Pediatric Fluid Management

and

Blood Product Therapy

Joy Loy, M.D.MetroHealth Medical Center

April, 2004

ASA Fasting Guidelines

Clear liquids 2 hours

Breast Milk 4 hours

Infant Formula

Neonates 4 hours

Infants 6 hours

Nonhuman Milk 6 hours

Solids 8 hours

• water, juice without pulp, carbonated

beverages, clear tea, black coffee

• should not contain alcohol

• type of liquid ingested important than

volume infants < 5 mos 10 ml/kg children and adults 15 ml/kg

Clear Liquids

• is NOT a clear liquid

• does contain milk solids

Breast Milk

• cleared from the stomach more

quickly than nonhuman milk

ASA Fasting Guidelines

• pre-op fast does not guarantee an empty stomach

• timing of last fluid ingestion has little relation to

volume of gastric contents at induction

ASA Fasting Guidelines

• gastric fluid volume and pH are independent

of duration fluid fast beyond 2 hours

• main determinant: endogenous gastric

secretion

ASA Fasting Guidelines

• reduces the risk of pulmonary aspiration

• offering clear liquids up to 2 hours before

induction

> reduces hunger and irritability

> preserves hydration

> risk of hypoglycemia

BODY FLUID COMPOSITION

Total Body Water (TBW) =

Intracellular Fluid ( ICF ) +

Extracellular Fluid ( ECF )

Compartments

a) interstitial fluid ( ISF ) : no protein

b) plasma volume ( PV ) : with protein

* ISF and PV basically same electrolyte content

Body Fluid Composition

INFANT CHILD ADULT

Total Body Water 75 % 70 % 55-60 %

ECF 40 % 30 % 20 %

ICF 35 % 40 % 40 %

Fat 16 % 23 % 30 %

PHYSIOLOGIC CONSIDERATIONSDevelopmental Factors

CVS :

• incomplete myocardial development

• immature sympathetic innervation

IMPLICATION:

neonates and young infants are more

sensitive to

hypovolemia

PHYSIOLOGIC CONSIDERATIONSDevelopmental Factors

RENAL:

• immature renal function at birth

GFR

25% of adult level at term

adult level at age of 2 years

concentrating capacity of newborn kidney

term infant : max. 600-700 mOsm/kg

adult : max. 1200 mOsm/kg

PHYSIOLOGIC CONSIDERATIONSDevelopmental Factors

free H2O clearance :

excrete markedly dilute urine up to 50

mOsm / kg vs. 70-100 Osm/kg in adults

Na reabsorption

HCO3 /H exchange

urinary losses of K+ and Cl-

PHYSIOLOGIC CONSIDERATIONSDevelopmental Factors

IMPLICATION:

Newborn kidney has limited

capacity to compensate for volume

excess or volume depletion

PHYSIOLOGIC CONSIDERATIONSDevelopmental Factors

HEPATIC :

• limited hepatic glycogen stores

> risk of hypoglycemia

> provide 5%-10% dextrose in fluid

maintenance

> supplemental insulin for sustained

hyperglycemia from dextrose

PHYSIOLOGIC CONSIDERATIONSMetabolic and Fluid Requirements

metabolic rate

O2 consumption

neonates: 6-9 ml/kg/min

adults: 3 ml/kg/min

growth 120 kcal/kg/day

PHYSIOLOGIC CONSIDERATIONSMetabolic and Fluid Requirements

fluid requirement

> greater BSA to mass ratio in infants

> other factors:

radiant warmers fever

illness injury

thinner skin and lack of keratinization of

stratum corneum in premature neonates

Compensatory Mechanisms

1) Temporary mechanism

2) Definitive mechanism

Compensatory Mechanisms

Temporary Mechanism

> activated to maintain normal BP and normal

fluid volume

a) endogenous vasopressors

ADH, angiotensin II, catecholamines

b) transcapillary refill: ISF PV (skin turgor)

c) ADH : free H2O absorption

caution : hyponatremia using hypotonic

fluids

Compensatory Mechanisms

Definitive Mechanism

> through the kidneys

> activation of renin - angiotensin -

aldosterone (RAA) system

> urine output and urine specific gravity

Maintenance Fluids

replaces water and electrolytes lost under ordinary conditions

• Evaporative / insensible water loss (ISWL)

• Urinary and stool losses

• Growth

Maintenance Fluids

1) Evaporative or Insensible Water Loss (ISWL)

• solute-free H2O losses from skin and lungs

• 30-35 % of total maintenance volume

• 1/3 of total maintenance requirement

• affected by ambient humidity and temperature

• minimum replacement : 60-100 ml/kg/day

Maintenance Fluids

2) Urinary Losses

• 280-300 mOsm /kg of H2O

specific gravity 1.008-1.015

• 2/3 of total maintenance fluids

3) Growth

Maintenance FluidsHourly Maintenance Fluid Requirement

1) 4 - 2 -1 rule

WEIGHT FLUID

0 - 10 kg 4 ml/kg/hr

10 - 20 kg 2 ml/kg/hr

> 20 kg 1 ml/kg/hr

* reliable up to body weight of 80 kg

Hourly Maintenance Fluid Requirement

2) Holliday and Segar

WEIGHT FLUID/day

0 - 10 kg 100 ml / kg /day

10 - 20 kg 1000 + 50 ml/kg/day

> 20 kg 1500 + 20 ml/kg/day

* based on caloric requirement of hospitalized patients

Maintenance FluidsHourly Maintenance Fluid Requirement

3) OH Method

WEIGHT FLUID/hr

0 - 10 kg 4 ml / kg / hr

10 - 20 kg 20 + 2 ml/kg/hr

> 20 kg 40 + 1ml /kg/hr

Choice of Maintenance Fluids

• Remains controversial

• Hypotonic solution

D5 1/2 NS + 20 mEq KCl

D5 1/4 NS : may be a better choice in

neonates due to their limited ability

to handle Na + loads

• Balanced salt solution

Guide for Maintenance Fluid Therapy

Newborn Term

Day 1 50-60 ml/kg/day D10 W

Day 2 100 ml/kg/day D10 1/2 NS

>Day 7 100-150 ml/kg/day D5-D10 1/4

NS

Older Child

4-2-1 rule

Holliday & Segar method

Daily Electrolyte Requirements

Na 2-3 mEq /kg/day day 2-3

K 1-2 mEq /kg/day day 3-4

Cl 2-3 mEq /kg/day

Ca 20-100 mg/kg/day day 1

* 1 mEq = 1 mmol

Glucose Requirements

term and preterm infants : 5 - 6 mg/kg/min

goal: maintain normoglycemia 40 - 120 mg/dl

D10W 60-80 ml/kg/day >1kg infants

D5W 100 ml/kg/day <1kg infants

Perioperative Fluid Management

3 Phases

1. Maintenance Fluid Replacement

2. Replacement of Preop Deficit

3. Replacement of Ongoing Losses

Perioperative Fluid Management

Maintenance Fluid Replacement

4 - 2 -1 rule WEIGHT FLUID

0 - 10 kg 4 ml/kg/hr

+

10 - 20 kg 2 ml/kg/hr

+

> 20 kg 1 ml/kg/hr

Perioperative Fluid Management

Preoperative Deficit

DEHYDRATION

MILD (1-5 %) history of vomiting or diarrhrea urine output (1st)

MODERATE (6-10%) skin turgor sunken eyes and fontanelles weight loss dry mucous membranes lethargic

Perioperative Fluid Management

Preoperative Deficit

SEVERE (11-15%) cardiovascular instability BP mottled skin tachycardia anuria sensory changes

20% coma shock

Perioperative Fluid Management

Preoperative Deficit Therapy

Components:

1) dehydration severity Hx and PE

electrolyte values

serum tonicity

2) type of dehydration isotonic hypotonic hypertonic

Perioperative Fluid Management

Preoperative Deficit Therapy

3) replacement of deficit

• goal: restore CV, CNS and renal

function

• monitor adequacy based on response

clinical condition

urine output and urine specific gravity

vital signs

Perioperative Fluid Management

Estimated Preop Fluid Deficit

number of fasting hrs x maintenance fluids

infuse 1/2 on the first hr

infuse 1/4 on the 2nd hr

infuse 1/4 on the 3rd hr

Perioperative Fluid ManagementChoice of Fluids

Isotonic Crystalloids

• generally the most appropriate for preop

and intraop deficits

Hypotonic Fluids

• can cause significant hyponatremia

Perioperative Fluid Management

Lactated Ringers (LR)

reasonable for maintenance fluids

less expensive than other BSS

provide Na and K

avoid infusion with blood due to calcium content

Perioperative Fluid Management

Normal Saline (NS)

higher Na content (154)

preferred in patients high risk for cerebral edema

prolonged infusion can lead to :

hypernatremia

hyperchloremia

metabolic acidosis

Perioperative Fluid Management Composition of IV Crystalloid Solution

SOLUTION pH Osm Gluc Na K CL Lact Ca

mg/dl mmol/L

D5 5.0 253 500 -- -- -- -- --

LR 6.7 273 -- 130 4 109 28 3

D5 LR 5.3 527 500 130 4 109 28 3

D5 0.22% NSS 4.4 330 500 38.5 -- -- -- --

D5 0.45% NSS 4.2 407 500 77 -- 77 -- --

0.9% NSS 5.7 308 -- 154 -- 154 -- --

Normosol R 7.4 295 -- 140 5 98 acetate 27 -- gluconate 23

Stoelting RK: Pharmacology and Physiology in Anesthetic Practice, ed 2, Philadelphia 1991, JB Lippincott

Perioperative Fluid Management Composition of Colloid Solutions

Na Cl Osm

5% Albumin 145 100 330 mOsm/L

Hespan 154 154 308 mOsm/L

Hextend 143 124 307 mOsm/L

Is intraoperative

glucose necessary?

Perioperative Fluid Management Intraoperative Glucose Administration

Effects :

intraop hyperglycemia

hyperosmolality

osmotic diuresis

worsen neurologic outcome during cerebral

ischemia

Perioperative Fluid Management Intraoperative Glucose Administration

Exceptions : patients at risk for hypoglycemia

• neonates and young infants

• debilitated patients with chronic illness

• patients on parenteral nutrition

• neonates of diabetic mothers

• Beckwith-Wiedeman syndrome

• nesidioblastosis

Perioperative Fluid Management Intraoperative Glucose Administration

Existing infusions of dextrose-containing fluid

may be continued at a reduced rate (50% of

maintenance) to compensate the effect of surgical

stress on glucose control

Perioperative Fluid Management

1) Real Losses

blood loss insensible losses

urine output drainage from various sites

2) 3rd Space Loss

trauma peritonitis

burns upper GI drainage

Replacement of Ongoing Losses

Perioperative Fluid ManagementReplacement of Ongoing Losses

Degree of Additional Fluid Tissue Trauma Required

Minimal Incision 3-5 cc/kg/hr

Moderate Incision 5-10 cc/kg/hr with viscus exposure

Large Incision 8-20 cc/kg/hr with bowel exposure

Perioperative Fluid ManagementReplacement of Ongoing Losses

EBL Replacement

• crystalloid (3:1 ratio) 3 cc / 1 cc blood lost

• colloid solution (1:1 ratio) 1 cc / 1 cc blood lost

• blood products (1:1 ratio) 1 cc / 1cc blood lost

Perioperative Fluid ManagementReplacement of Ongoing Losses

Albumin

• 25 % and 5% solutions

• pooled from human donors

• no ABO testing or blood filter required

• remains expensive

• in short supply

Is albumin risk-free?

Perioperative Fluid ManagementComposition of Colloid Solution

New Zealand : albumin may be related to Creutz-Jacob

disease (CJD) or prion disease with long incubation period

(>5-10 yrs)

processing of human albumin does not destroy the prions

no blood screening for prion diseases

Perioperative Fluid ManagementReplacement of Ongoing Losses

Determinants of Blood Transfusion

1) Estimated Blood Volume

2) Preoperative Hematocrit

3) Co-existing Illness

Perioperative Fluid ManagementReplacement of Ongoing Losses

Estimated Blood Volume

Premature Neonates 95 -100 ml /kg

Full Term Neonates 85-90 ml / kg

Infants 80 ml / kg

Adults 75 ml / kg (male)

65 ml / kg (female)

Perioperative Fluid ManagementReplacement of Ongoing Losses

Guidelines for Pediatric Normal & Acceptable Hematocrit

NORMAL (x) ACCEPTABLE

premature 40-45 (45) 35

newborn 45-65 (54) 30-35

3 months 30-42 (36) 25

1 year 34-42 (38) 20-25

6 years 35-43 (38) 20-25

Perioperative Fluid ManagementBlood Product Replacement

Normal Hematocrit

Hct within 2 standard deviations for age

Acceptable Hematocrit

Hct that is tolerated by infants and children without

the need for blood transfusion

Perioperative Fluid ManagementBlood Product Replacement

Allowable Blood Loss (ABL)

Hct patient - Hct target X EBV

Hct patient

Perioperative Fluid ManagementBlood Product Replacement

PRBC

10 cc/kg will the hgb by 3 gm/dl and hct by 10%

(adult:1 unit will the hgb by 1 gm/dl and hct by 2-3%)

Platelets and FFP 10-15 ml/kg

given when EBL > 1-2 x the patient’s blood volume

1 unit / 10 kg raises the platelet count by ~ 50,000/uL

Cryoprecipitate 1 unit/10 kg

SUMMARY

Total Intraoperative Fluid Replacement

MF + EFD + ISL + EBL

MF : Maintenance Fluid

EFD : Estimated Preop Fluid Deficit

ISL : Insensible Losses

EBL : Estimated Blood Loss

Summary

Brief Procedures ( myringotomy, PET)

replacement may be unnecessary

1-2 hr Procedures

IV placement after inhalation induction

replace 10-20 cc/kg + EBL in 1st hour

Longer and Complex Procedures

4-2-1 rule

acute intravascular loss: 10-20 cc/kg LR / NS

Summary

Meticulous fluid management is required in pediatric

patients due to limited margin of error

Liberalization of fasting guidelines compatible with

safety limits preop deficit

Crystalloid solution is the first choice to restore

intravascular volume

Summary

Tranfusion trigger points

preop hematocrit and hemodynamics

co-existing medical problems

potential for further blood loss

25% decrease in EBV

Limit glucose-containing solutions for patients at

risk for hypoglycemia