Protein-energy malnutrition

Introduction to protein-energy malnutrition Protein-energy malnutrition (PEM) is a nutritional deficiency caused by insufficient food supply or disease factors. It is clinically manifested as marasmus and mastic dystrophy syndrome (kwashiorkor). Weight loss is due to long-term diet. The lack of heat, protein and other nutrients, or the patient's digestive, absorption and utilization of food caused by obstacles. This type is mainly lack of energy, and has a lack of protein. It is characterized by progressive weight loss, reduction of subcutaneous fat, edema and dysfunction of various organs. Malignant malnutrition is characterized by a lack of protein in the diet, and the supply of heat is still sufficient. Mainly manifested as dystrophic edema, but most patients are somewhere in between, light chronic protein-energy malnutrition is often neglected, it affects the growth and development of children, immune function, easy to get sick and difficult to recover. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific people Mode of infection: non-infectious Complications: nutritional anemia, hypoglycemia, bacterial infection

Protein-energy malnutrition

Insufficient intake (35%):

Famine, war or economic backwardness cause food shortage or imbalance, mental disorders, anorexia nervosa and upper gastrointestinal obstruction and other diseases can not be normal as normal people. This has led to malnutrition.

The body needs to be increased and the supply is insufficient (30%):

More common in infants and young children, pregnant and lactating women, in addition, hyperthyroidism, cancer, tuberculosis, diabetes and other consumptive diseases increase the consumption of various nutrients in the body, if the lack of supplementation can also occur protein-energy malnutrition.

Digestive malabsorption (25%):

Stubborn and long-term vomiting, diarrhea and digestive dysfunction associated with other diseases.

Pathogenesis

The occurrence of protein-energy malnutrition is a complex pathophysiological process. When the protein and energy supply in food is insufficient, the body begins to reduce the nutrient requirements of tissues and organs through physiological regulation, and the body can survive in a low-nutrient environment. However, when protein and energy continue to be deficient, physiological dysfunction and failure of the adaptation mechanism can lead to death.

1. Protein metabolism: When protein and energy supply are insufficient, the protein content in plasma decreases, and the rate of protein synthesis and decomposition slows down.

Albumin: The content of the body bank is reduced, mainly in the extravascular part, and the rate of decomposition and synthesis decreases. When serum albumin drops to 30g/L, other substances in the body such as lipoprotein, alanine and proline are apparent. change.

Globulin: The concentration in plasma and the distribution in the body are not significantly changed, but plasma ferritin is significantly decreased.

In vivo protein conversion rate: Although the degree of protein deficiency in various tissues and organs in the body is different, the rate of synthesis and decomposition changes. Generally, after 5 to 6 weeks from the start of protein deficiency, the conversion rate is reduced by 30%, and high protein feed is supplied during animal experiments. 23% of the amino acids are converted to urea excreted, but when the protein is insufficient, only 3.4% of the amino acids are converted into urea, and the amount of nitrogen is reduced.

2. Amino acid metabolism: In severe protein-energy malnutrition, the concentration of amino acids in plasma can be reduced to 1/2 of normal, especially branched-chain amino acids and threonine, and valine-type proline can be reduced to 30 mol. /L (250mol/L in normal children), the concentration of alanine in the plasma before edema may be due to increased gluconeogenesis or decreased urea production, and later alanine as a glucose-forming substance However, when used, the concentration in plasma decreased, and the ratio of phenylalanine to tyrosine also decreased in late protein-energy malnutrition.

3. Carbohydrate metabolism: When protein-energy malnutrition, blood sugar is generally reduced, lean type is more obvious than edema type, and gluconeogenesis is strengthened. Studies have shown that 8% of children with malnutrition are derived from protein decomposition products. The recovery period can be increased to 16%.

4. Lipid metabolism: protein-energy malnutrition often complicated with fatty liver, triglyceride, cholesterol, -lipoprotein content in normal or slightly increased blood, triglyceride, cholesterol, - in edema blood The content of lipoproteins is normal or slightly lower.

5. Body fluids and minerals: protein-energy malnutrition, whether it is thin or edematous, with fluid retention, edema, extravascular extracorporeal fluid space expansion is the main cause of increased body fluids, degree of edema and hypoalbuminemia Related to the mechanism of edema can be seen in Figure 1, protein-energy malnutrition, the overall potassium content and magnesium content decreased, sodium content increased.

Protein-energy malnutrition is divided into the following three types: 1 severe protein deficiency (kwashiorkor), heat is mainly supplied by carbohydrates; 2 severe energy intake (marasmus), also known as leanness and weakness; 3 mixed type (kwashiorkor marasmus), "kwashiorkor" is a transliteration of Ghanaian in Africa. It is translated as "red child". The hair and skin of the sick child are often red, which is caused by the serious shortage of protein and essential amino acids in the food, which causes the hair to turn from black to gray or Red, rough skin, Kwashiorkor is also known as malignant malnutrition syndrome.

Protein-energy malnutrition prevention

Active prevention, infants should be breast-fed in 6-7 months, add complementary foods on time, diversify their diet, give high-calorie, high-protein, vitamin-rich foods, and actively treat various chronic diseases. And gastrointestinal disorders to prevent the occurrence of various diseases.

Protein-energy malnutrition complications Complications, nutritional anemia, hypoglycemia, bacterial infection

(1) Nutritional anemia, which is most common in small cell hypochromic anemia. Anemia is associated with the lack of iron, folic acid, vitamin B12, protein and other hematopoietic materials.

(2) Micronutrient deficiency Malnutrition can have multiple vitamin deficiency, especially fat-soluble vitamin A, D deficiency is common. In the case of malnutrition, the symptoms of vitamin D deficiency are not obvious, and the symptoms are more prominent when the growth and development of the recovery period is accelerated. About 3/4 of the sick children are associated with zinc deficiency.

(3) infection due to low immune function, it is susceptible to various infections, such as repeated respiratory infections, thrush, pneumonia, tuberculosis, otitis media, urinary tract infections; infant diarrhea often prolonged unhealed malnutrition, forming a vicious circle.

(4) children with spontaneous hypoglycemia may suddenly appear pale, unconscious, slow pulse, apnea, body temperature does not rise, but generally no convulsions, if not treated promptly, can cause death due to respiratory paralysis.

Protein-energy malnutrition symptoms Common symptoms Ascites expression apathy diarrhea cheek depression is monkey sputum irritability septicemia skin elasticity poor response

First, the clinical manifestations of protein-energy malnutrition vary according to individual differences, severity, time of onset, etc. Clinical symptoms include weight loss and reduction, subcutaneous fat reduction and disappearance, and varying degrees of dysfunction in various organ systems throughout the body. Clinically, it is generally divided into marasmus, edema type (kwashiorkor) and mixed type (marasmickwashiorkor) type 3. It is light, medium and heavy according to the degree of nutritional deficiency. It can be divided into acute, subacute and chronic according to the pathogenesis. 3 types.

1. Weight loss type: Due to the serious lack of energy, it is characterized by weight loss, subcutaneous fat disappearance, dry and slack skin and loss of elasticity and luster. Those who are severely thin are "skin and bones".

Hair is yellow and sparse, easy to fall off, cheek depression is monkey-like, patients are weak, weak, weak pulse, blood pressure, hypothermia, visceral organs atrophy, lymph nodes are easy to reach, children are obviously small, irritated, cold Sensitive, severe cases with diarrhea, vomiting, and can lead to dehydration, acidosis and electrolyte imbalance, often the cause of death.

2. Edema type: due to severe protein deficiency, characterized by systemic edema, edema is first seen in the lower limbs, the back of the foot, gradually and the whole body, the patient is soft and weak, the expression is indifferent, the appetite is diminished, often accompanied by diarrhea, hepatosplenomegaly Ascites, severe edema type can be complicated by bronchial pneumonia, pulmonary edema, sepsis, gastrointestinal infections and electrolyte imbalance, often the cause of death.

3. Hybrid: Most patients have a lack of protein and energy, so the clinical manifestation is a mixture of the above two types.

Second, due to the different clinical types of protein-energy malnutrition, it is difficult to diagnose mild, moderate and chronic malnutrition, so comprehensive diagnosis is needed.

1. Medical history: According to the dietary situation, understand the history of inadequate food intake and the history of diseases affecting the body's digestion and absorption.

2. Clinical manifestations:

(1) Symptoms: There are no obvious symptoms in the early stage, only the appetite is poor, the child's height, the weight is slightly lower than normal, the condition continues to develop, the digestive function may decrease, the respiratory tract infection may occur, and the severe malnutrition may be thin, refused to eat. The expression is indifferent, unresponsive, often accompanied by multiple vitamin deficiency and various complications such as angular cheilitis, corneal softening, purpura, etc., and finally into the systemic edema and inhibition state.

(2) Signs:

1 Weight: Protein-energy malnutrition affects children's growth and development, weight loss, Gomez et al. have suggested that: I degree malnutrition is 75% to 90% of the standard weight, and II degree malnutrition is 60% of the standard weight. 75%, III degree malnutrition <60%, has diagnostic significance.

2 Height: During childhood, the height of the child rises linearly, and the increase of protein-energy malnutrition continues to slow down. Generally, it is compared with the average height of the region. It has a diagnostic value. The height is X±2S~X±S. The lower finger height is less than X±2S, but it is necessary to pay attention to the comprehensive analysis. Because the height is normal, protein-energy malnutrition can also occur; otherwise, the short stature is not all malnourished.

Protein-energy malnutrition check

1. Plasma albumin: normal value > 35g / L, 30 ~ 34g / L when the nutritional status is low, 25 ~ 25g / L when the nutrition is low; when the plasma albumin <25g / L, the body has obvious pathology Variety.

2. Transferrin: The half-life of serum transferrin in the body is 8-10 days, which is shorter than albumin (about 20 days), so the nutritional status is more sensitive than albumin, and the normal value is 1.7-2.5g/L. Degree malnutrition was 1.0 to 1.5 g/L, and severe malnutrition was <1.0 g/L.

3. Prealbumin: The half-life of prealbumin in the body is only 2 days, so it is more sensitive to evaluate the nutritional status. The normal value is 280-350 mg/L, and the protein-energy malnutrition is obviously decreased.

4. Determination of serum amino acids: The ratio of non-essential amino acids to essential amino acids in serum changes in the early stage of nutrient deficiencies, which is more sensitive than changes in plasma proteins and albumin. The normal value is 2 to 3.

Serum amino acid ratio = glycine serine glutamate taurine / leucine isoleucine valine methionine.

Its ratio > 3 has diagnostic reference value.

5. Urea to creatinine ratio: When ingesting a low-protein diet, the urea excretion in urine is reduced, so the ratio decreases.

6. Urinary hydroxyproline excretion: The discharge of hydroxyproline is related to the growth rate. The amount of urinary urinary excretion is reduced. The amount of hydroxyproline and creatinine in urine can be determined. Acid index.

Hydroxyproline index = hydroxyproline (mol/ml) / creatinine [mol / (ml · kg)].

This index is relatively constant within 3 years of age, and preschool children are 2.0 to 5.0, < 2 means slow growth.

7. Electrocardiogram examination: showing sinus bradycardia and QRS wave low voltage, ST-T abnormality, visible U wave.

8. Two-dimensional echocardiography: showing a narrowing of the heart, a small number of visible heart chambers, and a decrease in cardiac output.

9. Chest X-ray examination: the heart is reduced, a small number of patients with mild heart enlargement, chest wall and spinal osteoporosis.

Protein-energy malnutrition diagnosis and identification

Weight/height ratio:

A. Applicable to the evaluation criteria for children before Xueling:

Obesity > 22.0; excellent 22 ~ 19; normal 19 ~ 15; lean 15 ~ 13; malnutrition 13 ~ 10; wasting disease <10.

B. Applicable evaluation criteria for all ages after school age:

Obesity > 156; obesity 156 ~ 140; medium 140 ~ 109; thin 109 ~ 92; excessive thin <92.

3 triceps sebum thickness: the standard value is 12.5mm for males and 16.5mm for females, and is converted to a percentage equivalent to the normal standard at the time of evaluation.

4 Length around the limb: Measurement of the length of the mid-arm circumference.

Upper arm muscle circumference length (cm) = upper arm circumference (cm)

The normal standard value is 25.3cm for males and 23.2cm for females. The evaluation method is also calculated as the percentage (%) equivalent to the normal standard value: normal value >90%, mild malnutrition 80% to 90%, moderate malnutrition 60%~ 80%, severe malnutrition <60%.

Children with edema due to the apparent lack of protein should be differentiated from heart, kidney edema, tuberculous peritonitis, ascites due to cirrhosis, and allergic edema.

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