Tutorial

Fluid Therapy

Can be life-saving in certain conditions Loss of body water, whether acute or chronic, can cause a range of problems from mild headache to convulsions, coma, and in some cases, death. Though fluid therapy can be a lifesaver, it's never always safe, and can be very harmful.
Fluid therapy Importance !

Water has many functions in the body !

WATER

We are approximately two-thirds water

To be exact, men are 60% water, whilst women are slightly less at 55%. A 70 kg. man will therefore contain about 42 litres, and a 70 kg. woman nearer 38 litres. The reason for this difference between the sexes is that women contain an extra 5% adipose tissue; the difference is only occasionally of clinical significance.


Body muscle mass is rich in water, while Adipose Tissue has a lower percentage of water content.That’s why:Overweight or obese people have a lower percentage of water compared to someone who's lean and muscular. Women typically have a lower percentage of total body water than men due to a higher percentage of body fat.Older adults tend to have a lower concentration of water overall, due to an age-related decrease in muscle mass. Children tend to have a higher percentage of water weight-as much as 70-80% in a full-term neonate. How much of you is water?

Total body fluid ( 60%)……..42L (20)%.....14L (40)%......28L Extracellular fluid (1/3) Intracellular fluid (2/3) (5)%....3.5L (15)%.....10.5L intravascular interstitial fluid

Intracellular Volume

Extracellular Volume
Interstitial Volume
Plasma Volume
Total Body Water
60%
42L
40%
28L
20%
14L
15%
10.5L
5%
3.5L
(AVG. 70 KG WEIGHT)



2/3 of the total body water . Found inside the plasma membrane of the body's cells. In humans (average 70 KG), the intracellular compartment contains on average about 28 liters of fluid .
Intracellular Fluid

Extracellular Fluid

Accounts for 1/3 of the TBW, either: Interstitial. Intravascular. 3rd space.

1- Interstitial compartment Its small, narrow spaces between tissues or parts of an organ. It is filled with what is called interstitial fluid When excessive fluid accumulates in the interstitial space, edema develops. In the average male (70 kg) human body, the interstitial space has approximately 10.5 liters of fluid ( 15% of the TBW) Importance: It acts as the microenvironment that allows movement of ions, protein and nutrients across the cell barrier .

2-Intravascular compartment The main intravascular fluid in humans is blood; the average volume of blood in humans is approximately 70-75 ml/kg

3- Third space The third space is space in the body where fluid does not normally collect in larger amounts. For examples the peritoneal cavity and pleural cavity are major examples of the third space. Small amount of fluid does exist normally in such spaces, and function for example as lubricant in the case of pleural fluid .

Daily Fluid Balance

Intake:
Insensible Loss-Lungs -Sweat
Urine & faeces

Normal Intake of Water

1300mls -2000 free water 700 bound to food 300mls additional water comes from catabolism


Normal Water Exchange
Avg daily ml Min daily ml Sensibleurine 800-1500 300 fecal 100- 200 50 Insensiblelungs/skin 600-900 500 sweat up to litres 500

● Normal Daily fluid Requirements : 30-35 ml/kg/day for adult (about 2.4L/day) + 1 mmol/kg/day Na+ + 1 mmol/kg/day K+

Fever (Water requirements increase by 100 to 150 mL/day for each C degree of body temperature elevation. Sweating . Tachypnea. Polyuria.

Water requirements increase with

Why give fluids?
Replace intravascular volume Improve tissue perfusion Replace fluid deficits (dehydration) Meet maintenance in NPO patient Replace ongoing losses (Drains, burns, etc.) Anesthetic and surgical support Replacement of specific components (blood, plasma)

Goal

normal haemodynamic parameters normal electrolyte concentration

Fluid shifts in disease

Fluid loss: GIT: diarrhoea, vomiting, etc. Renal: diuresis. Vascular: haemorrhage. Skin: burns. Fluid gain: Iatrogenic. Heart / liver / kidney failure.

History and Clinical Exam

Safe, cheap, and it works! Ask patient if thirsty, vomiting, diarrhea,
Assessment of volume status


Clinical Vital Signs Physical exam. Labs/studies Acid-base status Lactate Levels Oxygen consumption Mixed Venous Oxygen Saturation
Look at the patient: Pulse Blood pressure Capillary refill Mucous membranes Peripheral circulation Thirst

Vital Signs are Vital

Urine output is the most sensitive (first to change) sign of volume contraction Heart rate changes second Blood pressure changes late

Clinical Signs of Adequacy of Perfusion

Urine output Mental status Capillary refill Skin color Temperature Pulse rate

Routes of Fluid Administration

Enteral: - limited by patients ability to handle - can use to prevent gut-atrophy - can combine with other methods (NG tube). Intraperitoneal: - fairly rapid absorption - aseptic technique - warm fluids



Subcutaneous: - not for sever dehydration or shock - 10-20 ml/kg/site - aseptic technique

Intravenous: - peripheral vs. central line - moderate/severe dehydration, shock - cutdowns (20G needle technique) - change catheters every 72 hours - crystalloids, colloids, blood products, IV feeding

IV therapy

It is an effective, and efficient method of supplying fluid directly into intravenous fluid compartment producing rapid effect ,with availability of injecting large volume of fluid more than any other method of administration.

Which fluid to use ?

The fluids used in clinical practice are usefully classified into: Colloids, Crystalloids, Blood products Whole blood FFP Platelets

Types of Fluid

The IV Fluid Supermarket
CrystalloidsDextrose in waterD5WD10WD50WSalineIsotonic (0.9% or “normal”)Hypotonic (0.45%, 0.25%)HypertonicComboD51/2NSD5NSD10NSRinger’s lactate “physiologic”.(K, HCO3, Mg, Ca) Colloids Albumin 5% in NS 25% (Salt Poor) Dextrans Hetastarch Blood


A substance dissolved in another substance There are many SOLUTES, for example: Plasma proteins (eg. albumin, globulins, fibrinogen) Ions (sodium chloride, magnesium, calcium, bicarbonates) Food molecules (eg. glucose, amino-acids), waste products as urea
What are Solutes?



Term refers to the solute concentration in the body fluid by weight. The number of milliosmols (mOsm) in a kilogram (kg) of solution. In humans normally the osmolality in plasma is about 275-295 mOsm/Kg
What’s Osmolality?

Body fluid compartments

Colloid Solutions that contain large molecules that don't pass the cell membranes. When infused, they remain in the intravascular compartment and expand the intravascular volume and they draw fluid from extravascular spaces via their higher oncotic pressure

2.Crystalloid Solutions that contain small molecules that flow easily across the cell membranes, allowing for transfer from the bloodstream into the cells and body tissues. This will increase fluid volume in both the interstitial and intravascular spaces (Extracellular) It is subdivided into: * Isotonic * Hypotonic * Hypertonic

When to consider a solution isotonic? When the concentration of the particles (solutes) is similar to that of plasma, So it doesn't move into cells and remains within the extracellular compartment thus increasing intravascular volume.


Types of isotonic solutions include: 0.9% sodium chloride (0.9% NaCl) lactated Ringer's solution 5% dextrose in water (D5W) Ringer's solution
Isotonic Fluids

0.9% sodium chloride (Normal Saline)

Simply salt water that contains only water, sodium (154 mEq/L), and chloride (154 mEq/L). It's called "normal saline solution" because the percentage of sodium chloride in the solution is similar to the concentration of sodium and chloride in the intravascular space.

Solutions
Na+
K+
Ca2+
Mg2+
Cl-
HCO3-
Dextrose
mOsm/L
0.9% NaCl
154
154
308



When to be given?1- to treat low extracellular fluid, as in fluid volume deficit from- Hemorrhage - Severe vomiting or diarrhea - Heavy drainage from GI suction, fistulas, or wounds2- Shock 3- Mild hyponatremia4- Metabolic acidosis (such as diabetic ketoacidosis)5- It’s the fluid of choice for resuscitation efforts.6- it's the only fluid used with administration of blood products….

is the most physiologically adaptable fluid because its electrolyte content is most closely related to the composition of the body's blood serum and plasma. Another choice for first-line fluid resuscitation for certain patients, such as those with burn injuries.
Ringer's lactate or Hartmann solution

To replace GI tract fluid losses ( Diarrhea or vomiting ) Fistula drainage Fluid losses due to burns and trauma Patients experiencing acute blood loss or hypovolemia due to third-space fluid shifts. Notice. Both 0.9% sodium chloride and LR may be used in many clinical situations, but patients requiring electrolyte replacement (such as surgical or burn patients) will benefit more from an infusion of LR.
 When to be used?

LR is metabolized in the liver, which converts the lactate to bicarbonate. LR is often administered to patients who have metabolic acidosis Don't give LR to patients with liver disease as they can't metabolize lactate - used cautiously in patients with sever renal impairment because it contains some potassium - LR shouldn't be given to a patient whose pH is greater than 7.5

Like LR, contains sodium, potassium, calcium, and chloride in similar. But it doesn't contain lactate. Ringer's solution is used in a similar fashion as LR, but doesn't have the contraindications related to lactate.
Ringer's solution

It is considered an isotonic solution, but when the dextrose is metabolized, the solution actually becomes hypotonic and causes fluid to shift into cells.
 Dextrose 5%

D5W provides free water that pass through membrane pores to both intracellular and extracellular spaces. Its smaller size allows the molecules to pass more freely between compartments, thus expanding both compartments simultaneously It provides 170 calories per liter, but it doesn't replace electrolytes. The supplied calories doesn't provide enough nutrition for prolonged use. But still can be added to provide some calories while the patient is NPO.
How does it work?

- D5W is not good for patients with renal failure or cardiac problems since it could cause fluid overload. - patients at risk for INCREASED intracranial pressure should not receive D5W since it could increase cerebral edema - D5W shouldn't be used in isolation to treat fluid volume deficit because it dilutes plasma electrolyte concentrations - Never mix dextrose with blood as it causes blood to hemolyze. - Not used for resuscitation, because the solution won't remain in the intravascular space.
Take Care !


Be aware that patients being treated for hypovolemia can quickly develop hypervolemia (fluid volume overload) following rapid or overinfusion of isotonic fluids. Document vital signs, edema status, lung sounds, and heart sounds before beginning the infusion, and continue monitoring during and after the infusion.
Precautions in usage of Isotonic solutions

Frequently assess the patient's response to I.V. therapy, monitoring for signs and symptoms of hypervolemia such as: hypertension / bounding pulse / pulmonary crackles / peripheral edema / dyspnea/ shortness of breath / jugular venous distention (JVD) Monitor intake and output If edema is present, elevate the patient's legs.

monitor for signs and symptoms of continued hypovolemia, including: urine output of less than 0.5 mL/kg /hour / poor skin turgor tachycardia weak, thready pulse hypotension

Signs of hypo / hypervolaemia:

Signs of …Volume depletion Volume overloadPostural hypotension HypertensionTachycardia TachycardiaAbsence of JVP @ 45o Raised JVPDecreased skin turgor OedemaDry mucosae Pleural effusionsSupine hypotension Pulmonary oedemaOliguria AscitesOrgan failure Organ failure

HYPOTONIC FLUIDS

Compared with intracellular fluid (as well as compared with isotonic solutions), hypotonic solutions have a lower concentration of solutes (electrolytes). And osmolality less than 250 mOsm/L . Hypotonic crystalloid solutions lowers the serum osmolality within the vascular space, causing fluid to shift from the intravascular space to both the intracellular and interstitial spaces. These solutions will hydrate cells, although their use may deplete fluid within the circulatory system.

TYPES OF HYPOTONIC FLUIDS

0.45% sodium chloride (0.45% NaCl), 0.33% sodium chloride, 0.2% sodium chloride, and 2.5% dextrose in water Hypotonic fluids are used to treat patients with conditions causing intracellular dehydration, when fluid needs to be shifted into the cell , such as: Hypernatremia Diabetic ketoacidosis Hyperosmolar hyperglycemic state.

Precautions with hypotonic solutions

Never give hypotonic solutions to patients who are at risk for increased ICP because it may exacerbate cerebral edema Don't use hypotonic solutions in patients with liver disease, trauma, or burns due to the potential for depletion of intravascular fluid volume

The decrease in vascular bed volume can worsen existing hypovolemia and hypotension and cause cardiovascular collapse Monitor patients for signs and symptoms of fluid volume deficit In older adult patients, confusion may be an indicator of a fluid volume deficit. Instruct patients to inform you if they feel dizzy or just "don't feel right."


HYPERTONIC SOLUTIONS
What is hypertonic solutions? Solution that have a higher tonicity or solute concentration. Hypertonic fluids have an osmolarity of 375 mOsm/L or higher The osmotic pressure gradient draws water out of the intracellular space, increasing extracellular fluid volume, so they are used as volume expanders.

Some examples and Indications:

1- 3% sodium chloride (3% NaCl): May be prescribed for patients in critical situations of severe hyponatremia. Patients with cerebral edema may benefit from an infusion of hypertonic sodium chloride 2- 5% Dextrose with normal saline (D5NS): which replaces sodium, chloride and some calories

Precautions with hypertonic fluids:

Hypertonic sodium chloride solutions should be administered only in high acuity areas with constant nursing surveillance for potential complications / their potential for causing intravascular fluid volume overload and pulmonary edema. It is better to store hypertonic sodium chloride solutions apart from regular floor stock I.V. fluids .

Colloid solutions 

How does it work? It expand the intravascular volume by drawing fluid from the interstitial spaces into the intravascular compartment through their higher oncotic pressure. the same effect as hypertonic crystalloids solutions but it requires administration of less total volume and have a longer duration of action because the molecules remain within the intravascular space longer. Its effect can last for several days.

colloids…

Type of fluid
Effective plasma volume expansion/100ml
duration
5% albumin
70 – 130 ml 16 hrs
25% albumin
400 – 500 ml 16 hrs
6% hetastarch
100 – 130 ml 24 hrs
10% pentastarch
150 ml
8 hrs
10% dextran 40
100 – 150 ml 6 hrs
6% dextran 70
80 ml
12 hrs



Crystalloids or colloids…??? Crystalloids – recommended as the initial fluid of choice in resuscitating patients from hemorrhagic shock Svensen C, Ponzer S… Volume kinetics of Ringer solution after surgery for hip fracture. Canadian journal of anesthesia 1999 ; 46 : 133 - 141 “ No evidence that resuscitation with colloids reduces the risk of death, compared with crystalloids in patients with trauma or burns or after surgery” Roberts I, Alderson P, Bunn F et al : Colloids versus crystalloids for fluid resuscitation in critically ill patients.. Cochrane Database Syst Rev(4) : CD 000567, 2004

Colloid solutions 

Examples: 5% albumin (Human albumin solution) - The most commonly utilized colloid solutions. - It contains plasma protein fractions obtained from human plasma and works to rapidly expand the plasma volume used for: volume expansion moderate protein replacement achievement of hemodynamic stability in shock states. - considered a blood transfusion product and requires all the same nursing precautions used when administering other blood products. -It can be expensive and its availability is limited to the supply of human donors

Precautions when using Colloid solutions: The patient is at risk for developing fluid volume overload As for blood products, use an 18-gauge or larger needle to infuse colloids. Monitor the patient for signs and symptoms of hypervolemia, including: Increased BP Dyspnea or crackles in the lungs edema.

Closely monitor intake and output. Colloid solutions can interfere with platelet function and increase bleeding times, so monitor the patient's coagulation indexes. Anaphylactoid reactions are a rare but potentially lethal adverse reaction to colloids. Take a careful allergy history from patients receiving colloids (or any other drug or fluid), asking specifically if they've ever had a reaction to an I.V. infusion

Replacement Maintenance Repair deficit

How much fluid to give ?

BACIC PRINCIPLES

Replace
Maintain
Repair
Abnormal loss: GIT, 3rd space, Ongoing loss, septic and Hypovolemic shock
IWL + urine
Acid base, electrolyte imbalances

Fluid Resuscitation

Correction of existing abnormalities in volume status (as in hypovolemic shock) ,How to know that the patient has Hypovolemic Shock? The patient has the following sings and symptoms: 1- Anxiety or agitation 2- Cool, Pale skin 3- Confusion 4- Decreased or no urine output 5- Rapid breathing 6- Disturbed consciousness 7- Low blood pressure 8- Low body temperature 9- Rapid pulse, often weak and thready

What is the Parameters used to assess volume deficit? 1- Blood pressure 2- Urine output 3- Jugular venous pressure. Severe volume depletion or hypovolemic shock: Rapid infusion of 1-2L of isotonic saline (0.9% NS) as rapidly as possible to restore tissue perfusion

Maintenance therapy

Maintenance therapy is usually undertaken when the individual is not expected to eat or drink normally for a longer time (eg, postoperatively or patient on a ventilator)

Maintenance Requirements

This includes: insensible urinary stool losses
Body weight Fluid required0-10Kg 100ml/kg/dnext 10-20Kg 50 ml/kg/dsubsequent Kg 20ml/kg/d 15ml/Kg/d for elderly

70 Kg Man Needs

1st 10kg x 100mls = 1000mls 2nd 10kg x 50mls = 500mls Next 50kg x 20mls= 1000mls TOTAL 2500 mls /d

On Going Losses

NG drains fistulae third space losses Concentration is similar to plasma Replace with isotonic fluids corrects any existing water and electrolyte deficits.


FLUID OVERLOAD (HYPERVOLEMIA)
It is excessive accumulation of fluid in the body, due to: 1- Excessive parenteral infusion 2- Deficiencies in cardiovascular or renal fluid volume regulation

Signs and Symptoms 

They are not always typical but most commonly are: 1- Edema (swelling) - particularly feet, and ankles 2- Difficulty breathing while lying down 3- Crackles on auscultation 4- High blood pressure 5- Irritated cough 6- Jugular vein distension 7- Shortness of breath (dyspnea) 8- Strong, rapid pulse

Management of Hypervolemia

1- Prevention is the best way 2- Sodium restriction 3- Fluid restriction 4- Diuretics

How to calculate IV flow rates !

Intravenous fluid must be given at a specific rate, neither too fast nor too slow. The specific rate may be measured as ml/hour, L/hour or drops/min. To control or adjust the flow rate only drops per minute are used.

What is a drop factor? Drop factor is the number of drops in one milliliter used in IV fluid administration (also called drip factor). A number of different drop factors are available but the Commonest are: 10 drops/ml (blood set) 15 drops / ml (regular set) 60 drops / ml (microdrop)

How to calculate IV flow rates ?

The formula for working out flow rates is: Example: 1500 ml IV Saline is ordered over 12 hours. Using a drop factor of 15 drops / ml, how many drops per minute need to be delivered?

= gtts / min(flow rate)

= 31 drop/ minute

How to calculate drug dosage?

Common Conversions: 1 Liter = 1000 Milliliters 1 Gram = 1000 Milligrams 1 Milligram = 1000 Micrograms Remember! Before doing the calculation, convert units of measurement to one system.

DH
x V = Amount to Give
D = dose ordered or desired dose H = dose on container label or dose on hand V = form and amount in which drug comes (tablet, capsule, liquid)

Example: The ordered dose is Ceftriaxone 750 mg IV. the container contain 1g in a 10 ml vial. How to calculate? You should convert first g to mg , then : (D) 750 mg X (V) 10 ml = 7.5 ml (H) 1000 mg

IV lines common Problems

Infiltration when the catheter unintentionally enters the tissue surrounding the blood vessel and the IV fluid go into the tissues. Phlebitis Inflammation of a blood vessel Hypothermia When large amounts of cold fluids are infused rapidly Local infection (Abscess) A microscopic organism may use the tiny hole in the skin created by the IV catheter to find its way into the body, and cause an infection

IV Modes of administration

Peripheral IV line: placed into a peripheral vein PICC : Central line that is placed via the peripheral vasculature. Its tip terminates in the superior vena cava Peripheral midline catheters: Shorter version of the PICC, Its tip terminates in the axilla Hickman lines: Skin tunneled cuffed central catheters

Remember !

Treat IV fluids as “prescription” like any other medicationDetermine if patient needs maintenance or resuscitationChoose fluid type based on co-existing electrolyte disturbances Don’t forget about additional IV medications patient is receivingChoose rate of fluid administration based on weight and minimal daily requirementsAvoid fluids in patients with ECF volume excessAlways reassess whether the patient continues to require IV fluid


The rules of fluid replacement
Replace blood with blood Replace plasma with colloid Resuscitate with colloid Replace ECF depletion with saline Rehydrate with dextrose

Last Slide It’s Over THANK YOU !