Remember the Primary Exam does not define you



The viva component of the exam is almost upon us again. I sincerely hope that all of you sitting over the next few days, leave the exam with a sense of calm, knowing that you have done everything you can…

Last exam sitting, I posted  The primary exam does not define you. The sentiments of the post hold true and I would encourage those of you sitting to read it.

Today, as the examiners finalise and double check their questions, I hope that you are able to spend some time doing something which brings you joy…


IT_GS 1.9 Effect of patient position

You would normally see a study tip from me on a Friday, but not this week I am sorry.

Instead another in the series of changes that can be made to normal physiology, which help test your understanding of a topic…

And returning to one of my favourite photo topics… seen at the Monterey Bay Aquarium



IT_GS 1.9 Outline the physiological changes that occur with and the implications for anaesthetic management of the following patient positions:

  • Supine
  • Trendelenberg and reverse trendelenberg
  • Lateral
  • Lithotomy
  • Prone


Trendelenburg position reduces FRC and increases the work of breathing in a spontaneously breathing patient     TRUE/FALSE

Prone positioning, per se, causes minimal cardiovascular change TRUE/FALSE

The prone position improves V/Q matching in posterior lung segments, improving oxygenation   TRUE/FALSE

Lithotomy position improves lung compliance by flattening the lumbar lordosis   TRUE/FALSE

Lower limb compartment syndrome is a rare complication of lithotomy position due to reduced perfusion pressures    TRUE/FALSE

BT_PO 1.37 The effects of ageing on the respiratory system

I have previously posted on the cardiovascular changes that occur with ageing .

Today the effects on the respiratory system. You will find all of today’s answers in Nunn’s Respiratory physiology, which covers the effects of ageing quite well.

I was searching for a fitting photo for today’s post and, not being a fan of self portraits, decided on this one… IMG_2523.JPG

…although I suspect this person was actually quite young in 79AD (seen at Pompeii)

BT_PO 1.37 Describe the effects of ageing (and many other things) on ventilation

Advanced age causes a widening of the distribution of V/Q ratios    TRUE/FALSE

Normal ageing causes a decrease in lung compliance    TRUE/FALSE

DLCO decreases linearly with increasing age  TRUE/FALSE

FRC gradually declines with age during adult life     TRUE/FALSE

Closing capacity increases with age and equals FRC in the upright position at the age of about 75 yrs    TRUE/FALSE

BT_PO 1.108 Alteration in drug response due to hepatic disease

If I want to check a registrar’s understanding of a certain topic, I will often ask about the basic physiology or pharmacology and then add a complication. This might be a disease process, a drug or an altered state of physiology. Those who have memorised an answer soon come unstuck when they are asked to apply their knowledge.

When you look through the ANZCA Primary Syllabus, such that it is, you will find a number of LOs related to these “complications”, including this one…..

BT_PO 1.108 Describe alterations to drug response due to hepatic disease

This little guy was in the case with the bears from yesterday’s photo (oh, how times have changed….)



The clearance of propofol is minimally affected by hepatic disease  TRUE/FALSE

Patients with hepatic failure have a hyper-dynamic circulation, which will protect them from the cardiac depression effects of an induction dose of propofol     TRUE/FALSE

Reduced plasma protein levels may result in a longer than expected duration of action for highly protein bound drugs     TRUE/FALSE

All volatile anaesthetic agents have been shown to decrease hepatic blood flow independent of a reduction in mean arterial pressure   TRUE/FALSE

Oral bioavailability of drug with a high extraction ratio, such as morphine, may be markedly reduced in patients with severe liver disease     TRUE/FALSE



BT_PM 1.16 Opioid dose conversion

Ok this is a bit of a weird one for the primary syllabus in my books. It could be asked in an MCQ but I don’t think it would be asked in a viva, because we all know it is virtually impossible to do mental arithmetic under pressure!

It is of practical consideration for us though and is something we do all the time, when managing patients in the post operative period.

There are various opioid conversion tables out there, including an app produced by the FPM. If you look the app, I would suggest that you look at the “practical considerations” in the information section (it is a bit hidden at the bottom of the Opioid Dose Equivalence  page)

I think this poor patient needs more of whichever opioid he has received…. Taken at the Legend of Hong Kong Toys exhibition. I hate to think what happens when you turn that toy on…..


BT_PM 1.16 Outline the dose conversion between commonly used opioids

No change in tramadol dose is required when switching from oral to s/c dosing  TRUE/FALSE

Twice as much oral compared with intravenous morphine is required to produce the same analgesic effect   TRUE/FALSE

It is easy to calculate an equipotent dose of morphine for a patient taking methadone  TRUE/FALSE

When switching a patient between one opioid and another, equipotent doses of the two drugs tend to underestimate the amount of the new opioid that will be required  TRUE/FALSE

A buprenophine patch 20mcg/hr is equipotent to a 12.5mcg/hr fentanyl patch  TRUE/FALSE

Phew – well done!

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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 it😉 –  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!

Study tip: Answering SAQs – make the most of your unconscious brain, but don’t let it fool you….

Ok, that title is a little cryptic, but bear with me….

We have probably all had experiences when we are asked to recall something which we are sure that we know (for me this is often a person’s name), but seems impossible to drag up from the depths of our brain. We give up and then the answer just pops into our consciousness. Perhaps this is your unconscious brain at work.

How can you use unconscious brain to your advantage during the SAQs? As soon as you read the questions your brain will start working on them. Make sure that you read all of the questions carefully in the first 10 minutes. Spend a bit of time carefully checking to see exactly what the question is asking, as you want to set your brain off on the right track. I will assume that you have studied well and have a good knowledge base. In spite of this, some questions may initially seem tricky: perhaps the information doesn’t spring to mind; you may not be sure how to structure the answer. That’s ok – don’t panic! Panic is shocking for your memory. Send these questions to the unconscious mind and get on with answering the questions you feel more confident with. When the time comes to answer the questions that you have set aside, hopefully your mind will have worked on them in the background and that knowledge will be easier to access.

Now for your second part – don’t let the unconscious brain fool you. This part applies to your SAQ practice. I suspect, and hope, that all of you are practising past SAQs. How do you do this? Here are some options:

  1. Do you select 6 questions at the start of your study session to write at the end?
  2. Do you choose some questions the day before to attack the following day?
  3. Have you put a whole lot of individual past SAQs in a box, from which you randomly pick a selection to look at and answer straight away?
  4. Do you have a friend/colleague put a set of questions in a sealed envelope to open and answer under exam conditions?

If you picked 3 or 4 – perfect! You are receiving a true reflection of how you could answer that question in the exam. The results may be confronting, but it will show your where a brush up is needed.

If you picked 1 or 2, I would contend that you are giving yourself an advantage that you will not have in the exam. You are giving your brain extra time to work on these questions even if you consciously try not to think about them.

There are still a couple of weeks until the next written exam. It’s not too late to give yourself some good quality SAQ practise. Any holes that you find in your knowledge should be easier to learn as this information is likely to have meaning for you.

Good luck everyone!! I am not sure that I will be back on the blog until after the written, but I wish you all of the best…..

….and just to finish, I couldn’t leave you photo free.


“Brain” jellyfish, Mljet, Croatia

BT_PO 1.36 Discuss the physiological effects of hypoxaemia

Keeping with a similar theme….

I have to admit I was feeling a bit low on inspiration as I was writing this post and was wondering which LOs would be of specific interest to you, the reader.

If you have any LOs which you would  like to see a post on, please leave a comment and I will write on them at a future date. A full list of the more than 300 options can be found here

I have updated the Oxygen Cascade post to include quite a nice little article from BJA education…

…and here is another photo from the Plitvice Lakes….


BT_PO 1.36 Discuss the physiological effects of hypoxaemia, hyper and hypocapnia, and carbon monoxide poisoning

Hypoxaemia causes activation of the sympathetic nervous system  TRUE/FALSE

Hypoxaemia causes vasodilation in all tissue beds    TRUE/FALSE

Hb concentration rises acutely with hypoxia due to auto transfusion from the spleen TRUE/FALSE

Alveolar ventilation increases linearly as PaO2 falls below normal levels    TRUE/FALSE

In response to significant hypoxia, neuronal tissue initially becomes hyperpolarised TRUE/FALSE

BT_PO 1.41 Nitric Oxide

Staying on a vaguely respiratory topic….

This little molecule is actually mentioned in two LOs, so double bang for your buck today.


But perhaps Nitric Oxide itself will give you the most bang!!

BT_PO 1.41 Outline the pharmacology of drugs used to treat pulmonary hypertension including nitric oxide

BT_PO 1.58 Describe the pharmacology of anti-hypertensive agents and their clinical application, including the following agents:

  • nitric oxide
  • plus lots of others….


Nitric oxide is synthesised from l -arginine                                   TRUE/FALSE

Nitric oxide for inhalation is stored in cylinders diluted with nitrogen   TRUE/FALSE

Nitric oxide inhibits platelet activation                                           TRUE/FALSE

Inhaled nitric oxide improves oxygenation by reducing V/Q mismatch   TRUE/FALSE

Effects of NO on the immune system are beneficial                     TRUE/FALSE


BT_SQ 1.6 Oximetry

There have been a couple of posts on this topic before, but as we were talking about oxygen, I thought it might be worth revisiting.

Here is a comprehensive review of the sources of error with pulse oximetry, following a discussion of the principles. See the link to the CinderHK page below for more information on good references.


Slightly off topic,  though I think fascinating, here is a picture of the absorption spectrum of different contaminants of glass. The glass used in long distance telecommunication fibre optic cables is ultra pure. The signal is transmitted in the IR spectrum, at about 1.5μm, such that the attenuation of the signal is only 0.2dB per km! I took this photo at the Hong Kong Science Museum.

BT_SQ 1.6 Describe the methods of measurement applicable to anaesthesia, including clinical utility, complications and sources of error in particular:

  • Oximetry
  • Plus heaps of others 😉


Pulsatile venous flow may cause an over estimation of SpO2                              TRUE/FALSE

The red:IR absorption modulation ratio (R) equals 1 at SpO2 85%                      TRUE/FALSE

Intravenous injection of indocyanine green causes a transient reduction in SpO2   TRUE/FALSE

The accuracy of SpO2 in humans has not been calibrated below 70%               TRUE/FALSE

Red nail polish is likely to cause inaccurate SpO2 readings                                  TRUE/FALSE