dengue fever – practice parameters

Dengue fever – practice parameters

Dengue fever management

The first principle…..

Dengue virus infection has no specific therapy


Why should I know about dengue management

Case fatality rate of dengue hemorrhagic fever in most countries is 5 %

Most fatal cases are among children and young adults


Why should I know about dengue management

Most important mosquito-borne viral disease of humans

Global distribution comparable to malaria 2.5 billion people live in areas at risk for

epidemic transmission Annually tens of millions of dengue fever and

hundreds of thousands of dengue hemorrhagic fever occur


Illustrative case scenario

Master Rahul is a three-year-old boy who presented with fever since 3 days

His intake was poor and he had vomited twice on the day he presented

He was febrile when seen

He was given amoxycillin (Mox kid DT), mefenemic acid (Ponstan) and B-complex syrup


Case vignette

No diagnosis was attempted Blanket therapy in blinded manner

He was ‘listless’ next day

Seen by another pediatrician and admitted


Course…

Treated with antimalarial therapy and ceftrioxone (presumably for enteric fever)

Leukopenia warranted consideration of typhoid

Elevated transaminases considered as ‘malarial versus enteric hepatitis’


Case vignette – tests

Blood culture negative, tests for malaria and leptospira negative

Serology for dengue - positive


First principle

Fever and constitutional symptoms in any patient-consider dengue in the differential

Exclude other treatable diseases that mimic dengue like malaria, leptospira and enteric fever


Therapeutic strategies

Symptomatic therapy

Supportive therapy

Specific therapy

Preventive therapy


Management options

No specific therapy

Treatment is essentially supportive


Symptomatic management

Avoid dehydration Adequate oral hydration and intake Paracetamol for fever and myalgia Avoid aspirin and NSAIDs – to avoid gastric

bleed and Reye’s syndrome Evaluate for impending complications, such

as early evidence of dengue hemorrhagic fever


Management hierarchy

No hemorrhagic manifestations and patient is well-hydrated: home treatment

Hemorrhagic manifestations or hydration borderline: outpatient observation center or hospitalization

Warning signs (even without profound shock) or DSS: hospitalize


Out patient management

Paracetamol Hydration Rest Instruction regarding danger signs Repeated clinical evaluation Bare minimum tests: HCt, Platelet count, AST


Danger Signs

Abdominal pain - intense and sustained Persistent vomiting Abrupt change from fever to hypothermia,

with sweating and prostration Restlessness or somnolence


Follow up for outpatients

For patients with bleeding manifestations Serial HCt and platelets at least daily until temperature is normal for 1 to 2 days


When to admit

BP < 90/60 mm Hg HCt > 50 % Platelets < 50,000/cu.mm Bleeding other than petechiae When danger signs develop


Case vignette - course

Master Rahul was severely dehydrated warranting admission

Fortunately dehydration detected early


Management of dehydration in dengue


I.V Fluids for Moderate Dehydration

<7 kg 220 ml/kg/d

7 – 11 kg 165 ml/kg/d

12 – 18 kg 132 ml/kg/d

19 – 40 kg 88 ml/kg/d


Case vignette management

Master Rahul was 18 kg

Treated with 18 x 132 = 2356 ml, ie. 100 ml/hour RL solution


Rehydrating Patients > 40 kg

Volume required for rehydration is twice the recommended maintenance requirement

Formula for calculating maintenance volume: 1500 + 20 x (weight in kg - 20)

For example, maintenance volume for 55 kg patient is: 1500 + 20 x (55-20) = 2200 ml

For this patient, the rehydration volume would be 2 x 2200, or 4400 ml


Avoid invasive procedures when possible

Shock requires ICU treatment


Treatment of shock – WHO guidelines

Initial bolus of 5 % DNS or RL(10 to 20 mL per kg) infused rapidly

Followed by continuous infusion (10 to 20 mL/kg per hour)

Continue until vital signs and urine output normalize

Infusion rate then gradually reduced until it matches plasma fluid losses


Management pearls Adequacy of fluid repletion: Serial HCt, BP, pulse,

and urine output Shock on presentation: Vital signs every 30 minutes

and HCt every 2–4 hours Narrowing of pulse pressure an indication of

hypovolemia in children even with a normal systolic BP

Normalization of HCt is an important goal of early fluid repletion; however, a normal or low HCt may be misleading in patients with overt bleeding and severe hypovolemia


Keep vigil….

Close clinical observation even after normal blood volume is restored, because patients can develop shock for one to two days after initial fluid resuscitation which represents the period of increased vascular permeability in DHF

Most who present for medical attention before profound shock develops and who receive appropriate fluid therapy will recover quickly


Do not overdo things … !

Fluids lost into tissue spaces during the period of plasma leakage rapidly reabsorbed

So i.v fluid supplementation to be discontinued once patients take oral fluids and have normal HCt, vital signs, and urine output

Usually < 48 hours of i.v fluids needed Excessive fluid administration after this point can

precipitate hypervolemia and pulmonary edema


Master Rahul was followed up with serial HCt and platelets

Developed melena

Had coffee ground vomitus once


Management of bleeding complications


Significant bleeding

Gastrointestinal bleeding or menorrhagia can be severe enough to require blood transfusion.

Factors that contribute to bleeding: thrombocytopenia due to decreased platelet survival, DIC

Platelet transfusions rarely given, warranted with severe thrombocytopenia (<10,000/mm3) and active bleeding


Continue monitoring after defervescence

If any doubt, provide i.v fluids, guided by serial HCt, BP and urine output


Unproven therapies

Unknown if the use of steroids, intravenous immune globulin, or platelet transfusions to shorten the duration or decrease the severity of thrombocytopenia is effective


Immunomodulatory therapy

Corticosteroids have no role

They do not alter mortality, bleeding severity, duration of shock, need for fluid replacement, or complications


When to plan discharge

Clinical criteria Visible improvement in clinical picture No fever for 24 hours without anti-fever therapy Return of appetite with normal oral intake Normal urine output 3 days after recovery from shock No respiratory distress from pleural effusions/ascites

Lab criteria Stable hematocrit Platelets 50,000/mm3


Master Rahul improved and was discharged on day 7


Prevention is better than cure….


Dengue Vaccine?

No licensed vaccine at present Effective vaccine must be tetravalent Field testing of an attenuated tetravalent

vaccine currently underway Effective, safe and affordable vaccine will not

be available in the immediate future


Mosquito Barriers

Only needed until fever subsides, to prevent Aedes aegypti mosquitoes from biting patients and acquiring virus

Keep patient in screened sickroom or under a mosquito net


Closing balance…

Dengue virus infection has no ‘specific’ therapy

But so much can be done to the patient


Message…

Mortality reduction is five-fold Case fatality rate of dengue hemorrhagic

fever in most countries is 5 %

This can be reduced 5-fold ie to < 1 % with proper treatment


Apollo Experience

Retrospective collection of 21 cases

Year of study: 2005 – 2006

Positive dengue by serology

Data subject to collection bias


Demography

21 hospitalized patients

Male: Female :: 12: 9

Age range: 5 months to 65 years


Age (in years)

01234

5678

0 - 5years

6 - 20years

20 -50

years

> 50years

3-D Column 1


Clinical features (n=21)

Fever – 20 Vomiting – 8 Seizures – 2 Myalgias – 8 Sore throat – 1 Breathlessness – 2 Hemetemesis – 1 Melena – 1 Epistaxis – 1


Lab tests

Platelets: Normal – 4; Low – 17 Hematocrit rise in 11 Leukopenia in 15 Azotemia in 5; 1 needed peritoneal dialysis USG abdomen: hepatomegaly – 3;

splenomegaaly – 6 Pleural effusion – 5 Ascitis – 1 CT scan – 2 - Normal


Blood transfusion – 3 Platelet transfusion – 3

All were on antibacterial therapy – ? justification


Duration of hospitalization: 3 – 25 days Oldest person – 65 years, stayed for 25 days Usual duration of stay 7 – 10 days


Morbidity

One needed peritoneal dialysis

Four needed ventilatory assistance

One 35-year-old man expired

Others were asymptomatic at discharge


Dengue misconceptions

Dengue + bleeding = DHF Need 4 WHO criteria, capillary permeability

DHF kills only by hemorrhage Patient dies as a result of shock

Poor management turns dengue into DHF Poorly managed dengue can be more severe, but DHF is a

distinct condition, which even well-treated patients may develop

Positive tourniquet test = DHF Tourniquet test is a nonspecific indicator of capillary

fragility


Dengue - more misconceptions

DHF is a pediatric disease All age groups are involved

DHF is a problem of low income families All socioeconomic groups are affected

Tourists will certainly get DHF with a second infection Tourists are at low risk to acquire DHF

dengue fever – practice parameters

Health & Medicine

dengue fever management

principle fever

dengue positive

enteric fever leukopenia

dengue virus infection

specific therapy treatment

antimalarial therapy

blanket therapy