Fluids and Electrolytes David A. Listman, MD St. Barnabas Hospital Pediatric Emergency Medicine

Fluids and ElectrolytesFluids and Electrolytes

David A. Listman, MDDavid A. Listman, MD

St. Barnabas HospitalSt. Barnabas Hospital

Pediatric Emergency Pediatric Emergency MedicineMedicine

Goals and ObjectivesGoals and Objectives

Understand where fluid and salts are in Understand where fluid and salts are in bodybody

Understand and be able to orderUnderstand and be able to order maintenance fluidsmaintenance fluids Deficit fluidsDeficit fluids

Be familiar with causes and treatment of Be familiar with causes and treatment of hypo/ hypernatremiahypo/ hypernatremia

Provide fluids to patients in special Provide fluids to patients in special circumstancescircumstances

Body Fluid CompositionBody Fluid Composition Total body water (TBW)Total body water (TBW)

75-80% of body weight at birth75-80% of body weight at birth 60% of body weight after 1 year60% of body weight after 1 year

Intracellular fluidIntracellular fluid 2/3 of TBW or about 40% body weight2/3 of TBW or about 40% body weight

Extracellular fluidExtracellular fluid 1/3 of TBW or about 20% body weight1/3 of TBW or about 20% body weight

¾ Interstitial fluid¾ Interstitial fluid ¼ Plasma¼ Plasma

Need for Fluid TherapyNeed for Fluid Therapy

Maintenance of fluids in patients with Maintenance of fluids in patients with insufficient intake (i.e.. NPO)insufficient intake (i.e.. NPO)

Replacement of already diminished Replacement of already diminished fluid volume (i.e.. dehydration, fluid volume (i.e.. dehydration, trauma)trauma)

Replace ongoing losses (i.e.. GI, Replace ongoing losses (i.e.. GI, renal)renal)

Maintenance FluidsMaintenance Fluids

Replacement of insensible losses due Replacement of insensible losses due to heat dissipationto heat dissipation

Replacement of Urinary LossesReplacement of Urinary Losses Maintenance water needs are related Maintenance water needs are related

to caloric requirementto caloric requirement


Caloric requirementCaloric requirement 100 kcal/kg/24hr100 kcal/kg/24hr up to 10 kgup to 10 kg

1000 kcal +1000 kcal + 50 kcal/kg/24hr 50 kcal/kg/24hr per kg over 10 up to 20per kg over 10 up to 20

1500 kcal +1500 kcal + 20 kcal/kg/24 hr 20 kcal/kg/24 hr per kg over 20per kg over 20

Maintenance FluidsMaintenance Fluids Fluid requirementFluid requirement

40 ml/100 kcal/ 24 hr to replace insensible 40 ml/100 kcal/ 24 hr to replace insensible losseslosses

60 ml/100 kcal/ 24 hr to replace urine losses60 ml/100 kcal/ 24 hr to replace urine losses

100 ml/ 100 kcal/ 24 hours total100 ml/ 100 kcal/ 24 hours total

SO:SO:


Caloric requirementCaloric requirement 100 kcal/kg/24hr100 kcal/kg/24hr up to 10 kgup to 10 kg

1000 kcal +1000 kcal + 50 kcal/kg/24hr 50 kcal/kg/24hr per kg over 10 up to 20per kg over 10 up to 20

1500 kcal +1500 kcal + 20 kcal/kg/24 hr 20 kcal/kg/24 hr per kg over 20per kg over 20


Fluid requirementFluid requirement 100 ml/kg/24hr100 ml/kg/24hrup to 10 kgup to 10 kg

1000 ml +1000 ml + 50 ml/kg/24hr 50 ml/kg/24hr per kg over 10 up to 20per kg over 10 up to 20

1500 ml +1500 ml + 20 ml/kg/24 hr 20 ml/kg/24 hr per kg over 20per kg over 20


Fluid requirementFluid requirement 100/ 50/ 20100/ 50/ 20 Divided by 24 hours (or 25)Divided by 24 hours (or 25) 4 / 2/ 1 (cc’s per hour)4 / 2/ 1 (cc’s per hour)


Few examples:Few examples:

8 kg8 kg 8 x 100 = 800 cc’s/ day8 x 100 = 800 cc’s/ day 800 / 24 = 33.3 cc’s/ hr800 / 24 = 33.3 cc’s/ hr

oror 8 x 4 = 32 cc’s/ hr8 x 4 = 32 cc’s/ hr


Few examples:Few examples: 18 kg18 kg

10 x 100 = 100010 x 100 = 1000 8 x 50 = 4008 x 50 = 400 1000 + 400 = 1,400 cc’s/ day1000 + 400 = 1,400 cc’s/ day 1,400 / 24 = 58.3 cc’s/ hr1,400 / 24 = 58.3 cc’s/ hr

oror 10 x 4 = 4010 x 4 = 40 8 x 2 = 168 x 2 = 16 40 + 16 = 56 cc’s/ hr40 + 16 = 56 cc’s/ hr


Few examples:Few examples: 28 kg28 kg

10 x 100 = 100010 x 100 = 1000 10 x 50 = 50010 x 50 = 5008 x 20 = 1608 x 20 = 160 1000 + 500 + 160 = 1,660 cc’s/ day1000 + 500 + 160 = 1,660 cc’s/ day 1,660 / 24 = 69.2 cc’s/ hr1,660 / 24 = 69.2 cc’s/ hr

oror 10 x 4 = 4010 x 4 = 40 10 x 2 = 2010 x 2 = 20 8 x 1 = 88 x 1 = 8 40 + 20 + 8 = 68 cc’s/ hr40 + 20 + 8 = 68 cc’s/ hr

Maintenance fluidsMaintenance fluids

We’ve got the water, do we need We’ve got the water, do we need anything else?anything else?

Is it necessary to replace electrolytes?Is it necessary to replace electrolytes? Recent data shows significant risk of Recent data shows significant risk of

hyponatremia in hospitalized patientshyponatremia in hospitalized patients Hyponatremia can lead to fluid shift into Hyponatremia can lead to fluid shift into

cells causing cellular (and cerebral) cells causing cellular (and cerebral) edemaedema

Maintenance fluidsMaintenance fluids

Daily sodium requirementDaily sodium requirement2-4 meq / kg / day2-4 meq / kg / day

Daily Potassium requirementDaily Potassium requirement1-2 meq / kg / day1-2 meq / kg / day

This is a flat need per kilo and does not This is a flat need per kilo and does not decrease as water needs dodecrease as water needs do

Maintenance fluids- sodiumMaintenance fluids- sodium

This is a flat need per kilo and does This is a flat need per kilo and does not decrease as water needs donot decrease as water needs do

SoSo

As volume required goes down, As volume required goes down, sodium needed per liter goes upsodium needed per liter goes up

Maintenance fluids- sodiumMaintenance fluids- sodiumSome examples-Some examples-

10 kg child needs 20-40 meq Na10 kg child needs 20-40 meq Na++ per day per day

10 kg child needs 1000 cc’s per day10 kg child needs 1000 cc’s per day 20-40 meq/ liter20-40 meq/ liter

20 kg child needs 40-80 meq Na20 kg child needs 40-80 meq Na++ per day per day20 kg child needs 1500 cc’s per day20 kg child needs 1500 cc’s per day

26-53 meq/ liter26-53 meq/ liter

50 kg child needs 100-200 meq Na50 kg child needs 100-200 meq Na++ per day per day50 kg child needs 1800 cc’s per day50 kg child needs 1800 cc’s per day

55-110 meq/liter55-110 meq/liter

Sodium concentrations Sodium concentrations

Normal saline (0.9% NaCl/L) Normal saline (0.9% NaCl/L) 154 mEq Na+/L154 mEq Na+/L

1/2 normal saline (0.45% NaCl/L) 1/2 normal saline (0.45% NaCl/L) 77 mEq Na+/L77 mEq Na+/L

1/3 normal saline (0.33% NaCl/L) 1/3 normal saline (0.33% NaCl/L) 57 mEq Na+/L57 mEq Na+/L

1/4normal saline (0.2% NaCl/L) 1/4normal saline (0.2% NaCl/L) 34 mEq Na+/L34 mEq Na+/L

Ringer’s lactate Ringer’s lactate 130 mEq Na+/L130 mEq Na+/L(Contains 4 mEq K+, 109 mEq Cl-, 28 mEq bicarb (Contains 4 mEq K+, 109 mEq Cl-, 28 mEq bicarb equivalent all/Liter, and 3 mg/dl of Caequivalent all/Liter, and 3 mg/dl of Ca++++))

What else goes in it?What else goes in it? DextroseDextrose

5% dextrose is insufficient to nourish a 5% dextrose is insufficient to nourish a patientpatient

To spare catabolism of glycogen and To spare catabolism of glycogen and proteinprotein

What else goes in it?What else goes in it? PotassiumPotassium

Daily requirement 1-2 meq/kg/dayDaily requirement 1-2 meq/kg/day



Replacement of already diminished Replacement of already diminished fluid volume or deficit (i.e.. fluid volume or deficit (i.e.. dehydration, trauma)dehydration, trauma)


Treatment of volume lossTreatment of volume loss

Decrease in extracellular fluid Decrease in extracellular fluid Initial treatment- rapid expansion of ECFInitial treatment- rapid expansion of ECF

Bolus of isotonic fluid (i.e.. NS or LR)Bolus of isotonic fluid (i.e.. NS or LR) Should not include dextroseShould not include dextrose

Repeat bolus as necessary to improve perfusionRepeat bolus as necessary to improve perfusion Replacement of deficitReplacement of deficit Continue maintenanceContinue maintenance Frequent reevaluation of Frequent reevaluation of

Vital signVital sign ElectrolytesElectrolytes Urine output and urine specific gravityUrine output and urine specific gravity

Treatment of volume lossTreatment of volume loss

Decrease in extracellular fluid Decrease in extracellular fluid Initial treatment- rapid expansion of ECFInitial treatment- rapid expansion of ECF

Bolus of isotonic fluid (i.e.. NS or LR)Bolus of isotonic fluid (i.e.. NS or LR) Repeat bolus as necessary to improve Repeat bolus as necessary to improve

perfusionperfusion Replacement of deficitReplacement of deficit Continue maintenanceContinue maintenance Frequent reevaluation of Frequent reevaluation of

Vital signVital sign ElectrolytesElectrolytes Urine output and urine specific gravityUrine output and urine specific gravity

Estimate of Fluid DeficitEstimate of Fluid Deficit

SubtractSubtractpre-illness weight - current weightpre-illness weight - current weight

Calculate using current weight and % Calculate using current weight and % dehydrationdehydration

Pre-illness wt (kg)Pre-illness wt (kg) == 100 100

Current wt (kg)Current wt (kg) 100 - % estimated dehydration100 - % estimated dehydration

Current Weight x % dehydrationCurrent Weight x % dehydration (slightly underestimates)(slightly underestimates)

Estimate of DehydrationEstimate of Dehydration

MildMild ModerateModerate SevereSevere

Skin TurgorSkin Turgor Normal/ElasticNormal/Elastic ↓↓ Very Very ↓,Tenting↓,Tenting

Oral MucosaOral Mucosa Sl DrySl Dry Very DryVery Dry ParchedParchedTearsTears Sl ↓ Sl ↓ AbsentAbsent AbsentAbsentFontanelleFontanelle Normal/ FlatNormal/ Flat DepressedDepressed SunkenSunkenHeart RateHeart Rate Normal/ Sl ↑Normal/ Sl ↑ ↑↑ Marked TachycardiaMarked Tachycardia

Blood PressureBlood Pressure NormalNormal Normal/ Sl ↓Normal/ Sl ↓ ↓ ↓Urine OPUrine OP Mild OliguriaMild Oliguria OliguriaOliguria Oliguria/ AnuriaOliguria/ AnuriaCNS/ LOCCNS/ LOC Alert/ ResponsiveAlert/ Responsive Irritable/ListlessIrritable/Listless Minimal/NonresponsiveMinimal/Nonresponsive

Pulse QualityPulse Quality FullFull RapidRapid Rapid/ weakRapid/ weakSkinSkin Warm/ PinkWarm/ Pink Cool/ PaleCool/ Pale CoolCool

Estimate of DehydrationEstimate of Dehydration

Mild Mild Moderate Moderate SevereSevere

<1yr<1yr 5%5% 10%10% 15%15%OlderOlder 3%3% 6%6% 9%9%

Replacement of DeficitReplacement of Deficit

Deficit volume Deficit volume Replace ½ over 1Replace ½ over 1stst 8 hours 8 hours Replace ½ over next 16 hoursReplace ½ over next 16 hours

Don’t forget maintenance fluidDon’t forget maintenance fluid

Replacement of DeficitReplacement of Deficit

Example-Example- 16 kg child 10% dehydrated16 kg child 10% dehydrated

Bolus(es) normal saline 20 ml/kg rapidlyBolus(es) normal saline 20 ml/kg rapidly Maintenance 1,000 + 300= 1,300 / 24 = 54cc/hrMaintenance 1,000 + 300= 1,300 / 24 = 54cc/hr Deficit 1,600 mlDeficit 1,600 ml

800 over 1800 over 1stst 8 hours=100ml /hr 8 hours=100ml /hr 800 over next 16 hours = 50ml /hr800 over next 16 hours = 50ml /hr

Total 154 ml /hr x 8 hours then 104 ml/hr x16 Total 154 ml /hr x 8 hours then 104 ml/hr x16 hourshours

Not well approximated by 1 ½ maintenanceNot well approximated by 1 ½ maintenance



Replacement of already diminished Replacement of already diminished fluid volume or deficit (i.e.. fluid volume or deficit (i.e.. dehydration, trauma)dehydration, trauma)


Ongoing lossesOngoing losses

Continued loss in excess of normal Continued loss in excess of normal maintenancemaintenance GI loss- vomit/ diarrheaGI loss- vomit/ diarrhea Surgical drains/ NG tubeSurgical drains/ NG tube Increased insensible losses- feverIncreased insensible losses- fever Increased urine outputIncreased urine output

Ongoing lossesOngoing losses

Continued loss in excess of normal Continued loss in excess of normal maintenancemaintenance Volume can often be measuredVolume can often be measured

NG outputNG output StoolStool UrineUrine

Type of fluid needed for replacementType of fluid needed for replacement Can be measured Can be measured Can be estimatedCan be estimated

Oral RehydrationOral Rehydration

Better than IV if toleratedBetter than IV if tolerated What makes a good oral rehydration What makes a good oral rehydration

fluid?fluid? Proper balance of NaProper balance of Na++ and glucose and glucose

NaNa++/glucose co-transporter in intestine /glucose co-transporter in intestine non ATP dependantnon ATP dependant

Water follows passively Water follows passively


What makes a good oral rehydration fluid?What makes a good oral rehydration fluid? Proper balance of NaProper balance of Na++ and glucose and glucose

NaNa++/glucose co-transporter in intestine non ATP /glucose co-transporter in intestine non ATP dependantdependant

1 : 1 osmolar ratio1 : 1 osmolar ratio NaNa++ 90 meq/l, glucose 111meq/l (2% solution) 90 meq/l, glucose 111meq/l (2% solution)

Some KSome K++ to prevent Hypokalemia to prevent Hypokalemia

Oral RehydrationOral Rehydration What makes a good oral rehydration What makes a good oral rehydration

fluid?fluid?

MMWR November 21, 2003 / 52(RR16);1-16


Mild to moderate dehydrationMild to moderate dehydration Deficit 50-100 ml of ORS/kg body Deficit 50-100 ml of ORS/kg body

weight during 2-4 hoursweight during 2-4 hours Maintenance100 ml ORS/kg per day Maintenance100 ml ORS/kg per day limited volumes of fluid (e.g., 5 mL or 1 limited volumes of fluid (e.g., 5 mL or 1

teaspoon) should be offered at first, with teaspoon) should be offered at first, with the amount gradually increased as the amount gradually increased as tolerated. tolerated.

Hypo/ HypernatremiaHypo/ Hypernatremia

More to do with water than salt More to do with water than salt status (usually)status (usually) HyponatremiaHyponatremia

free water excessfree water excess

HypernatremiaHypernatremia Free water deficitFree water deficit

HyponatremiaHyponatremia

Serum NaSerum Na++ < 135 < 135 Common in hospitalized children Common in hospitalized children Kidneys unable to dilute urine and Kidneys unable to dilute urine and

excrete free waterexcrete free water


Measure serum Osm to confirm low Measure serum Osm to confirm low serum Osm before aggressive serum Osm before aggressive treatmenttreatment Normal or high serum Osm with Normal or high serum Osm with

pseudohyponatremiapseudohyponatremia HyperglycemiaHyperglycemia HyperlipidemiaHyperlipidemia HyperproteinemiaHyperproteinemia


True hyponatremia causes influx of True hyponatremia causes influx of water into cellswater into cells Cellular swellingCellular swelling Cerebral edemaCerebral edema

Exacerbated by hypoxiaExacerbated by hypoxia


SymptomsSymptoms Headache, nausea, vomit, behavioral changesHeadache, nausea, vomit, behavioral changes Seizures, resp arrest, dilated pupils, Seizures, resp arrest, dilated pupils,

decorticate posturingdecorticate posturing


Causes of SIADHCauses of SIADH CNSCNS

MeningitisMeningitis CNS neoplasmCNS neoplasm HydrocephalusHydrocephalus

PulmonaryPulmonary PneumoniaPneumonia AsthmaAsthma TBTB Positive Pressure VentilationPositive Pressure Ventilation PneumothoraxPneumothorax

DrugsDrugs Vincristine, cyclophosphamideVincristine, cyclophosphamide CarbamazepineCarbamazepine


Post-operativePost-operative Multi-factorialMulti-factorial

Volume depletionVolume depletion StressStress ADHADH Hypotonic fluidsHypotonic fluids


Water intoxicationWater intoxication NewbornsNewborns

Fed dilute formula or water supplementFed dilute formula or water supplement Decreased ability to maximally concentrate Decreased ability to maximally concentrate

urineurine

Hyponatremia- treatmentHyponatremia- treatment

If neurologic signs/ seizureIf neurologic signs/ seizure Hypertonic 3% saline (514 meq/l)Hypertonic 3% saline (514 meq/l) 1 ml/kg/hr should raise Na1 ml/kg/hr should raise Na++ by 1 meq/l by 1 meq/l

GoalsGoals Raise NaRaise Na++ by 1 meq/hr until by 1 meq/hr until

Symptoms resolve Symptoms resolve oror Serum NaSerum Na++ has risen 20-25 meq/l has risen 20-25 meq/l oror Serum NaSerum Na++ 125-130 meq/l 125-130 meq/l

Hyponatremia- treatmentHyponatremia- treatment

AsymptomaticAsymptomatic Restrict free water intakeRestrict free water intake Avoid hypotonic fluidsAvoid hypotonic fluids


Recent evidence suggests use of Recent evidence suggests use of isotonic rather than hypotonic fluids isotonic rather than hypotonic fluids in post-op, gastroenteritis prevents in post-op, gastroenteritis prevents hyponatremia.hyponatremia.

HypernatremiaHypernatremia

Serum NaSerum Na+ + >145 meq/l>145 meq/l Debilitated patientsDebilitated patients Neurologically impaired patientsNeurologically impaired patients Ineffective breastfeedingIneffective breastfeeding

Inability to access sufficient free waterInability to access sufficient free water Inability to maximally concentrate urineInability to maximally concentrate urine


Clinical manifestationsClinical manifestations Water moves from intracellular to extracellular Water moves from intracellular to extracellular

spacespace Maintenance of ECF volume so classic signs of Maintenance of ECF volume so classic signs of

volume depletion are absentvolume depletion are absent Agitation, irritability, comaAgitation, irritability, coma


Clinical manifestationsClinical manifestations Water moves from intracellular to extracellular spaceWater moves from intracellular to extracellular space Cell shrinkageCell shrinkage Brain cell volume decreasesBrain cell volume decreases

If acute and rapid can lead to If acute and rapid can lead to Intracranial hemorrhageIntracranial hemorrhage Venous sinus thrombosisVenous sinus thrombosis

Over short time brain cells increase intracellularOver short time brain cells increase intracellular NaNa++, K, K++, amino acids, unmeasured organic substances, amino acids, unmeasured organic substances Not easily decreased so rapid rehydration will cause Not easily decreased so rapid rehydration will cause

cerebral edemacerebral edema


TreatmentTreatment Correct serum NaCorrect serum Na++ and water deficit and water deficit

Free water deficit = Free water deficit = 4ml x lean body weight (kg) x (serum Na4ml x lean body weight (kg) x (serum Na++ – desired Na – desired Na++ ) )

Add maintenance fluid and correct slowlyAdd maintenance fluid and correct slowly At least 48-72 hours if serum NaAt least 48-72 hours if serum Na++ > 170 > 170

Various Causes of Volume Various Causes of Volume LossLoss

Trauma- when is it time for bloodTrauma- when is it time for blood 20 ml’s/kg NS or LR x 220 ml’s/kg NS or LR x 2 Then whole blood or PRBC’sThen whole blood or PRBC’s

DiabetesDiabetes

IDDM what is the cause and presentationIDDM what is the cause and presentation Not enough insulin producedNot enough insulin produced Break down of fats and protein in response to low Break down of fats and protein in response to low

insulin levelsinsulin levels How does it present?How does it present? What are the fluid and electrolyte abnormalities?What are the fluid and electrolyte abnormalities?

GlucoseGlucose SodiumSodium PotassiumPotassium PhosPhos pHpH

DiabetesDiabetes

Very hyperosmolarVery hyperosmolar PseudohyponatremiaPseudohyponatremia Initial Boluses to restore intravascular Initial Boluses to restore intravascular

volumevolume Slow deficit replacement to prevent cerebral Slow deficit replacement to prevent cerebral

edemaedema Constant infusion of insulin regardless of Constant infusion of insulin regardless of

blood glucoseblood glucose Add IV glucose if necessaryAdd IV glucose if necessary

DiabetesDiabetes• Usual fluidsUsual fluids

– Initial bolus(es) of Normal SalineInitial bolus(es) of Normal Saline– After 1After 1stst hour hour

• Insulin infusion usually 0.1 units / kg/ hourInsulin infusion usually 0.1 units / kg/ hour• ½ NS with 20KCL and 20 K Phos at maintenance plus ½ NS with 20KCL and 20 K Phos at maintenance plus

slow deficit replacemementslow deficit replacemement

• Once sugar falls Once sugar falls – 2 bags2 bags

• ½ NS with 20KCL and 20 K Phos ½ NS with 20KCL and 20 K Phos • D10 ½ NS with 20KCL and 20 K Phos D10 ½ NS with 20KCL and 20 K Phos • Total of these 2 infusions to equal maintenance plus Total of these 2 infusions to equal maintenance plus

slow deficit replacementslow deficit replacement• Can titrate to provide anywhere from no dextrose to Can titrate to provide anywhere from no dextrose to

D10 without changing electrolytes depending on the D10 without changing electrolytes depending on the CBG’sCBG’s

BurnsBurns

Tremendous fluid lossesTremendous fluid losses Parkland formulaParkland formula

4 ml/ kg/ % BSA burns (24 ml/ kg/ % BSA burns (2ndnd and 3 and 3rdrd degree)/ 24 degree)/ 24 hourshours

half over first 8 hours ½ over next 16 hourshalf over first 8 hours ½ over next 16 hours

in addition to maintenancein addition to maintenance

SummarySummary

Provide water, sodium, glucose and Provide water, sodium, glucose and potassium to patients who have a potassium to patients who have a variety of disturbances of fluid and variety of disturbances of fluid and sodium balancesodium balance

Documents

Fluids and Electrolytes David A. Listman, MD St. Barnabas Hospital Pediatric Emergency Medicine