How should I manage a patient with suspected food poisoning who presents with severe dehydration?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 22 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Management of a patient with suspected food poisoning presenting with severe dehydration involves the following steps:

  • Assess severity: Identify signs of clinical shock such as altered responsiveness, pale or mottled skin, cold extremities, weak peripheral pulses, prolonged capillary refill time, and hypotension. These signs indicate the need for urgent intervention .
  • Initiate intravenous fluid therapy immediately if shock is suspected or confirmed: Administer a rapid intravenous infusion of 10 ml/kg of 0.9% sodium chloride solution. If shock persists, give a second rapid infusion of 10 ml/kg and consider other causes of shock and specialist consultation .
  • For ongoing rehydration after initial shock management: Use isotonic solutions such as 0.9% sodium chloride or 0.9% sodium chloride with 5% glucose for fluid deficit replacement and maintenance. The fluid deficit should be replaced slowly, typically over 48 hours, with frequent monitoring of plasma sodium, potassium, urea, creatinine, and glucose .
  • Monitor for hypernatraemic dehydration: If suspected (signs include jittery movements, increased muscle tone, hyperreflexia, convulsions, drowsiness, or coma), obtain urgent expert advice on fluid management and reduce plasma sodium at a rate of less than 0.5 mmol/l per hour .
  • Attempt early and gradual introduction of oral rehydration therapy (ORS) during intravenous fluid therapy: If tolerated, stop intravenous fluids and complete rehydration with ORS solution .
  • After rehydration: Encourage fluid intake and normal feeding, including breastfeeding or milk feeds, and avoid fruit juices and carbonated drinks until diarrhoea resolves .
  • Do not routinely give antibiotics unless there are specific indications such as suspected septicaemia or immunocompromise .

Educational content only. Always verify information and use clinical judgement.