Neonatal diarrhea can be prevalent in obstetric nurseries or newborn disease wards, hence it is also known as neonatal epidemic diarrhea. It can be caused by various pathogens, with Escherichia coli (O111B4, O119B14, O126B16) and rotavirus being the most common. Other pathogens such as Staphylococcus aureus, Salmonella, Coxsackievirus, Echovirus, or Candida albicans can also cause diarrhea. Most outbreaks are caused by bacteria carried by newly admitted infants or spread by nursery staff. The condition progresses rapidly, and the mortality rate is high among premature infants who contract the disease.

bubble_chart Diagnosis

1. The incubation period is short, with rapid progression, primarily presenting with gastrointestinal symptoms. The stool is watery or contains mucus and blood streaks. In severe cases, children may experience more than 10 episodes of diarrhea daily, frequent vomiting, accompanied by high fever (or hypothermia), dysphoria, cold extremities, and other signs of toxic infection, as well as grade II or higher dehydration and acidosis.
2. Severe cases may develop acute necrotizing small intestine colitis, manifesting as abdominal distension and fullness, vomiting, and hematochezia, necessitating prompt abdominal imaging. Secondary lactose malabsorption may lead to persistent diarrhea, with fecal reducing substances exceeding 0.5g/dl.
3. Pathogenic bacteria can be identified through stool culture, and viral particles can be directly observed under electron microscopy via stool smear. Additionally, a fourfold or greater increase in serum antibody titers is diagnostically significant. The viral isolation rate peaks at 3–4 days.
4. Blood chemistry tests reveal metabolic acidosis in affected children. Serum Na, K, and Cl levels aid in guiding fluid replacement.

bubble_chart Treatment Measures

1. Strictly implement the disinfection and isolation system. If there is an epidemic trend, immediately stop admitting new patients.
2. Fasting: For those with severe vomiting and diarrhea, fast for 8–12 hours to reduce the burden on the gastrointestinal tract and restore digestive function. Then feed breast milk or diluted milk. For those with lactose intolerance, feed rice water-diluted milk or milk substitutes. For mild cases, only reduce the amount or frequency of feeding.
3. Enhance nursing care: Accurately and meticulously record intake and output. Rinse the buttocks after defecation and apply cod liver oil ointment around the anus to prevent diaper rash.
4. Fluid therapy: For grade I dehydration without vomiting, administer oral rehydration. For moderate to grade III dehydration or frequent vomiting, administer intravenous fluids.
   1. Fluid volume: Calculate based on cumulative losses, ongoing losses, and physiological needs. In practice, the total fluid volume for grade I dehydration is approximately 120–150 ml/kg per day, for grade II dehydration about 150–200 ml/kg per day, and for grade III dehydration 200–250 ml/kg per day. If continued rehydration is needed on the second day, calculate based on ongoing losses and physiological needs. The physiological requirement for infants within the first week is about 60–100 ml/kg per day, and after the first week, about 110–120 ml/kg per day.
   2. Fluid composition: (1) Oral rehydration salt (ORS): Can be used for grade I dehydration without significant vomiting. Discontinue once diarrhea improves. The formula is 2.77 g glucose, 0.35 g sodium chloride, 0.15 g potassium chloride, and 0.25 g sodium bicarbonate per 100 ml of fluid. (2) Intravenous fluids: Generally, physiological needs are supplemented with 1/4–1/5 isotonic solution. Ongoing losses are estimated based on vomiting and diarrhea, mostly supplemented with half-isotonic fluids. Cumulative losses are supplemented with 1:1 solution or 3/5 isotonic fluid. Severe dehydration may lead to shock, requiring rapid intravenous infusion of 2:1 solution (2 parts normal saline, 1 part 1.4% sodium bicarbonate) at 20 ml/kg or plasma at 15–20 ml/kg within 1 hour, or partial intravenous push, followed by 1:1 solution (1 part normal saline, 1 part 10% glucose). Administer half the volume in the first 8 hours and the remainder over the next 16 hours. Neonates often have high blood potassium levels, so potassium supplementation is not needed in the first 3 days after birth. If blood potassium is low and urine output is present, slowly infuse 1–2 ml/kg of 10% potassium chloride into the IV bottle over no less than 6–8 hours.
   3. For metabolic acidosis, use 5% sodium bicarbonate at 3–5 ml/kg per dose, diluted and slowly infused intravenously. Alternatively, calculate based on BE and CO₂ combining power. BE × body weight (kg) × 0.3 = sodium bicarbonate (mmol) supplementation.
5. Infection control: Select antibiotics based on the pathogen. For Escherichia coli enteritis, use gentamicin 10–15 mg/(kg·d), divided into 3–4 oral doses; polymyxin E 10–20 mg/(kg·d) orally; pipemidic acid 30–40 mg/(kg·d) orally; neomycin 50–100 mg/(kg·d) orally; ampicillin 50–100 mg/(kg·d), intramuscular or oral. For more severe cases, cephalosporins (e.g., cefotaxime, cefuroxime, ceftriaxone) may be used. For Candida albicans enteritis, use nystatin (100,000–150,000 U per dose, 3–4 times daily orally) or clotrimazole 20–30 mg/(kg·d) divided into 3 oral doses. If viral infection is confirmed, antibiotics are not needed.
6. Application of microecological regulators: Aim to restore normal intestinal flora and rebuild the natural biological barrier of the gut, such as bifidobacteria and lactobacillus preparations. In recent years, smectite 0.5 g three times daily has shown good efficacy in enhancing the intestinal barrier.

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bubble_chart Prevention

1. Promote breastfeeding.
2. Strictly isolate children with diarrhea, and staff must diligently implement the disinfection and isolation protocols.
3. If an outbreak of diarrhea occurs in the maternity ward's nursery or the hospital's newborn disease ward, immediate centralized isolation should be enforced, and new patients should not be admitted to the ward.
4. Mothers with diarrhea should be immediately isolated and actively treated, and breastfeeding should be temporarily suspended. The infant should also be isolated, with stool cultures performed and appropriate measures taken.