What is the initial management for a patient with acute gastritis and moderate dehydration?

Initial Management of Acute Gastritis with Moderate Dehydration

For a patient with acute gastritis and moderate dehydration, initiate oral rehydration solution (ORS) at 100 mL/kg over 2-4 hours as first-line therapy, with nasogastric administration if oral intake fails, reserving intravenous fluids only for inability to tolerate ORS or clinical deterioration. 1

History and Physical Examination

Critical Historical Elements

• Quantify fluid losses: Document number of vomiting episodes in past 24 hours, frequency and volume of any diarrhea, last urination time, and ability to tolerate oral fluids 2
• Assess duration: Determine onset time of symptoms (acute gastritis typically <48 hours) and progression pattern 3
• Identify red flags: Ask about bloody stools (dysentery), fever >38.5°C, severe abdominal pain, altered mental status, or signs of sepsis that would change management 1
• Document intake: Record all oral intake attempts, types of fluids given, and tolerance 2

Physical Examination Findings for Moderate Dehydration (6-9% Fluid Deficit)

• Mucous membranes: Dry oral mucosa and tongue 2
• Eyes: Sunken appearance 2
• Skin turgor: Decreased elasticity with skin tenting that returns within 2 seconds 2
• Urine output: Reduced frequency (oliguria) 2
• Mental status: Normal to mildly lethargic but arousable 2
• Vital signs: Mild tachycardia, normal blood pressure (orthostatic changes may be present) 2
• Capillary refill: Normal to slightly delayed (2-3 seconds) 2
• Weight measurement: Essential to quantify fluid deficit and monitor response—compare to recent known weight if available 2

Key distinction: Prolonged skin retraction time, decreased perfusion, and rapid deep breathing are more reliable predictors of dehydration severity than sunken fontanelle or absence of tears 2

Rehydration Protocol

First-Line: Oral Rehydration Solution

• Administer reduced osmolarity ORS containing 50-90 mEq/L sodium at 100 mL/kg over 2-4 hours for moderate dehydration (6-9% deficit) 1, 2
• Give small, frequent volumes: 5 mL every 2-3 minutes initially, gradually increasing as tolerated to prevent vomiting 2
• Replace ongoing losses: Add 10 mL/kg ORS for each vomiting episode and any additional diarrheal losses 1, 2

Second-Line: Nasogastric ORS

• Consider nasogastric tube administration if the patient cannot tolerate oral intake but has normal mental status and no contraindications 1
• This approach is superior to IV rehydration in moderate dehydration when oral route fails 4

Reserve IV Fluids For:

• Failure of ORS therapy after adequate trial (continued vomiting preventing intake) 1
• Altered mental status or inability to protect airway 1
• Severe acidosis (serum bicarbonate ≤13 mEq/L predicts ORS failure) 5
• Ileus preventing enteral absorption 1
• Clinical deterioration to severe dehydration during ORS trial 1

If IV fluids become necessary: Use isotonic crystalloid (lactated Ringer's or normal saline) at 20 mL/kg boluses, reassessing after each bolus until perfusion normalizes, then transition back to ORS for remaining deficit 1

Adjunctive Pharmacotherapy

Antiemetics to Facilitate ORS Tolerance

• Ondansetron may be given to children >4 years and adults with persistent vomiting to enhance ORS compliance 1
• Dosing: 0.15 mg/kg orally dissolving tablet, wait 30 minutes, then reattempt ORS 3
• Evidence: Reduces IV rehydration need by 33% (from 54.5% to 21.6%) in children who initially failed ORS 3
• Timing: Only after initial rehydration attempt, not as routine first-line 1

Antimotility Agents: Generally Avoided

• Loperamide is contraindicated in children <18 years with acute gastritis/gastroenteritis 1, 6
• In adults: May use cautiously (2 mg) only after adequate rehydration and only if no fever or bloody stools present 1, 6
• Rationale: Risk of toxic megacolon in inflammatory conditions; not a substitute for fluid therapy 1

Antibiotics: Not Indicated

• Empiric antibiotics should be avoided for acute gastritis with vomiting and no dysentery 6
• Stool cultures not needed for typical acute gastritis without bloody diarrhea 2

Monitoring and Reassessment

Clinical Parameters Every 2-4 Hours

• Vital signs: Heart rate, blood pressure, respiratory rate 7
• Hydration markers: Skin turgor, mucous membrane moisture, urine output, mental status 1, 7
• Tolerance: Ability to retain ORS, frequency of vomiting 1
• Weight: Serial measurements to quantify rehydration progress 2

Criteria for Successful Rehydration

• Normal pulse and perfusion 1
• Improved mental status (alert, interactive) 1
• Moist mucous membranes 2
• Adequate urine output (at least one void) 2
• Ability to tolerate oral fluids without immediate vomiting 1

Nutritional Management

Early Feeding Protocol

• Resume age-appropriate normal diet immediately after rehydration or during the rehydration process 1, 6
• Continue breastfeeding throughout illness without interruption in infants 1
• No dietary restrictions: The outdated practice of "resting the bowel" should be abandoned 2, 6, 7
• Rationale: Early feeding promotes intestinal cell renewal, prevents nutritional deterioration, and is as safe as delayed feeding 2, 6

Common Pitfalls to Avoid

• Do not use sports drinks, juice, or soft drinks for rehydration—these have inappropriate osmolality and electrolyte composition 7
• Do not give ondansetron routinely before attempting ORS—reserve for persistent vomiting after initial ORS trial 1
• Do not rush to IV fluids in moderate dehydration—ORS has equivalent efficacy with fewer complications 1, 2
• Do not withhold food once rehydrated—early feeding improves outcomes 1, 6
• Do not use loperamide in children or in any patient with fever/bloody stools 1, 6

Disposition Criteria

Safe for Discharge When:

• Rehydration complete (clinical signs normalized) 1
• Tolerating adequate oral intake without immediate vomiting 1
• Reliable caregiver with clear return precautions 2
• Access to follow-up within 24-48 hours 3

Admission Indicated For:

• Failure of ORS therapy despite ondansetron (if used) 3, 8
• Severe acidosis (bicarbonate ≤13 mEq/L) predicting ORS failure 5
• Inability to maintain hydration with ongoing losses 1
• Social concerns about home management 2