Values and basic principles

Question 1

Normal IOP

Answer 1

10-21 mmHg

If >21 mmHg :

Glaucoma

Raised IOP

Question 2

When to stop statin due to hepatotoxicity?

Answer 2

>3 ULN!

Question 3

When to check renal arteries in ACEi / ARB use?

Answer 3

>30% Creatinine raise

Question 4

When to stop a statin due to myositis?

Answer 4

When CK is 5x ULN as this can lead to rhabdomyolysis and ATN

Question 5

Normal ABPI

ABPI indicating diabetic arterial disease

Answer 5

normal ABPI range 0.9-1.2

>1.3 = diabetic disease and is unreliable. Should do a toe measurement instead (classically) or more appropriately do doppler studies +

Question 6

Resection margins in SCC

Melanoma

Answer 6

If Lesion <20mm then margins of 4mm will do

If lesions >20 mm then need margins of 6mm

Melanoma -

Margins by Breslow’s thickness (Also clark’s classification)

Melanoma in situ - 5mm

<1mm - 1cm

1-4 mm - 1-2cm

>4 mm - 2cm

Question 7

Plasma Osmolality

Urine Osmolality

Answer 7

Plasma - 275-295

Urine - 300-900

Question 8

Drug doses in asthma

Answer 8

Salbutamol - 5m

Ipatropiam - 0.5 mg

Hydrocortisone - 100 mg (200mg for COPD)

MgSO4 - 2g IVI

Question 9

Working out PaO2 from FiO2

Answer 9

FiO2 - 10 is roughly what the PaO2 should be

Question 10

Normal cup to disc ratio?

Answer 10

0.4-0.7

>0.7 = Optic disc cupping (cup is the inner circle)

Other glaucoma features (bayonetting of vessels - beraks as they disappear and enter at the base, cup notching )

Question 11

DKA Monitoring

Resolution of DKA?

Answer 11

Fall in ketones by >0.5 mM/h

Inrease bicarb by >3 mM/h

Fall in glucose by >3 mM/h

Aim for a normal ptoassium level

Resolution:

Ketones <0.3 mM

Venous pH >7.3

Question 12

Cut offs for rockall score?

Components?

Answer 12

<3 - good prognosis

>8 - high risk of mortality

Components:

Age

Evidence of Shock

Comorbidities

Post endoscopy

Question 13

After how many hours do you check for:

Trop

Parecetomal levels

Answer 13

Trop - 12 hours

Paracetomal levels - 4 hours

Question 14

Botulinism

vs

Tetanus

Answer 14

Botulinism - Prevents the SNARE complex formation which normally leads to acetylcholine release across the synapse

Tetanus - Prevents the release of inihibitory neurotransmitters

Question 15

Leydig Cells

Sertoli Cells

Tumours secrete?

Answer 15

Leydig = Lad

So: oestrogens and androgens

Sertoli - Androgens

Question 16

Normal Pulmonary artery occlusioon pressure

What is this an indicator for?

Answer 16

8-12 mmHg

This is an indicator of the Left Atrial Pressure

Will be raised (overload) in : (>18)

• Cardiogenic Pulmonary Oedema
• Mitral stenosis
• Left vetnricular failure

Will be low in : (<5)

• ARDS

Question 17

Base Excess

What is it

Values

Answer 17

Base excess - measure of how many H+ ions would be required to return the pH to 7.3

<-3 = Metabolic Acidosis

>+3 = metabolic alkalosis

Question 18

Rectum

Anus

Relative anatomical concepts and figure

Answer 18

Rectum:

Sacral promantery —> levator ani

Anorectal ring –> puborectal sling + internal and external anal sphincter complex

Rectum is 12 cm long.

Anterior resection - Malignancies should be >5 cm from the anal verge / 2 cm from the anorectal ring

Anus:

Levator ani to the anal verge

Divided into:

upper 2/3 - Super rectal artery/ vein - insensate with colulmnar epitheliam

Internal iliac node drainage

Dentate line - between upper 2/3 and lower 1/3

Lower 1/3 - Inferior/middle rectal artery/vein - sensate with squamous epithelium

Superficial inguinal node drainage

Question 19

MOA

Organophosphate poisononing

Atropine MOA

Answer 19

Organophosphates - Phosphate radicals bind and reduce action of acetycholinesterases —> increasing the concentration of acetylcholine in synapse—> SLUDGEM symptoms (Salivation, lacrimation, urination, defecation, GI upset (diarrhoea), emesis, meiosis )

Atropine - Is a competitive inhibitor of the ACh- R. So will stop binding of acetylcholine to receptor —-> produces anticholinergic effects

Question 20

Drugs used in bradycardia

When are they used ?

Answer 20

Used in conjunction with adverse signs

Atropine - 500mcg IV

Isoprenaline - 5mcg/min IV (beta 1 and 2 agonist- no real alpha action)

adrenaline - 2-10mcg/min IV

Question 21

Recurrent laaryngeal nerves:

Anatomy

Which is more commonly injured in thyroid surgery

Answer 21

Anatomy -

Right comes off of the vagus nerve and travels superiorly after wrapping underneath the right subclavian artery

Left comess of the vagus nerve and travels superiorly after wrapping underneath the arch of the aorta at around the level of the common carotid artery

Right is injured more commonly in thyroid surgery due to the oblique ascemt

Question 22

Renin aldosterone ratios

High Renin low aldosterone

Low renin High aldosterone

Low renin and low aldosterone

Answer 22

High Renin low aldosterone - RAS

Low renin High aldosterone - Cushing’s/ Conn’s

Low renin and low aldosterone - Liddle’s syndrome

Question 23

Calculations

Osmolality?

Osmolar Gap?

Anion Gap?

Answer 23

Calculated Osmolality = 2Na+ Glucose + Urea

Osmolar Gap = Measured osmolality - Calculated osmolality (normal <10)

(If gap >10 indicates there is another toxic substance in the blood which is making up the difference like ethylene glycol, methanol etc.)

Anion Gap = Na - { Cl- + HCO3-) (normal is <11 (8-16) )

(If raised = Raised anion gap metabolic acidosis —> think about extra things in the blood which are contributing to the acidosis like lactate, ketones etc.)