In 2009 the disease burden of dengue in Sri Lanka was unprecedented with 35,010 cases and 346 deaths the highest recorded mortality to date. Given the known epidemiological trend we cannot foresee a reduction in the disease burden in the near future. Under the circumstances our role should be to ensure that no patient dies of dengue. This is a realistic goal which responsible clinicians should strive to achieve. This assertion is not speculative but based on an in-depth analysis of dengue-related deaths, new knowledge about the disease and personal experience.
Of the 80 patients who have died of dengue from January to June this year, 70% have been adults. This disparity is not due to a change in the disease but because the pediatricians have changed the way they manage their patients. It is unfortunate however that some of the physicians are resistant to change and have not kept pace with what is new.
Consequently, patients are deprived of a novel approach of care that has added a new dimension, particularly to fluid therapy which is the cornerstone of management. In view of the relatively good results obtained, clinicians often tend to think and justify their management as correct and remain complacent as the vast majority of symptomatic patients have dengue fever and will recover in any case. The few who develop dengue haemorrhagic fever are often slow leakers and even when the fluid therapy is less than optimal they too have a high chance of recovery.
Against this background what needs to be appreciated is that vast strides have been made in the understanding of the disease and refinements to fluid therapy. A clear understanding of the course of the disease makes one realize the high predictability of the outcomes. Such insight paves the way for a rational and scientific way to manage each stage of the disease.
Blind and empirical therapy is thus neither needed nor advocated in the basic management of dengue fever and dengue hemorrhagic fever. Properly timed appropriate specific interventions regarding both the quality and quantity of fluid as well as adjuvant therapy can thwart progression to a fatal outcome amidst cascading complications triggered by profound shock provided it is detected early and addressed aggressively within four hours of onset. Such success stories, of which there have been many in the recent past, reflect what can be achieved even from a seemingly hopeless position by those who have mastered the profundity of the disease and are committed to apply national guidelines with diligence to suit individual patient requirements.
The time is ripe, though belated, for those physicians who are still in a slumber to wake up and cast aside the pervading dogma and open up their hearts and minds to understand the basics of the disease and the subtleties of fluid management. It is only then, that they too can experience the delight of treating scientifically a truly fascinating disease with a highly predictable favourable outcome.
Readers are requested to refer to the National Guidelines on Management of DF& DHF of the Ministry of Health Sri Lanka for details on management. Copies are available at the Epidemiology Unit 231, De Saram Place, Colombo 10.
The electronic version is available on: www.epid.gov.lk.
For the benefit of busy physicians I have highlighted a few practice points of practical importance aimed to reduce morbidity and mortality (read the "Practice points" article below).
The writer is Consultant
Unit (formerly NHSL)
- Diagnose dengue infection early (not later than Day 3) Remember that dengue is hyperendemic in Sri Lanka and hence the need to think about dengue first in all acute febrile illnesses. Be vigilant.
- Early diagnosis requires only the intelligent application of data from full blood counts done from D2 or D3 onwards to the clinical features. Always check for diffuse blanching erythema which is very common and an exceedingly useful sign to diagnose dengue early.
- Identify the clinical type as DF (no plasma leakage) or DHF (evidence of plasma leakage & platelet count equal to or below 100,000/c.mm)
- Monitor vital signs and FBC even if the patient is haemodynamically stable to detect entry into the critical phase early. Be alert. Shock after admission reflects delayed or misdiagnosis, poor monitoring and or improper fluid therapy.
- Confirm plasma leakage by ultrasonography or CXR (R lateral decubitus) or biochemical data.
- Determine as accurately as possible the time of onset of plasma leakage and the predicted time of end of the critical phase. It can be accurately deduced by an intelligent analysis of the total & differential white blood cell counts, platelet counts and haematocrit of the entire series of FBCs available from D 2 onwards. This information is a basic prerequisite for accurate fluid therapy.
- Calculate the fluid quota for the entire period of plasma leakage i.e. M+5% for 48 hrs. Fluid rate has to be adjusted hour by hour based on the capillary haematocrit and vital signs during this period to match the dynamics of plasma leakage. Do NOT give fluid at a flat rate.
- Manipulate the use of crystalloids, Dextran, and Hetastarch intelligently in relation to the point in the time scale of the disease in the critical phase, and the balance of the fluid quota to prevent both shock as well as fluid overload. Be aggressive.
- Dextran is given as a bolus and NOT as an infusion.
- Do not give intravenous fluids nor Dextran during convalescence when the leaked fluid is being reabsorbed and tends to augment the risk of fluid overloading. Ensure a smooth convalescence.
- Always consider dengue shock syndrome first, in the initial diagnostic evaluation of any patient with a history of fever presenting in shock who is found to be afebrile at the time of shock. Clue to the correct diagnosis would be a high haematocrit with thrombocytopaenia. FBC is an urgent mandatory investigation.
- Accurate and rational management of all stages of the disease from its inception (particularly at the beginning of the critical phase) can prevent potentially fatal complications like liver, renal and respiratory failure as well as life threatening bleeding & DIC.