Fluid Therapy The first affiliated hospital SUN YAT-SEN university

Prof. Wang Huishen

王慧深

Last lesson Emphasis

Etiology(in/ex/no)

Pathogenesis(4+ex/b/v/no)

Clinical manifestation

Diagnosis DifferentialDiagnosis

(p/d/n)Treatment

Predisposing(4)

Diagnosis Not difficultAccording to clinical manifestation,

laboratory tests and character of stool.

+ +Infectious OrNoninfectious

Dehydration Degree and quality

Electrolyte disturbances

AndDisturbance of

acid-base balance

Severity clinical signs of dehydration

mild moderate severeWater loss

By weight

Spirit

SkinMocous

Anterior fontanel and eye ball

Tear

Urine output

Peripheral circulation

＜ 50ml/kg

＜ 5%

Slightly dispirited

slightly agitated

Slightly drySlightly dry

Slightlydepressed

Normal

Slightly reduced

normal

50 ～ 100ml/kg

5% ～ 10%

DispiritedAgitated

Dry, paleVery dry

depressed

Reduced

Little or No

Little cool

100 ～ 120ml/kg

＞ 10%

Extremely dispiritedapathy, hypnody,

coma

Gray mottledParched

depressed greatly

No

No urine output

Cool, weak

pulse,shock

Dehydration

Dehydration

Same proportion loss

P IF CP IF

C

Electrolyte lossmore

P hypotonic,IF+C hypertonic

Cell expansionSevere

Easy to shock

P: plasma, IF: interstitial fluid, C: cell

Isotonic

P IF C

Water lossmore

P hypertonicIF+C hypotonic

Cell hydrationMild

Thirsty

Acute diarrheaafter

vomiting greatly

Hypotonic Hypertonic

Na+ :130 ～150mmol/L

Na+: < 130mmol/L Na+: > 150mmol/L

Electrolyte disturbance

Diarrhea complicated

hyponatremia & hypernatremia

hypokalemia

hypocalcemia

hypomagnesemia

K+ (potassium)<3.5mmol/L (normal: 3.5 ～ 5.5 mmol/L)

causes ：

Excessive losses: vomit, diarrhea.

Inadequate intake.

Renal function of keeping kalium ,it continues

excluding kalium when with hypokalemia.

Clinical manifestation: electrolyte disorder

Hypokalemia

depressed

Tension of skeletal muscle ， tendon reflex ， even respiratory muscle weakness

Tension of smooth muscl , abdominal extension, intestinal sound or disappear

Myocardium excitability , arrhythmia, ECG: T-wave is low or inversion, U-wave occurs, prolonged P-R interval and Q-T interval, ST section descending.

Baseosis

hypokalemia K+ (potassium)<3.5mmol/L (normal: 3.5 ～ 5.5 mmol/L)

Clinical manifestation: nerve and muscular excitability

Ca2+ 1.75mmol/L (7mg/dl) ; ﹤ Mg2+ 0.6mmol/L (1.5mg/dl).﹤

Symptoms usually occur after dehydration and acidosis resolved, or fluid replacement.

Clinical manifestation: thrill, tetany, convulsion.

If convulsion hasn’t relieved after supplement

calcium, pay attention to hypomagnesemia.

hypocalcemia & hypomagnesemia

Case example

An 8 – month boy had diarrhea and vomited for 3 days, urine

stream reduced, irritability. PE: Pulse rate 150/min, weight

loss was 10%, blood pressure 65/40mmHg, skin color showed

grey and skin turgor looked like tents. Mucous membranes

were very dry; eye ball was sunken greatly, anterior fontanel

depressed greatly. Abdomen distended, bowel sound

diminished.

Questions:

1.What is the diagnosis? 2.How to administer the fluid therapy?

Answer 1 (diagnosis)

Acute diarrhea severe dehydration hypokalemia

Neonate……………... 80%

Older children………..65%

Adult…………………..60%

features of body fluid balance in children

The younger The larger proportion of body water

Total body water

(by body mass)

----amount of body fluid

features of body fluid balance in children

The youngerThe larger proportion

of extracellular water

Intracellular

Body fluid

Extracellular

Interstitial fluid

Plasma

Lymph fluid

Secretory juice

----distribution of body fluid

P6%

IF37%

IC35%

IF20%

IF10%

~15%

IF25%

IC40%

P5%

P5%

P5%

IC40%

IC40%~45%

Neonate 78% ~1y 70%

2y~14y 65% Adult 55%~60%

features of body fluid balance in children

P: plasma

IF: interstitial fluid

IC: intracellular

----distribution of body fluid in different ages (by BW)

features of body fluid balance in children

----water requirement

Requiring more water

Regulating function poorly

Easy water metabolism disturbance

Due to grow quickly, need 0.5%~3% water for growth.

Insensible water loss : 2 times more than adult.

Fluid exchange of digestive tract quicker.

Water metabolism higher: infant 1/2 by total fluid

adult 1/7 by total fluid.

Regulating function of water metabolism poorly:

kidney, lung.

features of body fluid balance in children

----water requirement

◆Similar with adultExtracellular:

Na+, Cl-, Hco3-

Intracellular:

K+, Mg, Hpo4=, protein

◆Features of neonate (Several days after birth) :

Composition of body fluid

Particularly in preterm infantK+, Cl-, P, lactic acid

Na+, Ca++, Hco3-

Function of excluding H+ Acidosis

Acid-base balance and adjust

----two concept

Acid-base balance

Acidity and alkalinity

Anion-cation balance

Anion and cation

Compensation of adjust has limit

Acid-base balance and adjust

----body liquid

Buffer system

lung ： exhale of store CO2 (respiratory)

kidney: exclude H+ and store Na+ (metabolic)

NaHCO3/H2CO3

Na2HPO4/NaH2PO4

Buffer system of plasma protein

Adjust HCO3- NaHCO3/H2CO3=20:1

PH ： 7.4 (7.35~7.45)

PaCO2 ： 40 (34~45) mmHg

SB ： 24 (22~27) mmol/L

BE ： -3 ~ +3 mmol/L

CO2CP ： 22 (18~27) mmol/L

Acid-base index

Blood gas analysis （ normal ）

Compensation & decompensation

Acid-base balance disorder

respiratory acidosis

respiratory alkalosis

metabolic acidosis

metabolic alkalosis

Dispirited, dysphoria, drowsiness, coma

Hypernea (Kussmauls breathing) ， exhalation cool

Expiratory gas smells ketone

Cherry lips

Nausea, vomit

Metabolic acidosis--clinical manifestation

Mild: breath frequency slightly

Severe: occur:

To cure water and electrolyte disturbance

Recover and maintain blood volume , osmotic pressure , Acidity , alkalinity and electrolyte

Normal physiological function

Fluid therapy Purpose

oral intravenous

Fluid therapy Method

prevention dehydration: Rice soup add salt solute （ 1/3 ）Mild dehydration: ORS 。Mild/moderate dehydration : ORS ——mild: ORS ： 50 ～ 80ml/kg ——moderate: ORS ： 80 ～ 100ml/kgSevere dehydration or vomiting and diarrhea —— intravenous

NaCl ： 3.5g

NaHCO3 (Sodium citrate) ： 2.5g (2.9g)

KCl ： 1.5g

GS ： 20g

oral rehydration salts （ ORS ）

Na+ 90mmol ／Ｌ，Ｋ +20mmol ／Ｌ，Cl － 80mmol ／Ｌ， HCO3 － 30mmol ／Ｌ

Add water to 1000ml 2 / 3 isotonic , Total osmotic pressure: 220mmol ／ＬCan be diluted in Children

口服补液盐 Oral rehydration salt (ORS)

WHO2002 年推荐的低渗透压 ORS 配方 成分 含量 ( 克 )

NaCl 2.6枸橼酸钠 2.9KCl 1.5葡萄糖 13.5水 1000ml

该配方中各种电解质浓度为： Na+ 75mmol/L ， K+ 20

mmol/L ， C1- 65 mmol/L ，枸橼酸根 10mmol/L ，葡萄糖 75m

mol/L 。总渗透压为 245 mOsm/Lsodium citrate could instead by NaHCO3

Na + -- GS transport in Small intestine

Na+–GScarrier

enterocyteBrush border intracellularintercellularblood

Na+

GS

Na+

GS

transport

promoteNa+ 、 H2O absorb

Na+(pump) intercellular space(Cl- )OP H2O into blood

Mechanisms of ORSMechanisms of ORS

Characteristics of ORS

---Advantages

Osmotic pressure similar with plasma(2/3 tonicity)2/3 tonicity)

Correct losses by proper concentration of

Na+ 、 K+ 、 Cl-

Children easily accept the tastes

Correct metabolic acidosis by sodium citrate

Promote Na+ and H2O absorption by 2% GS

Characteristics of ORS ---disadvantages

Liquid tonicity higher (2 / 3)

Can not be used as the maintenance media

Na+ concentration is relatively higher to neonates

and infants (proper diluted) .

ORS ：

Rice soup 500ml+ salt 1.75g

Fried rice noodles 25g + salt 1.75g

+ water 500ml (Cooking 2 － 3min)

GNS:

White sugar 10g + salt 1.75g + water 500ml (boil)

Simple preparation at home

Severe dehydration

intravenous

Osmotic pressure of plasma (OPP)

OPP= (crystal + colloid) osmotic pressure

Na+ 142 Cation: K+ 5(mmol) Ca++ 2.5 Mg++ 1.5

HCO3- 27

Anion: Cl- 103 (mmol) HPO4

= 1 SO4

= 0.5 Organo-anion 19.5

151 mmol/L 151 mmol/L

OPP range ： 280 － 320mOsm/L

Concentration of electrolyte and calculation

Osmotic pressure, osmol （ OSM ）

Dissolve 1mmol solute into 100ml water: 1mOsm.

100ml water

1mmol1mOsm

Concentration of electrolyte and calculation

To non electrolyte

1mmolGS 1mOsm

2mOsm1mmolNacl

To electrolyte

1mmolCacl2

3mOsm

Concentration of electrolyte and calculation

Na:Cl=3:2 （ in plasma ）

Fluid isotonic

Isotonic liquid: osmotic pressure similar with plasma

Sodium isotonic:Isotonic: 150mmol sodium in 1000ml

½ tonicity: 75mmol sodium in 1000ml

2/3 tonicity: 100mmol sodium in 1000ml

1/3 tonicity: 50mmol sodium in 1000ml

Liquid solution commonly used

5%GS

10%GS

0.9%NaCl

10%NaCl

Ringer

5% NaHCO3 11.2% NaL

10%KCl

Mixture

nonelectrolyte solution

electrolyte solution

glucose enter the body by oxidation change into water and CO2 for energy and water without tension

Percentage concentration: 5%GS 、 10%NaCl

Molar (mol, gram molecular weight) , mmol 1 mol NaCl=23+35.5=58.5g

Molarity (mol/L)

calculation ：

mol/L=

e.g. 0.9%NaCl= =0.154mol/L

Concentration of electrolyte and calculation

Percentage concentration of solute （ % ） 10

Molecular weight (atomic weight)

0.9×10

58.5=154mmol/L

10%NaCl ： 1ml=1.7mmol

5%NaHCO3 ： 1ml=0.6mmol

11.2%NaL ： 1ml=1mmol

10%KCl ： 1ml=1.34mmol

Calculation

The element and simple dispensing in the commonly mixed solution

Solution composition ratio dispensing (ml)

NS 10%GS 1.4%NB 10%GS 10%NaCl 5%NB 10%KCl

2:1 isotonic solution . 2 1 500 30 47

1:1 solution (1/2 tonicity) 1 1 500 20

2:3:1 solution (1/2tonicity)2 3 1 500 15 24 

4:3:2 solution (2/3tonicity)4 3 2 500 20 33 

1:2 solution (1/3 tonicity)1 2 500 15 

1:4 solution (1/5 tonicity) 1 4 500 9 

daily requirementrequirement (1/3tonic) 1 4 500 9 7.5

常用溶液成分溶 液 每 100ml 含 Na∶Cl 电解质渗透压

血 浆 （ 142 ： 103 ） 3 ： 2 300mmol/L

①0.9% 氯化钠 0.9g 1∶1 等张

②5% 或 10% 葡萄糖 5 或 10g

③5% 碳酸氢钠 5g 3.5 张

④1.4% 碳酸氢钠 1.4g 等张

⑤10% 氯化钾 10g 8.9 张

溶 液 每 100ml 含 Na∶Cl 电解质

1∶1 含钠液 ① 50ml,②50ml 1∶1 1/2 张

1∶2 含钠液 ① 35ml,②65ml 1∶1 1/3 张

1∶4 含钠液 ① 20ml,②80ml 1∶1 1/5 张

2∶1 含钠液 ① 65ml,④35ml 3∶2 等张

2∶3∶1 含钠液 ① 33ml,②50ml

④17ml 3∶2 1/2 张

4∶3∶2 含钠液 ① 45ml,②33ml 3∶2 2/3 张

④22ml

续 表

Water supplement & correct acidosis

Accumulative losses ---losses from onset to pre-treatment

ongoing losses

---continuing losses during treatment

daily requirement ---to maintain basically physiological function

Amount , composition and time

The first day fluid infusion ：

Dehydration Fluid replacement=losses (Accumulation + ongoing + daily )

Accumulation ongoing daily total amount (ml/Kg)

mild 50 10~30 60~80 90~120

moderate 50~100 10~30 60~80 120~150

Severe 100~120 10~30 60~80 150~180

Accumulation: accumulation lossesOngoing: Ongoing lossesOngoing lossesdaily: Physiological requirementPhysiological requirement

Severity clinical signs of dehydration

mild moderate severeWater loss

By weight

Spirit

SkinMocous

Anterior fontanel and eye ball

Tear

Urine output

Peripheral circulation

＜ 50ml/kg

＜ 5%

Slightly dispirited

slightly agitated

Slightly drySlightly dry

Slightlydepressed

Normal

Slightly reduced

normal

50 ～ 100ml/kg

5% ～ 10%

DispiritedAgitated

Dry, paleVery dry

depressed

Reduced

Little or No

Little cool

100 ～ 120ml/kg

＞ 10%

Extremely dispiritedapathy, hypnody,

coma

Gray mottledParched

depressed greatly

No

No urine output

Cool, weak

pulse,shock

Dehydration

AccumulationAccumulationlosseslosses

amount

mild ： 50ml/kg

moderate: 50~100ml/kgsevere ： 100~120ml/kg

Water supplement-1: accumulation losses

Amount , composition and speed:

--- according to the degree and quality of dehydration

composition

isotonic ： 1/2 tonicity(1:1)hypotonic ： 2/3 tonicity(4:3:1)Hypertonic:1/3~1/5 tonicity (1/3 tonicity)

speed

Principle: fast slowsevere ： bolus of isotonic fluid

2:1 isotonic : 20ml/kg(<300ml)

in 30’~1h(rapidly expand) others ： 8~12h (8 ～ 10ml/ （ kg·h ） iv

Water supplement-1: accumulation losses

AccumulationAccumulationlosseslosses

Dehydration :

OngoingOngoinglosseslosses

amount

1/2~1/3 tonicity(1:1)

speed

12~16h after stage-1 In 24h, steady speed 5ml/ （ kg·h ）

10~40ml/kg.d

composition

Water supplement-2: ongoing losses

dailydailyrequirementrequirement

amount

1/3~1/5 tonicity(Physical main medium)

speed

In 24h, steady speedAccompany with stage-2

60~80ml/kg.d（ including oral ）

composition

Water supplement-3: daily requirement

To master three principles

The volum of rehydration- AmountDeficit fluid

=(percentage of dehydration)×(body weight in Kg)

The type of fluid- CompositionIsotonic dehydration——1/2 tonicity solution

Hypotonic dehydration——2/3 tonicity solution

Hypertonic dehydration——1/3 tonicity solution

The speed of liquid-Time ： four steps

four steps(for fluid and electrolyte deficits)

Step 1. Expanding volume: restoration of circulation –emergency,

within 30 min to 1 hour

20ml/kg, 2:1 (isotonic )sodium solution

Step 2. supplement lost body liquid: first 8~10 hours

8~10ml/h

half of total loss volume

2:3:1 solution(1/2 tonicity)

Step 3. maintenance rehydration: - another half loss

- next 16 hours

5ml/(kg.h)

physical demand : 60~80ml/kg

4:1 solution(1/3~1/2 tonicity)

Step 4. repair of potassium deficit

four steps

mild ： correct etiological factor

Moderat & severe ：Alkaline solution requirement (mmol)

(40 –CO2CP Vol%)

　　　 2.2

= (22 - CO2CP mmol/L) 0.7 kg

= BE 0.3 kg

0.7 kg

Usually use the dose halved first and than according to blood gas analyses

Correct acidosis

=

Emergency :

Per-elevate 5mmol HCO3- 5mmol/L(10% CO2-CP)

need alkaline solution: 3mmol/kg

5%NaHco3 5ml/kg or 1.4% NaHco320ml/kg

Correct acidosis

Supplement potassium: 10%KCL

mild hypokalemia ： 200~300mg/ （ kg·

d ） 2~3ml/ （ kg·d ） oral

sever hypokalemia ： 300~450mg/ （ kg·

d ） 3~4.5ml/kg.d 10% KCl ivdrip

Supplement after urine or urination before coming diagnoses

Intravenous concentration<0.3% in the solute

speed ： >6~8h/d （ intravenous ）Time ： keep 4 ～ 6 day

interdiction ： directly intravenous ， because heart stop ！

Supplement potassium principle ：

Supplement Calcium and Magnesium

Convulsion emerged ： 10% Calcium Gluconate 10ml+25% Glucose 10ml IV

If convulsion hasn’t relieved after supplement calcium, ——give 25% Mg.Sulfas 0.2~0.4ml/kg deeply IM Q6h

be careful （ Calcium ） : HR<80 time /minute ， stop ！ Don’t leak out vessel Interval of the Digitalis Don’t injection with subcutaneous and intramuscular

first fast then slow

Principles of TherapyPrinciples of Therapy

first thick then thin

supplement potassium when having urine

adjust any time and monitor

Ongoing losses and Ongoing losses and daily requirementrequirement

daily requirementrequirement 60~80ml/kg (1/3~1/5 tonicity)

Ongoing losses follow the how much of the lostOngoing losses follow the how much of the lost in the any time ( in the any time ( 1/2~1/3 tonicity)

12~24H equal the speed iv drip

To continue the supplement potassium and correct acidosis

The second day fluid infusion ：

Neonate: to reduce the liquid and electrolytes

properly.

Severe malnutrition ： to reduce the water

amount properly, with low speed, 2/3~1/2 tonic

supplement 10% GS and / or plasma

Notes

An 8 – month boy had diarrhea and vomited for 3 days,

urine stream reduced, irritability.

PE: Pulse rate 150/min, weight loss was 10%, blood

pressure 65/40mmHg, skin color showed grey and skin

turgor looked like tents. Mucous membranes were very

dry; eye ball was sunken greatly, anterior fontanel

depressed greatly. Abdomen extended, bowel sound

diminished.

Answer question 2How to administer the fluid therapy?

The first day fluid infusion ：

Dehydration Fluid replacement=losses (Accumulation + ongoing + daily )

Accumulation ongoing daily total amount (ml/Kg)

mild 50 10~30 60~80 90~120

moderate 50~100 10~30 60~80 120~150

Severe 100~120 10~30 60~80 150~180

Accumulation: accumulation lossesOngoing: Ongoing lossesOngoing lossesdaily: Physiological requirementPhysiological requirement

Step 1 ： Plan supplementary fluid.

First body weight is calculated by

formula of growth and development section.

——(6+8×0.25=8kg)

——2:1 sodium :20ml×8=160ml

——finished intravenously within 30min.

Step 2 ： Acute loss

be always isotonic dehydration, so we choose ：

——2:3:1 (2:glucose , 3: sodium, 1: 1.4% bicarbonate )

——that belong to 1/2 tonicity.

——Repair of water and sodium deficits

● first 8-10 hours 8-10 ml/(kg·h)

● half of total loss volume

(160×8)ml/2=640 ml.

Step 3. ： 4:1 sodium

● be taken next 16 hours

5 ml/(kg·h)

● 80 ml/kg×8kg=640 ml (another half)

Step 4 ： Potassium supplement

8kg×0.4g=3.2g/d. That means about 10% potassium chloride solution

32ml will be used by intravenous infusion. Notice supplement potassium

——when urine stream must be seen;

——meanwhile, be aware of concentration(<0.3%)

——speed and time of it.