MBBS;MS. FICOG. MICOG.
Founder Principal & Controller,
Jhalawar Medical college , Jalawar.
Mahatma Gandhi Medical College,sitapura , Jaipur.
Total body water is 60% in male, 50% in female i.e. 30
Inraceullar fluid (ICF) –20 litres water (2/3).
Extracellular fluid (ICF)– 10 litres water (1/3).
>Plasma –2.2 litres (1/4).
> Interstitial fluid – 7.5 litres (3/4).
EcF volume and Osmalality regulation is controlled by 3
hormones –aldosterone, ADH Atrial natriuretic
hormoneION ICF ECF
Sodium 10mml/L 140mml/L
Potassium 150mml/L 4.5mml/L
Chloride Traces 105mml/L
It is decrease in whole body fluid volume
which includes both exta and intracellular fluid
Extracellular fluid loss is more important and
has to be assessed .
This fluid loss may be :
>Isotonic –Water and salt loss leading to
> Hypotonic – only water loss with minimal
electrolyte loss; leading to dehydration.
Isotonic Volume Depletion
Occurs due to diarrhea, vomiting and excess
> Fluid loss is only of ECF compartment and so
immediate reduction in intravascular volume
results leading to hypovolaemia and fall in BP.
> decreased Tissue perfusion.
features Dry tongue , rapid pulse, cold clammy
skin , sunken eyes , decreased BP, oliguria , raised
blood urea and decreased urinary sodium.
Hypovolaemia –Mild (<2l), Moderate (2-3L) ; severe
( > 3l ) fluid loss.
Hypotonic Fluid loss
> i.e. only water loss , occurs due to decreased
intake of water and diabetes insipidus .
> It causes dehydration and appropriate and
decrease in total body water in all fluid
compartments ( 2/3rd ICF , 1/3rd ECF ).
>As ECF loss is less ---intravascular fluids loss is
also less hence Fall in BP is also less .
Features severe thirst , confusion,
convulsions( due to hypernatraemia ), BP
relatively normal .
Dehydration : mild (weight loss 5%), moderate
(10%) , severe (15% ).
Evaluation is done by estimation of serum
Na+, urinary Na+ and blood urea .
Isotonic volume depletion is corrected by o.9%
normal saline infusion ,
Pure water depletion is corrected by more
water in take / IV 5% dextrose infusion .
Monitoring fluid therapy by skin and tongue
examination, weight gain pulse, BP, urine
output , CVP and PCWP.
Water & Salt excess
occurs in CCF , Cirrhosis, nephrotic syndrome ,
hypoproteinaemia, renal failure , excessive
TCRE, excess infusion of 5% dextrose only,
SIADH secretion, Psychogenic polydypsia.
It is managed by stopping fluid infusion or
procedure (TCRE), fluid restriction and treating
Excessive amount of intravenous dextrose(5%).
Bowel Wash by plane water in place of normal
In TCRE (TUR in urology ) hydro dissection in
tumour surgery , when excessive fluid Plane
water or glycine is used for uterine distension.
In syndrome of inappropriate Anti diuretic
hormone secretion which is commonly
associated with lobar pneumonia, empyema ,
oat cell carcinoma and head injury .
Drowsiness , weakness.
Convulsions , coma.
Nausea and vomiting.
Passage of dilute urine.
Distended neck veins.
Gain in body weight .
Circulatory over load –tachycardia, pulmonary
edema, hypertension and pedal edema.
Bilateral basal crepitations , ascites.
Raised CVP, PCWP.
>Haematocrit and sodium level (will show fall in
> Low Potassium and Low blood urea.ECG< X-ray
>Water and salt restriction and observation .
> Monitoring in ICU.
> Management of fluid and electrolyte balance as per
serum electrolyte reports.
> Infusion of( ½) hypotonic saline.
Administration of diuretics and hypertonic saline
should be avoided as it may de arrange serum
electrolytes which may lead to neuronal demylation
and FATL OUTCOME.
> Here only ECF loss occurs , ICF remains Normal.
> It is seen in diarrhoea , vomiting, intestinal
obstruction / fistula.
> Normal Saline infusion = to calculated ECF loss.
Only ECF Excess ,ICF remains normal.
It occurs when excessive infusion of saline with
impaired excretion as in renal diseases.
Raised JVP , cardiac failure and peripheral edema.
Treatment is fluid restriction and diuretics like
> Serum Sodium level is < 130mEq/L
> Severe degree hyponatraemia, when serum
sodium level < 100 mEq/L in acute type and in
chronic type serum sodium level <115 is taken
as reference value.
< May be due to water over loading (dilution)
or sodium loss.
Acute—presents as neurological manifestations.
Chronic – cause pontine myelonlysis , presents as behavioral
changes , weakness and central nerve palsies.
Other types may be
(a) hypervolaemic Hyponatraemia –Rapid absorption of fluid occurs
leading to dilution and decreased Na+ concentration. Decreased
osmalality results in migration of ECF in to ICF compartment and
hence patient develops cerebral and pulmonary edema ., causing
convulsions and respiratory symptoms.
-Urinary Na+ conc. Is 15 mmol/L.
-fluid restriction ,hypertonic saline (double strength) infusion and
loop diuratics like frusamide injection are the main lines of
- Monitoring is done by Serum Na= estimation and its correction till
it reaches above the level of 125mmol/L .
- correction should be slow and gradual at the rate of 2mEq/L /Hr
and up to 20 mEq/L in 24 hours. Serum Na+ estimation should be
done at 4 hourly interval .
- Rapid correction may lead to irreversible myelinlysis of pontine .
- Over correction should always be avoided.
(b) Hypovolumaemic hyponatraemia –
- Hypovolaemic as in dirrhoea and vomiting ,
hyponatraemic as urinary Na= level is <
- Due to forced diuresis and renal causes water is
lost and urinary Na+ level is more than
- It may be due to over correction of
hypovolaemia by only dextrose / hypotonic fluid.
- condition is treated by using Isotonic
fluid(normal saline ) therapy.
(c) Normovolaemic Hyponatraemia—
- It may be due to renal failure or Syndrome
of inappropriate ADH secretion
- Mild cases fluid restriction (1 litre /day )
will raise the Na+ level .
- In severe cases Vasopressin antagonist (
Demeclocyclin) will increase the diluting
ability of kidney . And Na+ level will improve.
( d) Pseudo-hyponatraemia –
- Plasma osmalality is mainly achieved by Na+ but small
portion of it i.e. 25% is due to other solutes like glucose ,
proteins, urea and lipids which do not move out easily from
vascular compartment, in IC / EC Spaces.
- When concentration of this substances increase , the Na+
level will fall causing Pseudo hyponatraemia.
Correction of increased element will correct the Na+ level.
- Intestinal obstruction,
-gastric outlet obstruction with excess of vomiting ,
-prolonged Ryle’s tube aspiration,
-Severe diarrhoea due viral cause –in colitis and cororectal polyposis,
-Immediate after surgery / trauma Na+ depletion occurs .
Serum electrolytes --- Low serum Na= Level.
Urinary Na+ level low,
Sodium deficit =
( 125- present Na+ ) X body weight in Kg X 0.6.
In acute cases --IV infusion of normal saline to
achieve slow and gradual correction of serum
Na+ level at the rate of 2mEq/L / hr.
Maximum 20mEq/L in 24 hrs. monitor Na=
Level at 4 hrs interval.
In chronic Case--< 1mEq/L/Hr and should
not exceed > 10mEq/l in 24 hrs.
Hypertonic saline 1.6 % or 3% can be used in
acute severe cases with caution of too early and
rapid correction is associated with myelinlysis
Cause is also treated simultaneously.
Type of Saline fluid NaCl content
0,9% normal saline /L 154mEq/L
3% hypertonic Saline 500 mEq/L
Serum Na+ level >150mEq/L., is taken as
>Drug induced like NSAID , Corticosteroids.
>Excess infusion of hypertonic saline /intra amniotic
hypertonic saline previously used for mid trimester
> excess of normal saline infusion causes overloading
in circulating salt and water. It is due to when water
deficit present in initial stage..
(A) Euvolaemic ( pure water loss ):
- It is due to decreased water intake as in coma,
bedridden people , post operative patients when iv
therapy has been stoped but pt does not take reqired
amount of water, patient in high fever leading to
external loss of water. It can also occur in diabetes
incipidus / chronic renal failure as renal loss of only
( B ) -Hypovolaemic:
-( Among loss of water and Na= but water is more lost
than Na+.) as in cases of vomiting ,diarrhoea , more
undue sweating ( extra renal ) , osmotic diuresis by
high concentration glucose/ mannitol infusion (renal ).
( C ) Hyper volaemic :
- (Both water and Na+ gain But Na= gain is more than
water.) as seen in more salt intake, excess steroids , Na
HCo3/ hyper tonic saline infusion ( salt gain )
Puffiness of face .
Increased urination .
Often dilated jugular vein.
Features of pulmonary Edema.
> Plasma and Urinary osmolality.
> Renal Function Test.
>Restriction of saline , Na+.
> Correction should be slow and gradual –
Initial infusion of normal saline ,then infusion of ½
strength (0.4.5% ) saline later with 5% dextrose ;
otherwise cerebral edema and hyperglycaemia can
> oral / nasogastric administration of water / other
fluids as condition improves.
Serum Potassium level < 3.5 mEq/L is leveled as
hypokalaemia.( normal range –4.0 to 4.5 mEq /L)
1.Sudden onset It occurs in diabetic coma cases
treated with insulin and saline infusion ; as insulin
causes influx of K+ in the cells and saline (containing
NO K+) dilutes its concentration in serum.
2. Gradual onset
Diarrhoea of any cause,
gastric aspiration / vomiting,
After trauma or surgery ,
duodenal fistula/ileostomy ,
insulin therapy ,
beta blockers ,
prolong diuretic therapy etc.
Muscular hypotonia (physical sign).
Weakness of respiratory muscles.
Inability to produce concentrated urine.
Nocturia and polyuria.
ECG– shows prolonged QT interval, depression of
ST segment , inversion of T wave and prominent
Often hypokalaemia is associated with alkalosis.
Serum potassium < 3.5 mEq/L.
> oral potassium 2gm ;6hrly , 15 ml K Cl
syrup(2ommol of K)
> Iv K CL 40mmol?L in5% dextrose / normal saline
slowly , often under ECG monitoring . Maximum
dose / hr is 20 mmol .
>Hypocalaemic alkalosis if present should be
treated carefully by iv Potassium .
Normal serum K+ level ranges from 4.0 to 4.5
Hyperkalaemia menifests when serum K+
exceeds 6.0 mEq/L
Rapid infusion of potassium.
Transfusion of stored blood –K+ diffuse out of stored RBC.
Diabetic Ketoacidosis .
Potassium sparing drugs like diuretic therapy
(spironolactone), beta blockers , cyclosperine .
Massive tissue destruction ,burns , trauma, tumor necrosis,
crush injury –intra cellular K+ is released in blood.
In vitro haemolysis, thrombocytosis , torniquet application
exercise cause pseudo hyperkalaemia.
Familial hyperkalaemic periodic paralysis.
Note Hyperkalaemia is dangerous state can result in cardiac
> High serum potassium level.
> Peak T wave on ECG.
( B ) Treatment
> IV infusion of 50 ml of 50% glucose with 10 units of
soluble insulin , slowly .
>Infusion of 10% cal gloconate IV ( cardio protection)
> CaCl2 is given Iv in severe cases as calcium in this form
is immediately released without hepatic metabolism.
> Dieresis using Frusemide –causes K+ excretion.
> Haemolysis / dialisis when required.
> continuous ECG monitoring ,
> Salbutamol / Albuterol nebulisation
> IV Sodium bicarbonate –shifts K+ in to cells – 50- 100 ml
slowly over 10 minutes in 7.5% concentration .
It is rare: serum magnesium level >
2.5mEq/L(normal level is 1.5- 2.5mEq/L ).
Intracellular magnesium is more 26mEq/L ( 2nd
more higher element).
Mg is mainly deposited in bones.
It is a co- factor for many enzymes necessary
for phosphorylation of glucose in cell and ATP
utilization in muscle fibers.
Daily dietary of Mg is 0.4 gram.
It is reabsorbed well in proximal renal tubules.
Advanced renal failure, patient treated with Mg containing
Diabetic ketoacidosis .
Over dose of Mg SO4 in treatment of PIH / Eclampsia.
> Loss of tendon reflex.
> Flaccid quadriplegia.
> Respiratory depression– muscle paralysis.
> renal out put decreased ; oligourea and anurea.
Monitoring urine out put should not go down < 3o ml in one
hour. Knee jerk, planter reflex should not depress.
Keep watch on respiration Rate. Serum Mg estimation .
Management next dose to be given after checking , respiratory
rate, urinary output and reflexes .
- I V inj. Ca gluconate / CaCl2 in 10% concentration, 10-20 ml
slowly over 20-30 minutes.
Serum MG < 1.5mEq/L
Causes Malnutrition , chronic alcoholism,
large GI fluid loss; patient on parenteral fluid
therapy for along time.
hyper reflexia, muscle spasm , parasthesia ,
tetany, it mimics hypo calcaemia associated
Treatment 2 gm ( 16mEq /L ) of MgSO4 given
IV slowly in 10 minutes. Later maintenance
dose of 1mEq /kg / day is infused as slow IV
Normal pH( - log of H+ ) is 7.36 – 7.44
When H+ increases pH decrases.
Factors which Control pH
.> Buffer System –
> Renal Control Of pH
> Respiratory Control of pH
Acid – is a substance that dissociates Waterto
release hydrogen Ion .
Base – is a substance that takes hydrogen Ion
Buffer – is combination of weak acid and
These buffers maintain the H+ concentration in
blood with in a fine limit / range .
Buffers are 1. Intra cellular .
Extra Cellular Buffer – Bicarbonate / Carbonic
acid , phosphate buffer and Plasma Protein
buffer arte extracellular natural buffers
.Bicarbonate / carbonic Acid buffer is most
important as carbonic acid level in blood is
regulated by lungs which removes excess of
Co2 gas. , while bicarbonate pare is contrilled
Intra Cellular Buffer – Haemoglobin and other
protein inside cell are playing major role of
intra cellular Buffer.
Acidosis---When pH of blood is < 7.35 .
Alkalosis ---- when pH is more > 7.45 .
H+ (nmol/L ) = K x H2Co3m mol /L
or K x d PCO2
HCO3 m mol/L
Here K is coefficien a constant factor =800( for H2 CO3 / HCO3
Carbonic acid (H2CO3) is solubility coefficient of CO2 in blood (d)
multiplied by partial pressure of CO2 (pCO2) d is 0.03ml/mmHg
/ ml blood .
pCO2 is 40 mmHg .
H2CO3 = d pCO2 = 0.03 x 40 ==1.2ml .
Normal blood Bicarbonate (HCO3) level is 24 m mol /L
So H+ is 800 x 1.2 devided by 24 = 40m mol / L
It is used to find out pH of blood using
Negetive log of K (800 for carbonic buffer ) is
called as pKa . It is 6.1 for H2CO3 / HCO#
pH = pKa + log HCO3 / H2CO3 means
6,1 + log 24 devided by 1.2 = 6.1 + log 20 =
6.1 + 1.3 = 7.4
Primary base excess . E.g. HCO3 . A standard
bicarbonate above 27m mol /L.
1. Repeated vomiting as in pyloric stenosis . Here
hypokalaemic alkalosis develop due to loss of K+
and acid in vomit .
2. Excess alkali intake e.g. antacid .
3. Cortisol excess due to over ingestion /injection
or cushing’ syndrome.
Clinical Features 1.Chine strokes breathing in
period of apnoea of 5-30 seconds.
2.Tetany due to alkalosis ---latent tetany revealed
by Trousseau’s sign .
Arterial blood gas analysis.
Normal saline or double strength saline IV with
slow IV infusion of KCl 40 m mom/L under ECG
pH < 7.7 causes life threatening alkalosis and
requires rapid correction by infusing dilute HCl
acid or Ammonium chloride with careful
Arterial PCO2 is below normal(45mmHg).
1. Hyperventilation during anaesthesia, severe
pain , hyper pyrexia , head injury .
2. High altitude.
3. encephalitis , hypothalamic tumors ,
salicylates over dose / poisoning , Liver
Clinical Features and Management
1. Headache , tingling , circum oral
anaesthesia ,tightness in chest ,tetany and
Arrhythmias are the features.
2.Low PaCO2 , low HCO3, High alkaline Ph .
3. It can be acute or chronic.
4. It is managed by O2 therapy , treating the
cause and tab Aceozolamide in high altitude.
5. respiratory depression is treated by CO2.
- It is state of excess acid / base deficit .
A standard Bicarbonate below 21 m mol /L.
a. Diabetic Ketoacidosis.
c. Hypoxia—CO2 accumulation.
d. Renal efficiency .
e. cardiac arrest ---Hypoxia.
f. Excessive exercise --- Lactic acid over production .
g. Intestinal strengulation , here anion gap is
Loss of base causing metabolic acidosis
b, Ulcerative Colitis .
c, Gastrocolic Fistula .
d, Intestinal Fistula .
e, Uretero-sigmoidostomy done for urinary
diversion --- results in Hyperchoraemic –
Hypokalaemic acidosis , anion gap is normal
a, Rapid, deep, noisy breathing – air hunger; known as
Cold clammy skin , Tachycardia, right heart strain , altered level
Cardiac Arrhythmia , hypotension .
Anorexia, vomiting , muscle weakness.
Ph < 7.2 A dangeorus and life threatening level.
Strongly acidic Urine.
Low standard HCO3.
Evaluation --. Do Arterial blood gas analysis. , showing Low
HCO3 level . Low Ph , anion Gap , Urinary anion Gap which is
zero or positive ,
Note __ U A G become negative in metabolic acidosis due to GI
cause as there is increased NH4Cl excretion .
If it is due to renal orgion UAG will be positive .
> correction oh hypoxia.
> 50M ML OF 8,4 % Sodium bicarbonate iv infusion –
NAHCO3 requirement in m Eq/L = Body weight in Kg X base deficit
>Correction of Electrolytes.
> Specific Treatment for acidosis depends on
.Type A (Shock , Respiratory , CO/ Cynide Poisoning , Anaemia )
. Type B ( Diabetic , hepatic , toxins / drugs .)
It needs only careful use of NaHCO3 in severe cases.
Dicholoroacetate therapy will stimulate Pyruvate Dehydrogenase
enzymes to reduce Lactate.
> Specific treatment is needed to start in cases of diabetic Ketoacidosis ,
Alcoholic acidosis , Salicylates poisoning and Renal cause .
Total base deficit / exceesve = Base deficit / excess X Body Wt In KG X
It is feature of respiratory insufficiency to breath out CO2 as
in respiratory failure ; resulting in High PCO2 and fall in
> During or after anasthesia .
> Chronic Bronchitis , obstructive lung disease, Emphysema.
> diseases of Thoracic cage.
> Upper abdominal surgery / disease3 decreasing abdomino
–thoracic respiration .
> Respiratory air ways obstruction .
> Myesthenia Gravis,
> Poliomyelits causing paralysis of respiratory muscles to
> Stroke, infection , obesity, Hypoventilation.
> Dyspnoea, confusion , psychosis ,
Hallucinations , sleep disturbances, tremors ,
jerks and personality changes .
> CNS changes are more common and severe
in Respiratory acidosis than in metabolic
acidosis . As in respiratory acidosis lipid
soluble C)2 crosses brain barrier easily than
> O2 Therapy ; ventilator support .
> O2 therapy should not be used in chronic
hypercapnoea unless it is realy indicated as
Hypoxia induced respiratory stimulation may
be decreased as more CO2 is washed out at
> Alkali therapy is also not started unless pH is
< 7.15. 0r there is severe bronchospasm .
It is a calculated estimation of the undetermined or
unmeasured ANIONS in blood .
ANION GAP = ( Na+ + K+ ) – ( HCO3- + Cl - ).
e.g. Total ANION – total Cation in blood
Normal anion gap is 10-16m mol /L.
Important unmeasured are +ve charged proteins ,
phosphate , sulphate and organic acids .
Important unmeasured Cations –Ve charged CA and
Albumin is main component of Anion Gap .
When albumin level in blood decreases by 1 gm /
dl –anion gap decreases by 2m Eq /L .
Increased Anion Gap Is seen In Normal Anion Gap Is seen in
Metabolic acidosis due to
Lactic acidosis. GIT Fistula .
Poisoning ( CO / salicylates/
Hyper chloraemic acidosis .
Osmolality of a solution is assessed by the
amount of solute dissolved in a solvent like
water measured in weight (Kg).
Osmolality of a solution is assessed by amount
of solute dissolved in solvent like water
measured in volume (litre) .
Normal plasma is 285 mOsm / Kg (275 -295 ).
* Plasma Crystalliod osmolality --2 Methods
a. Osmolality of plasma = 0.54/1.86 X 1o rase to power 3
mOsmol / Kg.
It is based on the fact that solution of 1mOsmol/ Kg
freezes at -1.86 degree Centigrade ; where as plasma freezes
at -0.54 degree Centigrade .
b . Osmolality of plasma= 2X(Na) +( Glucose mg%/18)
+ ( Blood urea mg % /6)
It is based on the concentration of major solutes ( Na , glucose
and urea) in plasma. Na+ contributes maximum in plasma
*Colloidal Osmotic Pressure It is difference in plasma
osmotic pressure and interstitial fluid pressure = 25 mmHg.
This is mainly due to concentration of Albumin in plasma.
Plasma proteins do not go out of capillary wall and do not
enter in interstitial compartment.
> For rapid restoration of fluid and electrolite
deficit as in dehydration as in cases of diarrhoa,
vomiting , burns, Haemorrhagic shock and sepsis.
> Total parentral nutrition.
> anaphylaxis, cardiac arrest , hypoxia.
> Post operative period .
> for maintenance , replacement of loss or as a
Advantage Controlled , accurate , adjustable,
rapid , predictable and specfic in terms of solutes
and solvent as per need of clinical situation.
Needs Hospitalisation : costaly ; needs to
practice universal aseptic measures.
Fluid over load; pulmonary edema; cardiac
Infection , thrombophlebitis ,
haematoma;cellulitis ion local area.
Pyogenic infection , air embolism , bacteraemia
Discomfort , poor acceptance by patient and
Daily requirement > Na –100mEq ; K– 60mEq ; Ca –
5mEQ ; Mg 1mEq.
NA + mEq/L K+ mEq/l Cl- mEQ /L Lactate
154 - - - -
130 4 109 28 3
Colloids are large molecules which shift the
fluid (solvent/ Water ) from interstitial
compartment to intravascular compartment.,
used as plasma volume expanders.
name Na K Cl Ca bicarbo