Dengue fever 2-7 DAYS Convalescent phase • 2-5 DAYS • Longer in adults 1
Dec 24, 2015
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Dengue fever
2-7 DAYSConvalescent phase• 2-5 DAYS • Longer in adults
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Dengue haemorrhgic fever
LeakageLasts48 hours2-7 DAYS 2-5 DAYS
Longer in adults
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• Plasma leakage is– Selective
• Pleural and peritoneal cavities
– Transient• Lasts 24-48 hours
– Functional
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transientselective
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Detection of DHF(detection of leakage)
At three levels• At the onset of leakage• At hemodynamic instability• Shock
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• Detect leakage
• Diagnose DHF
• Prevent Shock
• Clinical• Hematology• Radiology
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Detection: onset of leakage-clinical
Potential leaker-• Clinical deterioration with defervescence • Enlarged tender liver
Confirmed leaker-• Pleural effusions, free fluid in abdomen
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Detection of leakage-haematology
• White cell count• Platelet count• Haematocrit
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Timing the onset of critical period
17th 8 am
18th
8 am18th 8 pm
19th
8 am19th
8 pm20th 8 am
20th 8 pm
21st
8 am21st
8 pm
7500
7000
6500
6000
5500
5000
4500
4000
3500
3000
2500
2000
1500
260,000
240,000
220,000
200,000
180,000
160,000
140,000
120,000
100,000
80,000
60,000
40,000
20,000
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platelets
WBC
Slide- courtesy of Dr Lakkumar Fernando
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Platelet count
• Leakage occurs only after platelets drop below 100,000 mark
• A rapid drop of platelet is correlated with severity of leakage
• Rise in platelets occur at least `12 hours after the end of leakage phase
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Haematocrit
• Rise towards 20% above baseline considered significant
• This may not be seen in patients with– Intravenous fluid replacement– Concomitant bleeding
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Radiological diagnosis
• Ultrasound scan-– Oedema of the gall bladder wall (but seen in
dengue fever as well)– Fluid in pleural and/or peritoneal cavities
• CXR- right lateral decubitus (when clinically undetectable)
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Leakage phase-Basic principles of fluid therapy
• Leakage is time limited- maximum 48 hours• Not static but dynamic-
– Starting with a trickle– Reaching a peak– Then tapering off
• Maximum fluid required to counter the resulting hemodynamic instability is M+5% for 48 hours
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Dynamics of Plasma Leakage
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R0 Hr 24 Hr 48 Hr
F C6 Hr 36 Hr
Rapid SlowModerate
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Basics of fluid therapy
• Try and match the dynamics of leakage• Calculate the maximum fluid required for 48
hours with formula – M+5%= in 50 kg adult 4600ml
• Use sufficient amounts needed to maintain just adequate intravascular volume and circulation by monitoring the vital signs.
• It is not necessary to try and finish M+5%
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Try and match the leakage
• Patients with early leakage– Start with small volumes– Increase the rate gradually to keep
hemodynamically stable (pulse pressure >30) with HCT as a guide. Do not try to normalize HCT
– Gradually taper off after 24 hours while keeping HCT and vital signs as a guide again
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Try and match leakage
• In a patient presenting with SHOCK leakage will usually end in 24-36 hrs. Try and reduce fluids or stop altogether after 24-36 hrs.
• Patients who leak very rapidly with platelet counts dropping sharply usually have relatively shorter period of leaking
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• Keep systolic blood pressure above 100 mmHg• Keep pulse rate below 100/min• Keep pulse pressure above 30 mmHg• Keep UOP above and around 25 ml/hour
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Fluids used
• Crystalloids- normal saline and Hartmann’s solution – Most require only crystalloids– Used in maintenance and as boluses
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Fluids used
• Hyper-oncotic colloid solutions i.e dextran and 10% starch.
• Use only as boluses (500ml/hour)• Indications
– If shock does not respond to crystalloids– When shock detected in a overloaded patient– When heading towards fluid overload with crystalloids
only• Maximum doses-
– Dextran 30ml/kg/day Starch 50ml/kg/day
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• Iso-oncotic colloids i.e plasma, hemaccel – Not recommended
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• Fluids during end of leaking phase...
– If patient is well with stable pulse and blood pressure, do not try to correct the PCV
– Re-absorption will start soon and PCV will come down. Observe vital parameters closely
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Complications of DHF
• Too little fluid-profound or prolonged shock– Metabolic acidosis– multiorgan failure– DIC
• Too much fluid-fluid overload– Massive effusions- respiratory compromise– Pulmonary oedema
• Try to match leak
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End of leakage (Critical Phase)
Not always 48 hours from onsetCan be earlier
Important to detectMore fluid given afterwards can lead to fluid
overload
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End of leakage (Critical Phase)
•Clinical improvement•Return of Appetite•Haemodynamic stability (pulse, BP normal)•Diuresis•Stabilization of Hct•Rise in WBC followed by platelet count •Convalescent rash/generalized itching/bradycardia
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Management of shock
• Identify shock– Compensated shock- Pulse pressure <20
tachycardia – Decompensated shock- systolic BP<80,MAP<60– Profound shock- no pulse, BP
• Cause for shock– Leakage– Haemorrhage– Leakage with haemorrhage
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Leakage causing shock
• High haematocrit 20% or more• Treat with appropriate fluid
– Compensated shock– Hypotensive shock
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Haemorrhage causing shock
• Normal or low haematocrit– Misdiagnosed earlier as “myocarditis”
• Treat with blood
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Leakage and hemorrhage causing shock
• Normal or not so high HCT (equivocal) with shock
• HCT drops more than expected after fluid resuscitation
• Bring down HCT below 45 with crystalloid then blood
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Shock not responding to fluid-ABCS
• Acidosis-pH<7.35and HCO3 < 15• Bleeding• Calcium • Sugar
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Massive effusions, gross ascites
• Invariably due to fluid overload• Pleural effusions
– Respiratory embarrassment– May need to aspirate
• Gross tense ascites – Poor renal and splanchnic circulation– May need to relieve
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Pitfalls
• Shock in early leakage– Rapid leaker– Dehydration in febrile phase
• Shock without leakage– Haemorrhage during febrile phase
• Leptospirosis
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Management of shock
• Identify shock– Compensated shock- Pulse pressure <20
tachycardia – Decompensated shock- systolic BP<80,MAP<60– Profound shock- no pulse, BP
• Cause for shock– Leakage– Haemorrhage– Leakage with haemorrhage
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• Keep systolic blood pressure above 100 mmHg• Keep pulse rate below 100/min• Keep pulse pressure above 30 mmHg• Keep UOP above and around 25 ml/hour