6OSMOLALITY ICF and ECF are in osmotic equilibrium Change in osmolality in one of the compartments leads to water shift through the cell membranes to normalize equilibriumPlasma osmolality:mosm/kgCalculated based on formula:2xNa+glucose/18+BUN/2.8
8MAINTENANCE AND REPLACEMENT THERAPY Therapy of fluid and electrolyte disorders directed toward:Providing maintenance fluids and electrolyte requirementsReplenishing prior lossesReplace persistent abnormal losses
9MAINTENANCE AND REPLACEMENT THERAPY Maintenance fluid requirement take into account:Normal insensible water lossesskin and lungs:35%Urine:60%Stool5%Assuming that patient is afebrile and relatively inactive
10MAINTENANCE AND REPLACEMENT THERAPY Maintenance fluids are used when a child cannot be fed orally.Replacement therapy needed when patient has excessive ongoing losses from NG tube, ongoing diarrhea or vomiting or high urine output due to nephrogenic diabetes insipidus.Deficit therapy corrects dehydration or prior losses
11COMPOSITION OF MAINTENANCE FLUIDS WaterGlucoseSodiumPotassium
12GOALS OF MAINTENANCE FLUIDS Prevent dehydrationPrevent electrolyte disordersPrevent starvation ketoacidosisPrevent protein degradation
13MAINTENANCE WATER 1 ml of water needed for each calorie expended Body Weight (kg)Kcal/kgmL of Water/kg3-1010011-201000 kcal + 50Kcal/kg for eachkg > 10 kg1000 mL + 50 mL/Kg for each kg >10 kg> 201500 kcal + 20Kg > 201500 mL + 20mL/kg for eachKg > 20 kg
14GLUCOSE IN MAINENANCE FLUIDS How much glucose is required in maintenance fluids?Why?What % glucose solution will cover this requirement?
15GLUCOSE IN MAINENANCE FLUIDS 20% of patient’s true caloric requirements needed to prevent starvation ketosis and limit protein catabolism.Example: 10 kg baby will need 1000 kcal/day20% kcal/day from glucose1 g glucose provides 4 kcalX g glucose provides 200 kcalX =50 g50 g glucose in 1000 ml=> 5% glucose
16MAINTENANCE ELECTROLYTES SODIUM:2-3 mEq/kg/24 hr or 3 meq/100ccPOTASSIUM:1-2 mEq/kg/24 hr or 2 meq/100cc
17COMPOSITION OF IV SOLUTIONS FLUIDSSODIUM CONCENTRATIONSSODIUM CHLORIDE 0.9% NaCL154 mEq½ NS77 mEq1/3 NS52 mEq¼ NS38 mEq
18SELECTION OF SODIUM CONCENTRATION IN IV MAINTENANCE FLUIDS Based on Na requirement/kg/day10 kg baby needs 1000 cc of fluids and 30 meq/L Na=> ¼ NS20 kg baby needs 1500 cc of fluidsNa requirements=3meq x 20 kg=60 meq60 meq to be given in 1500 ccX meq to be given in 1000 cc=> and meq/L Na=> ¼NS-1/3 NS30 kg baby needs 1700 cc of fluids and 90 meq of Na to be given in this volume of fluids=> 53 meq/L=>1/3 NS-1/2 NS
19CALCULATION OF KCL REQUIREMENTS IN IV FLUIDS Calculate maintenance water requirementsCalculate KCL requirement/kg/dayAdjust KCL per liter of fluidsEXAMPLE:25 kg child needs 1600 cc of maintenance water25kgx1-2mEq/kg/24 hr=25-50 mEq/24hr of KCL1600 cc of water contains mEq of KCL1000 cc of water contains X mEq of KCLX= mEq=> 20 mEq
20REMEMBER! Maintenance fluids do not provide adequate calories. Patient will lose 0.5-1% of weight each day.TPN should be started for children who can not be fed enterally for more than a few daysCertain conditions increase or decrease maintenance requirements. Examples?For each 1 degree increase in temperature above 38-maintenance requirements are increased by 10%
21REPLACEMENT FLUIDSDiarrhea is often associated with loss of potassium and bicarbonate leading to metabolic acidosis and hypokalemia.Concurrently, volume depletion leads to hypoperfusion and lactic acidosis.
22ADJUSTING FLUID THERAPY IN DIARRHEA Average composition of diarrhea:Sodium: 55 meq/LPotassium: 25 meq/LBicarbonate: 15 meq/L
23APPROACH TO REPLACEMENT THERAPY GI losses can be measuredReplace losses as they occur every 2-6 hours depending on the rate cc by ccUse appropriate solution close in composition to electrolytes being lostChild should receive appropriate maintenance therapy in addition to replacement therapyDaily BMP
24LOSS OF GASTRIC FLUID Can occur via emesis or NG suction What electrolytes are lost with gastric fluids?Sodium 60 meq/LChloride 90 meq/LPotassium 10 meq/LWhat metabolic disturbances it can cause?hypokalemia and metabolic alkalosis
25THIRD SPACE LOSSES Occur after abdominal surgery Results in shift of fluid from intravascular space into interstitial spaceIsotonic loss- best replaced by NS or RLCannot be quantitatedReplacement is based on continuing assessment of intravascular volume status
26DEHYDRATION-the most frequent reason for hospitalization INCREASE LOSSESDECREASED INTAKEVomiting:AGEPyloric stenosisPyelonephritisIncreased ICPAbdominal obstructionAppendicitisPancreatitis, etcDiarrhea:Malabsorptionmilk-protein allergy,IBDDKA, DI, burnsGingivostomatitisPharyngitisFeverAltered mental statusPhysical restrictionDependence on caregiver
27CLINICAL SIGNS OF DEHYDRATION Symptom/SignMild DehydrationModerate DehydrationSevere DehydrationLevel of consciousness*AlertLethargicObtundedCapillary refill*2 Seconds2-4 SecondsGreater than 4 seconds, cool limbsMucous membranes*NormalDryParched, crackedTears*DecreasedAbsentHeart rateSlight increaseIncreasedVery increasedRespiratory rateIncreased and hyperpneaBlood pressureNormal, but orthostasisPulseThreadyFaint or impalpableSkin turgorSlowTentingFontanelDepressedSunkenEyesVery sunkenUrine outputOliguriaOliguria/anuria
29DEHYDRATION SCORING SYSTEM Score 0- no dehydrationScore 1-2- mildScore 3-6-moderateScore severe
30LABORATORY FINDING IN DEHYDRATION-BMP Disproportionate increase of BUN with little or no change of Creatininedue to increase passive reabsorption of urea in proximal tubule due to appropriate conservation of Na and water
31LABORATORY FINDINGS IN DEHYDRATION What changes in urinalysis may be present in dehydration?Elevation of spesific gravityProteinuria mg/dLFew WBC and RBCHyaline and granular casts
32APPROACH TO DEHYDRATION Acute intervention to restore intravascular volume and improve perfusionNS bolus 20 cc/hr over 20 minDeficit correction :Total amount of fluids includes maintenance and deficit fluidBolus is subtracted from the total volumeHalf of total fluids given over the first 8 hr, reminder half-over the last 16 hr
33ORAL DEHYDRATION THERAPY Best used in the absence of shockWhen poor perfusion is presentisotonic fluid bolus can restore perfusion, then oral rehydration can proceed.Glucose is actively absorbed and Na is co-transported across gut mucosaoptimal glucose transport at concentrations:glucose 2-2.5gm/L Na mEq/Lhigher glucose concentration will exacerbate diarrhea and Na loss
34ORAL REHYDRATION THERAPY Aim is to replace fluid deficit over 4-6 hoursCalculate total volume to be given over 4 hours:MILD=50 cc/kgMODERATE=100 cc/kgCalculate 5 min. aliquot volume:Administer aliquot over 5 min periodIncrease volume as toleratedMaintenance: 100 mL of ORS/kg/24
35ESTIMATED FLUID DEFICIT SeverityInfants (weight <10 kg)Children (weight >10 kg)Mild dehydration5% or 50 mL/kg3% or 30 mL/kgModerate dehydration10% or 100 mL/kg6% or 60 mL/kgSevere dehydration15% or 150 mL/kg9% or 90 mL/kg
36EXAMPLE7 y.o. boy is admitted with 2-day hx of vomiting and diarrhea. He is estimated to be 7% dehydrated and vomited all attempts at oral dehydration in ER. He was given 20 cc/kg of NS bolus prior to transfer to the floor.His weight is 23 kg
37EXAMPLE Maintenance water: 1560 cc=>65 cc/hr Maintenance Na= 2-3 meq x 23 kg=46-69meqMaintenance K=1-2 meq x 23=23-46 meqTotal fluid deficit=23kg x 0.07 x 1000cc/kg=1610 ccPrevious replacement=23 kg x 20cc/kg=460ccBalance fluid deficit= =1150cc=>1/2 is given over the first 8 hr=72 cc/hr; another ½ over the last 16 hr=36 cc/hr
38QUESTIONSYou are called to the ER to see a 4 month old baby boy for admission as he has been having nasal congestion and cough with decreases oral intake of one day duration. Wet diapers decreased in the past 24 hours.Vital signs as follow: HR of 160, RR of 50, O2 sat =95%,temp = 100.7, weight = 17 Ibs. Normal physicalexamination.What percentage of dehydration is he?How do you manage his fluidsBolusMaintenance fluids
39QUESTIONSYou are the resident in the pediatric floor and your fellow resident left you with an admission. The patient is a 5 year old male with sickle cell whom is being admitted as he has fever (Tmax 103F) x 2 days, vomiting x 2 days (1 to 2 episoded per day), pain all over and decreased po.Vital signs: pulse = 180, RR= 60, stable BP, O2 sat =88% and. Weight = 44 Ibs.Physical examination shows crackles, dry mucous membranes, cap refill 3 sec and he is in obvious distress as he is crying in painPercentage of dehydrationFluid management and type of fluid
40QUESTIONSYou are assessing a 4 year old female for diarrhea x 7 days, fever x 4 days with Tmax of 101F, decreased po intake and sleeping more than usual.Vital signs: T=102F, Pulse = 130, RR= 20, O2 sat =100%and BP = 60/50. Weight =35 IbPhysical examination pertinent for a girl that is lethargic but arousable to speech and touch, cap refil is 4 sec1) What is the percentage of dehydration ?2) What type of fluid are you going to use3) What is your management for her fluids
41QUESTIONSA one week old infant present to the ER with vomiting x 3 days, diarrhea x 3 days, not feeding well, decreased wet diapers x 2 days with no urine x 24 hours.Vital signs: Pulse = 180, RR= 80, Bp= 40/30, sat = 78%Weight = 7 IbsPhysical examination: lethargic, depressed anterior fontanelle, doghey skin, dry mucous memebranes and cap refil is 4 sec.What is the percentage of dehydrationWhat type of fluid would you use for a bolusWhat is her fluid management?
42QUESTIONSThis is a one year old female presenting to the ER s/p tonsillectomy 3 days ago as she is in pain, not eating or drinking well and with a fever. Decrease wet diapers x 1 day.Vital signs P=100, RR=22, BP= xx, sat =100%Weight =24 IbsPhysical examination: she is irritable with examination but consolable, cries with tears, cap refill 2 sec, tonsillar bed with whitish tissue, rest of exam normal1) Percent of dehydration2) What type of fluids are you going to use3) Would you give her a bolus? What about maintenace fluids.
43QUESTIONSThis is a 6 year old male with hx of asthma whom is presenting to the ER with c/o breathing fast, SOB, and wheezing x 1 day. Mother ran out of his medaications.Vital signs: P= 140, RR= 55, BP = xx, O2 sat = 85%Weight = 55 IbsPhysical examination pertinent for subcostal and intercostal retractions, expiratory wheezing and decrease air entry.Would you bolus him? If so with what?Type of fluids? Fluid management?