Overview
Definition:
Gastroenteritis is an inflammation of the stomach and intestines, typically caused by viral, bacterial, or parasitic infections, leading to vomiting and diarrhea
Inpatient management is reserved for severe dehydration or persistent symptoms requiring intravenous support and medications.
Epidemiology:
Viral gastroenteritis is the most common cause in children worldwide, with rotavirus being a leading pathogen historically
Bacterial causes include Salmonella, Shigella, Campylobacter, and E
coli
Incidence peaks vary seasonally and by pathogen
Inpatient admission rates are linked to severity of dehydration.
Clinical Significance:
Effective inpatient management of gastroenteritis is critical to prevent life-threatening dehydration, electrolyte imbalances, and refeeding syndrome
Optimizing IV fluid resuscitation and judicious use of antiemetics significantly improves patient comfort, reduces hospital stay, and prevents complications, making it a key area for DNB and NEET SS preparation.
Clinical Presentation
Symptoms:
Acute onset vomiting, often projectile
Watery diarrhea, sometimes with mucus or blood
Abdominal pain and cramping
Fever
Lethargy or irritability
Decreased urine output
Dry mucous membranes
Poor feeding or refusal to drink.
Signs:
Signs of dehydration: decreased skin turgor, sunken eyes, dry mouth, absence of tears, tachycardia, hypotension (late sign), decreased capillary refill time, reduced fontanelle pressure in infants
Abdominal distension or tenderness
Absent bowel sounds may indicate ileus.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on history and physical examination
Specific diagnostic criteria are not typically used for uncomplicated gastroenteritis
Stool studies are indicated in specific situations like suspected bacterial infection, bloody diarrhea, or prolonged symptoms to identify the causative agent.
Diagnostic Approach
History Taking:
Detailed history of onset and character of vomiting and diarrhea
Presence of fever, blood, or mucus in stool
Recent travel or sick contacts
Fluid intake and output
Previous episodes of dehydration
Medications used
Red flags: high fever, bloody diarrhea, severe abdominal pain, lethargy, or signs of shock.
Physical Examination:
Assess hydration status using clinical signs (skin turgor, mucous membranes, tears, fontanelle)
Measure vital signs (heart rate, respiratory rate, blood pressure, temperature)
Perform a thorough abdominal examination for tenderness, distension, masses, and bowel sounds
Assess mental status.
Investigations:
Routine investigations are often not required for mild to moderate dehydration
For severe dehydration or suspected complications: Serum electrolytes, BUN, creatinine (to assess hydration and renal function)
Complete blood count (CBC) to rule out severe infection
Stool studies (culture, ova and parasites, viral antigens) if indicated
Blood gas analysis if severe metabolic acidosis suspected.
Differential Diagnosis:
Other causes of vomiting and diarrhea: appendicitis, intussusception, malrotation with volvulus, surgical abdomen, urinary tract infection, pneumonia, otitis media, food allergies/intolerances, metabolic disorders, toxic ingestions, inflammatory bowel disease.
Management
Initial Management:
Primary goal is to correct dehydration and electrolyte imbalances
Oral rehydration therapy (ORT) is the preferred initial approach for mild to moderate dehydration
For inpatient management requiring IV fluids: establish intravenous access
Assess hydration status and calculate fluid deficit.
Medical Management:
Intravenous Fluid Resuscitation: For moderate to severe dehydration, use isotonic crystalloids like 0.9% Normal Saline or Lactated Ringer's
Initial bolus of 20 mL/kg over 1-2 hours, followed by maintenance fluids
Antiemetics: Ondansetron is the first-line antiemetic for inpatient management of vomiting due to gastroenteritis
Dosage: 0.1 mg/kg per dose IV, maximum 4 mg per dose, every 6-8 hours as needed
Metoclopramide can be used but has a higher risk of extrapyramidal side effects
Antidiarrheals are generally NOT recommended in children due to risks of prolonged illness and toxic megacolon.
Surgical Management:
Surgical intervention is rarely indicated for gastroenteritis itself but is crucial for underlying surgical conditions mimicking gastroenteritis, such as appendicitis, intussusception, or volvulus.
Supportive Care:
Monitor vital signs, hydration status, urine output, and electrolyte levels closely
Gradual reintroduction of oral feeds once vomiting has subsided, starting with clear liquids and progressing to a regular diet
Avoid milk-based formulas initially if lactose intolerance is suspected
Pain management with appropriate analgesics if required
Strict hand hygiene to prevent spread.
Complications
Early Complications:
Severe dehydration leading to hypovolemic shock
Electrolyte disturbances (hyponatremia, hypernatremia, hypokalemia, hyperkalemia)
Metabolic acidosis
Seizures (secondary to electrolyte imbalance or cerebral edema)
Renal failure
Intussusception (especially after rotavirus infection)
Toxic megacolon (rare, associated with C
difficile or EHEC).
Late Complications:
Post-infectious lactose intolerance leading to persistent diarrhea and malabsorption
Growth faltering if nutritional intake is inadequate
Rehydration syndrome (rare, if rehydration is too rapid).
Prevention Strategies:
Emphasis on oral rehydration therapy as the first line of treatment
Prompt recognition of dehydration and initiation of appropriate fluid management
Judicious use of antiemetics to facilitate oral intake
Good hygiene practices, including handwashing and safe food handling, to prevent infections
Vaccination against rotavirus.
Prognosis
Factors Affecting Prognosis:
Severity of initial dehydration
Presence of underlying comorbidities
Promptness and adequacy of treatment
Response to IV fluids and antiemetics
Etiology of the gastroenteritis.
Outcomes:
With prompt and appropriate inpatient management, most children recover fully within a few days
Complications are more likely in infants, immunocompromised children, or those with severe initial presentation.
Follow Up:
For uncomplicated gastroenteritis with full recovery, no specific follow-up is usually required
Children with significant dehydration, electrolyte disturbances, or underlying conditions may require closer follow-up to ensure complete recovery and address any nutritional deficits.
Key Points
Exam Focus:
DNB/NEET SS exam emphasis: Calculation of IV fluid deficits (bolus and maintenance)
Appropriate choice of IV fluids (isotonic crystalloids)
Dosing and indications for antiemetics (Ondansetron)
Recognition of red flags for surgical causes
Management of electrolyte imbalances.
Clinical Pearls:
Always assess hydration status before initiating IV fluids
Ondansetron is highly effective in reducing vomiting and facilitating oral rehydration
Differentiate between fluid deficit replacement and maintenance fluid requirements
Early reintroduction of oral feeds is key to recovery.
Common Mistakes:
Over-reliance on IV fluids without attempting ORT
Use of hypotonic fluids for resuscitation
Inappropriate use of antidiarrheals
Delaying consultation for red flag symptoms suggesting surgical abdomen
Underestimating fluid deficits in dehydrated children.