Dengue Fever: Management Guidelines

Dengue Fever: Management Guidelines

Management Guidelines depending on the clinical manifestations and other circumstances, patients may be sent home (Group A), be referred for in-hospital management (Group B), or require emergency treatment and urgent referral (Group C).

Group A

Patients who may be sent home. These are patients who are able to tolerate adequate volumes of oral fluids and pass urine at least once every six hours, and do not have any of the warning signs, particularly when fever subsides. Ambulatory patients should be reviewed daily for disease progression (decreasing white blood cell count, defervescence and warning signs) until they are out of the critical period. Those with stable haematocrit can be sent home after being advised to return to the hospital immediately if they develop any of the warning signs and to adhere to the following action plan:

  • Encourage oral intake of oral rehydration solution (ORS), fruit juice and other fluids containing electrolytes and sugar to replace losses from fever and vomiting. Adequate oral fluid intake may be able to reduce the number of hospitalization). [Caution: fluids containing sugar/glucose may exacerbate hyperglycaemia of physiological stress from dengue and diabetes mellitus.
  • Give paracetamol for high fever if the patient is uncomfortable. The interval of paracetamol dosing should not be less than six hours. tepid sponge if the patient still has high fever. Do not give acetylsalicylic acid (aspirin), ibuprofen or other non-steroidal anti-inflammatory agents (NSAIDs) as these drugs may aggravate gastritis or bleeding. Acetylsalicylic acid (aspirin) may be associated with Reye’s Syndrome.

Care Giver Instructions

Instruct the care-givers that the patient should be brought to hospital immediately if any of the following warning signs:

  • No clinical improvement
  • Deterioration around the time of effervescence
  • Severe abdominal pain
  • Persistent vomiting
  • Cold and Clammy extremities
  • Lethargy or irritability/restlessness
  • Bleeding (ex: black stools or coffee-ground vomiting)
  • Not passing urine for more than 4 to 6 hours

Patients who are sent home should be monitored daily by health care providers for temperature pattern, volume of fluid intake and losses, urine output (volume and frequency), warning signs, signs of plasma leakage and bleeding, haematocrit, and white blood cell and platelet counts.

Group B

Patients who should be referred for in-hospital management Patients may need to be admitted to a secondary health care center for close observation, particularly as they approach the critical phase.

  1. These include patients with warning signs
  2. Those with co-existing conditions that may make dengue or its management more complicated (such as pregnancy, infancy, old age, obesity, diabetes mellitus, renal failure, chronic haemolytic diseases)
  3. Those with certain social circumstances (such as living alone, or living far from a health facility without reliable means of transport)

Warning Signs

If the patient has dengue with warning signs, the action plan should be as follows:

Obtain a Reference Haematocrit

Obtain a reference haematocrit before fluid therapy. Give only isotonic solutions such as 0.9% saline, Ringer’s lactate, or Hartmann’s solution. Start with 5–7 ml/ kg/hour for 1–2 hours, then reduce to 3–5 ml/kg/hr for 2–4 hours, and then reduce to 2–3 ml/kg/hr or less according to the clinical response.

Reassess the Clinical Status

Reassess the clinical status and repeat the haematocrit. If the haematocrit remains the same or rises only minimally, continue with the same rate (2–3 ml/kg/hr) for another 2–4 hours. If the vital signs are worsening and haematocrit is rising rapidly, increase the rate to 5–10 ml/kg/hour for 1–2 hours. Reassess the clinical status, repeat the haematocrit and review fluid infusion rates accordingly.

Give the minimum intravenous fluid volume

Give the minimum intravenous fluid volume required to maintain good perfusion and urine output of about 0.5 ml/kg/hr. Intravenous fluids are usually needed for only 24–48 hours. Reduce intravenous fluids gradually when the rate of plasma leakage decreases towards the end of the critical phase. This is indicated by urine output and/or oral fluid intake that is/are adequate, or haematocrit decreasing below the baseline value in a stable patient.

Constant Monitor till Risk is Over

Patients with warning signs should be monitored by health care providers until the period of risk is over. A detailed fluid balance should be maintained. Parameters that should be monitored include vital signs and peripheral perfusion (1–4 hourly until the patient is out of the critical phase), urine output (4–6 hourly), haematocrit (before and after fluid replacement, then 6–12 hourly), blood glucose, and other organ functions (such as renal profile, liver profile, coagulation profile, as indicated).

If the patient has dengue without warning signs, the action plan should be as follows:-

Encourage Oral Fluids

If not tolerated, start intravenous fluid therapy of 0.9% saline or Ringer’s lactate with or without dextrose at maintenance rate. For obese and overweight patients, use the ideal body weight for calculation of fluid infusion. Patients may be able to take oral fluids after a few hours of intravenous fluid therapy. Thus, it is necessary to revise the fluid infusion frequently. Give the minimum volume required to maintain good perfusion and urine output. Intravenous fluids are usually needed only for 24–48 hours.

Monitor Temperature Pattern

Patients should be monitored for temperature pattern, volume of fluid intake and losses, urine output (volume and frequency), warning signs, haematocrit, and white blood cell and platelet counts. Other laboratory tests (such as liver and renal functions tests) can be done, depending on the clinical picture and the facilities of the hospital.

Group C

Patients who require emergency treatment and urgent referral when they have severe dengue Patients require emergency treatment and urgent referral when they are in the critical phase of disease such as when they have:

  1. Severe plasma leakage leading to dengue shock and/or fluid accumulation with respiratory distress
  2. Hemorrhages
  3. Organ Impairment (hepatic damage, renal impairment, cardiomyopathy, encephalopathy or encephalitis).

All patients with severe dengue should be admitted to a hospital with access to intensive care facilities and blood transfusion. Judicious intravenous fluid resuscitation is the essential and usually sole intervention required.

Crystalloid Solution

The crystalloid solution should be isotonic and the volume just sufficient to maintain an effective circulation during the period of plasma leakage. Plasma losses should be replaced immediately and rapidly with isotonic crystalloid solution or, in the case of hypotensive shock, colloid solutions. If possible, obtain haematocrit levels before and after fluid resuscitation.

IV crystalloid 5–7 ml/kg/hr for 1–2 hours, then: reduce to 3–5 ml/kg/hr for 2–4 hours; reduce to 2–3 ml/kg/hr for 2–4 hours. If patient continues to improve, fluid can be further reduced. Monitor HCT 6–8 hourly.

If the patient is not stable, act according to HCT levels: if HCT increases, consider bolus fluid administration or increase fluid administration; if HCT decreases, consider transfusion with fresh whole transfusion, Stop at 48 hours. There should be continued replacement of further plasma losses to maintain effective circulation for 24–48 hr,crossmatch should be done for all shock patients.

Blood Transfusion

Blood transfusion should be given only in cases with suspected/severe bleeding. Fluid resuscitation must be clearly separated from simple fluid administration. This is a strategy in which larger volumes of fluids (ex: 10 to 20 ml boluses) are administered for a limited period of time under close monitoring to evaluate the patient’s response and to avoid the development of pulmonary oedema.

The degree of intravascular volume deficit in dengue shock varies. Input is typically much greater than output, and the input/ output ratio is of no utility for judging fluid resuscitation needs during this period. The goals of fluid resuscitation include improving central and peripheral circulation (decreasing tachycardia, improving blood pressure, pulse volume, warm and pink extremities, and capillary refill time 50%), repeat a second bolus of crystalloid solution at 10–20 ml/kg/hr for one hour.

After this second bolus, if there is improvement, reduce the rate to 7–10 ml/ kg/hr for 1–2 hours, and then continue to reduce as above. If haematocrit decreases compared to the initial reference haematocrit.

Medication Summary

No specific antiviral medication is currently available to treat dengue. The treatment of dengue fever is symptomatic and supportive in nature. Bed rest and mild analgesic-antipyretic therapy are often helpful in relieving lethargy, malaise, and fever associated with the disease.

Acetaminophen (paracetamol) is recommended for treatment of pain and fever. Aspirin, other salicylates, and nonsteroidal anti-inflammatory drugs (NSAIDs) should be avoided.

Patients with dengue hemorrhagic fever or dengue shock syndrome may require intravenous volume replacement. Plasma volume expanders can be used in patients who do not respond to isotonic fluids.

Crystalloids for Fluid Therapy

Class Summary

Isotonic (0.9%) sodium chloride solution or lactated Ringer solution is administered intravenously to maintain intravascular volume, blood pressure, and urine output.

Lactated Ringer solution/isotonic sodium chloride solution

These fluids are used to expand intravascular volume. Both fluids are essentially isotonic and have equivalent volume restorative properties. Although administration of large quantities of either fluid may lead to some differences in metabolic changes, for practical purposes and in most situations, these differences are clinically irrelevant. Importantly, no demonstrable difference in hemodynamic effect, morbidity, or mortality exists with either product.

Volume Expanders(Class Summary)

Plasma volume expanders are used in the treatment of intravascular volume deficits or shock to restore intravascular volume, blood pressure, and tissue perfusion.

Dextran 40 (LMD)

Dextran 40 is a polymer of glucose. When infused, it increases intravascular volume, blood pressure, and capillary perfusion. It is used to restore intravascular volume when isotonic crystalloid administration is inadequate for that purpose.

Albumin

Human albumin is a sterile solution of albumin, which is the major plasma protein responsible for the colloid oncotic pressure of blood. It is pooled from blood, serum, plasma, or placenta from healthy donors. Infusion of albumin results in a shift of fluid from the extracellular space into the bloodstream, thereby decreasing hemoconcentration and blood viscosity.Albumin may be administered wide open when treating shock. Patient response must be assessed before repeating the dose.

Hetastarch (Hespan, Hextend)

Hydroxyethyl starch is a sterile solution of the starch responsible for the colloid oncotic pressure of blood. Hetastarch produces volume expansion through its highly colloidal starch structure.

Blood Products

In practice, platelet transfusions are usually given to patients who develop serious hemorrhagic manifestations or have very low platelet counts,although the exact platelet count at which platelets should be given has not been defined.

Transfused platelets survive only for a very short period in patients with shock syndrome. The degree of elevation of circulating platelets after transfusion varies directly with the amount of platelets transfused and inversely with the degree of shock.

There is some evidence of benefit with fresh frozen plasma transfusion in increasing platelet count, although the effect of plasma transfusion in dengue shock has not been studied in a controlled clinical trial. Blood transfusion is required in patients with severe hemorrhage,but there are no published data on its use.

Corticosteroids

The World Health Organization guidelines for management of dengue do not recommend the use of corticosteroids. Clinical trials of corticosteroids in dengue have been inconclusive so far, and for the most part have been underpowered and lacking in methodological quality. Some of the early studies demonstrated possible beneficial effects of corticosteroids in dengue shock.

However, a Cochrane review of these studies showed no benefit. Nonetheless, these randomized studies have been small and were performed over 20 years ago.A more recent study showed no beneficial effect of dexamethasone on platelet counts.A recent retrospective study showed some benefit with methylprednisolone in patients with severe dengue.

Although some clinicians use steroids in treatment, there is currently no clear evidence to justify the use of corticosteroids in the treatment of severe Dengue. There is a clear need for adequately powered, randomized, double-blind, placebo-controlled clinical trials. These are required in both children and adults. They can be used to evaluate fully the possible benefit or lack of benefit of corticosteroids in dengue infection.

Diet and Activity

No specific diet is necessary for patients with dengue fever. Patients who are able to tolerate oral fluids should be

encouraged to drink oral rehydration solution, fruit juice, or water to prevent dehydration from fever, lack of oral intake, or vomiting. Return of appetite after dengue hemorrhagic fever or dengue shock syndrome is a sign of recovery.

Bed rest is recommended for patients with symptomatic dengue fever, dengue hemorrhagic fever, or dengue shock syndrome. Permit the patient to gradually resume their previous activities, especially during the long period of convalescence.

Criteria for Discharging Patients

  1.  Absence of fever for at least 24 hours without the use of anti-fever therapy.
  2. Return of appetite
  3. Visible clinical improvement
  4. Good urine output
  5. Minimum of three days after recovery from shock
  6. No respiratory distress from pleural effusion and no ascites
  7. Platelet count of more than 50,000/mm.

References

“Dengue Haemorrhagic Fever – diagnosis, treatment, prevention and control”, 2nd Edition, WHO, Geneva, 1997.

“Regional Guidelines for Prevention and Control of Dengue/DHF”, WHO/SEARO, New Delhi, 1998

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