Prescribing IV fluids Flashcards
Outline the distribution of body fluids
Water makes up 60% and 55% of the total body weight of men and women respectively. There is about 30L of intracellular fluid, 11L of interstitial and 5L of vascular fluid in the human body.
What are indicators for prompt fluid resuscitation?
> SBP <100mmHg > HR >90bpm > Cap refill >2 secs > Cold periphery > RR >20
What are indicators for blood transfusion?
> Massive or ongoing haemorrhage
If Hb <8
If Hb 8-10 but they are symptomatic and have cardiac/respiratory/cerebrovascular disease
What are the risks of blood transfusion?
Immune reactions, infections, volume overload, electrolyte imbalance and religious objections.
When would you give irradiated blood in a transfusion?
Stem cell patients, those with leukaemia or anaemia
What are signs of volume depletion (hypovolaemia)?
o Reduced capillary refill o Tachycardic o Hypotensive (and postural hypotension) o Low/absent JVP o Decreased skin turgor and dry mucosa o Oliguria (less volume of urine) o Decrease in their daily weight chart
What are signs of volume overload (hypervolaemia)?
o Occasionally tachycardic
o Raised JVP
o Pulmonary oedema, pleural effusion, ascites, peripheral oedema
o Increase in their daily weight chart
What are crystalloids?
Water with varying levels of salts
What are colloids?
Protein-rich solution with salts as well as water
Give 3 examples of crystalloids.
Normal saline (0.9%), 5% dextrose, Ringers lactate (Hartmann’s solution)
Give 3 examples of colloids.
Gelofusine, volplex, haemaccel
What is Ringer’s lactate also known as?
Hartmann’s solution
What’s the maximum IV potassium a patient can be administered per hour?
20mmol/hour!
How does administering 1L of saline affect the intracellular and extracellular fluid levels of a patient?
Adminstering 1L of normal saline will cause an increase of 1L in the extracellular fluid, but not in the intracellular fluid
How does administering 1L of 5% dextrose affect the intracellular and extracellular fluid levels of a patient?
Administering 1L of this will lead to an increase of 330ml in the extracellular fluid and an increase in 670ml in the intracellular fluid (as there is glucose and just water, it follows the movement of salt, which leads to it travelling in several places rather than just in the ECF)
What complication can occur from giving normal saline?
Administering too much saline may lead to hyperchloramia and a metabolic acidosis (as it tips the acid base towards the production of HCl, be wary in ITU for example.
What complication can occur from giving Ringers lactate/Hartmann’s solution?
Contain K+ so be careful not to administer if a patient has hyperkalaemia –> can kill them.
What is the most common adverse reaction to colloids?
Allergic reaction
What is the daily requirement that needs to be met with fluid maintenance?
25-30ml/kg/day of water, 1mmol/kg/day of sodium and potassium, alongside 50-100g/day of glucose
Give an example of a prescription of IV fluids for routine maintenance only
25-30ml/kg/day 0.18% sodium chloride (saline) in 4% glucose/dextrose with 27 mmol/L K+ on day 1.
What monitoring is required for patient’s receiving IV fluids containing chloride concentrations >120mmol/L
Serum chloride daily
Describe the different cannula sizes, their colours and how long they take to infuse 1L of fluid
> 22G (BLUE) – 22 minutes to infuse 1L > 20G (PINK) – 15 minutes to infuse 1L > 18G (GREEN) – 10 minutes to infuse 1L > 16G (GREY) – 6 minutes to infuse 1L > 14G (RED) – 3.5 minutes to infuse 1L
