Dengue Emergency Management: EMT Guide

Dengue Viruses and Severe Dengue: EMT Assessment and Emergency Management

Why dengue requires careful reassessment. Dengue is a mosquito-borne viral infection that may improve after several days of fever or suddenly enter a critical phase with plasma leakage, shock, severe bleeding or organ impairment. The temperature may fall just as the patient deteriorates. Management is therefore guided by warning signs, perfusion, urine output, haematocrit trend, fluid balance and organ function—not by fever alone. Use current Ministry of Health, WHO and facility protocols.

1. Learning objectives

Describe dengue transmission, clinical phases and risk factors for severe disease.
Recognise warning signs, compensated shock, hypotensive shock, severe bleeding and organ impairment.
Perform a focused ABCDE assessment and identify important differentials such as malaria, sepsis, VHF and chikungunya.
Explain oral hydration, cautious IV fluid therapy, monitoring and criteria for referral/admission.
Apply safe analgesic, antipyretic, bleeding and transfusion principles.
Provide nursing care, mosquito-control advice, discharge safety-netting and outbreak prevention.

2. Definition, virus and transmission

Dengue is caused by dengue virus serotypes DENV-1, DENV-2, DENV-3 and DENV-4 and is transmitted mainly by infected Aedes mosquitoes. The mosquito often bites during daylight hours and breeds in small collections of clean standing water around homes, schools, health facilities and workplaces. A person with viraemia can infect mosquitoes that bite them; ordinary direct person-to-person spread is not the usual route, although blood, organ, pregnancy-related and sexual transmission have been described in specific circumstances.

Most infections are asymptomatic or mild. A second infection with a different serotype, infancy with maternal antibodies, pregnancy, very young/older age and major comorbidity can increase the risk of severe disease, but severe dengue can occur in anyone.

3. Clinical phases

Phase	Typical timing and features	What the EMT must do
Febrile phase	Usually 2–7 days of high fever, headache, retro-orbital pain, myalgia/arthralgia, nausea, vomiting, rash and fatigue	Assess hydration, malaria/VHF risk and warning signs; give safe oral fluids and paracetamol if appropriate.
Critical phase	Often around defervescence, approximately illness days 3–7; plasma leakage may cause rising haematocrit, pleural effusion, ascites, tachycardia and shock	Do not be reassured by falling fever. Observe closely, reassess after fluids and transfer warning-sign patients.
Recovery phase	Reabsorption of leaked fluid, improved appetite, stable perfusion, diuresis and sometimes a convalescent rash	Reduce IV fluid as perfusion improves; watch for fluid overload and pulmonary oedema.

Key warning: the 24–48 hours after fever settles can be the most dangerous period. A cooler patient may be entering shock, not recovering.

4. History and risk assessment

4.1 Symptom history

Day of illness and exact time fever began or settled.
Abdominal pain/tenderness, persistent vomiting, diarrhoea and ability to drink.
Nose/gum bleeding, heavy menstruation, haematemesis, melaena, haematuria or unusual bruising.
Breathlessness, chest pain, cough, restlessness, lethargy or reduced urine.
Severe headache, seizures, confusion, weakness or visual symptoms.

4.2 Exposure and host factors

Residence or travel in a dengue-affected area and mosquito exposure.
Previous dengue illness, pregnancy, infancy, older age or chronic liver, renal, cardiac or haematological disease.
Use of aspirin, ibuprofen, diclofenac, anticoagulants, antiplatelets, steroids or traditional remedies.
Potential malaria, VHF, COVID-19, typhoid or other infection exposure.

5. Warning signs and severe dengue

Warning sign	Why it matters	Action
Severe abdominal pain or tenderness	May indicate plasma leakage, organ involvement or an alternative surgical abdomen	Urgent clinician review and close observation/admission.
Persistent vomiting	Prevents oral hydration and accelerates dehydration	Measure losses, check perfusion and consider supervised IV therapy.
Clinical fluid accumulation	Pleural effusion or ascites may signal leakage	Monitor breathing, lung signs, oxygen need and fluid response.
Mucosal bleeding	May precede severe bleeding or reflect thrombocytopenia/coagulopathy	Avoid NSAIDs and trauma; assess haemoglobin/platelets and escalate.
Lethargy or restlessness	Can reflect poor perfusion, hypoxia, encephalopathy or pain	ABCDE, glucose and repeated mental-status assessment.
Liver enlargement or marked tenderness	Suggests significant disease and risk of organ impairment	Admit/observe according to protocol and monitor liver function.
Rising haematocrit with falling platelets	Supports plasma leakage and haemoconcentration	Trend results with clinical status; do not treat the number alone.

Severe dengue: severe plasma leakage causing shock or respiratory distress, severe bleeding, or severe organ impairment such as hepatitis, encephalopathy, myocarditis or acute kidney injury. Any of these requires urgent hospital-level management.

6. Initial contact and ABCDE

Perform hand hygiene, use standard precautions and isolate/triage according to respiratory, bleeding or VHF risk.
Airway: look for haematemesis, reduced consciousness, persistent vomiting and aspiration risk.
Breathing: check respiratory effort, SpO₂ and signs of pleural effusion or pulmonary oedema.
Circulation: assess pulse pressure, pulse quality, capillary refill, extremity temperature, blood pressure, urine output and mental status. Narrow pulse pressure and tachycardia may precede hypotension.
Disability: check AVPU/GCS and glucose; investigate seizures or confusion urgently.
Exposure: inspect for rash, petechiae, bleeding, dehydration, jaundice and fluid accumulation while preserving warmth and dignity.

7. Differential diagnosis

Condition	Overlapping features	Clues/tests that help
Malaria	Fever, headache, vomiting, thrombocytopenia, anaemia, confusion	Malaria RDT/microscopy, travel/residence, hypoglycaemia and severe-malaria signs.
Viral haemorrhagic fever	Fever, GI symptoms, rash, bleeding and shock	Outbreak/contact/travel history; follow high-risk isolation and public-health testing pathway.
Sepsis/meningitis	Fever, hypotension, confusion, vomiting and rash	Focal source, meningism, cultures, lactate and organ dysfunction.
Chikungunya/Zika	Fever, rash, myalgia/arthralgia	Prominent joint pain, conjunctivitis and pregnancy/travel context; local testing.
Leptospirosis or viral hepatitis	Fever, jaundice, renal/liver abnormalities	Animal/water exposure, conjunctival suffusion, renal/liver tests.

8. Investigations

Serial vital signs, capillary glucose, weight and urine output.
Full blood count with platelet count and haematocrit trend; a single platelet number does not define severity.
Electrolytes, urea/creatinine, glucose, AST/ALT, bilirubin, albumin and coagulation tests when severe.
Malaria testing in endemic/travel settings and tests for alternative diagnoses.
Dengue NAAT/RT-PCR or NS1 antigen early in illness, and IgM/IgG according to illness day and laboratory guidance.
Chest ultrasound/X-ray or other imaging when effusion, pulmonary oedema, abdominal pathology or organ impairment is suspected.
Do not delay resuscitation while waiting for dengue confirmation.

9. Management of dengue without warning signs

Confirm that the patient is haemodynamically stable, drinking, passing urine and has no warning sign or high-risk comorbidity.
Encourage frequent oral fluids, oral rehydration solution, soups and other tolerated liquids; monitor urine frequency and colour.
Use paracetamol/acetaminophen for fever or pain within safe age/weight and liver limits.
Avoid aspirin, ibuprofen, diclofenac and other NSAIDs because of bleeding and kidney risks.
Avoid routine corticosteroids and prophylactic platelet transfusion; use only under specialist indications.
Use mosquito nets/repellent during the first week of illness to prevent a mosquito from acquiring virus from the patient.
Arrange daily or protocol-based review during the critical window and give written return precautions.

10. Management of warning signs and shock

10.1 Goals

Restore effective circulation without worsening plasma leakage or causing fluid overload.
Maintain oxygenation, glucose, urine output and mental status.
Detect severe bleeding, organ injury and transition from leakage to reabsorption.

10.2 Compensated shock

Move to a monitored area and obtain IV access with minimal attempts.
Give a carefully calculated isotonic crystalloid bolus according to the local dengue algorithm and patient group.
Reassess pulse pressure, capillary refill, heart rate, blood pressure, breathing, lungs, mental status, urine output and haematocrit.
Repeat, reduce or stop fluids based on response and signs of overload; do not continue a fixed rate without reassessment.

10.3 Hypotensive shock or severe dengue

Activate senior, paediatric/obstetric and critical-care support immediately.
Use oxygen for hypoxaemia or shock; prepare airway support for exhaustion or reduced consciousness.
Administer the minimum IV crystalloid required to restore perfusion, reassessing after each intervention.
Consider colloid or blood products only under specialist/dengue protocol when shock is refractory or bleeding is significant.
Use vasopressors in critical care when shock persists after appropriate volume and the cause is addressed.
Monitor for pulmonary oedema, pleural effusion and rising abdominal pressure during resuscitation.

11. Bleeding, organ impairment and special situations

Apply direct pressure to external bleeding, use gentle handling and avoid IM injections, arterial puncture and unnecessary catheterisation.
Transfuse packed red cells or other components for clinically significant bleeding or haemodynamic compromise, not solely for a low platelet count.
Severe hepatitis: monitor glucose, coagulation and encephalopathy; avoid hepatotoxic medicines and seek specialist help.
Acute kidney injury: measure urine output, adjust medicines and avoid nephrotoxins; seek renal/critical-care advice.
Myocarditis or arrhythmia: ECG, troponin/echo where available and cautious fluid strategy.
Pregnancy: admit or consult obstetrics for warning signs, bleeding, shock or reduced fetal movement.
Infants and older adults may deteriorate quickly and require lower thresholds for admission and observation.

12. Nursing care and monitoring table

Need	Interventions	Escalation triggers
Perfusion	Frequent pulse/BP/pulse pressure, capillary refill, extremities, mental status and urine output	Narrowing pulse pressure, tachycardia, hypotension, cold skin or oliguria
Fluid balance	Measure oral/IV intake, urine, stool/vomit; review haematocrit and lungs	Persistent losses, rising haematocrit with instability or fluid overload
Bleeding	Inspect gums, nose, stool, urine, menses, skin and IV sites; use pressure and gentle care	Haematemesis, melaena, shock, falling haemoglobin or uncontrolled bleeding
Temperature/pain	Paracetamol when indicated, rest, light clothing and hydration	Severe pain, altered mental state or fever with new warning signs
Psychosocial support	Explain the critical phase, encourage safe fluids and involve caregivers in observation	Confusion, anxiety preventing intake or inability of caregiver to monitor

13. Infection prevention and mosquito control

Use standard precautions for blood and body fluids; add respiratory or VHF precautions when the differential requires them.
Keep the patient under a mosquito net or use repellent during the viraemic period.
Eliminate stagnant water in containers, tyres, gutters and flower pots; cover household water storage.
Use screens, long sleeves and approved repellents; support community vector-control campaigns.
Clean equipment and dispose of sharps safely; do not share needles or unsterile injection equipment.

14. Discharge and safety-net advice

Give a written return plan, especially for days 3–7 or whenever the fever is settling:

Return urgently for severe abdominal pain, repeated vomiting, bleeding, black stool, vomiting blood, extreme thirst, pale/cold skin, faintness, restlessness, drowsiness, difficulty breathing or very little urine.
Continue oral fluids and prescribed paracetamol; avoid aspirin, ibuprofen, diclofenac and unregulated herbal mixtures.
Use a mosquito net and return for scheduled platelet/haematocrit or clinical review.
Do not self-start antibiotics; seek review if fever returns, persists or another family member becomes ill.

15. Clinical scenarios

Scenario 1 – Fever settles, patient worsens. On day 5, a 19-year-old says the fever stopped but now has severe abdominal pain, persistent vomiting, tachycardia and cool hands. The EMT recognises the critical phase, checks perfusion and glucose, obtains IV access, avoids NSAIDs, arranges urgent monitored admission and starts protocol-guided fluids with repeated reassessment. Falling temperature is not used as reassurance.

Scenario 2 – Dengue with fluid overload. A patient treated for shock becomes breathless with basal crackles and rising oxygen requirement. The team pauses indiscriminate fluids, reassesses ultrasound/haematocrit and perfusion, gives oxygen, calls critical care and adjusts fluid therapy. More fluid is not automatically the answer.

Scenario 3 – Bleeding and thrombocytopenia. A patient has gum bleeding and a low platelet count but stable perfusion and haemoglobin. The team uses gentle oral care, avoids IM injections and NSAIDs, monitors for progression and does not order prophylactic platelets solely because the number is low; specialist guidance directs transfusion decisions.

16. Common errors

Assuming defervescence means recovery.
Giving large unmonitored IV volumes or stopping all fluid despite shock.
Using aspirin/NSAIDs or routine steroids.
Transfusing platelets prophylactically without a clinical indication.
Failing to test for malaria or other common causes of fever.
Sending a warning-sign patient home without critical-phase follow-up.
Ignoring pregnancy, infancy, older age, renal/liver disease or a second dengue infection.

17. Quick revision questions

Why can dengue become dangerous when the fever decreases?
List the seven major warning signs of severe dengue.
What findings suggest compensated shock?
Why is fluid therapy in dengue different from routine dehydration?
Which analgesics should be avoided and why?
When is blood transfusion considered?
What should be monitored after every IV-fluid change?
How can the patient and household prevent mosquito transmission?
Which dengue patients need admission or close observation?
Write a discharge safety-net message for day 5 of illness.

18. Key takeaways