DENGUE HAEMORRHAGIC FEVER-

DIAGNOSIS & MANAGEMENT.Dr.W.A.P.S.R Weerarathna

Registrar in Medicine

OBJECTIVES

• Introduction• Definition of DF/DHF/DSS• Differentiation• Phases of Dengue fever• Critical phase-definition/identification• Complications of Dengue fever• Management of DF & it’s complications• Features of recovery • Causes of Dengue death & prevention

Dengue viral infection

• 4 dengue serotypes.

• DEN 1, DEN 2 ,DEN 3, DEN 4.

• Main vectores- Aedes aegypti, Aedesalbopictus.

• Adults have more complications than children.

Main clinical manifestations of dengue infection

• 1.Undiffentiated febrile illness (UF) or viral syndrome.

• 2. Dengue fever. (DF)

• 3. Dengue haemorrhagic fever. (DHF)

Dengue Viral Infections

Asymptomatic Symptomatic

Undifferentiated Febrile Illnes(viral

syndrome)Dengue Fever(DF)

Classical DFDF with unusual

haemorrhage

Dengue Haemorrhagic

Fever(DHF)

Plasma Leakage

Non-shockDengue Shock

Syndrome(DSS)

Case definition-DF

• Probable case-A patient who has acute onset of high fever with 2 or

more of the following,• Headache• Retro-orbital pain• Myalgia• Arthalgia• Rash• Haemorrhagic manifestations(TT,petichiae ect..)• Lleukopenia AND

HI Ab >1280 or +ve IgM/IgG in convalescence OROccur in the same area as confirmed dengue case

• Confirmed case-

A patient who has +ve viral identification & or serologically confirmed.

• For rapid control of dengue outbreak, the provisional diagnosis of dengue infection is made when a patient with high fever has +vetourniquet test(TT) (or petechiae) & leukopenia (WBC<5000 cells/cumm).

• The positive predictive value (PPV) for dengue infection is as high as 83%.

Positive tournique test in dengue

• DHF signs and symptoms similar to DF in theearly febrile phase.

• Plasma leakage is the hallmark of DHF.

• Tendency to develop hypovolemic shock(dengue shock syndrome), due to plasmaleakage.

Dengue Fever Vs Dengue Haemorrhagic Fever

Criteria for guidance in the diagnosis of DHF

• Clinical crireria-

1. Acute sudden onset of high fever 2-7 days.

2. Haemorrhagic manifestations at least a +veTT.

3. Hepatomegaly.

4. Circulatory disturbance or shock.

• Laoratory criteria-

1. Platelet count <100 000 cells/cumm.

2. Haemoconcentration (rising Haematocrit>20%) or other evidence of plasma leakage.

eg:ascites,pleural effusion,low level of serum proteins/albumin/cholesterol.

Case definition-DHF

A patient with above first 2 clinical criteria and 2 laboratory criteria.

Case definition-DSS

• A DHF patient who has shock as shown by one of the followings:

Rapid & weak pulse

narrowing of the PP <20mmHg without hypotention eg:100/80, 90/70 mmhg or hypotention by (age).

poor CRFT >2 seconds.

Cold, clammy extremities,restlessness.

Eairly diagnostic indicators of Dengue infection

• Febrile phase-presentation of both DF & DHF are almost the same.

• Differentiation-only after afebrile for 24 hours without using antipyretics.

• DF-recover rapidly when they are afebrile.

• Mild DHF- will recover spontaneously.

• More sever DHF- rapidly go in to shock & die in short time (10-24 hrs)if no prompt treatment.

Eairly diagnosis of dengue infection

• 1. high fever & flushed face without coryza

SENSITIVITY(%) SPECIFICITY(%)

First day 73.3 93.3

Second day 90.5 89.2

Third day 85.5 87.9

• 2. Tourniquet test (TT)

• 3.Leukopenia-

WBC <5000 /cumm is found in 70% of dengue patients(DF/DHF).

WBC<5000/cumm with relative lymphocytosis & increased in atypical lymphocytes,indicates that within next 24 hours the patient will have no fever & he is entering the critical phase if he is a DHF case.

• 4. Elevation of liver enzymes,AST-

AST elevation is found in 90% of dengue patients (DF/DHF).

AST of >60 IU has PPV of 80% for the diagnosis of dengue infections.

Usually AST is slightly elevated, not more than 200 IU & AST level is about 2-3 times that of ALT levels.

Criteria for admission:

• Platelet count less than 100,000/mm3• Presence of warning signs :• Abdominal pain or tenderness• Persistent vomiting• Clinical signs of plasma leakage: pleural effusion,

ascites• Mucosal bleeding• Lethargy, restlessness• Liver enlargement >2 cm• Increase in HCT concurrent with rapid decrease in

platelet count

Management of suspected Dengue patient.

• Divided in to 3 phases according to the clinical course of the disease.

1. Febrile phase (2-7 days)

2. critical/leakage phase (24-48 hours)

3. Convalescence phase (1-5 days)

• Febrile phase-• 1. Reduction of fever-• Tapid sponge-if temp.is still high after adose of

paracetamol.• Antipyretics-only paracetamol 10mg/Kg/day prn• Aspirin/ibuprofen are contraindicated –may

cause massive GI bleeding.• 2.Nutritional support-• Soft, balanced nutritious diet• Milk,fruit juice,electrolyte solution are

reccomended if diet is refuced.• Plain water is not adequate & may cause

electrolyte imbalance.

• 3.Other supportive & symptomatic treatment-

• Severe vomiting-Domperidone 1mg/kg/day in 3 divided dosese

• Continuing anticonvulsants is reccomended if on febrile convulsion theraphy.

• Antibiotics are not necessary in suspected dengue patients.

• Steroides are ineffective to prevent shock in DHF.

• H2 receptor blockers are recommended in case with PUD.

• 4. consider IV fluid administration only in casease with severe vomiting & or dehydration.

• IVF-just to correct the dehydration & should be discontinue as soom as possible.

• If IVF > 1 day-the amount should be minimal.

• Too much IV fluid during febrile phase may cause complication of fluid overload in severe cases wich may lead to death.

• Usually towards the late febrile phase, after the 3rd dayof fever, usually around the 5th or 6th day of illness withdefeverence.

• Some may enter the critical phase while having high fever.

• Plasma leakage is due to increased capillary permeability.

• Plasma leakage in DHF is selective and transient and usually lasts for 24-48 hours.

Critical phase (leakage phase)

Fluid leakage during critical phase

CXR-right lateral decubitus veiw.

• 5.Advise the following warning signs & symptoms of shock-

Clinical deterioration when defeverence.Bleeding.Severe abdominal pain & vomiting.Very thirsty.Drowsy,sleeping all the time.Refusing to eat & drink.Shock/impending shock-cold/clammy skin &

extremities.skin mottling/delay CRFT <2 seconds/decreased

urine output or no urine for 4-6 hours.Behavior changes-confusion/speak fowl languge.

• 6.Follow-up-

• For clinical & laboratory changes ,preferably every day( if possible depending on individual cases)

• Beginning from the third day of the illness untillthey are afebrile for at least 24 hours without the use of antipyretics.

• Important points in the follow-up-

H/O bleeding/abdominal pain/vomiting/appetite/intake & UOP

physical examination : vital signs/liver size & tenderness/repeat TT if previously negative.

• FBC:

WBC<5000/cumm with lymphocytosis & increase in atypical lymphocytes - there will be no fever in the next 24 hours which is concurrent with critical period if they are DHF patients.

Platelets counts <100 000 cumm - the patient is entering the critical phase.

platelet counts <100 000 cumm & rising Hct of 10-20% - the patient is in the critical phase & IV fluid should be considered if oral intake is poor.

• LFT-optional

AST>200 IU & AST about 2-3 times that of ALT – likely to have dengue infection (PPV 80%)

AST>200 IU –hepatic encephalopathy is possible % careful monitoring of the patient/consciousness changes is critical.

Every patient with change in mentation, specially restlessness, confusion should have LFT done.

Fluid managementTotal amount given during the critical 48 hrs:

• Maintenance fluid for 24 hrs

• +

• 5% deficit for 24 hrs

• Maintenance (M) is calculated as follows

• For the 1st 10 kg -100 ml /kg

• For the 2nd 10 kg -50 ml/kg

• From 20 kg and above up to 50 kg -20 ml/kg

• 5% deficit is calculated as 50 ml/kg up to 50 kg

Treating shockBasis: Fluid extravasation is not uniform.

• parameters : vital signs & PCV

• Principles:

• Do not give fluid at a flat rate

• Give a bolus & gradually reduce the fluid rate

• (do not reduce the rate to low levels immediately after a bolus)

• Confine to M + 5%

Treating fluid overload• Should be treated according to the

haemodynamic status and the Hct of the patient.

• If in shock or has features of pulmonary oedemaand has high Hct, a bolus of colloid (dextran 40) as 10 ml/kg over an hour.

• Midway frusemide 1 mg/kg should be given.

• If in shock and has a normal or low HCt, immediate blood transfusion. Midway of the transfusion, frusemide. Until blood is available, a bolus of colloid (300-400 ml of Dextran 40)

• Indications for Blood Transfusions

• Overt bleeding ( > 10% or 6-8ml/kg)

• Significant drop of HCt

• Hypotensive shock + low/normal HCt

• Worsening metabolic acidosis

• Refractory shock after fluid 40-60 ml/kg

1. Fluid overload- acute pulmonary edema

2. Hemorrhages/ Revealed or concealed

Eg: Pulmonary Hemorrhages/ GI blood loss

3. Profound Shock

4. Multi Organ failure

Common causes of death in dengue

Prophylactic treatment-

There is no place! • Platelet transfusion

• FFP transfusion

• Steroid –hydrocortisone, dexa, methyl pred.

• Factor VII

• N acetyl cystine

• Avoid all NSAIDS.

Recovery is indicated with

A- Improved Appetite

B- Presence of Bradycardia

C- Convalesence rash/ Constitutional symptoms

D- Diuresis

• Abuse of Antibiotics

• Inappropriate use of anti pyretics

• Complications of NSAIDS/ Acetaminophen

• Early fluid replacement prior to leakage/ administration of unnecessary Iv Fluids

• Excessive use of hypotonic solution & delay in use of colloids/ blood during critical period

PITFALLS in management

• Failure to monitor rate / volume replacementMore enthusiastic fluid replacement leading to massive

pleural effusions/ Ascites & respiratory distressContinuation of IV fluid longer than the period of critical

phase- acute pulmonary edema

• Failure to recognize metabolic acidosis/ electrolyte metabolic disturbances- (ABCS)

• Failure to recognize concealed bleeding

PITFALLS in management Cont…

• Inappropriate platelet transfusions

• Misinterpretation of further drop in Hct during recovery by haemodilution due to reabsorption of leakage fluid, as concealed bleeding & proceeding with unnecessary blood transfusions

PITFALLS in management cont…

Dengue deaths can be prevented by ..

• Proper OPD treatment

• Appropriate admission

• Appropriate fluid therapy to prevent shock/overloading

• Monitoring

• Early detection of shock and treatment fluids +/-blood transfusions +/-Calcium

• Avoidance of NSAIDS, Steroids, platelets etc.

THANK YOU!