Phew – well done!

FullSizeRender 15

 

A big congratulations to all of you who sat the exam today – it is quite a feat of physical and mental endurance!

Now time for a bit of a break. Give yourselves a chance to recuperate and participate in normal life – can you remember itūüėȬ†– ¬†for the next week or so. Read a novel, take your partner out for dinner or enjoy dinner with friends, permit yourself an extra hour at the gym ( only if that won’t be torture), go to the beach or the bush, binge watch your favourite TV show….

For those of you who like cooking, and who are not too health obsessed, I could recommend making this recipe, pictured above, touted by my favourite podcast.

It is quite normal to feel a bit down in the dumps after a big effort such as today’s.¬†Here¬†is my post from after the written exam in February. We seem to be programmed to remember and dwell on the things we have done wrong, or that upset or scare us, rather than those we have done right. Perhaps this has an evolutionary advantage to stop us getting ourselves into dangerous situations. In the coming days you are likely to mull over those things that you forgot to write down in the exam. It’s Ok. No one can possibly write all there is to know about a topic, under pressure, in 10 minutes…

I like the advice at the end of this article. We can overcome those negative thoughts by creating a bank of good ones. So have a go now, whilst the day is fresh in your mind, and think of 5 or 10 things that went well today ( making it through the exam definitely counts as one). In the coming days, if misery sets in, look back at your list and encourage yourself – well done!

Mineraloglucoaldosticosteroids

BT_PO 1.90

Describe the pharmacology of * insulin preparations *oral hypoglycaemic *corticosteroid drugs.

Intravenous dexamethasone has a slow onset of action. TRUE/FALSE

Prednisone and dexamethasone are synthetic corticosteroids with predominantly mineralocorticoid effects. TRUE/FALSE

The anti-inflammatory response of corticosteroids is a mineralocorticoid effect. TRUE/FALSE

Mineralocorticoid effects of synthetic corticosteroids are less than the natural hormones. TRUE/FALSE

Dexamethasone lacks mineralocorticoid effects. TRUE/FALSE

 

 

Bleedy McBleedster

BT_PO 1.121

Describe methods to reverse the effect of warfarin

BT_PO 1.120

Describe the pharmacology of warfarin and other anticoagulant drugs

The metabolic clearance of warfarin is inhibited by amiodarone. TRUE/FALSE

Third generation cephalosporins reduce the anticoagulant effect of warfarin. TRUE/FALSE

Intravenous vitamin K should return the prothrombin time to a normal range within 1 hour. TRUE/FALSE

Skin necrosis is a side effect of warfarin therapy. TRUE/FALSE

Warfarin can be reversed with recombinant factor VIIa TRUE/FALSE

Big Owie

BT_PO 1.120

Describe the pharmacology of warfarin and other anticoagulant drugs

Warfarin has a mild effect on platelet function. TRUE/FALSE

Peak concentration of warfarin occurs at 36 hours. TRUE/FALSE.

Despite its low protein binding, warfarin has a long elimination half time after oral administration. TRUE/FALSE

Warfarin crosses the placenta and is found in significant levels in breast milk. TRUE/FALSE

The elimination half time of warfarin may be prolonged by volatile anaesthetic agents. TRUE/FALSE

 

Gastro-intestinal changes in pregnancy

 

SS_OB 1.1

Describe the physiological changes and their implications for anaesthesia that occur during pregnancy, labour and delivery, in particular the respiratory, cardiovascular, haematological and gastrointestinal changes.

There is delayed gastric emptying for 12 weeks gestation. TRUE/FALSE/CONTROVERSIAL

During pregnancy, liver blood flow remains unaltered. TRUE/FALSE

The lower oesophageal sphincter becomes incompetent in pregnancy solely due to the loss in the angle of the gastro-oesophageal angle. TRUE/FALSE

Epidural analgesia using local anaesthetics and no opioids can reduce gastric emptying. TRUE/FALSE

Gastrin from the foetus may slow gastric emptying TRUE/FALSE

 

 

Hepatic metabolism of drugs

BT_PO 1.108

Describe the alteration to drug response due to hepatic disease.

Metabolic clearance is usually constant and independent of dose. TRUE/FALSE

For drugs with an extraction ratio of nearly 0, a change in liver blood flow produces a nearly proportional change in clearance. TRUE/FALSE

Alfentanil is an example of a drug whose hepatic metabolism is capacity-limited. TRUE/FALSE

In cirrhosis, hepatic drug clearance is usually reduced. TRUE/FALSE

CYP3A4 is responsible for nearly half of all drug metabolism. TRUE/FALSE. Hint…this is the enzyme system affected by grapefruit juice (and interestingly, propofol).

Corpus Curare Spiritumque

There have been some really good study / exam tips lately, so I thought I’d post something with a motivational flavour. (Also, I resisted doing a history post because it’s too close to the exam to risk taking you on a procrastination tangent).

 

ANZCA motto

 

“Corpus Curare Spiritumque” is the Latin motto which appears on the ANZCA coat of arms.

It translates as “To care for the body and its breath of life”. I think this encapsulates really well, so much of what anaesthetists do.

Whether we are in theatre, attending a trauma, in pre-admission clinic, or on a ward round, we are always focused on the whole patient. Especially in theatre, sometimes we are the only doctors who seem to have a handle on the big picture!

We are doctors who are good at keeping people alive. However, the full meaning of the “breath of life” can extend to include every aspect of homeostasis.

In order to live up to the lofty motto chosen by the Founding Fellows of the College, anaesthetists need a solid grounding in basic sciences. ¬†That’s because we are surrounded every day by pharmacology, altered physiology, and technology.

At the end of the day, I hope that you can see the value and impact of all your study for the primary exam, in terms of your ability as an anaesthetist to “care for the body and its breath of life”.

 

 

Thiopentone

BT_GS 1.30 Describe and compare the pharmacokinetics of intravenous induction agents …

BT_GS 1.31 Describe and compare the pharmacodynamics of intravenous induction agents …

Thiopentone is a terrific drug. Unfortunately, the current generation of trainees lack familiarity and confidence with it. 

T / F  compared with propofol, a standard induction dose of thiopentone causes less vasodilation and less hypotension

T / F  when diluted with 20 mL water, 500 mg thiopentone makes a 2.5% solution, with a pH of 11  (regarding the pH, can you explain why you think this is true or false? Why is this pH necessary / not necessary?)

T / F  in plasma, thiopentone is 80% bound to albumin

T / F  thiopentone is a weak base with pKa 7.6 Рtherefore, 12% of an injected dose will be available to cross the blood brain barrier

T / F  the majority of thiopentone is metabolised to inactive metabolites

T / F  thiopentone effectively blunts the upper airway reflexes

♦♦♦♦♦

Now that you’ve become fascinated by thiopentone, it would be useful to use this knowledge to answer some SAQ’s.

  1. Write short notes on the pharmacology of thiopentone.
  2. Compare and contrast the pharmacology of propofol and thiopentone.
  3. Explain the advantages and disadvantages of propofol and thiopentone for induction of general anaesthesia.

These 3 SAQ’s are in ascending order of complexity, in terms of the level of understanding they are testing. Regurgitating your summary notes (Q1) is low level knowledge – a candidate may score highly without really understanding what they are writing. But Q3 requires not only the application of PK and PD data – this information must be further organised to address the advantages and disadvantages. Scoring well on this question would demonstrate a high level of understanding (appropriate given the “core” nature of the drugs in question).

Have a go at answering the 3 SAQ’s above. While the 3 answers will each contain some of the same information, the final answers will be quite different. Hopefully this will help you reflect on the importance of reading the question!!

 

 

Calcium

BT_PO 1.88 Outline the regulation of plasma calcium including the actions and control of vitamin D, parathyroid hormone and calcitonin

T / F  of the total calcium in plasma, 20% is present in the free ionised form

T / F  a decrease in plasma calcium causes the release of parathyroid hormone

T / F  PTH acts by directly (i) releasing calcium from bone, (ii) increasing calcium absorption from the GIT, and (iii) decreasing renal calcium excretion

T / F  vitamin D is converted to 1,25-dihydroxy cholecalciferol by UV light, which then acts to increase calcium absorption from the GIT

T / F  hypocalcaemia can prolong the QT interval

T / F  10 mL of 10% calcium chloride contains 6.8 mmol Ca++, and 10 mL of 10% calcium gluconate contains 2.2 mmol Ca++

Extra discussion questions:

  1. Following a total thyroidectomy, patients can develop hypocalcaemia. Can you explain why? What symptoms would develop, and what physiology explains these?
  2. Patients with bony metastases can develop hypercalcaemia. What is the mechanism of this? What symptoms would develop, and what physiology explains these?

Insulin

BT_PO 1.90 Describe the pharmacology of insulin preparations …
BT_PO 1.85 Describe the control of blood glucose

T / F  the beta cells of the islets of Langerhans secrete proinsulin, which is then cleaved in the plasma to insulin

T / F  soluble insulin (Actrapid) starts working 30 minutes after S/C injection

T / F  insulin aspart (Novorapid) is more rapidly absorbed than Actrapid because it consists of only the A chain of amino acids

T / F  insulin glargine (Lantus) is slowly absorbed because the insulin is complexed with zinc and protamine

T / F  biguanides act by increasing cellular sensitivity to insulin

T / F  insulin increases the uptake of glucose into the liver, by upregulating the number of GLUT-4 transporters