IV Fluids Flashcards
Describe in what compartments a 70kg man’s total body water (42L) would be?
- 28L intracellular fluid
- 11L interstitial fluid (extracellular)
- 3L plasma fluid (extracellular)
What are the possible causes for increased water loss via the urine?
- Poorly controlled diabetes
- Diuretics
What are the possible causes for increased water loss via the GI tract?
- Cholera
- Vomiting
- IBD
- Laxatives
- Bowel prep
What are the possible causes for increased water loss via the skin (sweat & insensible losses)?
- Burns
- Pyrexia
- Long operation with bowel exposed to air
What are the possible causes for increased water loss via the respiratory system?
- O2 ventilation dries up patient
- Increased respiratory rate
- Fever
List some symptoms of hypovolaemia?
- Anxiety
- Clammy skin
- Confusion
- Decreased urine output
- Weakness
- Pale skin
- Rapid breathing
- Sweating
List some symptoms of hypervolaemia?
- Oedema
- Headache
- Cramps
- Stomach bloating
- Dyspnoea
- Tachycardia
Fluid retention in sick patients with leaky capillaries can lead to what?
- Ileus
- Poor mobility peripheral oedema
- Pressure sores
- Pulmonary oedema
- Poor wound healing
- Anastomotic breakdown
What does excess chloride lead to?
- Renal vasoconstriction
- Increased sodium and water retention (decreased urine)
Describe euvolaemic patients?
- Veins are well filled
- Extremities are warm
- Blood pressure and heart rate are normal
Describe hypovolaemic patients?
- Cool peripheries
- Respiratory rate >20
- Systolic BP <100mmHg
- FEWS >/=5
- HR >90bpm
- Postural hypotension
- Oliguria
- Confusion
Describe hypervolaemic patients?
- Oedematous
- Inspiratory crackles
- High JVP
What are the reasons for a patients not needing IV fluids?
- Drinking adequately
- Receiving adequate fluids via NG feed or TPN
- Receiving large volumes with drugs or drug infusions or a combination
What is the treatment for hypervolaemia?
- Fluid restriction
- Gentle diuresis
What are the reasons for a patient needing IV fluids?
- Not drinking
- Lost/losing fluid
Why would a patient need maintenance fluids?
- Patient does not have excess losses above sensible loss/urine
- Patients having to fast over 8hrs
If a patient has no other intake, how much maintenance fluid would they need?
30ml/kg/24hrs
Why would a patient need replacement fluids?
- If there are losses either previously or current
- This fluid is in addition to maintenance fluid
Why would a patient need resuscitation fluids?
If patient is hypovolaemic as a result of dehydration, blood loss or sepsis and requires urgent correction of intravascular depletion to correct the deficit
What fluid would you give for diabetic special circumstances?
0.18% NaCl/ 4% Glucose/ KCl with IV insulin
What should you remember when giving a head injury patient fluids?
Avoid fluids containing glucose
How should IV fluids be given if a patient is on fluids for over 6hrs or if the fluid contains potassium?
Via volumetric pump
What should you always remember when giving maintenance fluids?
NEVER give them at more that 100ml/hr
What is the preferred maintenance fluid to prescribe?
0.18% NaCl/ 4% glucose with or without added potassium (20mmol) in 500ml
What volume of maintenance fluid should you give frail elderly patients with renal impairment or cardiac failure / patients who are malnourished / at risk of refeeding syndrome?
20-25ml/kg/day
What maintenance fluid should you give if the patient is at refeeding risk?
Pabrinex IV
What fluid can be given to prevent starvation ketosis?
50-100g glucose in 24hrs
What can occur in patients with upper GI losses?
Hypochloraemia (loss of Cl)
What can cause hyponatraemia?
- Large GI losses
- Too much fluid
- SIADH
- Chronic diuretic use
What is the possible treatment for hyponatraemia?
0.9% NaCl or fluid restriction and frequent U&E’s
How should you give replacement potassium fluid?
- In maintenance fluid
- Give upto 40mmol in 100ml bags via a central line at 25-50ml/hr
- Must be given by pump
- Give Kay-Cee-L/ Sando-K orally if possible
What can lead to potassium loss?
Diarrhoea
How should you replace fluid/electrolytes?
By adding up all the losses over the previous 24hrs and give this volume as Plasmalyte 148
What fluid should you prescribe for upper GI/bile losses?
0.9% NaCl with KCl
What fluid contains lactate?
Hartmann’s solution
What fluid contains acetate & gluconate?
PlasmaLyte 148
What 2 fluids should you use in urgent resuscitation?
- PlasmaLyte 148
2. Colloid (Gelaspan/Albumin)
When should you only give Albumin?
Severe sepsis
What fluids should you prescribe for severe blood loss?
- Initially use colloid / PlasmaLyte 148 until blood/clotting factors arrive
- Use O negative blood for torrential bleeding
- Severely septic patents with circulatory collapse may need inotropic support in a critical care area
In what scenarios should you consider critical care referral?
- GCS = 8 or falling
- O2 saturation <90% on 60% O2 or higher
- PaCO2 > 7kPa unresponsive to NIV
- Persistent hypotension and/or oliguria unresponsive to 2000ml fluid/ or concern over cardiac function
- Metabolic acidosis: base deficit -8 or worse, bicarbonate <18mmol/l, lactate >3mmol/l and not improving in 2hrs
- Aggressive/agitated patients whose treatment (oxygen,IV therapy) is compromised due to agitation
What coagulates blood products?
Calcium
What type of fluid should you give a patient if you want to draw fluid out of the intracellular space and into the extracellular space (cerebral oedema)?
Hypertonic solution
What is a colloid fluid?
Protein based and has allergenic potential
Give 3 examples of colloid fluids?
- Blood
- Hydrolysed gelatin
- 4.5% Albumin
What is crystalloid fluids?
Aqueous solutions of mineral salts or other water-soluble molecules
Give 5 examples of crystalloid fluids?
- Normal saline (NaCl)
- 5% Dextrose
- 0.18% NaCl/ 4% Dextrose
- Hartmann’s
- Plasmalyte
Who are at risk of fluid overload?
- Heart failure
- Hepatic failure
- Renal failure
- Excess fluid prescribing
When would you prescribe parenteral nutrition fluids?
Used to provide complete fluid, electrolyte and nutritional needs for patients who cannot eat or drink for an extended time
What is the average loss of fluid via urine?
~1500ml
What is the average loss of fluid via faeces?
~100ml
What is the average loss of fluid via sweat?
50mls
What is the average loss of fluid via insensible losses?
~900ml
What is the total body loss of fluid on average in a day?
~2550ml
What happens if the total body sodium falls?
Osmolality (tightly regulated) stays the same and the total volume falls (including plasma volume)
What are compensatory mechanisms really linked to?
- Low volume (low GFR, stimulation of JGA)
- High volume (increased GFR and release of ANP)
What syndrome is typical of hyperaldosteronism?
Conn’s syndrome
What 2 things can Conn’s syndrome lead to?
- Hypertension from increased fluid volume
2. Hypokalaemia