Dengue Fever Critical Phase

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Questions and Answers

What is the usual time period during which patients with plasma leakage become worse?

Days 12-15 of illness

Days 3-8 of illness (correct)

Days 1-3 of illness

Days 8-12 of illness

What is a likely consequence of profound and/or prolonged shock?

Respiratory failure

Hypertension

Metabolic acidosis (correct)

Tachycardia

What is an early sign of plasma leakage?

Haemorrhagic manifestations

Decrease in platelet count

Increase in haematocrit (correct)

Pleural effusion

What is the usual duration of the period of clinically significant plasma leakage?

24-48 hours Signup and view all the answers

What is a common haemorrhagic manifestation of plasma leakage?

Easy bruising Signup and view all the answers

What can precede clinical detection of pleural effusion and ascites?

All of the above Signup and view all the answers

What can reduce the degree of haemoconcentration?

Early intravenous fluid therapy Signup and view all the answers

What is a consequence of severe shock?

Decrease in haematocrit Signup and view all the answers

What is the purpose of adopting the distinction between dengue and severe dengue?

For more consistent reporting in national and international surveillance systems Signup and view all the answers

What is a common feature of influenza not typically seen in dengue?

Gastrointestinal symptoms Signup and view all the answers

What is the characteristic of diseases that mimic dengue and severe dengue?

They have similar symptoms to dengue Signup and view all the answers

Which of the following is a characteristic of chikungunya that distinguishes it from dengue?

Symmetric arthritis of small joints Signup and view all the answers

What is the purpose of clinical manifestations associated with fever and epidemiological information in diagnosing dengue?

To rule out other diseases that mimic dengue Signup and view all the answers

What is a laboratory feature that is highly predictive of dengue diagnosis?

Leukopenia Signup and view all the answers

What is the benefit of using virological tests in diagnosing dengue?

It can diagnose dengue more accurately Signup and view all the answers

Which of the following is a symptom that can be misdiagnosed as infectious hepatitis?

Fever, vomiting, and liver enlargement Signup and view all the answers

Which of the following diseases can mimic the febrile phase of dengue?

Influenza, measles, chikungunya, and infectious mononucleosis Signup and view all the answers

What is a common feature of primary infection with HIV that can mimic dengue?

High fever, malaise, rash, and generalized adenopathies Signup and view all the answers

What is the purpose of the WHO dengue classification and case definitions?

To provide a standard for reporting dengue cases Signup and view all the answers

Which of the following is a characteristic of SARS that can make diagnosis difficult?

Early laboratory features are not predictive Signup and view all the answers

Which of the following is a reference for the classification and case definitions of dengue?

WHO/HTM/NTD/DEN/2009 Signup and view all the answers

What is a characteristic of adenovirus infection?

Fever associated with rash, abdominal pain, leukopenia, and lymphopenia Signup and view all the answers

Why is it necessary for clinicians to be familiar with the epidemiological characteristics of febrile diseases in the locality?

To rule out other diseases that mimic dengue Signup and view all the answers

What is a characteristic of dengue that distinguishes it from other diseases?

Evidence of plasma leakage during defervescence and thrombocytopenia Signup and view all the answers

What is the title of the journal in which the article by Alvarez M et al. was published?

American Journal of Tropical Medicine and Hygiene Signup and view all the answers

What is the purpose of the stepwise approach to the management of dengue as suggested in Table 6?

To provide health-care workers with a guide for managing dengue patients Signup and view all the answers

What is the method used by Prado I et al. to detect dengue virus?

PCR detection of dengue virus using dried whole blood Signup and view all the answers

In which year was the article by Guzman MG et al. published?

1999 Signup and view all the answers

What is the organ where dengue virus RNA was not detected by Rosen L et al.?

Brain Signup and view all the answers

What is the technique used by Hall WC et al. to demonstrate yellow fever and dengue antigens?

Immunohistochemical analysis Signup and view all the answers

What is the title of the book edited by Gubler DJ and Kuno G?

Dengue and Dengue Hemorrhagic Fever Signup and view all the answers

What is the study by Limonta D et al. about?

Apoptosis in tissues from fatal dengue shock syndrome Signup and view all the answers

What is a characteristic of patients who are able to tolerate adequate volumes of oral fluids?

Passing urine at least once every 6 hours Signup and view all the answers

Which of the following is a co-existing condition that may affect the patient's condition?

Pregnancy Signup and view all the answers

What is an indication for laboratory tests such as full blood count (FBC) and haematocrit (Hct)?

Presence of severe plasma leakage with shock and/or fluid accumulation Signup and view all the answers

What is a common finding in patients with severe shock?

Lethargy and restlessness Signup and view all the answers

What is a social circumstance that may affect the patient's condition?

Living alone Signup and view all the answers

What is an indication for starting I.V. fluid therapy?

Presence of severe plasma leakage with shock and/or fluid accumulation Signup and view all the answers

What is a laboratory test that may be indicated in patients with severe shock?

Other organ function tests Signup and view all the answers

What is a characteristic of patients with severe bleeding?

Experiencing severe organ impairment Signup and view all the answers

Study Notes

Dengue Fever

Patients with increased capillary permeability may exhibit warning signs, mainly due to plasma leakage, marking the beginning of the critical phase.

Critical Phase

The critical phase usually occurs around the time of defervescence, when the temperature drops to 37.5-38°C or less and remains below this level, typically on days 3-8 of illness.
Progressive leukopenia followed by a rapid decrease in platelet count usually precedes plasma leakage.
An increasing hematocrit above the baseline may be one of the earliest additional signs.
The period of clinically significant plasma leakage usually lasts 24-48 hours.
The degree of plasma leakage varies, and a rising hematocrit precedes changes in blood pressure (BP) and pulse volume.

Haemoconcentration and Fluid Therapy

The degree of haemoconcentration above the baseline hematocrit reflects the severity of plasma leakage.
However, this may be reduced by early intravenous fluid therapy.
Frequent hematocrit determinations are essential because they signal the need for possible adjustments to intravenous fluid therapy.

Pleural Effusion and Ascites

Pleural effusion and ascites are usually only clinically detectable after intravenous fluid therapy, unless plasma leakage is significant.
A right lateral decubitus chest radiograph, ultrasound detection of free fluid in the chest or abdomen, or gallbladder wall edema may precede clinical detection.

Haemorrhagic Manifestations

Haemorrhagic manifestations such as easy bruising and bleeding at venepuncture sites occur frequently.
If shock occurs when a critical volume of plasma is lost through leakage, it is often preceded by warning signs.

Consequences of Shock

With profound and/or prolonged shock, hypoperfusion results in metabolic acidosis, progressive organ impairment, and disseminated intravascular coagulation.
This can lead to severe haemorrhage causing the hematocrit to decrease in severe shock.

Differential Diagnoses of Dengue

A number of infectious and non-infectious diseases mimic dengue and severe dengue.
Clinical manifestations associated with fever, epidemiological information, and virological tests (if available) are particularly useful in patients with acute undifferentiated fever.
Conditions that present with an influenza-like syndrome, such as influenza itself, measles, chikungunya, infectious mononucleosis, and human immunodeficiency virus (HIV) seroconversion illness, may mimic the febrile phase of dengue.

Clinical Management

Health-care workers at the first levels of care should apply a stepwise approach to the management of dengue.
Laboratory tests, such as full blood count (FBC) and hematocrit (Hct), are essential for monitoring and treatment.

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Description

Learn about the critical phase of dengue fever, including warning signs, plasma leakage, and changes in leukopenia and platelet count. Understand the timeline of disease progression.