Dengue Fever

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presentation given to doctors working at BHU and RHC at EDO office.

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Dengue Fever

  1. 1. Dengue Fever Dr .AAMIR HALEEM F.C.P.S. (MEDICINE)
  2. 2. Dengue fever genus Flavivirus, family Flaviviridae also known as breakbone fever.(bonecrusher disease) Aedes aegypti
  3. 3.  WHO says some 2.5 billion people, two fifths of the worlds population, are now at risk from dengue and estimates that there may be 50 million cases of dengue infection worldwide every year. epidemic in more than 100 countries
  4. 4. Dengue Fever Dengue virus Most prevalent vector- borne viral illness in the world Main mosquito vector is Aedes aegypti Year round transmission
  5. 5. Incidence 50-100 million dengue fever infections per year globally 500,000 cases of severe dengue, dengue hemorrhagic fever or dengue shock syndrome 100-200 cases annually in U.S. Average case fatality 5%
  6. 6. Distribution Endemic in more than 100 tropical and subtropical countries Pandemic began in Southeast Asia after WW II with subsequent global spread Several epidemics since 1980s Distribution is comparable to malaria
  7. 7. Dengue Viral Infection (10,000) Asymptomatic Symptomatic (majority) (9000) (1000) UnusualViral Syndrome DF DHF dengue- (500 (400) (100) expanded dengue syndrome(<<1 %) With No Plasma leakage bleedin bleedin g g DHF DSS (98%) (1-2%) 5/13/2012 LAKKUMAR FERNANO 7
  8. 8. Incubation period3-14 days (commonly 4-7 days)
  9. 9. Clinical Presentation Spectrum of illness• non-specific febrile illness• classic dengue• dengue hemorrhagic fever• dengue shock syndrome• other (CNS dysfunction, liver failure, myocarditis)
  10. 10. Classic Dengue Acute febrile illness with headache, retro-orbital pain, myalgias, arthralgias ―Break-bone fever‖ High fever 5-7 days Second fever for 1-2 days in 5% patients Followed by marked fatigue days to weeks Classic dengue 15-60% of infections Nausea, vomiting, diarrhea (30%) Macular or maculopapular confluent rash (50%) Respiratory symptoms: cough, sore throat (30%)
  11. 11. Dengue Hemorrhagic FeverWHO classification of DHF Thrombocytopenia (platelet count <100,000) Fever 2-7 days Hemorrhagic manifestations with a positive tourniquet test, petechiae, ecchymoses or mucosal bleeding. Hemoconcentration or evidence of plasma leakage (ascites, effusion, decreased albumin)
  12. 12. Dengue Hemorrhagic Fever Usually occurs in secondary infections after actively or passively (maternal) acquired immunity to a different viral serotype Only 2-4% of secondary infections result in severe disease Mortality is 10-20% if untreated, but decreases to <1% if adequately treated Plasma leakage may progress to dengue shock syndrome
  13. 13. Disease Factors Dengue-2 serotype most virulent Increased severity with secondary infections Increased risk in children <15 years and elderly. Greatest risk of DHF in infants. More severe in females Increased mortality with comorbid conditions Less common in malnourished children
  14. 14. Clinical Case Definition forDengue Hemorrhagic Fever 4 Necessary Criteria: Fever, or recent history of acute fever Hemorrhagic manifestations Low platelet count (100,000/mm3 or less) Objective evidence of “leaky capillaries:”  elevated hematocrit (20% or more over baseline)  low albumin  pleural or other effusions
  15. 15. Four Grades of DHF Grade 1  Fever and nonspecific constitutional symptoms  Positive tourniquet test is only hemorrhagic manifestation Grade 2  Grade 1 manifestations + spontaneous bleeding Grade 3  Signs of circulatory failure (rapid/weak pulse, narrow pulse pressure, hypotension, cold/clammy skin) Grade 4  Profound shock (undetectable pulse and BP)
  16. 16. DF or DHF?DF vs DHF Important to differentiate Two different clinical conditions from the beginning of the illness; Though they look very similar on the first 2 days However badly managed DF will never become DHF (DF does not progress to DHF)5/13/2012 LAKKUMAR FERNANO 16
  17. 17. Difference between DF & DHF Dengue Fever(DF)  No plasma leakage  Plt may be decreased to <100,000 in about 50% of patients  Leucopenia (<5000) also present  Headache, muscle/ joint/ bone pain, haemorrhagic manifestations seen in both DF and DHF  MP rash seen more in DF than DHF5/13/2012 LAKKUMAR FERNANO 17
  18. 18. Hemorrhagic Manifestations of DF Skin hemorrhages: petechiae, purpura, ecchymoses Gingival bleeding Nasal bleeding Gastrointestinal bleeding: hematemesis, melena, hematochezia HematuriaHaemorrhagic Manifestations not enough to call it DHF5/13/2012 LAKKUMAR FERNANO 18
  19. 19. Difference between DF & DHF Dengue Fever(DF)  No plasma leakage – but H’agic manifestations can occur  Platelets drop to <100,000 in  about 50% (NOT ALL)  Occasionally even to as low as 5000!!!  But when it is < 50,000 significant chance that it is not just DF 5/13/2012 LAKKUMAR FERNANO 19
  20. 20. Dengue Haemorrhagic Fever(DHF) Key feature is PLASMA LEAK  Haemorrhagic manifestations + (at least +ve Hess’s)  (tender hepatomegaly- more in DHF)  Plt < 100,000 in ALL  Plasma leakage: • Rising Hct  20% or More OR even less but towards 20% if on IV fluids or on excess oral fluids,5/13/2012 LAKKUMAR FERNANO 20
  21. 21. Dengue Haemorrhagic Fever(DHF) Key feature is PLASMA LEAK  Haemorrhagic manifestations + (at least +ve Hess’s)  (tender hepatomegaly- more in DHF)  Plt < 100,000 in ALL  Plasma leakage: • Rising Hct  20% or More OR even less but towards 20% if on IV fluids or on excess oral fluids, • Se Cholesterol <100mg/dl •5/13/2012 Se Albumin <3.5 g/dl FERNANO LAKKUMAR 21
  22. 22. Dengue Haemorrhagic Fever(DHF) Key feature is PLASMA LEAK  Haemorrhagic manifestations + (at least +ve Hess’s)  (tender hepatomegaly- more in DHF)  Plt < 100,000 in ALL  Plasma leakage: • Rising Hct  20% or More OR even less but towards 20% if on IV fluids or on excess oral fluids, • Se Cholesterol <100mg/dl (or drop of 20mg/dl) •5/13/2012 Se Albumin <3.5 g/dl FERNANO (or drop of 0.5g/dl) 22 LAKKUMAR
  23. 23. Dengue Haemorrhagic Fever(DHF) Key feature is PLASMA LEAK  Haemorrhagic manifestations + (at least +ve Hess’s)  (tender hepatomegaly- more in DHF)  Plt < 100,000 in ALL  Plasma leakage: • Rising Hct  20% or More OR even less but towards 20% if on IV fluids or on excess oral fluids, • Se Cholesterol <100mg/dl (or drop of 20mg/dl) •5/13/2012 Se Albumin <3.5 g/dl FERNANO (or drop of 0.5g/dl) 23 LAKKUMAR
  24. 24. Natural Course of DHF Febrile phase: High fever for 2 – 7 days Critical phase: Plasma leakage Lasts 24- 48 h Usually on D5/ D6, but earliest on D3 Convalescent phase: 2-5 days Longer in adults5/13/2012 LAKKUMAR FERNANO 24
  25. 25. Natural Course of DF Febrile phase: High fever for 2 – 7 days No critical phase in DF!!! Convalescent phase: 2-5 days Longer in adults5/13/2012 LAKKUMAR FERNANO 25
  26. 26. Patient is in critical phase and confirmed to be DHF if … Fever D 3 or beyond Platelet < 100,000 (WBC < 5,000) Evidence of plasma leak  Effusions : pleura/ peritoneum (CXR/ USS)  Hct rise of 20% from baseline  Low albumin/ low cholesterol Hemorrhagic manifestations  (not essential if objective evidence of plasma leak+) Laboratory confirmation of dengue infection NOT5/13/2012 essential LAKKUMAR FERNANO 26
  27. 27. Detection of critical phase Defervescence Drowsy Rapid pulse Narrow pulse pressure (≤20 mmHg) Hypotension Rising Haematocrit Low Albumin level Low Cholesterol level5/13/2012 LAKKUMAR FERNANO 27
  28. 28. Haematocrit Rise of Hct by 20% over the baseline indicates leakage Eg: if baseline PCV 35% 42% = 20% rise5/13/2012 LAKKUMAR FERNANO 28
  29. 29. Danger Signs in Dengue Hemorrhagic Fever  Abdominal pain - intense and sustained  Persistent vomiting  Abrupt change from fever to hypothermia, with sweating and prostration  Restlessness or somnolenceMartínez Torres E. Salud Pública Mex 37 (supl):29-44, 1995.
  30. 30. Clinical Case Definition for Dengue Shock Syndrome4 criteria for DHF Evidence of circulatory failure manifested indirectly by all of the following:  Rapid and weak pulse  Narrow pulse pressure ( 20 mm Hg) OR hypotension for age  Cold, clammy skin and altered mental status Frank shock is direct evidence of circulatory failure
  31. 31. Unusual Presentations of Severe Dengue Fever Encephalopathy Hepatic damage Cardiomyopathy Severe gastrointestinal hemorrhage
  32. 32. Signs and Symptoms of Encephalitis/EncephalopathyAssociated with Acute Dengue Infection  Decreased level of consciousness: lethargy, confusion, coma  Seizures  Nuchal rigidity  Paresis
  33. 33. Physical Exam  Nonspecific findings  Conjunctival injection, pharyngeal erythema, lymphadenopathy, hepatomegaly (20- 50%)  Macular or maculopapular rash (50%)
  34. 34. tourniquet test The tourniquet test is performed by inflating a blood pressure cuff to a point mid-way between the systolic and diastolic pressures for five minutes. A test is considered positive when 10 or more petechiae per 2.5 cm2 (1 inch)are observed. In DHF, the test usually gives a definite positive result (i.e. >20 petechiae). The test may be negative or mildly positive during the phase of profound shock.
  35. 35. Laboratory Findings Leucopenia Thrombocytopenia (<100,000) Modest liver enzyme elevation (2-5x nml) Serology:• Anti-dengue IgM• Anti-dengue IgG• Dengue NS1 antigen• Dengue RNA by PCR• Dengue Virus culture
  36. 36. Virology Flavivirus family Small enveloped viruses containing single stranded positive RNA Four distinct viral serotypes (Den- 1, Den-2, Den-3, Den- 4)
  37. 37. Dengue Viruses Four closely related single-stranded RNA Dengue viruses (DEN-1, DEN-2, DEN-3 and DEN-4) Each serotype provides specific lifetime immunity, and short-term cross-immunity (A person can be infected as many as four times, once with each serotype)
  38. 38. Pathophysiology  Transmitted by the bite of Aedes mosquito (Aedes aegypti)  Incubation 3-14 days  Acute illness and viremia 3-7 days  Recovery or progression to leakage phase
  39. 39. Dengue Mosquito Aedes aegypti is the most important dengue mosquito It breeds in collections of water close to dwellings Common breeding sites are; - Domestic water storage containers - tanks, jars, drums, flower vases with water - Roof gutters /sun shades - Used tyres, discarded tins, cans, pots, yogurt cups, polythene bags, tree axils & - Many more places where rain water collects
  40. 40. The most common epidemic vector of dengue in the world isthe Aedes aegypti mosquito. It can be identified by the whitebands or scale patterns on its legs and thorax.
  41. 41. Replication and Transmission of Dengue Virus (Part 1)1. Virus transmitted 1 to human in mosquito saliva 22. Virus replicates in target organs 43. Virus infects white 3 blood cells and lymphatic tissues4. Virus released and circulates in blood
  42. 42. Replication and Transmission of Dengue Virus (Part 2)5. Second mosquito 6 ingests virus with blood6. Virus replicates in mosquito midgut and other organs, 7 infects salivary glands 57. Virus replicates in salivary glands
  43. 43. Treatment No specific therapy Supportive measures: adequate hydration acetaminophen (if no liver dysfunction) avoid ASA and NSAIDs DHF or DHF w/ shock: IV fluid resuscitation and hospitalization blood or platelet transfusion as needed
  44. 44. Fluid Management in Dengue.. Initially (During the 1st 2 days) dengue shock is extremely rare within 1st 2 daysThere is NO LEAKAGE Can give fluids freely How Much to Give?  GIVE THE NORMAL MAINTENANCE(M) or More as replacement if there is vomiting diarrhoea Give electrolyte solutions not plain water5/13/2012 LAKKUMAR FERNANO 46
  45. 45. Fluid Management in Dengue The critical phase is only 48 hrs (24- 50+) Some fluid restriction is essential during the critical phase(24-48hrs) The final outcome/morbidity/mortality will largely depend on the fluid management of the critical phase5/13/2012 LAKKUMAR FERNANO 47
  46. 46. Fluid Management in Dengue… After 3rd Day  May start leaking any time  DONT ASK TO DRINK PLENTY OF FLUIDS  SOME FLUID RESTRICTION IS USEFUL  LOOK FOR SIGNS OF LEAKING & platelets dropping <100,0005/13/2012 LAKKUMAR FERNANO 48
  47. 47.  WITHTHE NEW GUIDELINES ...AND WITH CORRECT FLUID THERAPY IN DENGUE THERE SHOULD BE NO WALKED IN , DEAD PATIENTS!!!
  48. 48. How to time the onset ofcritical phase and predict end.... Have serial FBCs done during the illness , ideally from the same reliable lab Beyond Day 3...when WBC is dropping below(or close to) 5000 and platelets are <150,000 and dropping do more than once/day DO FBC – Not PCV & Platelets!!!
  49. 49. How to time the onset of critical phase? 17th 18th 18th 19th 19th 20th 20th 21st 21st 8 am 8 am 8 pm 8 am 8 pm 8 am 8 pm 8 am 8 pmWBC 3200 2800 1900 2900 3700 4500 6000 7000 7300N% 53 41 31 26 25 31 33 43 58L% 44 56 68 71 73 67 66 55 41PCV 39 36 39 42 43 39 44 43 38%Plt 25200 12100 11000 61000 22000 18000 12000 8000 19000 0 0 0 Onset End
  50. 50. How to time the onset of critical phase? 17th 18th 18th 19th 19th 20th 20th 21st 21st 8 am 8 am 8 pm 8 am 8 pm 8 am 8 pm 8 am 8 pmWBC 3200 2800 1900 2900 3700 4500 6000 7000 7300N% 53 41 31 26 25 31 33 43 58L% 44 56 68 71 73 67 66 55 41PCV 39 36 39 42 43 39 44 43 38%Plt 25200 12100 11000 61000 22000 18000 12000 8000 19000 0 0 0 Onset End
  51. 51. How to confirm pt is in the critical phase..? Look for evidence of LEAKING  effusions pleural and/or peritoneal cavities Oedema, facial puffiness, leg/arm swelling are not suggestive of leaking but only suggest fluid overload
  52. 52.  Look for evidence of LEAKING  effusions pleural and/or peritoneal cavities Do not wait till these are clinically detectable Do USS chest/abdomen (rpt if needed) CXR R/lat decubitus (or PA for follow up and when clinically detectable) Very occasionally a very small pl effusion may be seen in pts with DF or when platelets are >100,000 but without other evidence of leaking; they will not progress (rpt CXR) L/sided effusion absorbing fluid?
  53. 53. Once in the critical phase... Monitor properly  Pulse; BP; HCT.....accurate values are needed for correct decision making on changes of fluid rates! Use capillary HCT(PCV) -  What we get from FBC counts are not always good for comparison  Venous HCT in a patient with IV fluids running can be sometimes misleading  Except while in prolonged and profound shock Capillary HCT is the BEST-NOT VENOUS!!!
  54. 54. Pulse and BP Not always easy manually  Sp. If oedematous / fluid overloaded Use a monitor (multi para monitor ) When the values on the monitor are doubtful re-check with another monitor If TWO monitors give similar values believe the monitor even if you cannot confirm manually
  55. 55. UOP (Urine Output).. When to catheterize...??Pros and cons of catheterization..If platelets counts are dropping fast and coming low better to do it before it drops too much to avoid bleeding while catheterizing..Measure UOP every hour  > 0.5ml/kg/hr
  56. 56. Duration of critical phase... Total maximum duration of leaking is only 48 hrs if it start slowly Once the patient is in SHOCK the leaking will usually end in 24 hrs look to see whether fluids can be reduced a lot or stopped after 24 hrs... Also patients who leak very rapidly with counts dropping sharply be prepared to anticipate relatively short period of leaking In Infants too it may be short 24hrs
  57. 57. Duration of critical phase... Your initial timing may proved to be sometimes wrong!!! Be prepared to change what you decided earlier / or shift the timing based on more information you receive while Mx
  58. 58. Fluid therapy... Each patient can be managed in many different ways and with different rate and choice of IV fluids but try to master the ways of giving the „smoothest‟ and the most „uneventful‟ recovery for the pt AVOID BOTH SHOCK & FLUID AIM: OVERLOAD
  59. 59. Fluid Management in Dengue…  Once patient is in the critical phase (24- 48hrs) TOTAL FLUIDS= MAINTENANCE+5% DEFICIT5/13/2012 LAKKUMAR FERNANO 61
  60. 60. Fluid quota for critical phase... Calculation M+5% Maintenance  1 st 10 kg 100ml/kg  2 nd 10 kg 50ml/kg  Balance wt 20ml/kg 5% body wt = 50ml/kg Eg: 22kg  (100x10 + 50x10+ 20x2) + 50x 22 1540 + 1100 = 2640ml5/13/2012 LAKKUMAR FERNANO 62
  61. 61. Fluid Management during the critical phase (DON’T OVER LOAD LEAKING VESSELES) Total amount of fluids = Maintainance + 5% deficit This includes both IV and oral fluids This amount of fluids is given over 24-48 hours Ideal body weight or actual body weight is used for calculation (whichever is smaller) BUT Maximum body weight for which fluid is calculated is only 50kg in ALL5/13/2012 LAKKUMAR FERNANO 63 children, adults, pregnancy..
  62. 62. TOTAL FLUID VOLUME INCRITICAL PHASE(usually 48HRS) Fluidvolume equivalent to (FLUID QUOTA)  Maintenance(only one day’s calculated volume) + 5% of body weight(i.e 50ml/kg) calculated for ideal body weight (or actual body weight if it is lower than IBW; maximum BW only 50kg) is the total fluid volume that should be given during the entire critical phase(leaking phase) irrespective of its length! This is usually 24-48 hrs and most patients it is 48 hours. Occasionally it 50 hrs or little more. Still one should try not to exceed this volume. (*note that it is almost one day’s fluids that is given over 2 days and maximum weight for which fluid is calculated is5/13/2012 50kg even if the actual weight is well above 50kg) LAKKUMAR FERNANO 64
  63. 63. Fluid Management during the critical phase In shock M+5% should be given over 24 h In non shock over 48 h If allocated fluid volume exceeds and shock still remains can give, but keeping in mind about the amount exceeded If UOP is 0.5-1 ml/ kg/h then the amount of fluid given is adequate If UOP is more that it suggests too much fluid5/13/2012 LAKKUMAR FERNANO 65
  64. 64. Critical Phase Fluids in DHF The maximum recommended total critical phase fluid volume for any given pt will not exceed 4600mlMaximum BWt 50 kg  M+5% - (maintenance – 100x10+ 50x10 + 20x 30 + (50x 50) When pt is in hospital or seen from the onset  When Mx begins with the onset of leaking total fluids should be given over 48 hrs. When Pt presents in SHOCK  The pt is already in the peak of leaking and has only 24 more hrs before the leaking stop. The total M+5% can here be givenLAKKUMAR FERNANO5/13/2012 over 24 hrs 66
  65. 65. IV fluids Normal Saline/ Hartmann <6/12 may use N/2 Dextran 40 (Dextran 40 in Saline) – Hyper-oncoticosmolarity of 310 mOsm/L. Oncotic pressure 1693 mmHg. Sodium Content — Dextran 40 10% in sodium chloride 0.9% provides 77 mEq of-->  High oncotic pressure  volume expender  Molecular wt 10,000- 100,000(average 40,000) when given as a bolus all molecules tend to stay together 6% Hetastarch (voluvan) - osmolality -308mosm/ mol wt 100,000 – leaking less ; volume expansion –less *** about 60% of pts with dengue shock could be managed only with crystalloids5/13/2012 LAKKUMAR FERNANO 67
  66. 66. WHAT FLUIDS AND WHEN? Initiallywhen pt come in shock (with no fluid overload) give N saline(crystalloids). If BP pulse not recordable give as fast as possible –free flow or 20ml/kg but only till BP/pulse can be felt  After this only 10ml/kg boluses  After 2 saline boluses consider colloids5/13/2012 LAKKUMAR FERNANO 68
  67. 67. WHAT FLUIDS AND WHEN? Initiallywhen pt come in shock (with no fluid overload) give N saline(crystalloids). If BP pulse not recordable give as fast as possible –free flow or 20ml/kg but only till BP/pulse can be felt  After this only 10ml/kg boluses  After 2 saline boluses consider colloids5/13/2012 LAKKUMAR FERNANO 69
  68. 68. When to give colloids? Crystalloids also leak through leaky capillaries during leaking phase and will not hold on volume and PCV for long(not more that 1-2 hrs) Colloids will not leak easily and will hold on to volume and maintain PCV for longer period (4-5 hrs) BEST COLLOID IS DEXTRAN 40! What about FFP will also readily leak !5/13/2012 LAKKUMAR FERNANO 70
  69. 69. Plasma (FFP) transfusion FFP almost have no place in the treatment of DHF/DSS!  Too large amount (40-50 ml/kg) to be given in order to correct coagulopathy  It is not effective in holding the intravascular volume because it iso-oncotic (the osmolarity is about 280-300 milli-osmole  readily leak!!!  **if FFP is given to provide clotting factors for pt with liver failure what is the point in allowing it to leak out of the vascular compartment by giving it during leaking phase?  If you are to keep FFP within the circulation better to give it AFTER the leaking stops!If you give Vit K from the time you notice significant rise of LFTs even such5/13/2012need could be avoided! LAKKUMAR FERNANO 71
  70. 70. Blood & blood component used in DHF/DSS patients Crystalloid 100% Platelet 0.4% Colloid Blood 20-25% 10-15% Courtesy of Prof5/13/2012 LAKKUMAR FERNANO 72 Siripen- Thailand
  71. 71.  Fluids that could be used as IV push for resuscitation  N saline,(FFP,) Haemaccel,gelfundin, hetastarch  If pulse/BP un-recordable give 20ml/kg fast (DHF IV)  If not(some pulse+) give 10ml/kg,  In dengue leaking is generally <10ml/kg/hr  After resuscitated  change to crystalloid  **FOR INITIAL RESUSCITATIONDO NOT USE DEXTRAN as its hyperosmoler nature may not open microcirculation5/13/2012 LAKKUMAR FERNANO 73
  72. 72. Use of colloids- Dextran40 One dose of dextran (10ml/kg/bolus) will bring down the haematocrit by 10 points during critical phase If Hct is 52% it should drop to 42% (or 43%)5/13/2012 LAKKUMAR FERNANO
  73. 73. How much colloids to give? Needed only during critical phase Both Dextran and hetastarch should ONLY be given as BOLUSES (NEVER as a continuous drip).  10ml/kg iv Dextran 40 maximum 3 doses(total 30ml/kg/day) per 24 hr period (i.e 6 doses over 48hrs)  Before Dextran take blood for cross matching Hetastarch maximum 5 doses over 24 hrs(10 boluses over 48 hrs) 5/13/2012 LAKKUMAR FERNANO 75
  74. 74. During critical 48 hrs... While giving fluid to maintain pulse/BP/PCV  If enough fluid left from total quota (M+5%) give crystalloids  If only little fluid is left from quota use more colloids. (keeping in mind the maximum)  Keeping checking ..., “On a time scale are you heading for fluid overload?”  if so, switch to a colloid5/13/2012 LAKKUMAR FERNANO 76
  75. 75. Furosemide*(frusemide).. Colloids when there is fluid overload.. When there is evidence of fluid overload use Furosemide with starch or dextran. (0.5-1mg/kg halfway during the bolus) But when furosemide is given be prepared to wait with the pt for at least 60minutes after the injection (effects like BP drop will occur within 60min) (* BNF’s spellings)5/13/2012 LAKKUMAR FERNANO 77
  76. 76.  when platelets are low may need but only in very exceptional circumstances  (Thailand only in <0.4% of pts with DHF)  Each platelet pack is 50-150ml  contribute to fluid overload  No prophylaxis plt. transfusion  At the initial phase the platelet drop >.100,000 is due to BM suppression but later when it drops <100,000 the cause is increase platelet consumption and the BM become hypercellular with increase production5/13/2012 LAKKUMAR FERNANO 78
  77. 77.  Fluids during end of leaking phase...  even if PCV is high if pt is well and pulse BP OK do not try to correct the PCV  Reabsorption will start soon and PCV will come down. WAIT5/13/2012 LAKKUMAR FERNANO 79
  78. 78. New fluid regimen...A form of fluid restriction during leakage phase  Help prevent FLUID OVERLOAD  Also prevent shock – give what is needed to maintain BP, Pulse and produce enough UOP (0.5-1ml/kg/hr)Prevention of shock  avoid organ failure, avoid DIC, coagulopathy due to Liver failure5/13/2012 LAKKUMAR FERNANO 80
  79. 79. Pts with complications .... Usually due to PROLONG SHOCK FLUID OVERLOAD5/13/2012 LAKKUMAR FERNANO 81
  80. 80. Prolonged shock 10 hours untreated - Death!!! > 4 hours untreated  Liver failure- prognosis 50%  Liver + Renal failure - prognosis10%  3 organs failure (+respiratory failure) – Prognosis is a miracle!!!5/13/2012 LAKKUMAR FERNANO 82
  81. 81. Complicated DHF When a pt is deteriorating with no response to fluid therapy…. A: Acidosis B: Bleeding C: Calcium S: Sugar5/13/2012 LAKKUMAR FERNANO 83
  82. 82. Acidosis Acidosis is common in profound shock Prolonged acidosis makes patients more prone to DIC Correct acidosis if pH is <7.35 and if HCO3- level <15 mmol/l One may use empirical NaHCO3 1ml/kgs slow bolus (max 10ml) diluted in equal volume (may repeat upto 50ml)5/13/2012 LAKKUMAR FERNANO 84
  83. 83. Hypocalcaemia Every patient with complicated DHF has hypocalcaemia. Dengue patients who develop convulsions are likely to have hypocalcaemia.(may give them empirical calcium) Detection of hypocalcaemia:  Measure serum Ca2+ level  Corrected QT interval in ECG5/13/2012 LAKKUMAR FERNANO 85
  84. 84. When to give calcium? Ifthe patient is complicated , and deteriorating or not showing expected improvement to fluid Rx think of hypocalcaemia. Give empirical calcium to such pts  Dose 1ml/kg of 10% Ca Gluconate slow bolus diluted in N saline over 10-15 min(look for bradycaria while pushing slowly) Max: 10ml. Can even give every 6Hrs if pt is not improving5/13/2012 LAKKUMAR FERNANO 86
  85. 85. Bleeding... When to suspect...?(when overt bleeding absent) 1. At presentation ...  After 20 ml fast NS bolus  No pulse !! Get ready with blood in case it is needed  ask for uncross matched O-ve blood and also sent for DT  Cant sustain BP even after colloid bolus and adequate fluid resus  PCV drop without pt improving  PCV drop > 10 points after 10ml/kg dextran x 1hr
  86. 86. Also consider blood transfusion Ifblood loss visible eg H’,mesis etc is > 10% of blood volume Even with bleeding the PCV drop may take time(4-5hrs). When the pt does not show improvement important to do repeat PCVs frequently
  87. 87. How to manage bleeding Use PRC or WB PRC as 5ml/kg at a time  If there is fluid overload(most frequently) WB-as 10ml/kg (if no fluid overload) Even if bleeding is likely and if PCV is >45% do not give blood without bringing down the PCV first by giving a colloid. Most of the time with blood give 0.5-1mg kg of frusemide at the middle5/13/2012 LAKKUMAR FERNANO 89
  88. 88. Mortality/Morbidity Treated DHF/DSS is associated with a 3% mortality rate. Untreated DHF/DSS is associated with a 50% mortality rate.
  89. 89. Vaccination No current dengue vaccine Estimated availability in 5-10 years Vaccine development is problematic as the vaccine must provide immunity to all 4 serotypes Lack of dengue animal model Live attenuated tetravalent vaccines under phase 2 trials New approaches include infectious clone DNA and naked DNA vaccines
  90. 90. PreventionBiological: Target larval stage of Aedes in large water storage containers Larvivorous fish (Gambusia), endotoxin producing bacteria (Bacillus), copepod crustaceans (mesocyclops)Chemical: Insecticide treatment of water containers Space spraying (thermal fogs)
  91. 91. Public Health Major and escalating global public health problem Global demographic changes: urbanization and population growth with substandard housing, water, and waster management systems Deteriorating public health infrastructure with limited resources resulting in ―crisis management‖ not prevention Increased travel Lack of effective mosquito control
  92. 92. Mosquito control: Options available “Mosquitoes take about 7 days to complete life cycle. The first three Stages: eggs,larva and pupa are aquatic. Therefore, the best way to prevent mosquito breeding is to remove stagnant clear water”
  93. 93. THANK YOU You’re welcome!

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