[Dengitool: Mini Sheet] Dengue Fever in Children & Adolescents: A Clinician's Pocket Guide

WHO SEARO 2011 Dengue Severity Classification

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Recap: IV Fluid Management in Dengue Fever

1. Oral Hydration First:

• Always start with ORS (Oral Rehydration Solution) if the patient can take oral fluids. This is crucial to maintain hydration without the need for IV fluids.

2. Indications for IV Fluids:

• When IV fluids are necessary, the initial choice should be isotonic solutions such as 5% Dextrose in Normal Saline (5%D/NSS), 5% Lactated Ringer's (LR), or 5% Acetated Ringer's (Aceta).

3. Initial IV Fluid Rate:

• Begin with an infusion rate of 5-7 ml/kg/hour for the first 1-2 hours to stabilize the patient.

4. Adjusting the Fluid Rate:

• Monitor and adjust the rate based on the patient’s clinical response:
  • Improving: Reduce the rate to 3-5 ml/kg/hour for the next 2-4 hours.
  • Further Improvement: Further reduce to 2-3 ml/kg/hour for the next 2-4 hours.

5. Monitoring and Further Adjustments:

• Regularly assess urine output (IO) and hematocrit (Hct) to guide fluid adjustments.
• If Hct is rising, monitor more frequently (every 2-4 hours), and check vital signs every 1-2 hours.
• If the patient shows clinical improvement, continue to monitor IO and vital signs as needed.

6. Special Monitoring Practices:

• Urine Specific Gravity (USpec): Assess fluid volume status every 4 hours.
• Hematocrit (Hct): Monitor every 4-6 hours to detect any signs of worsening plasma leakage or hemoconcentration.

7. Managing High-Risk Patients:

• High-risk groups such as infants, the elderly, pregnant women, obese patients, and those with underlying conditions may require more cautious fluid management. Watch for warning signs of severe dengue and escalate care promptly.

8. Advanced Care for Persistent Shock:

• For patients with persistent shock, start with isotonic crystalloids. If the shock is refractory, consider using colloid solutions like 5% Human Albumin at a rate of 10-20 ml/kg/hour.
• Fluid resuscitation should be aggressive, and close monitoring is necessary to prevent fluid overload or worsening of the patient’s condition.

9. Avoid Hypotonic Solutions:

• Do not use hypotonic fluids (e.g., 0.45% saline) as they can exacerbate hyponatremia, a common complication in dengue fever.

10. Monitoring for Complications:

• Frequent monitoring of vital signs, urine output, and hematocrit levels is essential to assess the patient's response to fluid therapy.
• Bleeding management: For minor bleeding, apply local pressure and consider tranexamic acid if necessary. In cases of major bleeding, blood products such as packed red blood cells, platelets, fresh frozen plasma (FFP), and cryoprecipitate may be required.

Key Takeaways:

• Early recognition and appropriate fluid management are crucial to preventing shock and other complications in dengue fever.
• Isotonic crystalloids are the preferred initial fluids, with adjustments made based on clinical response and hematocrit trends.
• Colloids may be necessary in severe cases, particularly when isotonic crystalloids are insufficient.
• Always tailor fluid management to the individual patient's needs, considering their risk factors and the severity of their illness.

Remember: This is a simplified guide intended for quick reference and memorization. Always use clinical judgment and consult with senior colleagues or specialists in complex cases. Refer to the full guidelines for comprehensive recommendations.

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The Threat

• Dengue is endemic in Thailand, with over 100,000 cases yearly, peaking in the rainy season (May-July).
• It primarily affects school-aged kids, but infants, adults with underlying conditions, and the elderly are also at risk.
• Most infections are mild or don't show symptoms, but severe dengue can be fatal without proper care.

How It Attacks

Dengue virus makes blood vessels leaky, drops platelet levels, and messes with clotting:

1. Leaky Vessels:
   • Virus activates immune cells, causing inflammation and fluid to leak out of blood vessels.
   • Leads to fluid buildup in the chest (pleural effusions), belly (ascites), thicker blood (hemoconcentration), and even shock (DSS).
2. Low Platelets:
   • Virus suppresses bone marrow, reducing platelet production.
   • The body also destroys its own platelets.
3. Bad Clotting:
   • Liver inflammation and damaged blood vessels make it hard for blood to clot properly.

Dengue's Many Faces

1. Undifferentiated Fever (UF): Looks like any other viral illness, needs lab tests to confirm.
2. Dengue Fever (DF): Most common, high fever, headache, severe body aches, sometimes rash. Usually goes away on its own.
3. Dengue Hemorrhagic Fever (DHF): Leaky blood vessels, bleeding, can lead to shock. This is where things get dangerous.
4. Expanded Dengue Syndrome (EDS): Weird and serious stuff - brain, liver, heart problems. Difficult to diagnose, needs specialists.

Dengue's Timeline

1. Febrile Phase (2-7 days): Sudden high fever, headache, pain, maybe vomiting and some minor bleeding.
2. Critical Phase (1-2 days): Fever drops, but this is when severe dengue develops. Watch for:
   • Warning Signs: Persistent vomiting, bad belly pain, lethargy, bleeding, enlarged liver, swelling, cold/clammy skin, little or no urine.
   • Shock (DSS): Weak pulse, narrow pulse pressure, low blood pressure.
3. Recovery Phase (2-3 days): Things improve, fluid goes back where it belongs, blood counts get better. Watch for fluid overload if too much IV fluid was given.

Making the Diagnosis

• Suspect dengue based on symptoms, recent travel, or local outbreak.
• Confirm with lab tests:
  • Virus detection: NS1 antigen (days 1-5) or RT-PCR (days 1-5).
  • Serology: IgM and IgG antibodies (from day 5 onward).
  • CBC: Look for low platelets, low WBCs, high hematocrit if plasma leakage.
  • Liver function tests: AST and ALT will be elevated.
• Tourniquet Test: Can be done at bedside, but not very reliable.

Management: Home vs. Hospital

Mild Dengue (Usually Outpatient):

• Supportive Care: Rest, plenty of fluids, paracetamol for fever. NO NSAIDs!
• Monitor Closely: Check for warning signs, do a CBC on day 3-4. If platelets are low, check CBC daily.
• Hospitalize if:
  • Warning signs appear.
  • Platelet count is very low, hematocrit is high, liver enzymes very high, any signs of organ problems.
  • Patient is in a high-risk group.

High-Risk Groups:

• Infants, elderly, pregnant women, obese (BMI > 30), people with blood disorders (thalassemia, G6PD), heart problems, or chronic diseases (diabetes, etc.). Anyone taking corticosteroids or NSAIDs.

Severe Dengue (Hospitalization Essential):

• Fluid Management: Keep the circulation going!
  • Start with isotonic crystalloids (normal saline).
  • Use colloids (albumin) if leakage is bad or in shock.
  • Dextran-40 can be used with caution, watch for kidney and bleeding problems.
  • NEVER use hypotonic fluids!
  • Monitor vital signs, urine output, and hematocrit frequently.
• Bleeding Management:
  • Minor bleeding: Pressure, tranexamic acid, oral contraceptives for heavy periods.
  • Major bleeding: Packed red cells, platelets, FFP, cryoprecipitate. Massive transfusion protocol for severe cases.

Dengue Complications: Be Prepared!

1. Acute Kidney Injury (AKI):
   • Caused by poor blood flow, direct viral damage, or immune attack on the kidneys.
   • Monitor urine output and creatinine closely.
   • Consult nephrologist if severe or not improving.
2. Fluid Overload:
   • From giving too much IV fluid.
   • Reduce or stop fluids, use low-dose diuretics with caution.
3. Hemophagocytic Lymphohistiocytosis (HLH):
   • Rare, but life-threatening. Overactive immune system attacks the body.
   • Prolonged fever, enlarged liver/spleen, low blood counts, severe shock.
   • ICU care, immunosuppressants are needed.
4. Acute Intravascular Hemolysis:
   • Red blood cells break down quickly, especially in patients with thalassemia or G6PD deficiency.
   • Anemia worsens, jaundice, dark urine.
   • Hospitalize, monitor closely, transfusions may be needed.
5. Intra-Abdominal Hypertension (IAH):
   • Pressure builds up in the belly, can hurt organs.
   • Measure bladder pressure, drain fluid if needed.
6. Neurological Complications:
   • Encephalitis, brain swelling, seizures, strokes, and nerve problems can happen.
   • ICU care, neurology consult, supportive care, and specific treatments as needed.
7. Acute Liver Failure:
   • Liver shuts down, can be fatal.
   • Jaundice, encephalopathy, bleeding problems.
   • ICU care, liver specialists, possible transplantation.

Preventing Dengue

• Avoid Mosquito Bites: Repellents, nets, covering up.
• Control Mosquitoes: Eliminate breeding sites (standing water), community efforts are essential.
• Vaccines: Two options are available: Dengvaxia (for those already infected) and Qdenga (for anyone).

Referral: When to Send to a Higher Level

• If you're not sure about a diagnosis or the severity of dengue, refer to a higher level of care immediately.
• Refer patients with severe dengue, warning signs, complications, or if you don't have the resources to manage them properly.

Key Takeaway

• Dengue can be tricky - it can look mild one day and be life-threatening the next.
• Know the warning signs and when to hospitalize!
• Early recognition and aggressive supportive care are essential to saving lives.
• Prevention is key: Protect yourself and your community!