DENGUE:
Types
There are twomaintypesof volume expanders;crystalloidsandcolloids.Crystalloidsare aqueous
solutionsof minera...
[edit] Ringer'ssolution
Lactated Ringer'ssolutioncontains28mmol/Llactate,4 mmol/LK+ and 1.5 mmol/LCa2+. It isvery
similar-...
[edit] Comparisontable
Compositionof commoncrystalloidsolutionsSolution OtherName
[Na+](mmol/L) [Cl-](mmol/L) [Glucose](mm...
withrespiratorydistress;
– severe haemorrhages;
– severe organimpairment(hepaticdamage,renal impairment,cardiomyopathy,
en...
• If vital signsare still unstable (i.e.shockpersists),checkthe haematocritafterthe firstbolus.If the
haematocritincreases...
Considerrepeatingthe bloodtransfusionif there isfurtherbloodlossorno appropriate rise in
haematocritafterbloodtransfusion....
Patientswhoremaininshockwithlowornormal haematocritlevelsbutshow signsof fluid overload
may have occulthaemorrhage.Further...
Ringer’sLactate
Ringer’sLactate has lowersodium(131mmol/L) andchloride (115 mmol/L) contentsandan osmolality
of273 mOsm/L....
Upcoming SlideShare
Loading in...5
×

Dengue

729

Published on

Published in: Business, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
729
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
11
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Dengue"

  1. 1. DENGUE: Types There are twomaintypesof volume expanders;crystalloidsandcolloids.Crystalloidsare aqueous solutionsof mineral saltsorotherwater-soluble molecules.Colloidscontainlargerinsoluble molecules, such as gelatin;blooditself isa colloid. [edit] Colloids Colloidspreserve ahighcolloidosmoticpressure inthe blood,while,onthe otherhand,thisparameter isdecreasedbycrystalloidsdue tohemodilution.[1] Therefore,theyshouldtheoreticallypreferentially increase the intravascularvolume,whereascrystalloidsalsoincrease the interstitialvolume and intracellularvolume.However,there isstillcontroversyastothe actual difference inefficacydue tothis difference inaction.[1] Anotherdifference isthatcrystalloidsgenerallyare muchcheaperthan colloids.[1] [edit] Hydroxyethylstarch Main article:Hydroxyethyl starch Hydroxyethyl starch(HES/HAES,commontrade names:Hespan,Voluven) isone of the mostfrequently usedcolloids.Anintravenoussolutionof hydroxyethyl starchisusedtopreventshockfollowingsevere bloodlosscausedbytrauma, surgery,orsome otherproblem.Itincreasesthe bloodvolume,allowing redbloodcellstocontinue todeliveroxygentothe body. [edit] Crystalloids The most commonlyusedcrystalloidfluidisnormal saline,asolutionof sodiumchloride at0.9% concentration,whichisclose tothe concentrationinthe blood(isotonic).Ringer'slactate orRinger's acetate isanotherisotonicsolutionoftenusedforlarge-volume fluidreplacement.A solutionof 5% dextrose inwater,sometimescalledD5W,isoftenusedinsteadif the patientisatriskforhavinglow bloodsugaror highsodium.The choice of fluidsmayalsodependonthe chemical propertiesof the medicationsbeinggiven. Intravenousfluidsmustalwaysbe sterile.
  2. 2. [edit] Ringer'ssolution Lactated Ringer'ssolutioncontains28mmol/Llactate,4 mmol/LK+ and 1.5 mmol/LCa2+. It isvery similar- thoughnot identical to - Hartmann'sSolution,the ionicconcentrationsof whichdiffer. Ringer'sacetate consistsof 28 mmol/Lacetate,4 mmol/LK+ and 1.5 mmol/LCa2+. Normal saline Main article:Saline (medicine) Normal saline (NS) isthe commonly-usedtermforasolutionof 0.91% w/vof NaCl,about300 mOsm/L.[2] Lesscommonly,thissolutionisreferredtoasphysiological salineorisotonicsaline,neither of whichistechnicallyaccurate.NSisusedfrequentlyinintravenousdrips(IVs)forpatientswhocannot take fluidsorallyandhave developedorare in dangerof developing dehydrationorhypovolemia.NSis typicallythe firstfluidusedwhenhypovolemiaissevereenoughtothreatenthe adequacyof blood circulation,andhaslongbeenbelievedtobe the safestfluidtogive quicklyinlarge volumes.However,it isnow knownthatrapidinfusionof NScan cause metabolicacidosis.[3] [edit] Glucose (dextrose) Intravenoussugarsolutions,suchaswithglucose (alsocalleddextrose),have the advantage of providing some energy,andmaytherebyprovide the entireorpart of the energycomponentof parenteral nutrition. Typesof glucose/dextrose include: D5W (5% dextrose inwater),whichconsistsof 278 mmol/Ldextrose D5NS (5% dextrose innormal saline),which,inaddition,containsnormal saline.
  3. 3. [edit] Comparisontable Compositionof commoncrystalloidsolutionsSolution OtherName [Na+](mmol/L) [Cl-](mmol/L) [Glucose](mmol/L) [Glucose](mg/dl) D5W 5% Dextrose 0 0 278 5000 2/3D & 1/3S 3.3% Dextrose /0.3% saline 51 51 185 3333 Half-normal saline 0.45% NaCl 77 77 0 0 Normal saline 0.9% NaCl 154 154 0 0 Ringer'slactate Lactated Ringer 130 109 0 0 D5NS 5% Dextrose,Normal Saline 154 154 278 5000 Effectof addingone litre Solution Change inECF Change inICF D5W 333 mL 667 mL 2/3D & 1/3S 556 mL 444 mL Half-normal saline 667 mL 333 mL Normal saline 1000 mL 0 mL Ringer'slactate 900 mL 100 mL Supportive: Patientsrequire emergencytreatmentandurgentreferral whentheyare inthe critical phase of disease,i.e.whentheyhave: – severe plasmaleakageleadingtodengue shockand/orfluidaccumulation
  4. 4. withrespiratorydistress; – severe haemorrhages; – severe organimpairment(hepaticdamage,renal impairment,cardiomyopathy, encephalopathyorencephalitis). All patientswithsevere dengue shouldbe admittedtoahospital withaccessto intensivecare facilitiesandbloodtransfusion.Judiciousintravenousfluidresuscitation isthe essentialandusuallysole interventionrequired.The crystalloid solutionshould be isotonicandthe volume justsufficienttomaintainaneffectivecirculationduringthe periodof plasmaleakage.Plasmalossesshouldbe replacedimmediatelyandrapidly withisotoniccrystalloidsolutionor,inthe case of hypotensive shock,colloidsolutions (Textbox M).If possible,obtainhaematocritlevelsbefore andafterfluidresuscitation. There shouldbe continuedreplacementof furtherplasmalossestomaintaineffective circulationfor24–48 hours. Bloodtransfusionshouldbe givenonlyincaseswithsuspected/severebleeding. Treatmentof shock The action planfor treatingpatientswithcompensatedshockisasfollows(TextboxesD and N,Figure 2.2): Start intravenousfluidresuscitationwithisotoniccrystalloidsolutions at5–10 ml/kg/houroverone hour.Thenreassessthe patient’scondition(vitalsigns,capillaryrefill time,haematocrit,urine output). The nextstepsdependonthe situation. • If the patient’sconditionimproves,intravenousfluidsshouldbe graduallyreducedto5–7 ml/kg/hrfor 1–2 hours,thento3–5 ml/kg/hrfor2–4 hours,thento 2–3 ml/kg/hr,andthenfurtherdependingon haemodynamicstatus,whichcanbe maintainedforupto24–48 hours.(See textboxesHand J fora more appropriate estimate of the normal maintenance requirementbasedonideal bodyweight).
  5. 5. • If vital signsare still unstable (i.e.shockpersists),checkthe haematocritafterthe firstbolus.If the haematocritincreasesorisstill high(>50%),repeatasecondbolusof crystalloid solutionat10–20 ml/kg/hrforone hour.Afterthissecondbolus,if there isimprovement,reduce the rate to7–10 ml/ kg/hrfor 1–2 hours,andthencontinue toreduce as above.If haematocritdecreasescomparedtothe initial reference haematocrit(<40%inchildrenandadultfemales,<45% in adultmales),thisindicates bleedingandthe needtocross-matchand transfuse bloodassoonas possible (see treatmentfor haemorrhagiccomplications). • Furtherbolusesof crystalloidorcolloidal solutionsmayneedtobe given duringthe next24–48 hours. A decrease inhaematocrittogetherwithunstablevital signs(particularlynarrowingof the pulse pressure,tachycardia,metabolicacidosis,poorurine output) indicatesmajorhaemorrhage andthe need for urgentbloodtransfusion.Yeta decrease inhaematocrit togetherwithstable haemodynamicstatus and adequate urine outputindicates haemodilutionand/orreabsorptionof extravasatedfluids,soin thiscase intravenous fluidsmustbe discontinuedimmediatelytoavoidpulmonaryoedema. Treatmentof haemorrhagiccomplications Mucosal bleedingmayoccurin anypatientwithdengue but,if the patientremainsstable withfluid resuscitation/replacement,itshouldbe consideredasminor.The bleeding usuallyimprovesrapidly duringthe recoveryphase.Inpatientswithprofoundthrombocytopaenia,ensure strictbedrestand protectfrom traumato reduce the risk of bleeding.Donotgive intramuscularinjectionstoavoid haematoma.Itshouldbe notedthatprophylacticplatelettransfusionsforseverethrombocytopaeniain otherwise haemodynamicallystable patientshave notbeenshowntobe effectiveandare notnecessary Severe bleedingcanbe recognizedby: – persistentand/orsevere overtbleedinginthe presence of unstable haemodynamicstatus,regardlessof the haematocritlevel; – a decrease inhaematocritafterfluidresuscitationtogetherwithunstablehaemodynamicstatus; – refractoryshockthat failstorespondto consecutive fluidresuscitation of 40-60 ml/kg; – hypotensive shockwithlow/normalhaematocritbefore fluidresuscitation; – persistentorworseningmetabolicacidosis±a well-maintainedsystolicblood pressure,especiallyinthose withsevere abdominaltendernessanddistension.
  6. 6. Considerrepeatingthe bloodtransfusionif there isfurtherbloodlossorno appropriate rise in haematocritafterbloodtransfusion.There islittleevidence to supportthe practice of transfusing plateletconcentratesand/orfresh-frozenplasmaforseverebleeding.Itisbeingpractisedwhenmassive bleedingcannot be managedwithjustfreshwhole blood/fresh-packedcells,butitmayexacerbate the fluidoverload. Causesof fluidoverloadare: – excessive and/ortoorapidintravenousfluids; – incorrectuse of hypotonicratherthanisotoniccrystalloidsolutions; – inappropriate use of large volumesof intravenousfluidsinpatientswithunrecognizedsevere bleeding; – inappropriate transfusionof fresh-frozenplasma,plateletconcentratesandcryoprecipitates; – continuationof intravenousfluidsafterplasmaleakage hasresolved(24–48hours from defervescence); – co-morbidconditionssuchascongenital orischaemicheartdisease,chroniclungandrenal diseases. Early clinical featuresof fluidoverloadare: – respiratorydistress,difficultyinbreathing; – rapidbreathing; – chestwall in-drawing; – wheezing(ratherthancrepitations); – large pleural effusions; – tense ascites; – increasedjugularvenouspressure(JVP). Late clinical featuresare: – pulmonaryoedema(coughwithpinkorfrothysputum± crepitations,cyanosis); – irreversibleshock(heartfailure,oftenincombinationwithongoing hypovolaemia).
  7. 7. Patientswhoremaininshockwithlowornormal haematocritlevelsbutshow signsof fluid overload may have occulthaemorrhage.Furtherinfusionof large volumesof intravenousfluidswillleadonlytoa poor outcome. Othercomplicationsof dengue Both hyperglycaemiaandhypoglycaemiamayoccur,eveninthe absence of diabetesmellitusand/or hypoglycaemicagents.Electrolyte andacid-baseimbalancesare alsocommonobservationsinsevere dengue andare probablyrelatedtogastrointestinal lossesthroughvomitinganddiarrhoeaortothe use of hypotonicsolutionsforresuscitationandcorrection of dehydration.Hyponatraemia,hypokalaemia, hyperkalaemia,serumcalciumimbalancesandmetabolicacidosis(sodiumbicarbonate formetabolic acidosisisnotrecommendedforpH≥ 7.15) can occur. One shouldalsobe alertforco-infectionsand nosocomial infections. Choice of intravenousfluidsforresuscitation Basedon the three randomizedcontrolledtrialscomparingthe differenttypesof fluidresuscitation regime in dengue shockinchildren,there isnoclearadvantage tothe use of colloidsovercrystalloidsintermsof the overall outcome.However,colloidsmaybe the preferredchoice if the bloodpressure hastobe restored urgently,i.e.in those withpulse pressure lessthan10 mm Hg. Colloidshave beenshowntorestore the cardiacindex and reduce the level of haematocritfasterthancrystalloidsinpatientswithintractableshock(18–20). An ideal physiological fluidisone thatresemblesthe extracellularandintracellularfluidscompartments closely. However,the availablefluidshave theirown limitationswhenusedinlarge quantities. Therefore itisadvisable to understandthe limitationsof these solutionstoavoidtheirrespective complications. Crystalloids 0.9% saline (“normal”saline) Normal plasmachloride rangesfrom95 to 105 mmol/L. 0.9% Saline isasuitable optionforinitialfluid resuscitation,butrepeatedlarge volumesof 0.9% saline mayleadtohyperchloraemicacidosis. Hyperchloraemicacidosismayaggravate orbe confusedwithlacticacidosisfromprolongedshock. Monitoringthe chloride andlactate levelswillhelptoidentifythisproblem.Whenserumchloride level exceedsthe normal range,itis advisable tochange tootheralternativessuchasRinger’sLactate.
  8. 8. Ringer’sLactate Ringer’sLactate has lowersodium(131mmol/L) andchloride (115 mmol/L) contentsandan osmolality of273 mOsm/L.It maynot be suitable forresuscitationof patientswithsevere hyponatremia.However, it isa suitable solutionafter0.9Saline hasbeengivenandthe serumchloride level hasexceededthe normal range. Ringer’sLactate shouldprobablybe avoidedinliverfailure andinpatientstaking metforminwhere lactate metabolismmaybe impaired. Colloids The typesof colloidsare gelatin-based,dextran-basedandstarch-basedsolutions.One of the biggest concernsregardingtheiruse istheirimpactoncoagulation.Theoretically,dextransbindtovon Willebrandfactor/FactorVIIIcomplex andimpaircoagulationthe most.However,thiswasnotobserved to have clinical significance influidresuscitationindengueshock.Of all the colloids,gelatine hasthe leasteffectoncoagulationbutthe highestriskof allergicreactions.Allergicreactionssuchasfever,chills and rigorshave alsobeenobservedinDextran70.Dextran40 can potentiallycause anosmoticrenal injuryinhypovolaemicpatients.

×