dengue diagnosis and management

dengue

1. SEMINAR ON DENGUE FEVER DIAGNOSIS AND MANAGEMENT MODERATOR PRESENTER DR. D. KALITA NISHANT AGARWAL ASST. PROF. PGT DEPARTMENT OF PEDIATRICS, GMCH.

2. INTRODUCTION Dengue is a self limiting acute mosquito transmitted disease characterized by fever , headache, muscle, joint pains, rash, nausea and vomiting. The dengue viruses are the members of the genus flavi virus. There are four virus serotypes of which DEN1 and DEN2 widespread in India. Dengue viruses are transmitted by the bite of female Aedes ( Ae ) mosquitoes. other species such as Ae albopictus , Ae . polynesiensis and Ae . Niveus may also transmit dengue.

3. All ages and both sexes are susceptible to dengue fever . Infected person can transmit the virus to the mosquito 1 day before onset of febrile episode and remain infectious for next 6-7 days. Migration of patient during viremia to a non endemic area may introduce it into the area.

4. CLINICAL CLASSIFICATION (old) Dengue Fever : An acute febrile illness of 2-7 days duration with two or more of the following manifestations: Headache, retro-orbital pain, myalgia , arthralgia , rash, haemorrhagic manifestations.

5. 2. Dengue Haemorrhagic Fever : a). A probable or confirmed case of dengue PLUS b). Haemorrhagic tendencies evidenced by one or more of the following – Positive tourniquet test. Petechiae , ecchymoses or purpura . Bleeding from mucosa, gastrointestinal tract, injection sites or other sites. Haematemesis or malena PLUS

6. c). Thrombocytopenia (<100,000 cells per cumm ) PLUS d). Evidence of plasma leakage A rise in average haematocrit for age and sex >/= 20%. A more than 20% drop in haematocrit following volume replacement treatment compared to baseline. Signs of plasma leakage (pleural effusion, ascites , hypoproteinemia ).

7. 3. Dengue Shock Syndrome : All the above criteria for DHF PLUS Evidence of circulatory failure manifested by rapid and weak pulse and narrow pulse pressure (<20 mm Hg) or hypotension for age, cold and clammy skin and restlessness.

8. Grading of Dengue Fever DF : Fever of 2-7 days with two or more of the following: Headache Retro orbital pain Myalgia Arthralgia with or without leukopenia Thrombocytopenia and no evidence of plasma leakage DHF I: above criteria plus tourniquet test and evidence of plasma leakage. T hrombocytopenia with platelet count less than 100000/ cumm and Hct rise more than 20% over baseline.

9. Grading of Dengue Fever( contd ) DHF II : above plus some evidence of spontaneous bleeding in skin or other organs (black tarry stool, epistaxis, gum bleeds) and abdominal pain. Thrombocytopenia with platelet count less than 100000/ cumm and Hct rise more than 20% over baseline . DHF III (DSS): Above plus circulatory failure. Thrombocytopenia with platelet count less than 100000/ cumm and Hct rise more than 20% over baseline.

10. Grading of Dengue Fever(contd.) DHF IV : Profound shock with undetectable blood pressure or pulse. Thrombocytopenia with platelet count less than 100000/ cumm and Hct rise more than 20% over baseline.

11. THE TOURNIQUET TEST Is performed by inflating a blood pressure cuff to a midpoint between the systolic and diastolic pressure for five minutes. The test is considered positive when 10 or more petechiae per square inch over the forearm. In DHF , the test usually gives a definite positive test with 20 petechiae or more. The test may be negative or only mildly positive during the phase of profound shock (DSS). If tourniquet test is found negative it should be repeated. Early diagnosis of disease and admission of DHF patients in hospitals are important in order to reduce case fatality rates.

12. Dengue Infection symptomatic A symptomatic Mild dengue Severe dengue Mod dengue DF with risk factors &co morbid condition DF with warning signs and symptoms Undifferentiated DF Fever without complication Without capillary leakage DF/DHF with significant hemorrhage DHF with shock (DSS) Severe organ involvement Severe met disorder DF with warning signs and symptoms DHF I and DHF II with minor bleeds Infants Haemoglobinopathies Immunocomp Patients on steroids, anticoagulants or immunosuppresants

13. PATHOGENESIS Binding of the new virus to cross reactive non neutralising antibody from the previous infection or passively acquired antibodies in infant facilitating the uptake by mononuclear phagocytes This enable amplified viral replication (ADE)the resulting increase in viral load then drives an immuno pathogenic cascade. The resultant exaggerated cytokine response leads to a transient increase microvascular permeability as well as activation of the coagulating system.

14. THE COURSE OF DENGUE ILLNESS Febrile phase— High-grade fever for 2-7 days with facial flushing, skin erythema , generalized body ache, myalgia , arthralgia and headache. Some patients may have sore throat, injected pharynx and conjunctival injection, Anorexia, nausea and vomiting Rash may be seen on the 3 rd or 4 th day which may be rubelliform or maculopapular in nature. difficult to distinguish dengue clinically from non-dengue febrile diseases. clinical features are indistinguishable between severe and non-severe dengue cases.

15. Critical phase Temperature drops, Increase capillary permeability in parallel with increasing haematocrit levels. significant plasma leakage usually lasts 24–48 hours. Progressive leukopenia followed by a rapid decrease in platelet count usually precedes plasma leakage. Pleural effusion and ascites may be clinically detectable depending on the degree of plasma leakage and the volume of fluid therapy.

16. Shock occurs when a critical volume of plasma is lost. It is often preceded by warning signs. Mild haemorrhagic manifestations like petechiae and mucosal membrane bleeding may occurs. Massive bleeding may occur but not common. With prolonged shock progressive organ impairment, metabolic acidosis and DIC may occurs.

17. Severe organ impairment such as severe hepatitis, encephalitis or myocarditis and/or severe bleeding may also develop without obvious plasma leakage or shock. Those who improve after defervescence are said to have non-severe dengue. Those who deteriorate will manifest with warning signs. This is called dengue with warning signs. Some cases will deteriorate to severe dengue.

18. Recovery phase A gradual reabsorption of extravascular compartment fluid takes place in 2-3 days. General well-being, improves appetite returns, gastrointestinal symptoms abate, haemodynamic status stabilizes and diuresis ensues. Some patients may have a rash of “isles of white in the sea of red’’. Massive pleural effusion, Ascites , pulmonary edema or CCF may occur at any time if excessive intravenous fluids have been administered. The haematocrit stabilizes, White blood cell count usually starts to rise but the recovery of platelet count is typically later .

19. The course of dengue illness

20. Differential diagnosis of dengue fever ( febrile phase ) Flu-like syndromes- -- Influenza, measles, Chikungunya , infectious mononucleosis , HIV seroconversion illness Illnesses with a rash -- Rubella, measles, scarlet fever, meningococcal infection, Chikungunya , drug reactions Diarrhoeal diseases -- Rotavirus, other enteric infections Illnesses with neurological manifestations- ---- Meningo /encephalitis Febrile seizures

21. Differential diagnosis of dengue fever ( critical phase ) Infectious ---- Acute gastroenteritis, malaria, leptospirosis , typhoid, typhus, viral hepatitis, acute HIV seroconversion illness, bacterial sepsis, septic shock Malignancies ---Acute leukaemia and other malignancies Other clinical pictures Acute abdomen( acute appendicitis, acute Cholecystitis , perforated viscus ), Diabetic ketoacidosis , Lactic acidosis, Platelet disorders, Renal failure, Respiratory distress ( Kussmaul’s breathing), Systemic Lupus Erythematosus

22. APPROACH TO THE MANAGEMENT OF DENGUE

23. Step I—Overall assessment History-- The history should include: date of onset of fever/illness; quantity of oral intake; assessment for warning signs. diarrhoea; seroconversion illness.

24. change in mental state/seizure/dizziness; urine output (frequency, volume and time of last voiding); Other relevant histories,--- such as family or neighbourhood dengue, travel to dengue endemic areas, co-existing conditions e.g. infancy,

25. Physical examination-- should include: assessment of mental state; assessment of hydration status; assessment of haemodynamic status checking for tachypnoea / acidotic breathing/pleural effusion; checking for abdominal tenderness/ hepatomegaly / ascites ; examination for rash and bleeding manifestations; tourniquet test (repeat if previously negative or if there is no bleeding manifestation).

26. INVESTIGATION Complete blood count- Hb , TC, DLC, Platelet, haematocrit , PBS study A drop of platelet count <100000 cells/ cumm usullay found inbetween 3-10 days of illness. A rise of haematocrit occurs in critcal phase particularly in shock cases. Increase by 20% or more is objective evidence of plasma leakage. Haematocrit may become normal or decrease if there is haemorrhage. There is drop in tolal number of WBC and neutrophil with relative lymphocytosis and increase atypical lymphocyte towards the end of febrile phase.

27. Additional tests when indicated include Liver function test— transaminase leve may be mildly elevated. Coagulation profile Both APTT and PT may be prolong in severe haemorrhagic manifestation. Low fibrinogen and elevated fibrin degradation product levels are signs of DIC. Urea creatinine and serum electrolyte— ( Na + K + Ca 2+ Bicaronate ), lactate BUN is elevated in prolong shock. Hyponatremia is most common electrolyte abnormality in DHS and DSS. Hypocalcemia .

28. Stool for occult blood- guaiac test. Hypoalbuminaemia Blood sugar. Cardiac enzyme and ECG Urine specific gravity. Chest x ray and USG.

29. Laboratory tests to confirm the diagnosis . Virus isolation Viral nucleic acid detection(RT PCR). NS1 antigen detection- Serology Haemoagglutination test. Complement fixation test Neutralization test IgM capture-(MAC ELISA), Indirect IgG ELISA Within 5 days of illness After 5 days of illness

30. During the early stages of the disease, virus isolation, nucleic acid or antigen detection can be used to diagnose the infection. At the end of the acute phase of infection, serology is the method of choice for diagnosis. To distinguish primary and secondary dengue infections, IgM / IgG antibody ratios are now more commonly used than the haemagglutination -inhibition test (HI) NS1 antigen detection- NS1 antigen appears as early as day 1 of life, hence used for early diagnosis. Specificity is near 100% and sensitivity in first 4 days of illness is 90% in primary and 70% in secondary dengue.

31. IgM / IgG Ratios greater than 1.2 (using the patient’s sera at 1/100 serum dilution) or 1.4 (using serum dilution of 1/20) suggest a primary infection. IgG titres higher than 1/1280 by HIA or ELISA are also suggestive of a secondary infection.

32. Step II—Diagnosis, assessment of disease phase and severity On the basis of evaluations of the history, physical examination and/or full blood count and haematocrit , determine whether the disease is dengue, which phase it is in (febrile, critical or recovery), whether there are warning signs, the hydration and haemodynamic status of the patient, and whether the patient requires admission

33. CRITERIA FOR DENGUE ± WARNING SIGNS

34. CRITERIA FOR SEVERE DENGUE

35. Dengue Infection symptomatic A symptomatic Mild dengue Severe dengue Mod dengue DF with risk factors &co morbid condition DF with warning signs and symptoms Undifferentiated DF Fever without complication Without capillary leakage DF/DHF with significant hemorrhage DHF with shock (DSS) Severe organ involvement Severe met disorder DF with warning signs and symptoms DHF I and DHF II with minor bleeds Infants Haemoglobinopathies Immunocomp Patients on steroids, anticoagulants or immunosuppresants Home Mx Monitoring and possible hospitalization Tertiary level care

36. Admission criteria Any warning signs. Bleeding from any site independent of the platelet count. Any signs of organ impairment--- renal, cardiac, neurological or hepatic. Co existing condition ---peptic ulcer, haemolytic anemias , Overweight or obese (rapid venous access difficult in emergency), and Infancy. Sign and symptoms related to hypotension. Social circumstances-- Living far from health facility, Without reliable means of transport. Findings through further investigations--Rising haematocrit , Pleural effusion, ascites or asymptomatic gall-bladder thickening.

37. Step III—Management Disease notification In dengue-endemic countries, cases of suspected, probable and confirmed dengue should be notified as soon as possible so that appropriate public health measures can be initiated. Laboratory confirmation is not necessary before notification, but should be obtained.

38. Management decisions 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).

39. Group A Patients who do not have warning signs AND who are able: To tolerate adequate volumes of oral fluids To pass urine at least once every 6 hours

40. Action plan Oral intake of ORS, fruit juice and other fluids containing electrolytes and sugar. Plain water alone may cause electrolyte imbalance. Paracetamol for high fever. Tepid sponge if the patient still has high fever. Avoid acetylsalicylic acid (aspirin), ibuprofen or other NSAIDs as these drugs may aggravate gastritis or bleeding. Acetylsalicylic acid (aspirin) may be associated with Reye’s Syndrome.

41. Instruction for the care-givers no clinical improvement, deterioration around the time of defervescence , severe abdominal pain, persistent vomiting, cold and clammy extremities, lethargy or irritability/restlessness, bleeding, not passing urine for more than 4–6 hours.

42. MONITORING daily 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 .

43. Group B – Patients with warning signs, co-existing conditions ( infancy, obesity, renal failure, chronic haemolytic diseases), and certain social circumstances (living far from a health facility without reliable means of transport).

44. DENGUE FEVER WITH RISK FACTOR RL 7 ml/kg/hr Assessment at 1 hours Discharge when stable for 24-48 hrs RL 3 ml/kg/hr Further improvement RL 5ml/kg/hr improvement RL 15 ml/kg/hr No improvement No improvement RL 10 ml/kg/hr Assessment at 2 hours Look for aneamia , acidosis, and myocardial dysfunction No improvement Colloids 10 ml/kg/hr Continue IVF until table for 24 hs No improvement Assessment at 3 hrs

45. 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. For infants < 6 months old, D5 0.45 NaCI is preferable if available (D5 0.45 NaCI is prepared by mixing equal volumes of D5 0.9 NaCL and D5W.

46. Monitor 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).

47. Group C severe plasma leakage leading to dengue shock and/or fluid accumulation with respiratory distress; severe haemorrhages; severe organ impairment (hepatic damage, renal impairment, cardiomyopathy , encephalopathy or encephalitis).

48. FLUID MANAGEMENT IN SHOCK

49. Choice of IVF for resuscitation Crystalloids (Ringer's lactate or 0.9 NaCI solutions) have been shown to be safe and as effective as colloid solutions ( dextran , starch, or gelatin ) in reducing the recurrence of shock and mortality. Crystalloids should be used as first line in fluid resuscitation in compensated dengue shock. Colloids have been shown to restore the cardiac index and reduce the level of haematocrit faster than crystalloids in patients with intractable shock. colloids may be the preferred choice if the blood pressure has to be restored urgently, i.e. in those with pulse pressure less than 10 mm Hg.

50. Normal Saline 0.9% Saline is a suitable option for initial fluid resuscitation, but repeated large volumes of 0.9% saline may lead to hyperchloraemic acidosis. Hyperchloraemic acidosis may aggravate or be confused with lactic acidosis from prolonged shock. Monitoring the chloride and lactate levels will help to identify this problem. When serum chloride level exceeds the normal range, it is advisable to change to other alternatives such as Ringer’s Lactate.

51. Ringer’s Lactate Ringer’s Lactate has lower sodium (131 mmol /L) and chloride (115 mmol /L) contents and an osmolality of 273 mOsm /L. It is not be suitable for resuscitation of patients with severe hyponatremia . However, it is a suitable solution after 0.9 Saline has been given and the serum chloride level has exceeded the normal range. Ringer’s Lactate should probably be avoided in liver failure.

52. Colloids The types of colloids are gelatin -based, dextran -based and starch-based solutions. Of all the colloids, gelatine has the least effect on coagulation but the highest risk of allergic reactions. Allergic reactions such as fever, chills and rigors have also been observed in Dextran 70. Dextran 40 can potentially cause an osmotic renal injury in hypovolaemic patients.

53. Assessment of improvement

54. Compensated Shock (Systolic Pressure maintained + signs of reduced perfusion) Start isotonic crystalloid ^ 10-20 mL/kg/hr for 1 hour IV crystalloid, reduce gradually 10 mL/kg/hr for 1-2 hrs 7 mL/kg/hr for 2 hrs 5 ml/ kg/hr for 4 hrs 3mL/kg/hr As clinical improvement is noted, reduce fluids accordingly Further boluses may be needed for the next 24- 48 hrs Stop IV fluids at 48 hrs IMPROVEMENT * Check HCT Crytalloid (2 nd bolus ) or colloid 10-20 mL/kg/hr for 1 hr IMPROVEMENT * Reduce IV crystalloids 7-10 mL /kg/hr for 1-2 hours Severe overt bleed Urgent blood transfusion Colloid 10-20 mL/kg/hr .evaluate to consider blood transfusion if no clinical improvement ^ Colloid is preferable if the patient has already received previous boluses of crystalloid * Reasses the patient’s clinical condition, vital signs, pulse volume, CRT and temp of extremities IV : intravenous, HCT : haematocrit,↑ : increased ,↓ : decreased   YES   NO YES NO HCT↑ HCT↓ YES NO

55. Hypotensive shock Patients with dengue shock should be frequently monitored until the danger period is over. A detailed fluid balance of all input and output should be maintained. Parameters that should be monitored include vital signs and peripheral perfusion (every 15–30 minutes until the patient is out of shock, then 1–2 hourly). In general, the higher the fluid infusion rate, the more frequently the patient should be monitored and reviewed in order to avoid fluid overload while ensuring adequate volume replacement.

56. Hypotensive Shock Try to obtain an HCT level before fluid resuscitation Start isotonic crystalloid or colloid ^ 20mL/kg over 15-30 mins     IV crystalloid or colloid 10mL /kg/hr for 1 hour IV colloid 10 mL/kg/hr for 1 hour reduce gradually 7.5 mL/kg/hr for 2 hrs 5 mL/kg/hr for 4 hrs 3 ml/ kg/hr for 4 hours which can continue till 24- 48 hours   As clinical improvement is noted, reduce fluids accordingly   Stop IV fluids at 48 hrs IMPROVEMENT * Check HCT IV Crytalloid /colloid ^ (2 nd bolus) or colloid 10 mL/kg/hr for 30-60 min IMPROVEMENT * Reduce IV crystalloids 7-10 mL /kg/hr for 1-2 hours Severe overt bleed Urgent blood transfusion Colloid 10-20 mL/kg/hr .evaluate to consider blood transfusion if no clinical improvement ^ Colloid is preferable if the patient has already received previous boluses of crystalloid * Reasses the patient’s clinical condition, vital signs, pulse volume, CRT and temp of extremities IV: intravenous, HCT : haematocrit,↑ : increased ,↓ : decreased   YES   NO YES NO HCT↑ HCT↓ YES NO

57. Treatment of haemorrhagic complications Mucosal bleeding may occur in any patient with dengue but, if the patient remains stable with fluid resuscitation/replacement, it should be considered as minor. In patients with profound thrombocytopaenia , ensure strict bed rest and protect from trauma to reduce the risk of bleeding. Do not give intramuscular injections to avoid haematoma. prophylactic platelet transfusions for severe thrombocytopaenia in otherwise hemodynamically stable patients have not been shown to be effective and are not necessary.

58. Risk of major bleeding have prolonged/refractory shock; have hypotensive shock and renal or liver failure and/or severe and persistent metabolic acidosis; are given non-steroidal anti-inflammatory agents; have pre-existing peptic ulcer disease; are on anticoagulant therapy; have any form of trauma, including intramuscular injection.

59. Severe bleeding can be recognized by : a decrease in haematocrit after fluid resuscitation together with unstable haemodynamic status; refractory shock that fails to respond to consecutive fluid resuscitation of 40-60 ml/kg; hypotensive shock with low/normal haematocrit before fluid resuscitation;

60. Action plan Give 5–10ml/kg of fresh-packed red cells or 10–20 ml/kg of fresh whole blood at an appropriate rate and observe the clinical response. It is important that fresh whole blood or fresh red cells are given. Consider repeating the blood transfusion if there is further blood loss or no appropriate rise in haematocrit after blood transfusion. Transfuse platelet concentrates when massive bleeding can not be managed with just fresh whole blood/fresh-packed cells.

61. Causes of fluid overload :- excessive and/or too rapid intravenous fluids; incorrect use of hypotonic; inappropriate use of large volumes of IVF in patients with unrecognized severe bleeding; inappropriate transfusion of fresh-frozen plasma, platelet concentrates and cryoprecipitates ; continuation of IVF after plasma leakage has resolved; co-morbid conditions such as congenital heart disease. Treatment of Fluid overload

62. Early signs fluid overload : – respiratory distress, difficulty in breathing; – rapid breathing; – chest wall in-drawing; – wheezing; – large pleural effusions; – tense ascites ; – increased jugular venous pressure (JVP). Late signs fluid overload : – pulmonary oedema (cough with pink or frothy sputum ± crepitations , cyanosis); – irreversible shock (heart failure, often in combination with ongoing hypovolaemia ).

63. Treatment of fluid overload (cont.) Oxygen therapy should be given immediately. If the patient has stable haemodynamic status and is out of the critical phase, discontinue IVF. If necessary, give oral or intravenous furosemide . If the patient has stable haemodynamic status but is still within the critical phase, reduce the intravenous fluid accordingly. Avoid diuretics during the plasma leakage phase. If in shock despite clinical signs and symptoms of fluid overload Give 10ml/kg/hr of colloid. Once with BP is stable, administer IV furosemide 0.5 to 1mg/kg/dose; If BP is unstable, check ABCS and other electrolyte imbalance.

64. Cardiac complication Cardiac involvement may be seen during the period of shock and convalescence. Variable manifestations may be seen from myocarditis , arrhythmias to evidence of systolic or diastolic dysfunction presenting as heart failure and/or shock. Investigation should include an echocardiogram, ECG, chest x-ray and CPKMB.    

65. Management of Myocardial dysfunction. Systolic dysfunction should be treated with inotropes like dopamine, dobutamine or their combination and diastolic dysfunction should be treated with milrinone . fluids should be computed 50-75% of maintenance depending on the degree of heart failure. In patients with uncompensated shock due to hypovolemia but with heart failure, the recommendation for fluid boluses should be followed. At any point if fluid overload is considered, furosemide should be given once BP is stable.

66. Management of myocarditis If DF or DHF is complicated by myocarditis in the convalescent phase, bed rest is recommended. In addition, physical activity after discharge is restricted anywhere from 2 to 4 weeks up to 6 months depending on severity of the myocarditis . Management of Cardiac Arrhythmias During the period of convalescence, variable arrhythmias observed range from sinus node dysfunction (sinus bradycardia , junctional rhythm), conduction abnormalities like first degree AV block, Wencheback . In patients with cardiac arrhythmia but with no signs of heart failure, Usually no treatment is needed. 

67. Other complications of dengue Electrolyte and acid-base imbalances are also common observations in severe dengue and are probably related to gastrointestinal losses through vomiting and diarrhoea or to the use of hypotonic solutions for resuscitation and correction of dehydration. Hyponatraemia , hypokalaemia , hyperkalaemia , serum calcium imbalances and metabolic acidosis can occur. Patients who present with convulsion and/or coma may have Encephalopathy

68. Laboratory Investigations (ABCS) for patients who present with profound shock or have complications, and in cases with no clinical improvement inspite of adequate volume replacement

69. Criteria for discharge All of the following must be present: A. Clinical •No fever for 48 hrs •Improvement in clinical status (general well-being, appetite, hemodynamic status, urine output, no respiratory distress). •Minimum of 2-3 days have elapsed after recovery from shock B. Laboratory • Increasing trend of platelet count. (> 50000/ cumm ) • Stable hematocrit without IVF.

70. REFERENCES WHO guidelines for diagnosis, treatment, prevention and control. NVDCP guidelines for clinical management of dengue fever, dengue haemorrhagic fever and dengue shock syndrome. Immunopathogenesis of dengue virus infection journal. Nelson Textbook of PEDIATRICS(19 th edition). IAP guidelines for management of dengue MISSION UDAY