• Acute sequestration in a body
compartment that is not in equilibrium
– Intestinal obstruction
– Severe pancreatitis
– Major venous obstruction
– Capillary leak syndrome
Daily Fluid Balance
Insensible fluid loss = 500 ml through skin
= 400 ml through lungs
= 100 ml through stool
Insensible fluid input = 300 ml due to Oxidation
Daily insensible fluid loss = 1000 ml – 300 ml
= 700 ml
Electrolyte concentration of body fluids (mEq/L)
Electrolytes ECF ICF
Phosphate and Sulphate
Major Cation Sodium Potassium and
Major Anion Chloride and
Calculating Plasma Osmolality
Plasma = 2 X Na + Glucose ( mg/dl) /18 + BUN(mg/dl) /2.8
The effective plasma osmolality is determined by those solutes in the
plasma which do not freely permeates cell wall and act to hold water
within the ECF.
So Lipid soluble solutes such as urea which can cross the cell memebrane
does not contribute to osmotic pressure gradient between ECF and ICF.
Effective osmolality = 2 X Na (mEq/L) + Glucose (mg/dl) / 18
(mOsm / Kg)
BASIC PRINCIPLES OF I.V. FLUID THERAPY
1) Accurate, controlled & predictable way of administration.
2) Immediate response.
3) Prompt correction of serous fluid & electrolyte disturbances.
1) Condition when oral intake not possible. E.g.- coma, surgery.
2) Moderate to severe dehydration and shock.
3) Severe vomiting and diarrhea.
4) Hypoglycemia ,where 25% dextrose is life saving.
5) As vehicle for various I.V. medication. E.g.- antibiotics
6) Total parenteral nutrition
7) Treatment of critical problems like – Shock, Cardiac arrest, forced
diuresis in drug overdose, poisoning
1) More expensive , need strict asepsis.
2) Improper selection of type of fluid used can lead to serious
3) Improper volume & rate of infusion can be life threatening.
4) Improper technique of administration can lead to complication.
1) Preferable to avoid in patients with congestive heart failure &
1) Local - Hematoma, infiltration , infusion phlebitis.
2) Systemic - Circulation overload, Rigors, air embolism ,septicemia.
3) Others - Fluid contamination, mixing of incompatible drugs
Classification of I.V. Fluids
5 % Dextrose
10 % Dextrose
Isotype – M
Isotype – E
SPECIAL FLUIDS :
COLLOID SOLUTION :
Isotonic or normal saline (0.9% NaCl)
One litre fluid contains - Na+ = 154 mEq
Cl- = 154 mEq
Distributed chiefly in extracellular fluid, so it will increase intravascular volume
1) Resuscitation fluid in diarrhea, vomiting , excessive diuresis.
2) Treatment of Hypovolemic shock.
3) Initial fluid therapy in Diabetic ketoacidosis.
4) Fluid challenge in pre-renal ARF.
5) AS vehicle for certain drugs and can be safely given with blood.
1) Avoid in hypertensive or pre-eclamptic patients.
2) CHF ,Renal diseases and cirrhosis.
Dextrose normal saline( 5% dextrose with 0.9%NaCl )
One litre fluid contains - Glucose = 50 gm
Na+ = 154 mEq
Cl- = 154 mEq
Distributed chiefly in extracellular fluid,
1) Correction of salt depletion and hypovolemia with supply of energy.
2) Fluid compatible with blood transfusion.
3) Correction of vomiting or nasogastric aspiration indused alkalosis.
1) Anasarca – cautious use in anasarca of cardiac , hepatic and renal disease
2) Hypovolemic shock- Rapid infusion can cause Hyperglycemia and osmotic diuresis
even in presence of fluid deficit.
Each 1 Litre of fluid contains -
Sodium = 130 mEq Calcium = 3 mEq
Potassium = 4 mEq Bicarbonate = 28 mEq
Chloride = 109 mEq
Ringer lactate is the most physiological fluid as its electrolyte content is nearly similar
to that of plasma.
Because of high Sodium conc. It rapidly expands intravascular volume and so very
effective in treatment of severe hypovolemia.
1) Correction of severe Hypovulemia rapidly with large fluid volume.
2) For replacing fluid in post operative patients, burns , fractures etc.
3) Treatment of Diarrhia induced hypovolemia with hypokalemic metabolic acidosis.
4) In Diabetic keto acidosis , RL provides glucose free water.
5) For maintaining normal ECF fluid and electrolyte balance during and after surgery.
1) Ringer lactate can lead to lactic acidosis in patients with Liver disease ,
Hypoxia and shock
2) Severe CHF.
3) Addison’s disease
4) In vomiting or continuous Nasogastric aspiration
5) Along with Blood transfusion
6) The calcium in RL binds with certain drugs like amphotericin, thiopental
and reduces their bioavailability and efficiency.
ISOLYTE – M (maintenance sol. With 5% dextrose)
One litre fluid contains - Glucose = 50 gm Phosphate = 15 mEq
Na+ = 40 mEq Acetate = 20 mEq
Cl- = 38 mEq
K+ = 35 mEq
• Isolyte – M is the richest source of potassium so very useful in treatment of hypokalemia
• Proportions of electrolytes in Isolyte-M is almost similar to maintenance requirement of the
1) For Parenteral fluid therapy ,it’s the ideal maintenance fluid.
2) To correct hypokalemia secondary to diarrhea , bilious vomiting etc.
1) Acute and chronic renal failure.
2) Hyponatremia .
3) Adrenocortical insufficiency.
4) In patients with burns.
ISOLYTE – E (Extracellular replacement solution )
One litre fluid contains - Glucose = 50 gm Acetate = 47 mEq
Na+ = 140 mEq Ca ++ = 5 mEq
Cl- = 103 mEq Mg++ = 3 mEq
K+ = 10 mEq Citrate = 8 mEq
• Isolyte – E has electrolyte similar to ECF except double the conc. of potassium and
• Only I.V. fluid available that can correct magnesium deficiency.
2) Metabolic acidosis.
3) Maintenance of ECF volume preoperatively.
2) Continuous Nasogastric aspiration.
3) In metabolic alkalosis due to drugs and bicarbonate
Sodium Bicarbonate ( NaHCO3)
Commonly used preparation is 7.5%, 25 ml ampoule
One ampoule contains 22.5 mEq Sodium and 22.5 mEq Bicarbonate
Amount to be infused :-
Approximately 50% of the calculated deficit is corrected in 4 Hrs
and rest gradually over 24 hrs
Amount of NaHCO3 required (in mEq/L) =
0.5 X weight in Kg X ( Desired HCO3 - actual HCO3 )
1) Sodium bicarbonate should not be given as bolus except in
2) Avoid overdose and alkalosis by giving repeated small doses and
3) Never treat Acidosis without treating the etiology.
4) In presence of renal failure , treatment with sod. Bicarbonate
may cause tetany and pulmonary oedema.
5) Never correct acidosis without correcting the assosiated
hypokalemia. NaHCO3 will shift potassium from ECF to ICF , this
will aggravate hypokalemia
6) Never mix inj. Calcium with inj. NaHCO3 in same syringe as it
may precipitate calcium carbonate.
7) Avoid mixing of inj. NaHCO3 with inotropes.
1) Metabolic acidosis.
2) Cardiopulmonary resuscitation and shock.
3) Treatment of Hyperkalemia.
4) Alkaline forced diuresis in acute poisoning of barbiturates
Hypokalemia , volume overload , hypocalcaemia
1) Respiratory and metabolic alkalosis.
3) Cautious use in CHF , CRF , cirrhosis.
Injectable Potassium Chloride
Commonly used preparation is 15% KCl 10ml ampoule.
1 ml = 150 mg KCl = 2mEq Potassium.
So 1 ampoule = 10 ml = 20 mEq Potassium.
1) Added in potassium free I.V. fluids for prevention of Hypokalemia
2) For treating Hypokalemia.
3) Added to potassium free peritoneal dialysis fluid for maintaining proper K+
Basic rules for using Inj. KCl :-
1) Never give direct I.V. KCl injection.
2) Always use injection potassium chloride diluted in infusion.
3) Never add more than 40 mEq / litre.
4) Never infuse more than 10 mEq / hr.
5) Never add KCl in Isolyte – M.
6) Moniter serum K+ levels closely.
1) Cautious use in renal failure as hyperkalemia is a potential risk.
2) Never use injection KCl without knowing potassium status.
Albumin is a physiological plasma protein.
Heat treated preparation of human serum albumin is commercially
available in a 5% solution (50 gm/dl) and a 25% solution (250 gm/dl).
As Sodium load is small, 25% albumin is also called salt poor albumin
1) For Plasma volume expansion in cases of acute hypovulemic shock, burns.
2) Correction of hypoproteinemia as in liver disease, nephrotic syndrome etc.
3) As an exchange fluid to replace removed plasma in therapeutic
1) Nausea and vomiting.
2) Febrile reaction .
3) Allergic reaction and anaphylactic shock.
Precautions and contraindications :-
1) Fast infusion will rapidly increase circulatory volume with
resultant overload and pulmonary oedema.
2) Infusion of albumin solution is contraindicated in patients with
severe anemia or cardiac failure
3) Should be given with caution to patients with low cardiac
4) Albumin solution should not be used for parenteral nutrition.
Dextrans are glucose polymers produced by bacteria incubated in sucrose media.
Available in two forms :
DEXTRAN 70 -- mol.wt 70,000
DEXTRAN 40 – mol.wt 40,000
Both forms effectively expand Intra vascular volume but can not be a substitute for
whole blood due to lack of oxygen carrying capacity and no clotting factors
1) For short term rapid expansion of plasma volume for correction of hypovolemia.
2) Prophylaxis of Deep vein thrombosis and postoperative thromboembolism.
3) To improve blood flow and microcirculation in threatened vascular gangrene.
1) Acute renal failure.
2) Hypersensitivity reaction.
3) It may interfere with blood grouping and cross matching..
1)Severe oligo-anuria and renal failure.
2) Known hypersensitivity to dextran.
3) Severe CHF or circulatory overload.
4) Bleeding disorders.
5) Severe Dehydration.
1) The hematocrit should not be allowed to fall below 30.
2) Correct dehydration during dextran infusion to maintain
adequate urine flow.
3) Anticoagulant effect of heparin enhanced by dextran.
4) Along with dextran infusion patient may require blood
coagulation factor or electrolyte.
Volume Deficit-Clinical Types
• Total body water:
– Water loss (diabetes insipidus, osmotic diarrhea)
– Salt and water loss (secretory diarrhea, ascites, edema)
– Third spacing
– Acute hemorrhage
MAP= CO x SVR
• BP HR JVP
• Cool extremities
• Reduced sweating
• Dry mucus membranes
– Lost skin turgor,
– sunken eyeballs
– Weight loss
– Hemodynamic effects
Approach to IVF in the Medical Pt
• First let’s review the equation for estimating serum
Serum osmolality = 2 (Na+) + Glucose/18 + BUN/2.8
• See how much more sodium adds to your osmolality then
• That’s why D5 ½NS is inappropriate for most medical patients
who are hypovolemic.
• They need isotonic fluids (normal saline).
• Also, remember that dextrose gets almost immediately
metabolized to water and CO2 when it enters the circulation
so it is not osmotically active for too long.
The 4 Types of Patients
When considering appropriate IV fluids as you are writing
admission order, keep in mind that in general, there are
4 types of medical patients when it comes to
administering IV fluids:
Pneumonia, Sepsis, Hemorrhage, Gastroenteritis
CHF, renal failure, cirrohsis
NPO Patient, surgical patient, euvolemic
Awaiting surgery, unsafe swallow
Determining Appropriate IVF
Step 1: Assess volume status
• What is the volume status of my patient?
• Do they have ongoing losses?
• Can my patient take PO safely?
• Are the NPO for a reason?
Step 2: Determine Access
• Peripheral IV
• Central line
• IO line
Step 3: Select Type of Fluid
Always use Normal Saline for goal of volume resuscitation
Normal saline is almost isotonic with blood so it is the best choice!
On surgery or if going to administer more than 3-4L often use LR. (Addition of lactate that is metabolized to
bicarbonate to help buffer acidosis)
Avoid additional IVF
Maintain access IV access with HepLock
NPO Patient now euvolemic
Administer maintenance fluids. Goal is to maintain input of fluids to keep up with ongoing losses and
normal fluid needs
For average adult NPO for more than 6-12 hours, consider D51/2NS at 75-100cc/hr
Consider pt co-morbidities
Constantly reassess, at least 2x day or with any change
Don’t give fluids blindly ie: if the patient is pre-procedure but is old (predisposed to fluid overload because
of stiff LV) or has history of CHF, be CAREFUL!
Pearl: the reason for giving dextrose (D5) is to prevent catabolism.
Daily I/O’s, watch lytes
Normal PO Intake
No need for fluids if they are taking PO without problems!
Step 4: Determine Rate
• In medical patients, the rate is always a ballpark and
you have to use your clinical judgement. (Not
applicable for PEDS!)
• If you are trying to fluid resuscitate that patient, you
might be giving fluids “wide open” or 500 cc/hr.
• The hypovolemic pt may need multiple 1L bolus to
reestablish intravascular volume
• If you are just giving fluids to the average patient,
give fluids at 75-100 cc/hr. Adjust for individual
Holiday Segar Method
A peds method that can be helpful:
So a quick example:
For a 55 kg patient, the maintenance IV fluid rate would be
4*10 + 2*10 + 35*1 = 95 mL/hour.
Calculating Drip Rate
In the age of machines, we barely have to do this
anymore… but if you ever need to go old skool, here is
how to calculate the drip rate (drops/minute):
gtt = Volume to be infused (mL) x (gtt/mL)
min Time (minutes)
Drip Factor = (gtt/mL) Of the TUBING which is found on the
Example: Volume = 4000 ml
Time = 24 hours
Drip factor of tubing = 15 gtt/ml.
So…. [4000mL/(24h x 60min/h)] X 15gtt/ml = approx 42 drops/min
Example- GI Bleed
A 25 year old patient presents with massive hematemesis (vomiting blood) x 1
hour. He has a history of peptic ulcer disease.
Exam: Diaphoretic, normal skin turgor.
Supine BP: 120/70 HR 100
Sitting BP: 90/50 HR=140
What is the nature of his fluid deficit ?
What IV fluid resuscitation would you prescribe ?
What do you expect the hematocrit to be :
- at presentation ?
- after 12 hours of Normal Saline treatment?
Example- Diarrhea and Vomiting
• A 18 year old previously healthy medical student returns from a Caribbean
vacation with a healthy tan and severe diarrhea and vomiting x 48 hours.
• Sunken eyeballs, poor skin turgor and dry mucus membranes
• BP 80/70 HR 130 supine.
• Labs: Na 130 K=2.8
• What is the nature of his fluid deficit ?
• What fluid will you prescribe ?
• What would happen if D5W were to be used?
Example- Hyperosmolar State
A 85 year old nursing home resident with dementia, and known
diabetes was admitted with confusion.
Exam: Disoriented, Decreased skin turgor
BP: 110/70 supine 90/70 sitting..
Labs: Na= 150meq/L Wt=50kgs
BUN/Cr=50/1.8 Blood sugar= 1200 mg/dl Hct=45
What is the pathogenesis of her fluid and
electrolyte disorder ?
How would you treat her ?
Calculation of Water Deficit
Osm (P Na) x
Osm (P Na) x
A 50 kg female with Na=150
•Na x Normal Body Water = Na x Current Body Water
•140 x NBW = 150 x (0.5 x 50=25 liters)
•NBW = 26.8 liters
•Water deficit = NBW-CBW= 26.8-25=1.8 liters
The take-home message!
• Resuscitate with fluids early and aggressively
– They won’t get overloaded
– They won’t get pulmonary oedema
– They will be less likely to need ICU
• Be guided by markers of tissue perfusion
– Urine output
– Consider central venous oxygen saturations
• Crystalloids are generally adequate for most
situations needing fluid management.
• The composition of the solution and rate of
administration are important when addressing a
• Colloids may be indicated when more rapid
hemodynamic equilibration is required (inadequate