IV Fluid for Severe Dehydration Due to Diarrhea
For severe dehydration (≥10% fluid deficit, shock, or near shock) from diarrhea, immediately administer isotonic crystalloid solutions—either Ringer's lactate or normal saline—in 20 mL/kg boluses until pulse, perfusion, and mental status normalize. 1
Initial Resuscitation Phase
Severe dehydration constitutes a medical emergency requiring immediate IV access and aggressive fluid resuscitation. 1
Fluid Choice
- Both Ringer's lactate and normal saline (0.9% NaCl) are equally acceptable isotonic crystalloid solutions for initial resuscitation. 1
- Administer 20 mL/kg boluses rapidly and repeat as needed until hemodynamic stability is achieved. 1
- This may require two IV lines or alternate access sites (venous cutdown, femoral vein, or intraosseous infusion) in critically ill patients. 1
Resuscitation Endpoints
Stop aggressive boluses once ALL of the following are achieved: 1
- Normal pulse rate
- Adequate perfusion (capillary refill, skin turgor)
- Normal mental status/level of consciousness
- Urine output >0.5 mL/kg/hour
Transition Strategy
Once the patient's level of consciousness returns to normal and they can safely take oral fluids (no aspiration risk, no ileus), transition to oral rehydration solution (ORS) for the remaining fluid deficit. 1
When to Switch from IV to Oral
- Patient is awake and alert. 1
- No risk factors for aspiration present. 1
- No evidence of paralytic ileus. 1
- Hemodynamic stability maintained. 1
Completing Rehydration
- Administer ORS containing 50-90 mEq/L sodium to replace the remaining estimated deficit. 1
- Continue ORS until clinical dehydration is fully corrected. 1
- Replace ongoing stool losses with 10 mL/kg ORS for each watery stool. 1
Maintenance Phase
After complete rehydration, transition to maintenance fluids at approximately 90 mL/hour (for average adult) and resume age-appropriate diet immediately. 1, 2
- Add 20 mEq/L potassium chloride to maintenance fluids once urine output is established. 2
- Continue replacing ongoing losses with ORS throughout the illness. 1
- Reassess hydration status frequently to ensure adequacy of replacement. 1
Critical Pitfalls to Avoid
Do not continue aggressive fluid boluses beyond hemodynamic stabilization—this risks fluid overload without additional benefit. 2
Do not delay transition to oral rehydration once the patient can tolerate it—IV therapy is only necessary for the initial resuscitation phase in severe dehydration. 1
Do not use hypotonic solutions, fruit juices, or sports drinks for severe dehydration—only isotonic crystalloids are appropriate for initial resuscitation. 1
Special Considerations
- In patients with concurrent ketonemia, initial IV hydration may be needed before oral tolerance is achieved. 1
- Monitor for signs of ongoing hypovolemia (hypotension, tachycardia, poor perfusion) that would necessitate additional IV boluses. 2
- Central venous pressure monitoring and urinary catheterization should be considered in critically ill patients, balanced against infection and bleeding risks. 1