Fluids

Question 1

Types of crystalloid fluids

Answer 1

5% dextrose, 0.18% saline with 4% dextrose, 0.9% saline, Hartmann’s, 0.45% saline with 4% dextrose

Question 2

What are the two main types of fluids

Answer 2

Crystalloids and colloids

Question 3

What is 5% dextrose used for

Answer 3

Hypotonic on its own, used in severe hypoglycaemia

Question 4

What does 0.9% sodium chloride do

Answer 4

Replaces salts in the intravascular spaces

Question 5

What does Hartmann’s do

Answer 5

More physiological to blood so stays mostly in extracellular space

Question 6

What are the main components of crystalloid fluids

Answer 6

Water with some additives

Question 7

What are the main components of colloid fluids

Answer 7

Water which contain bigger molecules, which do not readily cross semi-permeable barriers

Question 8

Examples of colloids

Answer 8

Gelofusin, albumin, blood

Question 9

Complications of fluids

Answer 9

Volume overload, cerebral oedema, electrolyte disturbances, renal toxicity

Question 10

When fluids need to be prescribed

Answer 10

Maintenance, electrolyte replacement, resuscitation, drug administration

Question 11

What are the 5 R’s of fluids

Answer 11

Resus, rountine maintenance, replacement, redistribution, reassessment

Question 12

When is resus used

Answer 12

Acute cases, to correct fluid deficit - haemorrhage, sepsis, burns, severe D&V

Question 13

When is maintenance used

Answer 13

Replace ongoing fluid loss, indequate PO intake - peri-op patients, bowel obstruction

Question 14

What are factors which maintenance volume depends on

Answer 14

Age, weight, co-morbidities, clinical state, medications, anticipated time NBM

Question 15

What fluid is used for resus

Answer 15

Normal saline 250-500ml bolus stat

Question 16

What is euvolaemic hyponatraemia

Answer 16

Normal body sodium with increase in total body water

Question 17

What is hypovolaemic hyponatraemia

Answer 17

Decrease in total body water with greater decrease in total body sodium

Question 18

What is hypervolaemic hyponatraemia

Answer 18

Increase total body sodium with greater increase in total body water

Question 19

Causes of hypovolaemic hyponatraemia

Answer 19

Diuretic use, heart failure

Question 20

What are the risks of fast correction in chronic hyponatraemia

Answer 20

Risk of pontine demyelination

Question 21

Causes of normovolaemic hypernatraemia

Answer 21

Usually iatrogenic

Question 22

Causes of hypovolaemic hypernatraemia

Answer 22

Diabetes insipidus, osmotic diuresis (such as DKA)

Question 23

What is hypovolaemic hypernatraemia

Answer 23

Small volumes of concentrated urine associated with fluid loss.

Question 24

Causes of increased excretion of K+

Answer 24

Diuretics, endocrine causes such as Cushings and steroids, RTA, hypomagnesaemia, vomiting

Question 25

Causes of increased cellular uptake of K+

Answer 25

Salbutamol and insulin most notable - associated with DKA management

Question 26

Chronic causes of hyperkalaemia

Answer 26

CKD most common, diabetes, aldosterone insufficiency, diet

Question 27

Acute causes of hyperkalaemia

Answer 27

AKI, DKA, rhabdolyolysis, tumour lysis (post chemo) and medication (less common)

Question 28

ECG findings of hyperkalaemia

Answer 28

Peaked T waves, P wave flattening, PR prolonged, bradyarrhythmias, conduction blocks, QRS abnormalities

Question 29

Management of hypokalaemia

Answer 29

Oral or IV - slow infusion as part of maintenance regime

Question 30

Management of hyperkalaemia

Answer 30

Always treat cause, calcium gluconate 10ml 10% binds K+ and works in few mins, insulin and salbutamol shift K+ intracellularly, K binders are slow acting

Question 31

Causes of pseudo hyponatraemia

Answer 31

Hypertriglyceridaemia, high protein, hyperglycaemia, sorbitol/glycine

Question 32

Causes of water > soluble intake

Answer 32

Psychogenic polydipsia, beer potomania, low solute diet

Question 33

Causes of hypovolaemia, non-renal aetiology

Answer 33

GI losses, reduced PO intake, previous diuretic use

Question 34

Causes of hypovolaemia renal involvements

Answer 34

Renal salt wasting, current diuretic use, vomiting

Question 35

Causes of euvolaemic hyponatraemia

Answer 35

SIADH, adrenal insufficiency, hypothyroidism

Question 36

Causes of oedematous state

Answer 36

Heart failure, cirrhosis, nephrotic syndrome

Question 37

General criteria for DDAVP clamp

Answer 37

At risk for sodium over-correction, risk of cerebral osmotic demyelination

Question 38

Symptoms of severe hyponatraemia

Answer 38

Seizure, delirium, coma, herniation, neurogenic pulmonary oedema