No specific drugs
Plasma, Electrolytes, Platelets, Blood
Paracetamol, no Aspirin
Loss of plasma
The main abnormality seen in dengue haemorrhagic fever / dengue shock syndrome is a sharp increase in vascular permeability leading to a loss in plasma from the vascular tissues. Plasma leakage can lead to shock, which, if uncorrected, could eventually lead to death.
All patients demonstrate increased capillary fragility, depicted by positive tourniquet tests* and easy bruising. In prolonged uncontrolled shock, bleeding may lead to lethal shock. This bleeding is most likely to occur in the gastrointestinal tract / gastrointestinal haemorrhage.
In most cases, early and effective replacement of plasma losses with fluid and electrolyte solutions or plasma expander* results in a promising outcome. The prospects of the patient depend on early recognition and treatment of shock.
A continuous decrease in the platelet count synchronistic with a rise in the haematocrit* is an important indication of the onset of shock. Early signs of shock can be recognised by repeated platelet and haematocrit determinations. Observers should watch for signs of deterioration, or warning signs of shock like lethargy or restlessness, sharp abdominal pain, skin congestion, cold extremities or oliguria*.
Dengue Haemorrhagic Fever
Patients are prone to dehydrating due to vomiting and high fever; thus an ample volume of fluid by mouth is necessary. Instead of drinking water, it is advisable to drink fruit juice, electrolyte replacement solution or oral rehydration solution. However, the liquid drunk must be either coloured lightly or have no colour.
The person should not be allowed to go to school or work as this would enable the dengue virus to be transmitted to more people. This is because the only way in which dengue can be transmitted is if an female Aedes mosquito bites an infected person, and then bites another individual – who will become infective about eight days after being bitten.
Salicylates (including Aspirin) should be avoided as they may cause bleeding. Paracetamol can be taken to reduce fever. A dose of Paracetamol should be administered only when the body temperature is above 39 º C, but no more than 6 doses should be taken in a 24-hour period.
The critical period of the illness is after the third day. The haematocrit should be determined daily from the third day until the fever has subsided for 1 or 2 days. Changes in the haematocrit, vital signs or urine output can monitor plasma loss.
When is hospitalisation necessary?
If the patient has become dehydrated considerably, then immediate fluid expansion is necessary. Signs of such dehydration include:
– cool, mottled or pale skin
– changes in mental status
– narrowing of pulse pressure
– increased capillary refill time
– diminished peripheral pulses
– sudden rise in haematocrit, or a continuous rise even while administering fluids.
However, even if a medic has deemed the dengue case to not be severe, the symptoms should still be monitored.
Dengue Shock Syndrome
Shock, being a medical emergency, must be dealt with promptly by administering intravenous fluid to increase plasma volume. Patients, particularly children, may emerge in and out of shock during a 48-hour period. Thus the patient must be monitored round the clock by nursing staff.
Sedative therapy may be needed to control a nervous child. Agitation may be an early sign of hepatic failure. Long-acting sedatives must be avoided.
It should be given to all patients in shock. However, it must be noted that an oxygen mask or tent may elevate the patient’s anxiety, and so efforts must be made to reassure them.
This is usually needed only in cases of severe bleeding. A drop in the haematocrit with no signs of improvement even after administering fluid, indicates a significant internal haemorrhage. To avoid further bleeding, invasive devices and procedures should be limited to those that are mandatory.
Essential Laboratory Tests
To assess a patient’s condition, the following tests are recommended:
– blood gas and serum electrolytes studies
– liver function tests
– platelet count, prothrombin & thrombin time and partial thromboplastin time
How to Monitor Patients in Shock
– Blood pressure, pulse and respiration must be recorded every 30 minutes (or more frequently) until shock is overcome.
– Haematocrit or haemoglobin levels have to be noted every 2 hours for the first 6 hours, and then every 4 hours until stable.
– A fluid balance sheet must be maintained. It should contain details of the type of fluid and rate and volume of its administration. The volume and frequency of urine output must also be noted here.
Criteria for Discharging Patients
In order for patients recovering from dengue haemorrhagic fever / dengue shock syndrome to be discharged, the following conditions must be complied with:
– no fever for a minimum of 24 hours without the use of any medication to combat fever.
– Return of appetite
– Visible improvement
– Good urine output
– Stable haematocrit
– At least 2 days must have passed since recovery from shock
– No respiratory distress
– Platelet count of more than 50 000 per mm³
haematocrit – relative volume of blood occupied by erythrocytes (red blood cells).
oliguria – secretion of a diminished volume of urine in relation to the fluid intake.
positive tourniquet test – when a blood pressure cuff is inflated on the upper arm for 5
minutes, 20 or more petechiae per square inch are observed.
plasma expander – artificial plasma extender