IV FLUIDS Flashcards
Factors that determine body water content
Age
Sex
Hydration level
Average amount of water in an adults body
60%
Proportion of water in new borns
80%
Proportions of intercellular and extracellular fluid out of total body water
2/3- Intracellular
1/3- extracellular
Percentage of water in blood and kidneys, muscles and adipose tissue
Blood and kidneys- 83%
Muscle- 76%
Adipose tissue- 10%
Two important measures of body fluid balance
Oral or IV fluid intake
Urine output
Insensible fluid input
300ml due to oxidation
Insensible fluid loss
500ml- Skin
400ml- Lungs
100ml- Stool
Examples of abnormal fluid loss
Diarrhea
Abnormal sweating
Burns
Formula for daily fluid requirement in a normal person
Sum of urine output and insensible loss
Role of the major cations
Sodium- Fluid balance and Osmotic pressure
Potassium - Neuromuscular excitability and Acid base balance
Calcium- bone and blood clotting
Magnesium- Enzymes
Role of the major anions
Chloride - Fluid balance and Osmotic pressure
Bicarbonate - Acid base balance
Proteins- Osmotic pressure
Phosphate - Energy storage
Sulfate- Protein metabolism
Major intercellular cations and anions
Cations- Potassium and Magnesium
Anions- Phosphate
Major extracellular cations and anions
Cations - Sodium
Anions - Chloride and Bicarbonates
Why determines the distribution of water Amon the different fluid compartments
Osmotic pressure
Three basic principles to know for proper fluid therapy
Aetiology fluid deficit and type of electrolyte imbalance present
Associated illness
Clinical status
Contraindications of IV fluids
Avoid if patient can take oral fluids
Patients with congestive heart failure or volume overload
Local complications of IV fluids
Haematoma
Infusion phlebitis
Infiltration or Extravasation
Systemic complications of IV fluids
Circulation overload
Patients at high risk of circulation overload with IV fluids
Cardiac problems
Rigors
Air embolism
Septicaemia
Explain the types of IV lines
Central lines end in a large vein close to the heart
Peripheral end in a small vein in the periphery
Peripherally inserted central catheter / PICC- An IV line threaded through a peripheral vein to end near the heart
Tunneled line- Catheter is inserted into a central vein through the chest
What determines the type of catheter used and site of insertion for IV fluids
Desired substance to be administered
Health of the veins in the desired site of insertion
Explain the news score
The National Early Warning Score (NEWS2) is a system for scoring the physiological measurements that are routinely recorded at the patient’s bedside. Its purpose is to identify acutely ill patients
Parameters in the NEWS score
AB
Respiratory rate
O2 saturation
Any supplemental oxygen
C
Systolic BP
Pulse
D
AVPU score
E
Température
Classes in the NEWS score
Low 1-4
Medium 5-6
High 7 and above
Types of IV fluids
Hypertonic : more than 375mOsm/L
Isotonic: 250- 375
Hypotonic: less than 250
Examples of isotonic solutions
0.9% Normal saline
Ringers Lactate
Blood component
5% Dextrose Water D5W
Indications of isotonic solutions
Direct fluid replacement in
Diarrhea
Bleeding
Examples of hypotonic solutions
Half or 45% Normal Saline
0.33% NaCl
Examples of hypertonic solutions
D5W in Normal Saline
D5W in Half Normal Saline
10% Dextrose in Water (D10W)
Classify IV fluids
Two types
1. Blood and Products
- Non blood IV fluids
2.a Colloids
2. a.i. Proteinious
2.a.ii. Non proteinous2.b Crystalloids
Examples of crystalloids
Glucose containing
Electrolyte Solutions
Mixed solutions
Types of proteinous colloids and examples
- Gelatins
Heamacel
Gelofusin - Albumin
20% and 5%
Types of non proteinous colloids and examples
- Starch
HES
Pentastarch
Tatrastarch
2.Dextrans
Factors that drive fluid movement
Diffusion
Active Transport
Osmosis
Capillary filtration
What is the driving force for capillary filtration
Hydrostatic pressure
What balances out hydrostatic pressure
Colloid osmotic pressure from albumin
Components of the juxtaglomerular apparatus
Macula densa of the thick ascending limb
Juxtaglomerular or Granular cells of the afferent arteriole
Extraglomerular mesangial cell
Functions of the cells in the juxtaglomerular apparatus
Juxtaglomerular cells secrete renin
Macula sends cells osmoreceptors
Mesanglial cells regulate GFR
Functions of ANP
Suppresses release of renin, aldosterone and ADH
Increases glomerular filtration
Causes vasodilation
Why are older people more prone to dehydration
Thirst mechanism is less effective in older people
Three phases of rehydration
- Fluid resuscitation or emergency phase
- First 8 hours of Maintenance phase
- Next 16 hours of Maintenance phase
How to calculate degree of dehydration
Difference in pre-illness and illness weights divided by pre-illness weight multiplied by 100
Various degrees of dehydration based on body weight
Mild (less than 3% change in body weight), Moderate (3%–9% change in body weight)
Severe (greater than 9% change in body weight).
Types of dehydration
Isotonic dehydration
Hypotonic dehydration
Hypertonic dehydration
Treatments for mild and moderate dehydration
Oral fluid therapy
Mild 50ml/kg over 4 hours
Moderate 100ml/kg over 4 hours
Content of oral rehydration solutions
140mmol/L of carbohydrate
45mmol/l of sodium
20mmol/l of potassium
IV fluid delivery systems
Infusion pump
Gravity
Initial approach for children with moderate to severe dehydration
Isotonic fluid blouses (NS) in 20ml/kg max of 1L given over 20mins in moderate dehydration and given as fast as possible in severe dehydration
Blouses should be repeated until the child has restoration of intravascular volume
Maintenance phase for children with moderate to severe dehydration
Phase 2- 1/2 remaining deficit + 1/3 daily maintenance
Phase 3- 1/2 remaining deficit + 2/3 daily maintenance
When are maintenance fluids used
When patient is NPO (nil per oral)
Components of maintenance fluids
Water
Glucose
Sodium
Potassium
Role of glucose in maintenance fluids
Prevents starvation, ketoacidosis and hypoglycemia
Types of body sizes that can be used
Ideal body weight or dry body weight
Body surface area
Actual body weight
Preferred fluid for maintenance fluids
Isotonic fluids ( N/S OR LR)
Contraindications to isotonic fluids
Volume overload
Hypernatremia
Standard dextrose composition of maintenance fluids
D5W
Strategy for fluid replacement in oliguria
Provide maintenance fluids at a rate that replaces insensible loss
Maintenance fluid therapy for 0-10kg
100ml/oh at a rate of 4ml/kg/hour
Maintenance fluid therapy for 11-20kg
Volume/24 hours
1000ml + 50ml/kg for each kg over 10kg
Rate/hour
40ml + 2ml/kg for each kg over 10kg
Maintenance fluid therapy for more than 20kg body weight
Volume/24hours
1500ml + 20ml/kg for each kg over 20kg
Rate/hour
60ml +1ml/kg for each kg over 20kg
Maximum volume and rate for maintenance fluids
Volume/24 hours
2.4-3L
Rate/hour
100-120ml
Examples of elctrolyte solutions
Normal saline
Ringers solution (Na, K, Cl and Ça)
Lactated ringers ( Na, K, Cl, Ça and Lactate)
Ph and osmolarity of D5W
Ph- 3.2-6.5
Osmolarity - 252mosml/l