What Is the Pathophysiology of Diabetic Ketoacidosis?

Diabetic ketoacidosis (DKA) refers to the diabetic ketoacidosis, due to various causes, the insulin is significantly insufficient, the glucogenic hormones are not properly raised, resulting in hyperglycemia, hyperketones, ketonuria, dehydration, electrolyte disorders, metabolic Symptoms of pathological changes such as acidosis are one of the most common medical emergencies.

Basic Information

Causes of diabetic ketoacidosis

The main causes of DKA are infection, improper diet or treatment, and various stress factors. For patients with type 1 diabetes who have not been treated and whose disease has progressed rapidly, especially children or adolescents, DKA can be seen as the first symptom.

Acute infection

Is an important cause of DKA, including respiratory, urinary and skin infections are common, and the incidence is higher in winter and spring. Acute infection is also a comorbidity of DKA, which is a cause and effect of DKA, forming a vicious circle, and increasing the complexity of diagnosis and treatment.

2. Improper treatment

Such as discontinuation of medication (especially insulin) treatment, insufficient dose and resistance development. Especially in patients with type 1 diabetes, discontinuation or reduction of insulin treatment doses can often cause DKA. Patients with type 2 diabetes take a large amount of phenformin for a long period of time, especially when the liver and kidney function is poor, DKA can be induced; there are also reports of high-dose thiazide diuretics. In recent years, some patients believe that there is no effective treatment or "medicine" for effective treatment, and they have abandoned the scientifically accepted formal treatment plan, especially for patients with type 1 diabetes, and even discontinued insulin, which is more likely to induce DKA.

3. Uncontrolled diet and / or gastrointestinal disorders

Such as excessive diet, too sweet (too much sugar) or inadequate, alcoholism, or vomiting, diarrhea, etc., can aggravate metabolic disorders and induce DKA.

4. Other stress

Conditions such as severe trauma, anesthesia, surgery, pregnancy, childbirth, mental stimulation, and myocardial infarction or cerebrovascular accident. Elevated levels of glycemic hormone caused by stress, increased excitability of the sympathetic nervous system, and eating disorders can easily induce ketoacidosis.

Clinical manifestations of diabetic ketoacidosis

Ketoacidosis can be divided into mild, moderate and severe cases according to the degree. Mild actually refers to simple ketosis without acidosis; those with mild to moderate acidosis can be classified as moderate; severe refers to those with ketosis and coma, or carbon dioxide binding power without coma Below 10 mmol / L, the latter can easily enter a coma. Clinically, heavier DKA can have the following clinical manifestations:

1. Exacerbation of diabetes symptoms and gastrointestinal symptoms

During the DKA compensatory period, the patient presented with symptoms of diabetic symptoms such as polyuria, thirst, etc., with obvious weakness and weight loss; as the DKA progressed, he gradually lost appetite, nausea, vomiting, and even could not eat or drink. A small number of patients, especially children with type 1 diabetes, may have extensive acute abdominal pain, with abdominal muscle tension and weakened bowel sounds, which is easily misdiagnosed as acute abdomen. The cause is unknown, and may be related to dehydration, dilated gastrointestinal tract caused by hypokalemia, or paralytic intestinal obstruction. It should be noted or caused by the rare acute primary intra-abdominal disease that induces DKA. If it is not the latter, abdominal pain can be relieved by correcting the metabolic disorder.

2. Acidosis, big breath and keto odor

It is also known as Kussmaul respiration, which manifests as increased breathing frequency and deep breathing. It is caused by acidosis. It may occur when the blood pH is less than 7.2 to expel acid. When the blood pH is less than 7.0, the respiratory center may be inhibited. Respiratory paralysis. Severe DKA, some patients may have a rotten apple-like ketone odor in the breath.

3. Dehydration and / or shock

Patients with moderate to severe DKA often have signs and symptoms of dehydration. Hyperglycemia leads to a large amount of osmotic diuresis, and a large amount of Na in the extracellular fluid is excreted during acidosis, which makes dehydration into the water worse. When the amount of dehydration reaches 5% of the body weight, the patient may have signs of dehydration, such as dry skin, lack of elasticity, depression of the eyes and cheeks, low eye pressure, dry and red tongue. If the amount of dehydration exceeds 15% of body weight, there may be circulatory failure. Symptoms include increased heart rate, weak pulse, decreased blood pressure and body temperature, and severe cases can be life-threatening.

4. Disorder of consciousness

The clinical manifestations of disorders of consciousness vary greatly from individual to individual. The early manifestations are lack of energy, dizziness, headache, then irritability or drowsiness, and gradually go into drowsiness, and various reflections from dull and even disappear, eventually into a coma. The cause of the disturbance of consciousness has not yet been elucidated. Severe dehydration, increased plasma osmotic pressure, dehydration of brain cells and hypoxia have adverse effects on the function of brain tissues; it is believed that excessively high concentrations of ketone bodies in the blood, especially acetoacetate, may be closely related to the production of coma, and -hydroxy Excessive accumulation of butyric acid is an important factor leading to acidosis, while acetone is mostly excreted from the breath and is less toxic.

5. Induced disease manifestations

Each induced disease has its own special manifestations, and attention should be paid to avoid confusion or concealment with DKA and delay diagnosis and treatment.

Diabetic ketoacidosis test

Blood sugar and urine sugar are too high. Blood sugar is mostly 16.7 to 33.3 mmol / L, sometimes it can reach 55 mmol / L or more. Blood ketone body is> 4mmol / L. Urinary ketone body was positive. Acetone has no renal threshold. If there are too many ketone bodies and renal function is not impaired, although urinary ketones are positive, blood ketones are not high, and clinically, there is no ketoneemia. Renal function is mostly reduced in diabetic ketoacidosis. Plasma CO ₂ binding power is reduced by 30% by volume, or below 90%, and plasma pH is 16.

Diagnosis of diabetic ketoacidosis

The diagnosis of diabetic ketoacidosis is not difficult, and routine blood and urine tests can provide sufficient diagnostic evidence.

Treatment of diabetic ketoacidosis

The treatment principles of diabetic ketoacidosis include the removal of predisposing factors (such as infections), physiological saline supplementation, small-dose intravenous drip of insulin, potassium supplementation, etc. Patients with severe acidosis should be appropriately supplemented with basic drugs. If the patient is very likely to have ketosis or ketoacidosis, but it is too late to seek treatment, he should immediately adopt some simple methods, such as giving the patient more water, including drinking saline (1000 ml of water plus 9 grams of salt), every 2 to 3 hours deep intramuscular injection of 10 to 20 units of short-acting insulin, etc., and try to send to the hospital for treatment in time. Diabetic ketoacidosis has a tendency to recur, so after ketosis or ketoacidosis is corrected, patients should be vigilant about their incentives, adhere to the correct treatment method, treat early and effectively when infection occurs, and adjust insulin and other hypoglycemia in time The dose of the drug to prevent the recurrence of diabetic ketoacidosis.