Hyp

onat

rem

iaan

d H

yper

natr

emia

Dis

ord

ers

of W

ater

Bal

ance

Wat

er B

alan

ce

•W

ater

con

stitu

tes

app

roxi

mat

ely

55 -

60%

o

f th

e hu

man

bod

y (T

BW

).

•T

BW

is d

ivid

ed in

to:

•In

trac

ellu

lar

–2

/3

•E

xtra

cellu

lar

–1

/3•

Pla

sma

–¼

•In

ters

titia

l Flu

id –

¾

Dia

gram

fro

m U

pto

dat

e.

Dia

gram

fro

m U

pto

dat

e

•P

lasm

a os

mo

lalit

yin

hea

lthy

adu

lts is

m

ain

tain

ed w

ithin

a n

arro

w r

ange

27

5 –

290

mO

sm/k

g.

Stim

ulu

s fo

r A

VP

rel

ease

Dia

gram

fro

m U

pto

dat

e

•

Osm

otic

Reg

ulat

iono

f AD

H R

elea

se

Hyp

ovo

lem

icS

timul

usto

AD

H R

elea

se

An

ti D

iure

tic H

orm

on

eArg

inin

eV

aso

pre

ssin

(A

VP

)

Dia

gra

m f

rom

Upt

oda

te.

AV

P

•T

her

e ar

e tw

o m

ajo

r re

cep

tors

for

AV

P:

•T

he

V1

(V1

a an

d V

1b)

and

V2

rece

pto

rs.

•A

ctiv

atio

n o

f th

e V

1 r

ecep

tors

ind

uces

va

soco

nst

rictio

n an

d en

hanc

emen

t of

pro

stag

lan

din

rel

ease

.

•A

ctiv

atio

n o

f th

e V

2 r

ecep

tors

med

iate

s th

e an

tidiu

retic

resp

ons

e.

Vas

opr

essi

n b

ind

s to

V2

rec

epto

r ac

tivat

es a

den

ylcy

clas

ean

d p

rom

ote

s cA

MP

pro

duct

ion

, wh

ich

st

imu

late

s p

rote

in k

inas

eA

(P

KA

) an

d p

hosp

hor

ylat

esaq

uap

orin

2.

Th

is c

ause

s A

quap

orin

mo

vem

ent t

o

and

exo

cytic

inse

rtio

n o

f th

e ve

sicl

e in

to th

e ap

ica

l me

mb

ran

es.

Ren

al A

quap

orin

s: A

n o

verv

iew

. N

iels

en, S

, BJU

Int

. 200

2

Sch

emat

ic r

epre

sent

atio

n of

the

loca

lizat

ion

of r

enal

aq

uapo

rins

and

dist

ribut

ion

of a

quap

orin

1,2,

3 an

d 4

in th

e ki

dney

. Re

nal A

qua

porin

s: A

n ov

erv

iew

. N

iels

en,

S.

BJU

Int

. 2

002

Hyp

onat

rem

ia

•M

ost

co

mm

on

ele

ctro

lyte

dis

ord

er in

ho

spita

lized

p

atie

nts.

Stu

dy

by

Ho

orn

et a

l, in

Nep

hro

lDia

l Tra

nsp

lan

t 20

06, l

ooke

d a

t 2

,907

ho

spita

lized

pat

ien

ts o

ver

3 m

ont

hs th

e in

cid

en

ce o

f h

ypo

nat

rem

iaw

as 3

0% a

nd

seve

re h

ypo

nat

rem

ia(<

125

Meq

/L)

was

3%

.

•G

ener

ally

def

ined

as

S. N

a le

vel l

ess

than

13

6

mm

ol/L

, th

ou

gh d

efin

itio

n o

f sev

ere

hyp

on

atre

mia

varie

s fr

om 1

10

to 1

25

mm

ol/L

.

Hyp

onat

rem

ia

•P

artic

ular

ly p

reva

lent

in th

e el

derly

pop

ulat

ion

due to

:•

Ag

e re

late

d d

eclin

e in

ren

al fu

nct

ion

.•

Th

irst m

ech

anis

m d

imin

ish

es w

ith a

ge,

incr

easi

ng r

isk

of

volu

me

dep

letio

n.•

Dec

reas

ed a

bili

ty to

dilu

te th

e ur

ine.

•In

crea

sed

sec

retio

n o

f AV

P p

er u

nit i

ncr

ease

in p

lasm

a os

mo

lalit

yin

old

er p

atie

nts

.

•In

a s

tudy

of 1

19 N

ursi

ng H

om

e re

side

nts

over

the

age

of

60, 5

3% o

f res

iden

ts h

ad a

t lea

st o

ne e

piso

de o

f hy

pona

trem

iadu

ring

a 12

mon

th fo

llow

-up.

(M

iller

et

al,

Jour

nal A

mer

ican

Ger

iatr

ic S

ocie

ty 1

995)

Hyp

onat

rem

ia

•C

har

acte

rized

by

an e

xces

s o

f ext

race

llula

rw

ater

rel

ativ

e to

ext

race

llula

rso

diu

m.

•T

her

efor

e mai

nly

a p

rob

lem

of w

ater

b

alan

ce, t

hou

gh

the

tota

l sod

ium

con

ten

t in

p

atie

nts

with

hyp

ona

trem

iam

ay b

e no

rmal

, d

ecre

ased

or

even

incr

ease

d.

•E

xcre

tion

and

ab

sorp

tion

of fr

ee w

ater

by

kidn

eys

in u

nder

the

con

trol

of A

DH

Eva

luat

ion

of H

ypon

atre

mia

•In

itial

lab

s N

eed

ed:

•S

erum

Osm

olal

ity

•U

rine

Osm

ola

lity

–if

>10

0mm

ol/k

g th

ere

is e

leva

ted

AD

H p

rese

nt.

•U

rine

spo

t sod

ium

•O

ther

hel

pfu

l lab

s;•

Ser

um U

ric

acid

–lo

w in

SIA

DH

an

d sa

lt w

astin

g ne

phro

path

y

•T

SH

, Cor

tisol

, Cre

atin

ine

Eva

luat

ion

of H

ypon

atre

mia

Div

ided

into

:

•E

leva

ted

S. O

smo

lalit

y:

•H

yper

gly

cem

ia o

r m

ann

itoli

nfu

sion

•N

orm

al S

. Osm

ola

lity:

•

Hyp

erp

rote

inem

iao

r h

yper

lipid

emia

(pse

ud

ohyp

on

atre

mia

)

•D

ecre

ased

S. O

smo

lalit

y: W

ide

diff

eren

tial.

Pse

ud

ohy

po

nat

rem

ia

Clin

ical

Dia

gnos

tic

Alg

orit

hm f

or H

ypon

atre

mia

John

son

and

Fee

hally

(tex

tboo

k)

Hyp

ovol

emia

asso

ciat

ed w

ith d

ecr

ease

d to

tal b

ody

sod

ium

•G

I los

ses

and

Thi

rd S

pace

Seq

uest

ered

Los

ses:

•U

rine

Na

will

be

low

, u

sual

ly <

10m

mo

l/L a

nd

the

ur

ine

is

hyp

ero

smo

lar.

•In

pat

ien

ts w

ith v

om

iting

and

met

abol

ic a

lkal

osi

s, b

icar

bon

atur

iao

ccur

s an

d H

CO

3 is

lost

with

Na,

so

the

urin

e N

a m

ay

be

gre

ater

th

an 2

0m

mo

l/L,

the

Clh

ow

ever

will

stil

l be

<10

mm

ol/L

•D

iure

tics

•A

sso

ciat

ed w

ith h

igh

urin

e N

a >

20m

mo

l/L.

•H

ypon

atre

mia

occ

urs

alm

ost

exc

lusi

vely

with

the

use

of t

hia

zid

ed

iure

tics.

•U

nder

wei

ght

wo

men

and

eld

erly

pat

ien

ts m

ore

pro

ne

to it

.

•H

ypon

atre

mia

usu

ally

occ

urs

with

in 1

4 d

ays

of i

niti

ati

on o

f th

erap

y.

•S

alt L

osin

g N

ephr

opat

hy•

Occ

urs

in p

atie

nts

with

ad

vanc

ed C

KD

, and

dis

ord

ers

su

ch a

s B

arte

rs a

nd G

itlem

ans

synd

rom

e a

mo

ng

oth

ers,

an

d is

ch

arac

teriz

ed b

y h

ypo

nat

rem

iaan

d h

ypo

vole

mia

.

•M

iner

aloc

ortic

oid

defic

ienc

y•

Urin

e N

a >

20m

mo

l/L.

•D

ecre

ased

EC

F v

olu

me

pro

vid

es th

e s

timu

lus

for

vaso

pres

sin

rele

ase.

•O

smot

ic d

iure

sis

•D

iab

etic

pat

ient

with

sev

ere

hyp

erg

lyce

mia

, m

ann

itol

diur

esis

or

ure

a d

iure

sis

afte

r re

lief o

f urin

ary

trac

t obs

tru

ctio

n

•U

rinar

y N

a ty

pica

lly >

20

mm

ol/L

. N

a w

astin

g in

dia

betic is

ac

cen

tuat

ed b

y ke

ton

uria

.

•C

ereb

ral s

alt w

astin

g•

Usu

ally

occ

urs

with

sub

arac

hnoi

dh

emor

rhag

e. M

ech

ani

sm

pos

tula

ted

to b

e re

leas

e of

BN

P fr

om

bra

in w

ith r

esul

tan

t in

crea

se

in N

a ex

cret

ion

an

d h

ypov

ole

mia

Hyp

ervo

lem

iaas

soci

ated

with

incr

ease

d to

tal b

ody

sod

ium

•C

onge

stiv

e H

eart

Fai

lure

•D

ecre

ased

intr

avas

cula

r ci

rcul

atin

g v

olu

me.

•U

rine

Na

< 2

0mm

ol/L

•H

epat

ic F

ailu

re•

Sh

are

sam

e p

ath

oph

ysio

log

icm

ech

anis

ms

with

pat

ien

ts w

ith h

eart

fa

ilure

.

•N

ephr

otic

Syn

drom

e•

So

me

pat

ien

ts h

ave

intr

avas

cula

r vo

lum

e d

eple

tion

res

ulti

ng fr

om

hyp

oal

bu

min

emia

and

low

ered

pla

sma

onco

ticpr

essu

re.

•A

dvan

ced

CK

D•

Incr

ease

d in

frac

tion

al e

xcre

tion

of N

a an

d na

rro

w r

ang

e of

wat

er

han

dlin

g le

ads

to u

rine

Na

>20

mm

ol/L

and

wat

er r

ete

ntio

n.

Hyp

onat

rem

iaa

ssoc

iate

d w

ith n

orm

al

tota

l bo

dy s

odiu

m

•G

luco

cort

icoi

dde

fienc

y

•H

ypot

hyro

idis

m

•P

sych

osis

•P

osto

pera

tive

hypo

natr

emia

•D

rugs

•S

IAD

Syn

drom

e of

Inap

prop

riate

Ant

idiu

resi

sS

IAD

•N

ew

er te

rmin

olo

gy

sin

ce n

ot a

ll p

atie

nts

hav

e el

evat

ed c

ircu

latin

g le

vels

of A

VP

. It i

s d

ivid

ed

into

:•

SIA

DH

–S

ecre

tion

of A

VP

is in

depe

nden

t of s

erum

os

mol

ality

.•

Res

et O

smo

stat

–A

VP

doe

s be

com

e fu

lly s

uppr

esse

d,

resu

lting

in d

ilute

urin

e, b

ut a

t a S

. Na

low

er th

an

norm

al•

Mut

atio

ns in

the

wat

er c

hann

el r

egul

atin

g va

sopr

ess

in

rece

ptor

, res

ultin

g in

con

cent

rate

d ur

ine

in th

e ab

senc

e of

AV

P.

Dia

gnot

icC

riter

ia fo

r S

IAD

•E

ssen

tial f

eatu

res:

•S

. Osm

o<

275

mO

sm/K

g of

wat

er•

U.

Osm

o>

100

mO

sm/K

g of

wat

er•

Clin

ical

Euv

olem

ia•

Uri

nary

sod

ium

>40

mm

ol/L

(w

ith n

orm

al d

iete

rysa

lt in

take

).•

Nor

mal

thyr

oid,

adr

enal

and

ren

al fu

nctio

n.•

No

rece

nt u

se o

f ant

idiu

retic

s•

Su

pp

lem

enta

l fea

ture

s:•

Pla

sma

uric

aci

d <

4 m

g/dl

•B

UN

< 1

0m

g/dl

•F

eNa

>1%

: Feu

rea

>55

%•

Fai

lure

to c

orre

ct h

ypon

atem

iaaf

ter

0.9%

sal

ine.

Dru

gs a

ssoc

iate

d w

ith h

ypon

atre

mia

Joh

nso

n an

d F

eeh

ally

(Tex

tbo

ok)

Hyp

onat

rem

iano

t rel

ated

to

incr

ease

d A

DH

sec

retio

n•

If in

itial

urin

e o

smo

lalit

yis

< 1

00m

osm

ol/k

g:

•P

sych

ogen

ic P

olyd

ipsi

a

•B

eer

Pot

oman

ia

•If

initi

al u

rine

osm

ola

lity

is >

100

mo

smo

l/kg

:•

Res

et o

smos

tat

•S

alt l

osin

g ne

phro

path

y (r

enal

sod

ium

exc

retio

n fr

om

th

e ex

cess

ive

rele

ase

of n

atri

uret

icfa

ctor

in th

e b

rain

)

Low

Die

tary

Sol

ute

Inta

ke

•M

ost p

eopl

e ta

ke in

and

exc

rete

600

–10

00m

osm

ol/k

g.

Uri

nary

osm

oles

are

mai

nly

salt

and

urea

(gl

ucos

e us

ually

ge

ts m

etab

oliz

ed).

•E

xam

ple:

Per

son

is ta

king

in a

nd e

xcre

ting

600m

osm

ol/k

g.

If yo

u ca

n di

lute

you

r ur

ine

dow

n to

60m

osm

ol/k

g –

you

ca

n ex

cret

e up

to10

L ur

ine/

day.

•If

som

eone

onl

y ta

kes

in 2

40m

osm

ol/k

g, th

en a

t the

lo

wes

t ur

ine

osm

olal

ity(6

0 m

osm

ol/k

g), t

hey

can

only

exc

rete

ab

out 4

L of

uri

ne/d

ay.

The

refo

re, i

f tha

t per

son

dri

nks

any

mor

e th

an 4

L/da

y, th

e ex

tra

wat

er s

tays

beh

ind

and

caus

es

hypo

natr

emia

.

Psy

chog

enic

Pol

ydip

sia

•S

ame

con

cep

t app

lies:

•If

a p

erso

n is

taki

ng

in 6

00

mo

smo

l/kg

, at

max

imu

m u

rine

dilu

tion

( 6

0 m

osm

ol/k

g),

they

ca

n o

nly

get

rid

of

10

L o

f w

ater

. If

they

drin

k m

ore

than

th

at th

ey w

ill r

etai

n w

ater

an

d

bec

om

e h

ypo

nat

rem

ic.

Ran

ge o

f Sym

ptom

s of

H

ypon

atre

mia

•N

on

-sp

ecifi

c N

euro

log

ical

Sym

pto

ms:

•C

onfu

sion

•H

eada

che

•N

ause

a an

d vo

miti

ng•

Mus

cle

cram

ps•

Sev

ere

Ne

uro

log

ical

Co

mp

licat

ion

s:•

Sei

zure

s•

Bra

inst

em h

erni

atio

n•

Co

ma

•D

eath

Bra

in A

dapt

atio

n to

Hyp

onat

rem

ia

•O

smo

tic c

ereb

ral o

edem

ath

at o

ccur

s w

ith

pla

sma

hypo

-osm

ola

lity

and

hyp

ona

trem

iaaf

fect

s bo

th in

trac

ellu

lar

and

ext

race

llula

rco

mpa

rtm

ents

in th

e g

ray

and

wh

ite m

atte

r.

•C

ereb

ral o

edem

ais

cou

nte

ract

ed b

y an

ad

aptiv

e p

roce

ss k

now

n as

reg

ula

tory

vo

lum

e de

crea

se (

RV

D)

that

no

rmal

izes

cel

l vo

lum

e.

Bra

in A

dapt

atio

n to

Hyp

onat

rem

ia

•R

VD

(R

egul

ator

y V

olum

e D

ecre

ase)

:

•1-

Dis

plac

emen

t of f

luid

fro

m th

e in

ters

titia

l to

the ce

rebr

ospi

nal f

luid

and

sys

tem

ic c

ircul

atio

n (d

rive

n by

hy

dros

tatic

pre

ssur

e).

•2-

Ext

rusi

on fr

om

the

brai

n ce

lls o

f ino

rgan

ic,

osm

otic

ally

activ

e so

lute

s in

clud

ing

sodi

um c

hlor

ide

(l

ost w

ithin

min

utes

), p

otas

sium

(m

ore

gra

dual

ly –

com

plet

e in

abo

ut 3

hrs

).•

3-E

xtru

sion

fro

m th

e br

ain

of o

rgan

ic o

smol

ytes

, pr

imar

ily a

min

oaci

ds(m

yoin

osito

lis

the

mos

t pre

vale

nt

orga

nic

osm

olyt

ein

the

hum

an b

rain

) –

occu

rs o

ver

next

48

hrs.

•In

ani

mal

stu

dies

we

have

see

n th

ese

adap

tive

resp

onse

s lim

it th

e in

crea

se in

bra

in w

ater

to 4

% h

ighe

r th

an n

orm

onat

rem

ican

imal

. W

ithou

t the

ext

rusi

on o

f

the

orga

nic

osm

olyt

es, t

he in

crea

se in

bra

in w

ater

w

ould

be

>10

% -

whi

ch is

inco

mpa

tible

with

sur

viva

l.

Bra

in A

dapt

atio

n to

Hyp

onat

rem

ia

•A

cute

hyp

onat

rem

ia(o

ver

< 2

4 h

r) c

an

ove

rwh

elm

this

pro

tect

ive

mec

han

ism

.

•If

the

dec

line

in s

erum

Na

is s

low

and

g

radu

al (

> 4

8hr

s), c

ereb

ral s

wel

ling

and

the

neu

rolo

gic

al s

ympt

om

s ar

e m

inim

ized

.

Cor

rect

ion

of H

ypon

atre

mia

•T

he

pla

sma

sod

ium

co

nce

ntr

atio

n c

an b

e ra

ised

in

hyp

onat

rem

icp

atie

nts

eith

er b

y:•

Res

tric

ting

wat

er in

take

.

•B

y gi

ving

sal

t.

•B

y gi

ving

vas

opre

ssin

rec

epto

r an

tago

nist

.

•T

he

cho

ice

of t

her

apy

is p

rimar

ily g

ove

rned

by

the

cau

se a

nd

sev

erity

of t

he

hyp

on

atre

mia

.

Cor

rect

ion

of H

ypon

atre

mia

•S

ymto

mat

ic/A

cute

Hyp

onat

rem

ia-

corr

ect

by

1.5

–2

.0 M

eq/l

per

hr.

in fi

rst 4

hrs

, bu

t to

tal c

orre

ctio

n fo

r 24

hr.

sho

uld

stil

l be

abo

ut 1

2 M

EQ

/L p

er d

ay.

•A

sym

pto

mat

ic/C

hron

ic H

ypon

atre

mia

–co

rrec

t by

0.5

Meq

/L p

er h

r., o

r 1

0 –

12

Meq

/L p

er d

ay.

Cal

cula

ting

the

rate

of c

orre

ctio

nfo

r se

vere

sym

ptom

atic

hyp

onat

rem

iaw

ith 3

% s

alin

e b

ased

on

Na

defic

iet

Exa

mpl

e: 7

0kg

patie

nt w

ith S

. Na

of 1

10.

•(

0.6

x 70

kg)

x (

120

-110

) =

420

ME

Q d

efic

eito

f Na

.•

Cor

rect

at r

ate

of 1

.5m

eq/L

/hr

you

wou

ld r

equi

re to

giv

e 42

0meq

ove

r 6.

6hr.

-64

meq

/hr.

•3%

NS

has

513

ME

Q/L

of N

a –

ther

efor

e ro

ughl

y ev

ery

2cc

of 3

% s

alin

e w

ill h

ave

1meq

of N

a. Y

ou w

oul

d h

ave

to g

ive

128c

c/hr

.•

Thi

s sh

ould

be

the

initi

al c

orre

ctio

n ra

te fo

r th

e fir

st 4

hrs

, ch

ecki

ng th

e la

bs q

2hr

. Rem

em

ber

you

wan

t to

corr

ect

10

-12

ME

Q to

tal o

ver

24 h

rs.

Why

not

use

0.9

% N

S a

lone

to c

orre

ct S

. Na

in S

IAD

H•

Urin

e o

smo

lalit

yis

60

0m

osm

ols

/kg

and

we

giv

e N

S w

hic

h h

as a

pp

roxi

mat

ely

15

0m

eq o

r b

oth

Na

and

Cl(

tota

l 30

0m

osm

ol).

•N

aCle

xret

ion

is in

tact

in S

IAD

H.

•T

hen

the

30

0m

osm

ol w

ill b

e ex

cret

ed in

50

0cc

of

urin

e, le

avin

g b

ehin

d 5

00

free

wat

er a

nd

th

eref

ore

w

ors

enin

g u

nd

erly

ng

hyp

on

atre

mia

.•

In S

IAD

H, y

ou

nee

d to

hav

e in

take

wh

ich

is m

ore

co

nce

ntr

ated

than

the

urin

e (e

gw

ater

res

tric

tion

, sa

lt ta

blet

s, 3

% N

S o

r sa

line

plu

s la

six)

.

Tre

atm

ent o

f Chr

onic

Hyp

onat

rem

iadu

e to

SIA

D

•R

estr

ict f

luid

inta

ke

•E

nco

ura

ge d

ieta

ry in

take

of s

alt a

nd p

rote

in

•D

emec

locy

line

300

–6

00m

g b

id o

r u

rea

15

-60

gm d

aily

•V

asop

ress

in r

ecep

tor

anta

gon

ist (

whe

n

avai

lab

le o

rally

).

Tre

atm

ent o

f chr

onic

asy

mto

mat

ichy

pona

trem

iaJo

hns

on

and

Fee

hal

ly(T

extb

ook

)

Vap

tans

•A

VP

(A

rgin

ine

Vas

op

asin

) re

cep

tor

anta

gon

ist.

•C

on

ivap

tan

–IV

ag

en

t wo

rks

on b

oth

V2

an

d V

1

rece

pto

rs. A

pp

rove

d b

y F

DA

for

trea

tmen

t o

f eu

vole

mic

hyp

on

atre

mia

in h

osp

italiz

ed p

atie

nts

.

•Li

xiva

pta

nan

d T

olv

apta

n–

ora

l ag

ent,

acts

on

V2

re

cep

tors

.

•M

ain

sid

e af

fect

s se

em to

be

thirs

t.

Osm

otic

Dem

ylin

atio

nS

yndr

ome

•O

verl

y ra

pid

corr

ectio

n of

S.N

are

sults

in d

ehyd

rati

on o

f ne

uron

s an

d gl

iaw

hich

lead

s to

OD

S.

•C

orre

ctio

n of

hyp

onat

rem

iaca

uses

effl

ux o

f wat

er fr

om

the

brai

n, tr

igge

ring

a “

de-a

dapt

atio

n pr

oces

s”•

The

inor

gani

c an

d or

gani

c os

mol

ytes

whi

ch w

ere

lost

du

ring

RV

D (

regu

lato

ry v

olum

e de

crea

se)

re-e

nete

rth

e br

ain

and

re-e

stab

lish

osm

otic

equ

ilibr

ium

. •

The

reu

ptak

e of

org

anic

osm

olyt

esaf

ter

corr

ectio

n o

f hy

pona

trem

iais

slo

wer

than

the

initi

al lo

ss d

urin

g th

e ad

apta

tion

to h

ypon

atre

mia

.•

Peo

ple

with

mal

nutr

ition

, Chr

onic

ET

OH

abu

se a

nd

hypo

kale

mia

are

mor

e at

ris

k of

OD

S.

Osm

otic

Dem

ylin

atio

nS

yndr

ome

•In

clud

es b

oth

cen

tral

pon

tine

and

ex

trap

ontin

em

yelin

oly

isis

.

•B

egin

s w

ith le

thar

gy

and

affe

ctiv

e ch

ange

s,

follo

wed

by

mu

tism

or

dysa

rthr

ia, s

pas

tic

qua

drip

arei

sis

and

pse

udo

bulb

arpa

lsy.

Pat

ien

ts a

t ris

k fo

r n

euro

log

icco

mp

licat

ion

sJo

hns

on

and

Fee

hal

ly(t

extb

ook)

Hyp

erna

trem

iaP

atho

gene

sis

of H

yper

natr

emia

•D

ecre

ased

free

wat

er s

uppl

y.

•P

oor

acce

ss to

free

wat

er.

•H

ypot

hala

mic

lesi

ons

affe

ctin

g th

irst

.

•W

ater

loss

•R

enal

: Osm

otic

diu

resi

s, C

entr

al o

r N

ephr

ogen

icD

I.

•G

I: O

smot

ic d

iarr

hea

•In

sens

ible

loss

es: F

ever

, Exe

rcis

e an

d ex

posu

re to

he

at.

•S

olut

e lo

ad

•A

dm

inis

trat

ion

of h

yper

toni

c so

dium

con

tain

ing

solu

tions

.

Wor

kup

of H

yper

natr

emia

•W

hy

is th

e p

atie

nt n

ot d

rinki

ng?

•Is

ther

e in

crea

sed

free

wat

er lo

ss:

•?P

oly

uria

•U

osm

: if <

250

–D

I

•U

osm

: if >

300

–S

olut

e di

ures

is

•?G

I (O

smo

tic d

iarr

hea)

•Is

the

pat

ien

t get

ting

too

mu

ch s

olu

te?

Tre

atm

ent o

f Hyp

erna

trem

ia

•P

rovi

de

free

wat

er.

•C

alcu

late

the

free

wat

er d

efic

it:•

0.5

x b

od

y w

eig

ht x

(P

Na/

14

0 –

1)

for

me

n

•0

.4 x

bo

dy

wei

gh

t c (

PN

a/1

40

–1

) fo

r w

om

en

•R

ate

of c

orr

ectio

n fo

r N

a 0

.5m

eq/h

r.

Exa

mpl

e of

Hyp

erna

tre

mia

•6

0 ye

ar o

ld fe

mal

e w

ith A

RD

S o

n v

entil

ato

r su

ppo

rt o

n p

ress

ors

and

TP

N.

Hem

odyn

amic

ally

stab

le.

•P

Na

= 1

50

. U

rine

ou

tput

15

0m

l/hr

•U

osm

= 5

04

U N

a =

40

meq

•U

rine

dip

stic

k =

2+

S g

luco

se =

40

0

•W

hat

is th

e ca

use

of h

yper

nat

rem

ia?

•H

ow

wou

ld y

ou tr

eat h

im?

Cal

cula

ton

of w

ater

def

icit

•C

alcu

late

am

oun

t of w

ater

:•

0.4

x b

od

y w

eig

ht x

(P

Na/

14

0 -

1)

•0

.4 x

50

x (

15

0/1

40

-1

) =

1.4

lite

rs

•In

sen

sib

le lo

sses

=

1.0

lite

rs

•T

ota

l vo

lum

e =

2.4

lite

rs

•R

ate

(0.5

meq

/hou

r)•

Fo

r N

a to

go

fro

m 1

50

to 1

40 =

20

hrs

.

•P

resc

riptio

n: 2

400

/20

= 1

20m

l/hr

free

wat

er

Adr

ogu

eet

al.

Hyp

ern

atre

mia

. N

EJM

200

0; 3

42(2

0) 1

493

-149

8

•E

nd