Intravenous fluids Flashcards
How much water do we need each day?
25-30ml/kg/day
How much sodium do we need per day?
1mmol/kg/day
How much potassium do we need per day?
1mmol/kg/day
How much glucose do we need per day?
50-100g/day
What are the 2 main factors for body water content?
Fat vs muscle content
Age
What 4 questions must be asked before administering IV fluid?
Patient’s volume status?
Does the patient need fluids?
How much fluid do they need?
Types of fluid
What are the 3 levels of fluid volume status?
Hypovolaemic
Euvolaemic
Hypervolaemic
What are features of a euvolaemic patient?
Feels well, not thirsty Veins well filled Warm extremities Mild sweat Normal blood pressure and heart rate Normal urine
What are features of a hypovolaemic patient?
Nauseous and thirsty Flat veins Cool peripheries No sweat Low or postural blood pressure with high heart rate Concentrated oliguria Responds to SLR
What are features of a patient who is hypervolaemic?
Breathless, not thirsty Veins distended Warm and oedematous extremities Sweaty High BP and HR Dilute urine - oliguric or polyuric
What do you need to consider when working out water deficit?
Catheters Drains Input charts Vomit bowls Sputum pots Stool charts and stoma losses
What are examples of insensible water losses?
Sepsis - sweat Ventilation Open wounds Burns Bleeding
What is fluid resuscitation?
IV fluids given to restore circulation in hypovolaemia
What are the 4 types of fluid given?
Resuscitation
Routine maintenance
Replacement
Redistribution
What is the normal plasma osmolarity?
298 MOSML/L
What is tonicity?
Effective osmolarity
What determines tonicity and therefore water distribution?
Particles that are restricted to one compartment ie can’t pass membranes
What is the main extracellular fluid tonicity influencer?
Sodium
What is the main intracellular fluid tonicity influencer?
Potassium
What are symptoms of cell swelling?
Raised ICP
Compromised cerebral blood flow
Herniation
What are symptoms of cell shrinkage?
Intracranial haemorrhage
Venous sinous thrombosis
What are crystalloid fluids used for?
ECF expansion
When are colloids used?
Anaphylaxis
Coagulopathy
Renal failure
What is the highest rate of fluid that can be given for maintenance?
100ml/hr
How much maintenance fluid should be given each day?
30ml/kg/24 hours
2400mls per day at most
What fluid should be given for maintenance?
0.18%NaCl/4%glucose/0.3%KCl
After how long fasting should a patient be put onto maintenance fluid?
6 hours
How much fluid should be replaced after loss?
The same amount that was lost
What fluid should be used for replacement?
Plasmalyte 148
What type of fluid should be given for resuscitation?
Colloid
