an incorrect set of insulin doses, self-increase in the dose of antihyperglycemic drugs, lack of control over glucose levels, or a malfunction of the glucometer. There may also be a case of deliberate overdose of drugs that lower sugar levels by the patient with the aim of suicide or manipulating others.
Violation during hypoglycemic therapy can also occur when the pharmacokinetic properties of insulin and other drugs that lower glucose levels change , which can develop due to a slowdown in their excretion from the body in the presence of renal or hepatic insufficiency, as well as the production of antibodies to insulin, and as a result of a violation insulin injection techniques (incorrect choice of the injection site and injection depth, exposure to high temperatures).
An increase in insulin sensitivity as a result of prolonged physical activity and in the early postpartum period also leads to a failure in the use of drugs that lower sugar levels and the development of hypoglycemia.
Hypoglycemia also develops with errors in the diet and diet . The occurrence of a hypoglycemic state can be associated with skipping food intake, and with an insufficient amount of carbohydrates in the diet, which a person especially needs during physical exertion. Drinking alcoholic beverages, fasting, intentional weight loss can also cause hypoglycemia.
In patients with autonomic neuropathy, the development of hypoglycemia is associated with a slowdown in the movement of food from the stomach into the intestine , followed by its processing.
In patients with gastric resection, an alimentary form of hypoglycemia is observed, resulting from accelerated absorption of glucose , which leads to stimulation of the production of the hormone insulin, a large amount of which leads to rapid processing of glucose and a decrease in blood sugar levels. Alimentary hypoglycemia can develop for no apparent reason, in this case it is called idiopathic alimentary hypoglycemia.
The development of a hypoglycemic state can be provoked by neoplasms of islet cells of the pancreas – insulinomas, which produce a large amount of the hormone insulin.
Maintaining the balance of glucose in the human body is achieved through mechanisms such as glycogenolysis and gluconeogenesis, as well as through inhibition of glucose utilization by insulin-dependent tissues. The activation of these processes occurs due to hormones – glucagon, catecholamines, cortisol, growth hormone – which are insulin antagonists.
Their production increases with a decrease in the concentration of glucose in the blood to 3.8 mmol / l. If the glucose level drops to 2.7 mmol / L, the patient will experience symptoms of insufficient supply to the brain.
In patients with a short history of diabetes mellitus, the counter-regulation system functions similar to that of healthy people, however, with a prolonged course of the disease, its functioning is impaired, which manifests itself at first by a decrease in the production of glucagon, and then – in adrenaline. Such shifts dramatically increase the risk of developing a severe hypoglycemic condition.
Symptoms of hypoglycemia
The clinical manifestations of hypoglycemia consist of a number of symptoms, which are grouped into the category of general disorders, autonomic or neurogenic, neurological or neuroglycopenic, metabolic.
Symptoms of a general nature and neurogenic signs appear already with a decrease in glucose levels to 3.3 – 3 mmol / l. Patients, as a rule, complain of increased heart rate, increased nervousness and anxiety, increased sweating, hunger, burning sensation in the epigastric region. On examination, you can reveal pallor of the skin, trembling of the hands, impaired sensitivity.
Neuroglycopenic symptoms indicating an energy deficiency in the brain are complaints of patients about weakness, increased fatigue, decreased concentration, headaches and dizziness. Patients and their immediate environment may also note violations of the organs of vision and speech, changes in behavior, convulsions.
With a sharp decrease in blood glucose levels, a severe complication develops – hypoglycemic coma, characterized by loss of consciousness and lack of sensitivity to various stimuli.
Signs of hypoglycemia do not always appear gradually. Usually signs of the initial stage of hypoglycemia are severe hunger, hand tremors, sweating, tachycardia, irritability, feelings of aggression and fear. If these signs are eliminated in a timely manner by eating foods containing easily digestible carbohydrates, the process can turn without a trace. However, in the case of untimely relief of this condition, it is aggravated by the addition of such neurological signs as double vision, loss of the ability to orientate, hallucinations. The condition of the patients is similar to the picture of deep alcoholic intoxication or a hysterical reaction. In the absence of correction of the hypoglycemic state at this stage, the condition of patients is usually aggravated by an increase in the agitated state, the appearance of vomiting, the appearance of clonic and tonic seizures, clouding and loss of consciousness, followed by the onset of coma.
Patients with a long history of decompensated diabetes mellitus can observe the above symptoms of hypoglycemia with a blood glucose level of 5-7 mmol / l. This is the so-called false hypoglycemia. That is why, to confirm the diagnosis, one cannot rely only on clinical signs, laboratory data are needed that can confirm the falsehood or truth of hypoglycemia.
Methods for the diagnosis of hypoglycemia
Diagnosis of hypoglycemia consists of anamnestic data, the results of a physical examination, as well as laboratory and instrumental research methods. When examining a patient with hypoglycemia, moisture and pallor of the skin, an increase in heart rate, a decrease in blood pressure, and tremors of the extremities are usually noted.
When examining the level of glucose in the blood, hypoglycemia is diagnosed if the glucose concentration decreases to figures less than 2.8 mmol / l against the background of severe clinical symptoms, or below 2.2 mmol / l, regardless of the presence of clinical signs.
Instrumental research methods are resorted to in case of impaired consciousness and the development of a coma. For this purpose, electrocardiography is used, which makes it possible to exclude myocardial infarction and other pathological processes in the heart, magnetic resonance imaging or computed tomography, which helps to identify signs of traumatic brain injury and neoplasms in the brain and other organs.
Depending on the severity of the hypoglycemic state, they resort to non-drug therapy or treatment with medication.
In the case of mild hypoglycemia, it is possible for the patient to self-relieve its symptoms. To do this, it is enough to drink a glass of tea or water, with four teaspoons of sugar dissolved in them, or a glass of fruit juice, lemonade. It is not recommended to correct hypoglycemia with chocolate, pastry baked goods, cheese, sausage, since the fats contained in these products slow down the absorption of carbohydrates.
In case of impaired consciousness, indicating severe hypoglycemia, ingestion of carbohydrate foods inside is contraindicated. The patient is placed on his side, the oral cavity is freed from food debris and up to 100 ml of a 40% glucose solution is injected intravenously in a stream until consciousness is fully restored. Lack of consciousness after this manipulation serves as an indication for immediate hospitalization with simultaneous intravenous drip of 5-10% glucose solution. Before the arrival of emergency care, intramuscular or subcutaneous administration of 1 mg of glucagon is recommended, which allows you to restore consciousness within a short time. However, it should be remembered that glucagon is ineffective in hypoglycemia caused by excessive alcohol consumption and insulin overdose.
As soon as the patient’s consciousness is restored, easily digestible carbohydrates should be ingested to restore glycogen stores in the liver.
In the case of the development of hypoglycemic coma due to an overdose of hypoglycemic drugs of prolonged action, the drip administration of a 5-10% glucose solution is continued until the normal concentration of glucose in the blood is reached.
After normalizing the concentration of glucose in the blood, it is necessary to find out the cause of the hypoglycemic state, to correct the therapy that affects the level of sugar in the blood, diet and physical activity.
Prevention of hypoglycemia
It is necessary to inform and educate patients with diabetes mellitus on the self-recognition and relief of symptoms of hypoglycemia, adjustment of insulin doses and proper nutrition during exercise.
The patient should have easily digestible carbohydrates with him, which should be taken with unplanned physical activity in the amount of 1-2 XE. If the patient notes the appearance of signs of hypoglycemia, one should immediately stop physical activity and take easily digestible carbohydrates in the amount of 2 XE.
It is necessary to train a patient with diabetes mellitus to independently adjust insulin doses or calculate the amount of required carbohydrates, depending on the mode of physical activity, alcohol intake and other conditions in which there is a decrease in blood sugar levels.