What is the best approach for hydrating a patient?

Best Approach for Hydrating a Patient

The best approach for hydrating a patient should be tailored based on the severity of dehydration, patient condition, and ability to take oral fluids, with oral rehydration being the preferred first-line method when appropriate. 1

Assessment of Hydration Status

• Dehydration can be classified into two main types: low-intake dehydration (water-loss dehydration) and volume depletion (salt and water loss) 1, 2
• Low-intake dehydration is diagnosed by measured serum/plasma osmolality >300 mOsm/kg or calculated osmolarity >295 mmol/L 1, 2
• Volume depletion following blood loss can be assessed using postural pulse change (≥30 beats per minute) or severe postural dizziness resulting in inability to stand 1
• Volume depletion from vomiting or diarrhea should be assessed by checking for at least four of these seven signs: confusion, non-fluent speech, extremity weakness, dry mucous membranes, dry tongue, furrowed tongue, and sunken eyes 1

Hydration Approach Based on Patient Condition

For Well Patients with Low-Intake Dehydration

• Encourage increased oral fluid intake with drinks preferred by the patient (tea, coffee, fruit juice, water, etc.) 1
• Avoid sports drinks and oral rehydration therapy which are designed for volume depletion, not low-intake dehydration 1
• Monitor hydration status regularly until corrected 1

For Unwell Patients with Low-Intake Dehydration

• Offer subcutaneous or intravenous fluids in parallel with encouraging oral fluid intake 1
• Subcutaneous rehydration (hypodermoclysis) with appropriate solutions can be as effective as intravenous with similar rates of adverse effects 1
• For patients unable to drink, intravenous fluids should be considered 1

For Patients with Volume Depletion

• Administer isotonic fluids orally, nasogastrically, subcutaneously, or intravenously 1
• If hypovolemic and requiring fluid resuscitation, this should occur immediately 1
• Where electrolyte levels are low, replace with isotonic fluids (similar sodium, potassium, and glucose concentrations to body fluids) 1

Pediatric Hydration Approach

• For mild dehydration (3-5% fluid deficit): administer 50 mL/kg of oral rehydration solution over 2-4 hours 3
• For moderate dehydration (6-9% fluid deficit): administer 100 mL/kg of oral rehydration solution over 2-4 hours 3
• Start with small volumes (one teaspoon) using a teaspoon, syringe, or medicine dropper, then gradually increase as tolerated 3
• For severe dehydration: immediate IV rehydration with isotonic fluids until vital signs normalize 3

Special Considerations

For Dying Patients

• Treatment should be based on comfort rather than aggressive hydration 1
• Parenteral hydration and nutrition are unlikely to provide benefit for most dying patients 1
• In acute confusional states, consider short and limited hydration to rule out dehydration as a precipitating cause 1

For Patients with Dysphagia

• Patients with dysphagia are at high risk of dehydration, especially when using thickened fluids 1
• Consider chin-down swallowing technique with thin fluids as first-line therapy 1
• For stroke patients using thickened fluids, provide access to free water and use pre-thickened drinks rather than powder-thickened drinks at point of use 1

Monitoring Response to Hydration

• If dehydration persists after initial rehydration, reassess fluid deficit and restart therapy 3
• For ongoing losses (vomiting, diarrhea), replace each episode with appropriate fluid amounts 3
• If the patient shows signs of worsening dehydration, severe lethargy, or inability to drink, seek immediate medical attention 3

Common Pitfalls to Avoid

• Don't confuse "dehydration" and "hypovolaemia" which are incorrectly used interchangeably 2
• Don't rely solely on clinical signs for diagnosis as they can be subtle and unreliable outside of extreme cases 2, 4
• Don't use apple juice, sports drinks, or commercial soft drinks for rehydration due to inappropriate electrolyte content and high osmolality 3
• Don't assume dehydration is due to neglect; it often results from physiological and disease processes 5