Fluids Flashcards
(57 cards)
What is the best serial measurement for fluid balance and for calculating x px post operative fluid levels?
- serial measurements of their weight
Describe the fluid compsition (H2O%) in a healthy adult?
The body is
40% solid 💪
60% H20/fluid 💧 of which
- 20% of fluid is found extracellularly
- 40% intracellularly
How does fluid composition change with age
It decreases with age - older patients are drier and are at increased risk of dehydration
.
How much fluid should a person be drinking a day?
1.5 - 2L , but this is not standardised - you should be drinking water when you feel thirsty
Describe some ways in which we obtain fluid and lose fluid from our bodies?
- fluid intake - food 🥘 + H2O drink 🍸
- fluid out - faeces 💩 , urine 🚽 , sweat 💦 , tears 😭 , saliva 💧
Describe how the fluid balance changes with injury? 🤕
When a person is injured more ADH is released AND capillaries increase in their leakyness - this results in an increase in :
- water retention and sodium retention - this floods the affected area with fluid (oedema) and can lead to swelling and pa on nerves, discouraging movement and further trauma
- the increased leakyness of the capillaries will result in increased albumin loss via fenestrations and release of cytokines , H2 and PG to the site of injury —> brings inflamatory mediators to the site of damage for repair
Describe how the fluid balance changes when an injury is healed 😊
The capillaries become LESS leaky - thus inflammatory cytokine and albumine etc return or remain in the bloo d
- less peripheral oedema
- albumin retention in the blood
The px excretes the xs fluid as URINE
What are ongoing fluid losses?
These are the continuous + measurable fluid losses that exceed the normal daily requirements
What are some typical causes of ongoing fluid losses?
- vomiting, diarrhoea, xs sweat (ie fever) , surgery
- stoma output!
- polyuria
- diabetes insipidus
What is the main ion found in the extracellular body fluid and what is its tyical serum 🩸 concentration?
SODIUM
- 135 - 145mmol/L
What is the main ion found in the intracellular body fluid and what is its plasma 🩸 concentration?
K+
Bc it is intracellular, the plasma levels are of course low and are not a true representation of how much potassium is in the body - typical levels are between 3.5 - 5.3 mmol/L
What is the typical range for [Cl] in the blood 🩸
98 - 105 mmol/L
What is the osmolality of the blood? 🩸
180 - 200 mOsm
What are the risks associated with administering fluids TOO quickly?
- infusion reactions - anaphylactoid or skin reactions
- brain damage
What are the 5 Rs of prescribing IV fluids?
- Resus
- Routine Maintenance
- Replacement
- Redistribution
- Re -assessment
What are the two main reasons we prescribe fluids in 2ndary care?
Acute Fluid resusitation - ie acute cases of hypovolemia
Maintenance fluids - for patients who cant maintain an adequate oral intake of fluids.
What are some causes of hypovolemia?
- sepsis 🦠
- burns 🔥
- haemorrhage 🩸
- severe vomiting 🤮 or diarrhoea 💩
Why do we prescribe IV fluids to patients who are acutely hypovolemic?
Larger volumes are required to boost their circulating volume + they help to prevent patients experiencing SHOCK
What is hypovolemic shock?
Thus is when there is a reduced flood flow to organs due to reduced fluids circulating in the body
If a px presented to us with hypovolemic shock or acute hypovolemia or was an adult presenting with sepsis, what would be the 1st line treatment regarding IV fluids?
- BOLUS OF 500ml of a crystalloid over 15mins that has at least 130 - 154 mmol/L of Na+)
(Eg Hartmans, 0.9% NaCl, or dextrose 5%)
- Rx at least 30ml/kg in the 1st 3hrs
What are some pathological conditions that would make it difficult for a patient to maintain oral intake of fluids, thus requiring them to be rx maintenance fluids?
- bowel obstruction
- peri - operative px
