Cheese and Onion Revision

Question 1

How do local anaesthetics work?

Answer 1

LA enter the cell as they are un-ionised. There, they become ionised (as it is acidic) and block Na+ channels, preventing depolarisation of the cell and thus preventing the spread of the pain impulse.

Question 2

Give SEs of LAs.

Answer 2

Headache, dizziness, confusion, CNS depression (-> resp dep)

Myocardial depression and vasodilation - take BP before initiation

Question 3

What is the difference between lidocaine and bupivacaine?

Answer 3

Lidocaine has rapid induction, medium duration and good tissue penetration; and is an anti-arrhythmic.

Bupivacaine is slow onset, long duration but high carotid toxicity

Question 4

Give non-cardiac causes of arrythmias.

Answer 4

Caffeine, smoking, alcohol, pneumonia, drugs, metabolic imbalance, phaechromocytoma.

Question 5

What drugs can cause arrhythmias?

Answer 5

Beta agonists, digoxin, L-dopa, tricyclics, doxorubicin

Question 6

How do we investigate arrhythmias?

Answer 6

FBC, U&E, glucose, Ca2+, Mg2+, TSH, ECG

Question 7

What causes sick sinus syndrome?

Answer 7

Usually caused by sinus node fibrosis, typically in elderly patients. The sinus node becomes dysfunctional, in some cases slowing to the point of sinus bradycardia or sinus pauses, in others generating tachyarrhythmias such as AF or atrial tachycardia.

Question 8

What is tachy brady syndrome?

Answer 8

In some pts with sick sinus syndrome, they suffer from alternating tachycardic and bradycardic rhythms. This can be difficult to treat medically as treating one circumstance increases the risk of the other.

Question 9

Define narrow complex tachycardia

Answer 9

ECG shows rate of >100bpm and QRS complex duration of <120ms. They occur when the ventricles are depolarized via the normal conduction pathways.

Question 10

Give the differential diagnosis of narrow complex tachycardia.

Answer 10

Normal variant: sinus arrhythmia (rate changes w. inspiration/expiration), sinus rhythm with frequent ectopic beats
Atrial fibrillation
Atrial flutter with variable block
Multifocal atrial tachycardia

Question 11

How do we manage narrow complex tachycardia

Answer 11

Identify and treat the underlying rhythm, e.g. see if dehydrated/acid imbalance etc

Question 12

How do we manage AVNRT or AVRT?

Answer 12

Transiently block the AVN. Only works if not atrial in origin, get atrial flutter or atrial tachycardia. This can be achieved by:

• vagal manoeuvres (carotid sinus massage, Valsalva manoeuvre)
• IV adenosine

Question 13

What is focal atrial tachycardia?

Answer 13

Where a group of atrial cells act as a pace-maker, out-pacing the SAN. P-wave morphology is different to normal sinus.

Question 14

What is atrial flutter?

Answer 14

Electrical activity circles the atria 300 times per minute, giving a sawtooth baseline. The AVN passes some of these impulses on, resulting in ventricular rates that are factors of 300.

Question 15

What is atrioventricular re-entry tachycardia?

Answer 15

An accessory pathway (e.g. in WPW) allows electrical activity from the ventricles to pass to the resting atrial myocytes, creating a circuit: atria, AVN, ventricles, accessory pathway, atria. This direction is called the orthodromic conduction and results in narrow QRS complexes as ventricular depolarisation is trigged via the bundles of His. Conduction in the other direction is called antidromic and results in broad QRS complexes.

Question 16

What is atrioventricular nodal re-entry tachycardia?

Answer 16

Circuits form within the AVN, causing narrow complex tachycardias.

Question 17

What is propofol used for?

Answer 17

Used for induction or maintenance of anaesthesia in adults and children

Can also be used for sedation

Question 18

Give a gaseous sedative, and the drawbacks when compared to TIVA

Answer 18

Sevoflurane is non-irritant and is therefore often used for inhalational induction of anaesthesia; it has little effect on heart rhythm compared with other volatile liquid anaesthetics.

However, longer wake up and more drowsy for longer.

Question 19

How does propofol work?

Answer 19

Propofol is believed to work at least partly via a receptor for GABA.

Question 20

Give a muscle relaxant

Answer 20

Rocuronium

Question 21

Give a common SE of propofol.

Answer 21

Can cause stinging in the blood vessel when injected, especially if a smaller one

Question 22

Describe the pharmacology behind the mechanism of action of sevoflurane

Answer 22

Sevoflurane acts as a positive allosteric modulator of the GABAA receptor in electrophysiology studies of neurons and recombinant receptors.[13][14][15][16] However, it also acts as an NMDA receptor antagonist,[17] potentiates glycine receptor currents,[16] and inhibits nAChR[18] and 5-HT3 receptor currents.

Question 23

What is a MAC?

Answer 23

Minimum alveolar concentration is the concentration of a vapour in the alveoli of the lungs that is needed to prevent movement in 50% of subjects in response to surgical stimulus.

Question 24

Describe the pain seen in chronic pancreatitis

Answer 24

Epigastric pain that bores through to the back. Can be relieved by sitting forward or hot water bottles on epigastrium/back.

Question 25

How do we diagnose chronic pancreatitis?

Answer 25

Ultrasound +- CT: pancreatic calcifications confirm the diagnosis

Question 26

How do we manage chronic pancreatitis?

Answer 26

Abstinence from alcohol and smoking is important in managing symptoms and complications.

Analgesia can be used to manage the pain, although it can be severe and difficult to manage.

Replacement pancreatic enzymes (Creon) may be required if there is a loss of pancreatic enzymes (i.e. lipase). Otherwise, a lack of enzymes leads to malabsorption of fat, greasy stools (steatorrhoea), and deficiency in fat-soluble vitamins.

ERCP with stenting can be used to treat strictures and obstruction to the biliary system and pancreatic duct.

Question 27

Give three causes of acute pancreatitis

Answer 27

Gallstones, alcohol, ERCP

Question 28

How do we investigate pancreatitis?

Answer 28

FBC (for WCC)
U&E (for urea)
LFT (for transaminases and albumin)
Calcium
ABG (for PaO2 and BGC)
Amylase is raised more than 3x the upper limit of normal in acute pancreatitis (maybe normal in chronic)

Question 29

What is the Glasgow score?

Answer 29

Used to assess the severity of pancreatitis.
0-1 = mild
2 - moderate
3+ - severe

Question 30

Give the criteria for the Glasgow score.

Answer 30

PaO2 <8kPa
Age >55
Neutrophils (WBC > 15)
Calcium >2
uRea >16
Enzymes (LDH > 600 or AST/ALT >200)
Albumin <32
Sugar (glucose >10)

Question 31

How do we treat acute pancreatitis?

Answer 31

Initial resuscitation (ABCDE approach)
IV fluids
Nil by mouth 
Analgesia
Careful monitoring
Treatment of gallstones in gallstone pancreatitis (ERCP / cholecystectomy)

Question 32

Give three complications of acute pancreatitis

Answer 32

Necrosis of the pancreas
Infection in a necrotic area
Chronic pancreatitis

Question 33

Give causes of R hypochondriac pain

Answer 33

Gallstones, cholangitis, hepatitis, liver abscess, cardiac causes, lung causes

Question 34

Give three causes of epigastric pain

Answer 34

Oesophagitis, peptic ulcer, perforated ulcer, pancreatitis, GORD

Question 35

Give three causes of L hypochondriac pain

Answer 35

Splenic abscess, acute splenomegaly, splenic rupture

Question 36

Give two causes of lumbar pain.

Answer 36

Ureteric colic, pyelonephritis

Question 37

Give four causes of umbilical pain

Answer 37

Early appendicitis, SBO, gastroenteritis, ruptured AAA, mesenteric adenitis/ischaemia, Meckel’s diverticulitis, lymphomas

Question 38

Give five causes of R iliac pain.

Answer 38

Appendicitis, Crohn’s, obstruction, ovarian cyst, ectopic pregnancy, hernias

Question 39

Give three causes of hypogastric pain.

Answer 39

Testicular torsion, urinary retention, cystitis, placental abruption, PID, STI

Question 40

Give four causes of L iliac pain.

Answer 40

Diverticulitis, UC, constipation, ovarian cyst, hernias