Dr. U.Murali.M.S;M.B.A.

Professor of Surgery

Introduction

Intravenous fluids are chemically prepared solutions that are administered to the patient.

They are tailored to the body’s needs and used to replace lost fluid and/or aid in the delivery of IV medications.

Indications

For rapid restoration of fluid and electrolytes in dehydration due to vomiting, diarrhoea, shock due to haemorrhage or sepsis or burns.

Total parenteral nutrition. Anaphylaxis, cardiac arrest, hypoxia. Post gastrointestinal surgeries. For maintenance, replacement of loss or as a special

fluid.

Advantages

Provides the patient with life-sustaining fluids, electrolytes, and drugs.

Immediate and predictable therapeutic effects. Preferred for administering fluids, electrolytes, and

drugs in emergency situations. Allows fluid intake when a patient has GI

malabsorption. Permits accurate dosage titration for analgesics and

other drugs.

Disadvantages

Needs hospitalisation, costly.

Infection.

Pyrogenic reaction.

Discomfort, poor patient compliance.

Fluid overload – chances.

Electrolyte Requirements – Daily

Na+ 50 – 90 mmol / day

K+ 50 mmol / day

Ca+ 5 mmol / day

Mg+ 1 mmol /day

IV Fluid ?

The majority of an IV solution is sterile water.

Chemically, water is referred to as a “solvent.” A solvent is a substance that dissolves other materials called “solutes.”

Within IV solutions, the solutes can be molecules called electrolytes or other larger compounds such as proteins or molecules.

Daily Requirements

Maintenance Fluid formula

4 ml/kg/h for the first 10 kg

2 ml/kg/h for the next 10 kg

1 ml/kg/h for every kg over 20 kg

Therefore a 70 kg patient using the calculation:

40+20+50=110

will require 110 ml/h

Intra venous Fluids

IV fluids come in four different forms:

Colloids

Crystalloids

Blood and blood products

Colloid Solutions

Colloid solutions are IV fluids containing large proteins and

molecules that tend to stay within the vascular space (blood

vessels).

They shift the fluids from interstitial to intravascular compt.

Colloids are useful in maintaining blood volume. Colloids are

expensive, have specific storage requirements, and have a short

shelf life.

Commonly used colloid solutions include plasma protein

fraction, salt poor albumin, dextran.

Crystalloid Solutions

Crystalloid solutions are the primary fluid used for IV therapy.

Crystalloids contain electrolytes but lack the large proteins and

molecules found in colloids.

Crystalloids come in many preparations and are classified

according to their “tonicity.”

A crystalloid’s tonicity describes the concentration of

electrolytes (solutes) dissolved in the water, as compared with

that of body plasma.

Isotonic

Isotonic crystalloids have a tonicity that is equal to the plasma in the body.

The fluid will distribute evenly between the intravascular space and cells.

5% dextrose in H2O (D5W)

Lactated Ringers / 0.9% NaCL or Normal saline (NS)

Hypotonic

Hypotonic crystalloids have a tonicity lower than the body plasma.

Shift from the intravascular space to the extravascular space, and eventually into the tissue cells.

0.45% Na CL or half normal saline

Used for dehydration

Hypertonic

Hypertonic crystalloids have a tonicity higher than the body plasma.

The administration of a hypertonic crystalloid causes water to shift from the extravascular spaces into the bloodstream, increasing the intravascular volume.

5% dextrose in 0.45% NaCl (D5 ½ NS)

Commonly used fluid

Lactated Ringer’s (LR) is an isotonic crystalloid that contains sodium chloride, potassium chloride, calcium chloride, and sodium lactate in sterile water.

Normal saline solution (NSS) is an isotonic crystalloid that contains 0.9% sodium chloride (salt) in sterile water.

5% Dextrose in water (D5W) is packaged as an isotonic carbohydrate (sugar solution) that contains glucose (sugar) as the solute which is used by the cells to create energy.

Calculation – Drop rate

1ml = 16 drops For microdrip set 1ml = 60 drops.

A. QOF required in liters / day x 10 = Drop rate / mt

( 2.5 l is quantity of fluid / day. So 2.5 x 10 = 25 drops / mt )

B. Fluid to be infused in 1 hour divided by 4 = Drops / mt.

C. No. of microdrop / mt = volume in ml / hr

Summary

There are several different types of fluids used for IV therapy.

Depending on their specific type and makeup, IV fluids can cause the shift between the intracellular and extracellular compartments.

Therefore, it is important to choose the fluid most appropriate to the patient’s needs.

It is important to carefully examine the label on the bag to ensure the right fluid has been selected.