Workshop 2: Diarrhoeal

Question 1

Diarrhoea can result in the excessive loss of which substances?

Answer 1

1. Sodium
2. Chloride
3. Water
4. Potassium
5. Bicarbonate
6. Magnesium

Question 2

The loss of ____ and _____ can result in dehydration

Answer 2

Sodium

Water

Question 3

What happens as a result of volume depletion associated with dehydration

Answer 3

The glomerular filtration rate and tubular luminla flow rate is reduced

Question 4

When does serum creatinine rise?

Answer 4

When there is a reduction in extracellular fluid volume and a reduction in the glomerular filtration rate

Question 5

The loss of bicarbonate in diarrhoea can result in?

Answer 5

Metabolic acidosis

Question 6

The loss of potassium due to diarrhoea can result in?

Answer 6

Can cause life-threatening cardiac arrhythmias such as ventricular fibrillation and asystole

Question 7

Define asystole

Answer 7

The state of total cessation of electrical activity in the heart

Question 8

Define ventricular fibrillation

Answer 8

The rapid, erractic electrical impulses in the heart

Question 9

Why must you assess if the patient has had a history of cardiac disease before prescribing intravenous fluids

Answer 9

Patients with lefte ventricular dysfunction are liable to develop pulmonary oedema if given too much IV fluid too quickly

Question 10

When calculating the amount of IV fluid required over the next 24 hours, you must take into account 3 factors?

Answer 10

1. Measured losses
2. Insensible losses
3. Previous day’s deficit

Question 11

Describe measured losses

Answer 11

This includes: urine, vomit, diarrhoea etc.

These are the volume of fluids that has been lost by the body that can be measured

Question 12

Describe insensible losses

Answer 12

These are the fluids lost by the body that cannot be measured e.g. sweat, during respiration.

Around 800mL daily for a normal individual

Question 13

How can insensible losses be increased?

Answer 13

Increased as a consequence of increased sweating and in patients being ventilated

Question 14

Describe how to calculate previous day’s deficit?

Answer 14

Question 15

In what time frame must the previous day’s deficient must be replaced in

Answer 15

Aim: within 24 hours

In patients with cardiac disease, the PDD does not have to be replaced over the next 24 hours but can be replaced over 2 to 3 days (in these cases, must take into consideration the losses for those 2-3 days)

Question 16

What is the equation for the amount of fluid required over the next 24 hours

Answer 16

Question 17

What is the 2 main used types of intravenous fluids

Answer 17

5% dextrose

0.9% saline

Question 18

When is 5% dextrose used?

Answer 18

When there is no electrolyte losses

When water replacement is required only!!

Question 19

When is 0.9% saline used?

Answer 19

When there is sodium and water loss

Question 20

At what rate do you give intravenous fluids?

Answer 20

Maximum of 500mL bag every 2 hours

Maximum of 1.5L per day

Question 21

What is the minimum daily potassium loss per day

Answer 21

60 to 80mmol

40-60: urine

10: faeces
10: skin

Question 22

Why is potassium supplement required when giving IV fluids

Answer 22

Need to replace daily loss (60-80mmol)

If the patient has no oral intake, potassium must be supplemented

Question 23

How concentration of potassium chloride can be added to a 500ml bag of fluid

Answer 23

Maximum 20mmol

Question 24

What is the maximum amount of potassium chloride you can give IV per hour?

Answer 24

20mmol

Question 25

What is the maximum amount of potassium chloride you can give IV per litre of fluid?

Answer 25

40mmol 20mmol per 500mL bag

Question 26

What is the maximum amount of potassium chloride you can give a patient IV per day

Answer 26

140mmol

Question 27

Why does the urea level increase in dehydration

Answer 27

As the reduced luminal flow rate allows increased tubular urea rebasorption As there is an increase in renal reabsorption of urea mediated by ADH

Question 28

In what situations might the insensible losses increase?

Answer 28

Fever Ventilation Significant burns Asthma attack- increase respiration

Question 29

Why does the upper gut have very low populations of bacteria?

Answer 29

Multiple factors including: Gastric acidity Propulsive motility Pancreatic enzymes

Question 30

There are different species in the colon. The vast majority are?

Answer 30

Strict anaerobes

Question 31

Why is the large intestine an ideal place for the microflora

Answer 31

Stagnant motility Retropulsive contractions

Question 32

Describe the development of the gut microflora

Answer 32

Occurs in infancy, while the gut is being colonised by the commensal bacteria. Tolerance is established preventing an immune response to the colonic flora.

Question 33

What are the main actions of short chain fatty acids in relation to preventing diarrhoea?

Answer 33

They promote water absorption Inhibit pathogenic bacteria growth

Question 34

What would happen to the normal gut microbiota if a patient was on a large doses of broad spectrum antibiotics

Answer 34

BS antibiotics can inhibit the growth and metabolism of the normal colonic flora. Therefore can cause the reduction in the colonic flora Increasing the risk of colonising pathogen bacteria

Question 35

Describe acute watery diarrhoea

Answer 35

Last hours to days e.g. cholera

Question 36

Acute bloody diarrhoea may be caused by what?

Answer 36

E.coli 0157

Question 37

Define dysentery

Answer 37

Presence of blood and mucus in stool

Question 38

The microboe must possess ____ in order for an infection to occur

Answer 38

Virulence factors

Question 39

What is the inoculum required for pathogens?

Answer 39

Varies from organism to organism Depends on the immune status of the host

Question 40

List two standard infection control precautions to prevent the spread of diarrhoeal disease

Answer 40

Hand Hygiene. Personal Protective Equipment (PPE)

Question 41

List two transmission-based precautions to prevent the spread of diarrhoeal disease

Answer 41

Isolation of infectious patients Signage should be used on doors/areas to communicate isolation requirements and prevent entry of unnecessary visitors and non-essential staff.

Question 42

Compare selective and differential media

Answer 42

Selective media: allows certain types of organisms to grow and inhibit the growth of others Differenital: Used to differentiate closely related organisms

Question 43

Describe the pathogenesis of Clostridium difficle

Answer 43

C.diff produces enterotoxins that can cause epithelial cells to fall of the mucosa, leaving spaces through which fluid can be extruded.

Question 44

Describe the pathogenesis of E.coli 0157

Answer 44

Produces an heat stable enterotoxin. These enterotoxins are able to inhibit the enterocyte fluid absorption mechanism

Question 45

The small intestine and colon must absorb 8L of fluid per day. where does 8L come from ? cant all be from diet

Answer 45

2L of dietary fluid 6L from body secretions e.g. saliva, gastric, pancreatic and bile secretion

Question 46

The term enteric bacteria refers to

Answer 46

Refers to bacteria which reside in the intestines

Question 47

Give an example of bacteria can cause diarrhoea

Answer 47

Salmonella Campylobacter Clostridium difficle

Question 48

Give an example of viruses can cause diarrhoea

Answer 48

Rotavirus Noravirus

Question 49

Give an example of protozoa can cause diarrhoea

Answer 49

Giardia lamblia

Question 50

Which of the following parasites is a patient in the UK with no travel history most likely to have?

Answer 50

Cryptosporidium is commonly contracted in lambing season therefore many people would come into contact with it in the UK without travelling