Infantile diarrhea

　　Dyspepsia in infants and young children is a common disease with a high incidence in the summer and autumn seasons. The main pathogenic factors of this disease are mainly divided into three aspects: physique, infection, and dysregulation of digestive function.

　　1, Physical factors

　　This disease mainly occurs in infants and young children, and its endogenous characteristics are: ① The gastrointestinal tract of infants is not fully mature, the activity of enzymes is low, but the relative nutritional needs are high, and the burden on the gastrointestinal tract is heavy. ② The nervous, endocrine, circulatory systems, as well as the liver and kidney functions, are not fully developed during infancy, and the regulatory function is poor. ③ The immune function of infants is also not perfect. The antibody titer of Escherichia coli in serum is the lowest from birth to 2 years old, and then gradually increases. Therefore, infants and young children are prone to Escherichia coli enteritis. The antibody titer of Escherichia coli in breast milk is high, especially the secretory IgA of pathogenic Escherichia coli in colostrum is high, so breastfed infants are less likely to get sick and are less severe when they do. Similarly, the antibody level of rotavirus in young infants is low, and when the same group is epidemic, young infants are more likely to be affected. ④ The distribution of body fluids in infants is different from that in adults, with extracellular fluid accounting for a higher proportion, and metabolism of water is vigorous, with poor regulatory function, making it more likely to occur fluid and electrolyte disturbances. Infants are prone to rickets and malnutrition, which can lead to digestive dysfunction, and at this time, insufficient secretory IgA in the intestines can lead to prolonged diarrhea after diarrhea.

　　2, Factors of infection It is divided into infections inside and outside the digestive tract, with the former being the main cause.

　　(1) Infections inside the digestive tract: Pathogenic microorganisms can enter the child's digestive tract with contaminated food or water, which is why it is more common in artificially fed infants. There is also a possibility of infection if the utensils or food used for feeding are not disinfected or not disinfected sufficiently. Viruses can also be infected through the respiratory tract or water sources. Secondly, infection can occur from carriers of bacteria (viruses) among adults, such as after an outbreak of bacterial (or viral) enteritis in a ward, some medical staff become infected and become asymptomatic intestinal carriers (virus carriers), which can lead to the spread of pathogens.

　　(2) Infections outside the digestive tract: Infections of organs and tissues outside the digestive tract can also cause diarrhea, which is common in otitis media, pharyngitis, pneumonia, urinary tract infections, and skin infections, etc. Diarrhea is usually not severe and is more common in younger individuals. Part of the cause of diarrhea is due to digestive dysfunction caused by extraintestinal infections, and another part may be due to the same pathogen (mainly viruses) infecting both the intestines and outside the intestines.

　　(3) Disruption of intestinal flora caused by the abuse of antibiotics: Long-term and large-scale use of broad-spectrum antibiotics such as chloramphenicol, kanamycin, gentamicin, ampicillin, and various cephalosporins, especially when two or more are used simultaneously, can not only directly stimulate the intestines or stimulate the autonomic nervous system to increase intestinal peristalsis, reduce glucose absorption, and decrease the activity of disaccharidase, leading to diarrhea, but more seriously, it can cause intestinal flora disorder. At this time, the normal intestinal Escherichia coli may disappear or significantly decrease, while drug-resistant Staphylococcus aureus, Proteus, Pseudomonas aeruginosa, Clostridium difficile, or Candida albicans can reproduce in large quantities, causing enteritis that is difficult to control with medication.

　　3. Digestive dysfunction

　　(1) Diet factors; (2) Intolerance to carbohydrates; (3) Food allergy; (4) Drug effects; (5) Other factors: such as unclean environment, insufficient outdoor activities, sudden changes in living habits, sudden changes in external climate (known as 'wind, cold, summer, damp diarrhea' in traditional Chinese medicine), etc., are also easy to cause infantile diarrhea.

　　Diarrhea often leads to malnutrition, multiple vitamin deficiencies, and multiple infections.

　　1. Extra-digestive tract infections:Extra-digestive tract infections may be the cause of diarrhea, but they are also often infected due to reduced systemic resistance after diarrhea. Common ones include skin suppurative infections, urinary tract infections, otitis media, upper respiratory tract infections, bronchitis, pneumonia, phlebitis, and sepsis. Viral enteritis occasionally complicates myocarditis.

　　2. Thrush:Children with protracted course or pre-existing malnutrition are prone to develop thrush, especially after long-term use of broad-spectrum antibiotics. If medication is not stopped in time, fungi can invade the intestines, even causing systemic fungal disease.

　　3. Toxic hepatitis:Jaundice can occur during the course of diarrhea, more common in children with pre-existing malnutrition. It may be caused by enteritis caused by Escherichia coli, accompanied by septicemia caused by Escherichia coli, leading to toxic hepatitis. The condition can worsen rapidly after diarrhea, and death can occur quickly after jaundice. However, if it is discovered early and polymyxin, ampicillin, or carbenicillin is injected in time, most can be cured.

　　4. Malnutrition and vitamin deficiency:Long-term diarrhea or repeated multiple fasting, long-term insufficient caloric intake, can easily lead to malnutrition, anemia, and vitamin A deficiency. Chronic diarrhea can damage liver function, reduce the absorption of vitamin K, and decrease the prothrombin, leading to bleeding.

　　5. Other:Severe dehydration can lead to acute renal failure. In addition, there are: toxic intestinal paralysis, intestinal bleeding, intestinal perforation, intussusception, and gastric dilation. It can also cause acute heart failure, hypernatremia or hyponatremia, or hyperkalemia due to improper fluid infusion. Negligent care of vomiting in small infants can cause asphyxia.

　　Common symptoms of infantile diarrhea are divided into the following situations:

　　1. General symptoms  Varies due to the mild symptoms of diarrhea.

　　(1) Light diarrhea: Mainly characterized by an increased frequency of bowel movements, several times a day up to 10 times a day, the stool is loose, sometimes with a small amount of water, yellow or yellow-green in color, mixed with a small amount of mucus, the amount per bowel movement is not much, commonly seen as small white or pale yellow pieces, which are soap pieces formed by the combination of calcium, magnesium, and fatty acids. Occasionally, there may be a small amount of vomiting or regurgitation of milk, decreased appetite, normal body temperature or occasionally low fever, slightly pale complexion, good spirits, no other systemic symptoms, no weight gain or slight weight loss, fluid loss below 50ml/kg, clinical dehydration symptoms are not obvious, prognosis is good, the course of the disease is about 3 to 7 days. In children with rickets or malnutrition, diarrhea, although light, is often 3 to 7 times a day, yellow in color, often with mucus, foul-smelling, with a small amount of white blood cells visible in the stool examination. The consistency and frequency of the stool are unstable, lasting for a long time, and the nutritional condition becomes worse, often leading to urinary tract, middle ear, or other sites of infection.

　　(2) Severe diarrhea: It can develop from mild diarrhea, with 10 to 40 bowel movements per day. When it starts to become severe, the stool contains more water, occasionally mucus, and is yellow or yellow-green with a foul smell, showing an acidic reaction. In cases where diapers are not changed in time, the buttocks may be corroded, the epidermis peeled off and become red. As the condition worsens and food intake decreases, the smell of feces diminishes, the fecal mass disappears and becomes watery or like egg-drop soup, the color becomes lighter. The main components are intestinal fluid and a small amount of mucus, showing an alkaline reaction. The amount of stool increases to 10-30ml per time, with some cases reaching 50ml. Under the microscope, fat droplets, moving bacteria, mucus are seen, and red blood cells are occasionally seen in severe cases, with white blood cells reaching about 10 per high field of vision. Children have reduced appetite, often accompanied by vomiting, irregular low fever, severe cases with high fever, rapid weight loss, significant emaciation. If not timely rehydration, dehydration and acidosis will gradually worsen. A few severe cases may develop suddenly with high fever reaching 39-40℃, frequent vomiting, watery stools, and rapid onset of symptoms of water and electrolyte imbalance. In the past ten years, due to early diagnosis, severe cases of severe diarrhea have significantly decreased.

　　2. Symptoms of water and electrolyte imbalance  主要以脱水，acidosis as the main symptoms, sometimes with symptoms of hypokalemia and hypocalcemia.

　　(1) Dehydration: Children lose weight rapidly, become emaciated, have a lack of vitality, pale or even grayish skin, poor elasticity, sunken fontanelle and infraorbital depression, dry mucous membranes, sunken abdomen, thin and rapid pulse, decreased blood pressure and urine output. Dehydration is classified into mild, moderate, and severe degrees: ①Mild dehydration: Body fluid loss accounts for less than 5% of body weight, children may have slightly reduced vitality, pale complexion, slightly dry skin but good elasticity, slightly sunken infraorbital area, less frequent urination than usual; ②Moderate dehydration: Body fluid loss accounts for approximately 5-10% of body weight, children may be listless, restless, pale and grayish skin, dry, relaxed, poor elasticity, unable to flatten immediately after pinching, blue around the mouth,明显凹陷的fontanelle and infraorbital area, dry and rough lips and mucous membranes, dull heart sounds, sunken abdomen, cold extremities, significantly reduced urination; ③Severe dehydration: Body fluid loss accounts for 10-15% of body weight, children may be listless and apathetic, unresponsive to the surrounding environment, pale and grayish skin, extremely poor elasticity, unable to flatten after pinching, deeply sunken fontanelle and infraorbital area, eyes not closing, dry conjunctiva, no tears during crying, lack of luster in the cornea, cyanotic lips, dry and unclear mucous membranes, rapid heart rate, blood pressure difficult to measure, deep sunken abdomen, cold extremities, extremely small or no urine output.

　　When estimating the degree of dehydration, attention should be paid to the extent of eye socket and fontanelle indentation. Hypotonic dehydration is prone to reduced skin elasticity, while malnourished children usually have poor skin elasticity, which should also be noted.

　　Symptoms of different types of dehydration also vary. In hypotonic dehydration, due to the significant loss of extracellular fluid, the symptoms of dehydration appear early and are severe, but thirst is mild, while lethargy is severe. In hypertonic dehydration, intracellular fluid shifts outward, and the relative loss of extracellular fluid is less, resulting in marked thirst, fever, irritability, increased muscle tone, occasional convulsions, mild eye socket and fontanelle indentation, and relatively warm hands and feet. The pulse can be felt.

　　(2) Acidosis: It is mainly characterized by lethargy, deep breathing, resembling a sigh, and in severe cases, breathing may become rapid and even lead to coma. Newborns or young infants may not exhibit deep breathing or appear late. The main manifestations are drowsiness, pallor, refusal to eat, and weakness. When estimating acidosis, attention should be paid to the age of the child.

　　(3) Hypokalemia: Significant hypokalemia may appear more than a week after watery diarrhea, and it occurs earlier and more severely in children with malnutrition. Generally, hypokalemia symptoms are rare before fluid administration. After receiving potassium-free fluids, with the correction of dehydration and acidosis, hypokalemia symptoms gradually appear: lethargy, low muscle tone, muffled first heart sound, and in severe cases, abdominal distension, decreased or absent bowel sounds, weakened tendon reflexes. If potassium is not supplemented in time, severe hypokalemia may lead to muscle paralysis, even respiratory muscle paralysis, intestinal paralysis, bladder paralysis, disappearance of tendon reflexes, bradycardia, irregular heartbeat, systolic murmur at the apex, cardiac enlargement, which may be life-threatening. Hypokalemia symptoms often appear when blood potassium levels are below 3.5 mmol/L.

　　(4) Hypocalcemia: Children with malnutrition, rickets, or chronic diarrhea often experience irritability, hand and foot tetany, and even convulsions due to hypocalcemia after receiving intravenous fluids. Examination may show positive Foster's and patellar reflexes.

　　(5) Hypomagnesemia: A few children, after correcting dehydration, acidosis, and supplementing calcium, may develop hypomagnesia tetany, characterized by hand and foot tremors, convulsions, crying, irritability, inability to sleep, and some children may appear erythema on the forehead or skin folds.

　　In the past, infant and toddler diarrhea was one of the diseases with the highest incidence rate during infancy and was also one of the important causes of infant mortality. After many years of research in China, strengthened prevention and improved diagnostic and treatment levels have reduced the incidence and severity of the disease in recent years, but it is still a common disease in infants and toddlers. Therefore, understanding the preventive measures for infant and toddler diarrhea can effectively reduce the probability of infant and toddler diarrhea and better protect the health of infants and toddlers.

　　Even in cases of timely treatment or severe complications such as malnutrition or extraintestinal infection, deaths may still occur. Therefore, preventive measures for infant and toddler diarrhea are very important. So, what are the main preventive measures for infants and toddlers?

　　First, when bottle-feeding, attention should be paid to dietary hygiene and water source cleanliness. Rinse the feeding utensils with boiling water before each feeding, and sterilize them by boiling once a day.

　　Second, in cases of anorexia or during the early stage of fever, the intake of milk and other foods should be reduced, and water should be used instead, preferably in the form of oral rehydration salts mixed with beverages for oral intake.

　　Third, in cases of malnutrition, rickets, or extraintestinal infection, treatment should be given promptly to prevent concurrent diarrhea.

　　Fourth, infectious diarrhea, especially that caused by Escherichia coli, Salmonella typhimurium, or other Salmonella species and rotavirus, is highly contagious and easily spreads widely in the ward. It is necessary to carry out strict disinfection and isolation; otherwise, cross-infection is likely to occur in pediatric wards. The disinfection method with the best effect is ozonated acetic acid smoke, followed by new disinfection surface disinfection plus ultraviolet radiation. The ward for diarrhea cases should be thoroughly disinfected with ozonated acetic acid smoke once a month.

　　Fifth, children playing on the ground should wash their hands before and after meals.

　　Routine examinations include: urinalysis, Doppler echocardiography, electrocardiogram, blood routine, stool routine, etc.
　　1. Stool examination: bleeding, pus cells, protozoa, worm eggs, fat droplets, etc.

　　2. Small intestinal absorption function test: showing malabsorption of the intestines.

　　3. X-ray and endoscopy to detect the location of the lesion, the state of motor function, gallstones, etc.

　　4. Ultrasound examination.

　　5. Small intestinal mucosal biopsy, those with conditions should perform stool culture, electron microscopy, or virus isolation.

　　6. Other: For severe cases or those that are difficult to judge, serum sodium, potassium, chloride, and blood gas analysis should be measured, or carbon dioxide binding power, and serum should be measured when convulsions occur. It is necessary to analyze fluid and electrolyte imbalances according to medical history and clinical manifestations. Electrocardiogram examination is helpful to understand potassium levels: flat T waves, then inverted, ST segment depression, often U waves, sometimes fused with T waves, and in severe cases, ventricular premature beats and ventricular tachycardia may occur, and in some severe cases, ventricular fibrillation may occur.

　　After infants and toddlers develop diarrhea, they need to eat easily digestible foods such as thin gruel, soft noodles, minced fish, a small amount of vegetable puree, and fresh fruit juice, until the diarrhea stops and 2 weeks have passed.
　　Common infant and toddler diarrhea food therapy recipe:
　　1, Take 5 to 7 figs, decoct them in water for consumption.
　　2, Take 10 grams of black plum, decoct it into a soup and drink it as tea.
　　3, Take equal portions of raw rhizome juice and lotus root juice, and take them together.
　　4, Boil the peel of sour pomegranate in an appropriate amount of water, add brown sugar, and take frequently.
　　5, Boiled persimmon paste 2 pieces, placed on cooked rice and steamed, to be eaten in two servings.
　　6. Green beans and pepper in equal amounts, grind into powder, take 3 to 6 grams each time, 3 times a day, take with boiling water.
　　7. Rice Cake Charcoal: Roast 50 grams of rice cake to charcoal, grind into fine powder, take 3 to 6 grams each time, twice a day.
　　8. Ginger Sugar Drink: 5 slices of ginger, 50 grams of brown sugar, an appropriate amount of water, boil and drink while hot.
　　9. Yam Pudding: Roast yam, grind into powder, take 10 to 15 grams each time, mix with boiling water to form a paste, take with boiling water, 2 times a day.
　　10. Glutinous Rice Intestine Stabilizing Congee: Roast 30 grams of glutinous rice, add 15 grams of Chinese yam, cook into congee, add a little pepper powder after cooking, and eat with sugar or salt.
　　11. Carrot Soup: Mince 250 grams of carrots, boil in water for 10 minutes, filter the juice, add water to 500 milliliters, add an appropriate amount of sugar, and boil.
　　12. Tea: 10 to 15 grams of tea, brew with boiling water, or decoct with 30 grams of brown sugar, decoct until black, take in portions; or an appropriate amount of tea, a little salt, decoct and take in portions.
　　13. Yam and Egg Yolk Congee: Grind 30 grams of raw yam (dried) into fine powder, mix with warm water to form a thin paste, boil, add 2 cooked egg yolks, mix evenly, take 2 to 3 times a day on an empty stomach.
　　14. Sorghum Bran: Roast 30 grams of sorghum bran to a light brown color, with a fragrance, remove the excess coarse shell on top, take 3 grams each time, take with water, 3 times a day.
　　15. Portulaca Salad Soup: Fresh portulaca 250 grams (or dried product 60 grams), wash, chop, decoct for 10 to 20 minutes, remove the dregs, add an appropriate amount of rice, cook into soup, and take frequently.
　　16. Fried Rice Water: Wash a moderate amount of rice, dry it half dry, fry it to a light brown, add 6 to 10 grams of fried rice to 100 milliliters of water, simmer over low heat for 1 hour, add a little salt, and drink the soup.
　　17. Green Tea Honey Drink: Put 5 grams of green tea into water, add boiling water to infuse, cover the lid and soak for 5 minutes, add an appropriate amount of honey, drink while hot, 3 to 4 times a day, can treat bacillary dysentery.

　　Before treating infantile diarrhea with Western medicine, it is first necessary to clarify the cause of the disease and formulate a treatment method based on the etiology and clinical symptoms.

　　1. Basic Principles

　　① After the onset of diarrhea, give the digestive tract appropriate rest; ② control infection both inside and outside the intestines; ③ correct water and electrolyte disorders; ④ good nursing care.

　　2. Diet Therapy

　　Initially, give the digestive tract adequate rest. For light and moderate cases, reduce food intake to about half of the usual amount for 4 to 6 hours; for severe cases, 6 to 12 hours. During the period of reduced food intake, supplement with fluids: for light and moderate cases, prepare and take 'Initial Salt Solution' orally. Due to the sodium transport disorder promoted by glucose in viral enteritis, the concentration of oral glucose solution should not exceed 2%, and the sodium concentration should not exceed 50mmol/L; severe cases should receive intravenous fluid therapy. When resuming diet, for breastfed infants, reduce the duration of each feeding; for formula-fed infants, start with congee, thin lotus root powder, or diluted cow's milk (or yogurt), and gradually increase the milk volume and added sucrose from small to large, from dilute to concentrated. In addition to anorexia and severe vomiting, there is no need to worry about adding milk, as the body's nutrition is greatly consumed after diarrhea. Although the frequency of bowel movements may increase after increasing food, the absorption of the intestines is proportional to the amount of food intake. Prolonged fasting or slow increase in calories can lead to malnutrition. Generally, sufficient calories should be provided after 48 hours of treatment, and normal diet should be resumed around 5 days.

　　3. Liquid Therapy

　　(1) Oral Rehydration Salt: Since 1971, the World Health Organization has recommended the use of oral rehydration salt (ORS) solutions prepared from oral rehydration salt (oral rehydration salt, ORS) for the treatment of acute diarrhea in children of different pathogens and ages worldwide. Since 1980, it has been widely used in various provinces and cities in China, achieving good results. To prepare 1 liter of ORS beverage, 3.5g of NaCI, 2.5g of NaHCO3, 1.5g of KCI, and 20g of glucose are required. The electrolyte concentration is: Na 90mmol/L, K 20mmol/L, CI 80mmol/L, HCO3 30mmol/L, glucose 111mmol/L. Due to the fact that children with viral enteritis often have isotonic or hypertonic dehydration, ORS should be diluted 1/3 to 1/2 before oral intake, reducing the content of Na to 45-60mmol/L, K to 10-13.3mmol/L, Cl to 40-53.4mmol/L, HCO3 to 15-20mmol/L, and glucose to 56-74mmol/L, while still maintaining the absorption of water and sodium in the digestive tract. The amount of ORS given on the first day: for mild dehydration, 50-60ml/kg, to be taken within 4 hours; for moderate dehydration, 70-100ml/kg, to be taken within 4-6 hours. At the same time, potassium and calcium should be supplemented according to the subsequent method. Recently, the WHO has recommended using potassium citrate instead of sodium bicarbonate in the original formula, as the latter is prone to hygroscopicity while potassium citrate is more stable. Clinical applications have also confirmed the advantages of this substitution method. In addition, the WHO also advocates replacing the 20g of glucose in the ORS formula with 30g of rice powder or other cereal powder, believing that the taste is more palatable and easier for children to accept after using cereal powder, with fewer vomiting occurrences and faster formation of stool. Clinical practice has proven its efficacy. It can indeed promote the absorption of water and electrolytes. The Department of Pediatrics of West China University of Medical Sciences once replaced 20g of glucose in the original formula with 50g of rice powder, which could indeed prevent and treat dehydration, and was superior to using the original ORS formula. As for children who have difficulty taking ORS or those with severe dehydration and circulatory collapse, intravenous fluid replacement is required first. If it is not convenient to perform intravenous infusion in rural areas, ORS can also be administered through a gastric tube. If dehydration does not improve after oral or gastric tube administration of ORS, it is necessary to find a way to administer intravenous fluids.

　　(2) Parenteral fluid replacement: For children with vomiting or difficulty with oral fluid replacement and severe dehydration, treatment should be carried out step by step according to the principles of parenteral fluid therapy in the textbook. First, quickly restore the circulating volume and supplement cumulative loss, and then slowly supplement ongoing loss and physiological consumption. In the past decade, there has been a trend of decreasing total fluid supply and sodium content in fluid replacement internationally.

　　1) Total fluid replacement: The fluid replacement for the first 24 hours of treatment should include: cumulative loss, ongoing loss, and physiological consumption. The total amount to be supplemented according to the degree of dehydration is 120～200ml/kg (mild dehydration 120～150ml/kg, moderate dehydration 150～180ml/kg, severe dehydration 180～200ml/kg). Generally, feeding can be started 4～12 hours after the onset of symptoms, with the amount of milk calculated to be included in the above fluid volume. If diarrhea is still severe, some patients may still need intravenous fluid replacement on the second day. Hyperosmolar dehydration requires a slow correction of dehydration within 2～3 days. After the correction of dehydration, the daily fluid volume only needs to supplement the ongoing loss and physiological consumption, about 100～120ml/kg per day.

　　2) Composition of fluid: The content of fluid replacement on the first day: isotonic electrolyte solution (including Na+ and K+) and non-electrolyte solution (glucose solution) the total daily volume ratio is determined according to the nature of dehydration: isotonic dehydration should be 1:1 (equivalent to 1/2 tension electrolyte solution); hypotonic dehydration uses 2:1 (equivalent to 2/3 tension electrolyte solution); in the case of hypertonic dehydration, the ratio of the two should be 1:1 to 1:2 (total concentration equivalent to 1/3 tension electrolyte solution) according to the severity of hypernatremia, to avoid the rapid decrease of serum sodium concentration, causing relative water intoxication. Ronald Kallen suggested the average daily sodium concentration to be administered in 1990 as follows:

　　The concentration of sodium solution (mmol/L) to be administered according to the nature of dehydration (％): Isotonic dehydration 50-60.33; Hypertonic dehydration 30-40.2; Hypotonic dehydration 70-80.45; Severe hypotonic dehydration 90-110 0.6-0.7

　　For children with mild illness and good renal function, or when conditions are not met, electrolyte solution can be used alone with normal saline. However, when acidosis is obvious, '2:1 solution' (2 parts normal saline plus 1 part 1/6mol sodium bicarbonate or sodium lactate) should be used as sodium-containing fluid. For those with hypokalemia, after infusion and urination, add 0.3% potassium chloride dropwise to the remaining fluid.

　　3) Steps and speed of fluid replacement: The principle is to infuse the required fluid according to the sodium concentration, from strong to weak, from fast to slow. At the beginning of infusion: Isotonic and hypotonic dehydration uses '2:1' solution, hypertonic dehydration uses '3:4:2' solution (3 parts glucose solution, 4 parts normal saline, 2 parts 1/6mol sodium lactate solution) 20mlg/kg, infused within half to 1 hour to restore circulatory volume, and then gradually reduce the concentration of sodium-containing fluid, and infuse all the fluid within 24 hours (hypertonic dehydration within 48 hours), the general speed is 8-10ml/kg/hour, and hypertonic dehydration is 5-8ml/kg/hour. To prevent the rapid shrinkage of brain cells in hypotonic dehydration, it should be avoided to infuse hypertonic fluids.