Digestion (Tutorial)

Question 1

Fill in the digestion mindmap summary below:

Answer 1

Question 2

Case 1: (info card)

You encounter Mr T in clinic; he is 56 years old and a retired plumber. The nurse practitioner draws some

blood for routine tests and measures his height (176 cm) and weight (123 kg). He has been trying to watch

what he eats, but has made very few changes since his diagnosis last year. He mentions that he’s not as

thirsty as he used to be, and no longer suffers from blurred vision. Once the blood is drawn you notice on

the request card that one of the tests is called glycated haemoglobin (HbA1C)

Answer 2

Questions: On his diagnosis, underlying issue, treatments, and consequences of no treatment

Question 3

What is glycated haemoglobin?

What does elevated glycated haemoglobin (HbA1C) commonly indicate?

Answer 3

glycated Hb = HbA1C = glucose bound to Hb

T2DM - Type 2 Diabetes Mellitus

Question 4

What are the 2 underlying issues associated with T2DM?

Answer 4

1. Reduction in insulin secretion
2. Reduced cell sensitivity to insulin

Question 5

What treatments can be recommended for T2DM?

Answer 5

1. Lifestyle changes - e.g. reduced carbohydrates in the diet, regular exercise, etc.
2. Metformin - T2DM medication that helps increase cell sensitivity to insulin

Question 6

What are some issues that can arise without treatment (for T2DM)?

Answer 6

1. Retinopathy
2. Renal disease / renal complications
3. Neuropathy - nerve damage

Question 7

Case 2: (info card)

On your PCH hospital attachment you meet a patient during a walk-in rapid access chest pain clinic. Mr P, a 45-year old male, has been suffering from episodic central chest pain. The chest pain does not radiate down the left arm and is not associated with breathlessness.

He adds that the pain does not disappear with rest. Anecdotally, he mentions that he has been experiencing a throaty cough, despite not having any other cold-like symptoms. The cardiology SpR refers the patient for an exercise tolerance test, which comes back negative.

Question 8

What is the likely diagnosis for Mr P?

What is it caused by?

Answer 8

Acid reflux

When the sphincter at the bottom of the oesophagus relaxes at the wrong time / contracts ineffectively so HCl from the stomach is able to travel up the oesophagus

Also too much acid (HCl) production by the parietal cells in the stomach

Both of these irritate the oesophagus lining

Question 9

What does an exercise tolerance test involve?

Answer 9

ECG connected whilst exercising (e.g. treadmill, sitting on a bicycle etc.)

Question 10

What treatments can be recommended for acid reflux?

Answer 10

Not much can be done about the sphincter

But stomach acid production can be reduced using PPIs and H2 blockers (histamine H2-receptor antagonists e.g. ranitidine). However, H2 blockers have recently been banned (due to long term side effects) so only PPIs are currently being used in practice

Antacids - to neutralise the acid

Question 11

Case 3: (info card)

On your GP placement you encounter Miss G, a 14-year old girl that has been experiencing periodic abdominal pain and excessive flatulence. She is passing frequent watery stools, and experiences nausea like symptoms which are affecting her at school.

She notices that her symptoms are worst around 10:00a.m. and she eats a normal diet for her age (i.e. cereal for breakfast, sandwiches and crisps for lunch, and a cooked meal for dinner).

Question 12

What are the differential diagnoses for Miss G?

How would you choose between them to give the correct diagnosis?

Answer 12

Coeliac disease (gluten allergy), lactose intolerance

Lactose intolerance is correct, because if she had coeliac disease, then her symptoms would also be particularly bad after lunch (sandwich is likely to contain gluten)

Question 13

Explain the symptoms:

a) worsening at 10am
b) stomach cramps
c) diarrhoea

in the context of Miss G’s diagnosis:

Answer 13

a) Symptoms worse around 10 a.m. after breakfast - a couple hours after breakfast (assuming she has milk with her cereal)
b) Stomach cramps - bacteria in the colon ferment lactose that the body has left undigested
c) Diarrhoea - lactose is not broken down, decreases osmolarity of the chyme so more water is drawn in = watery stool

Question 14

What causes lactose intolerance?

Answer 14

Lactase enzyme is not present - lactose is not metabolised into glucose and galactose

Question 15

What treatment is recommended for lactose intolerance?

Answer 15

Diet modification - avoid lactose intake by e.g. reducing milk in the diet etc.

Question 16

Case 4: (info card)

During a work experience placement in an obstructive sleep apnoea clinic your consultant sees Mrs H, a non-diabetic 39-year old female, for her annual check-up. She is compliant with her continuous positive airway pressure (CPAP) device, which keeps her airway patent at night, so her nocturnal apnoeas are well controlled.

However, she is keen to get off the device as the noise of the machine is keeping her husband up at night. She is keen to lose weight (2015: 142 kg; today: 148 kg) and has tried diet and exercise with little success. Her blood glucose is normal. She is reluctant to pursue surgical options and asked if there are any pharmacological treatments that may help.

Question 17

What is obstructive sleep apnea?

Why does Mrs H have obstructive sleep apnea?

Answer 17

Characterised by repeated episodes of complete or partial obstructions of the upper airway during sleep - e.g. in the case of Mrs H, this is due to increased / too much weight on her neck and chest when she is laying down

Question 18

What is the underlying issue causing Mrs H’s obstructive sleep apnea?

Answer 18

Obesity - due to too much ingested food

Question 19

What are the side effects of obstructive sleep apnea?

i.e. the blockage in the airway that stops breathing can result in…?

Answer 19

Blockage in the airway stops breathing, resulting in:

Exhaustion

High levels of CO2 - wakes her up

Reduced oxygen saturation - hypoxia; brain and nerve cells are very sensitive to oxygen so some damage caused with each episode

Question 20

How can obesity be treated?

Answer 20

1. Lifestyle modifications
2. Gastrict bypass surgery - considered when their BMI is 35 and/or over and they have co-morbidities (e.g. diabetes), OR their BMI is 40 and/or over. This surgery makes the stomach smaller so the patient feels full more quickly, reduction in ingested food leads to weight loss

Through gut hormones, diabetes can be cured by taking out around 80% of the stomach