BT_RT 1.8 Blood Storage

There are six¬†LOs on transfusion physiology, and nine SAQs on the college website. That is more than Inhalational Agent Pharmacokinetics ūü§∑ūüŹĽ‚Äć‚ôāÔłŹ

BT_RT 1.8 Outline the changes that occur in stored blood

TRUE/FALSE  Granulocytes loose their antigenic properties within 4-6 hours of collection
TRUE/FALSE Plasma K+ concentration reaches approximately 30mmol/L at 28 days
TRUE/FALSE Factor VIII levels decrease to 50% at 21 days
TRUE/FALSE 10-20% of red cells transfused at maximum storage time are destroyed within 24 hours
TRUE/FALSE 2,3 DPG levels fall by 95% within 14 days of collection

BT_PO 1.131 Antibiotic Prophylaxis

People sometimes regard antibiotics as being non-core knowledge for the primary. Given that they are one of the drugs we use most commonly, this view is unwarranted.

BT_PO 1.131 Explain the principles of antibiotic prophylaxis

TRUE/FALSE Clindamycin may cause foetal toxicity if given before delivery at Caesarean Section
TRUE/FALSE A positive Coombs reaction with cephalosporins is associated with haemolysis in 10-20% of patients
TRUE/FALSE Cefazolin provides better prophylaxis than cephalothin because it has slower renal excretion
TRUE/FALSE First generation cephalosporins are microbials of choice for uncomplicated genitourinary procedures
TRUE/FALSE Single dose antibiotic prophylaxis is the second most common cause of in hospital microbial resistance

BT_GS 1.48 Regional Circulation

Back to some core pharmacology today ūüôā The link is to inhalational effects, although this LO itself is quite broad, and would cover a multitude¬†of agents.

BT_GS 1.48 Describe the effects of anaesthetic agents on regional circulation

TRUE/FALSE Nitrous oxide has similar vasodilating effects to sevoflurane
TRUE/FALSE Desflurane abolished autoregulation of cerebral blood flow at 0.7 MAC
TRUE/FALSE Sevoflurane reduces pulmonary vascular resistance
TRUE/FALSE Sevoflurane should not be used above 1.3 MAC because of the risk of coronary steal
TRUE/FALSE Sevoflurane causes a dose dependent decrease in hepatic arterial blood flow

BT_SQ 1.3 Anaesthetic Machines

It seems that we haven’t¬†done equipment for a while either.

BT_SQ 1.3 Outline the mandatory safety requirements for anaesthetic machines. Refer to College professional document T3: Minimum Safety Requirements for Anaesthetic Machines for Clinical Practice.

 

TRUE/FALSE A fresh gas outlet must have a standard 22mm, 15mm or 8.5mm connector compliant with ISO 5356.
TRUE/FALSE An anaesthetic machine must contain an integral high pressure relief valve to prevent high pressures in the breathing system
TRUE/FALSE The scavenging connector to the circuit must be a 22mm tapered conical fitting compliant with ISO 5356
TRUE/FALSE An anaesthetic machine which requires electrical power must have a backup power supply which permits normal operation for at least 20 mins
TRUE/FALSE The emergency oxygen flush must have a locking feature to facilitate use in airway emergencies

 

O2 Flush Boyles1.png

SS_PA 1.1 Paediatric Airway Anatomy

Oops, looks like we haven’t had any anatomy for a while.

SS_PA 1.1 Describe the anatomy of the neonatal airway, how this changes with growth and development and the implications for airway management

TRUE/FALSE Under extension of the neck may cause airway obstruction in the neonate

TRUE/FALSE Over extension of the neck may cause airway obstruction in the neonate

TRUE/FALSE Infants are obligate nasal breathers

TRUE/FALSE Neonates have a large tongue in comparison to the oropharynx

TRUE/FALSE Infants are unable to breathe via the mouth

Study Tip: Answering an SAQ

As you know, the marks from the SAQs are now more highly weighted. Historically, people have focused a lot on polishing their vivas, and paid comparatively little attention to the SAQs.

The good news is therefore: You may find it relatively easy to pick up a few more marks in the SAQs if you spend some time preparing for them specifically.

Some tips

The SAQ is marked using a marking scheme. Once you make a point, you will get the mark. Don’t repeat yourself. No matter how many times you say the same thing, you still only get that mark.

Answer the question, the whole question and nothing but the question. If in doubt, however, err on the side of answering a bit more broadly.

The questions often address complex issues. Don’t be tempted to give a medical student answer. DO NOT try to guess the examiner’s personal preference. Explain what the issues are, and if appropriate, the benefits and drawbacks of a technique.

Don’t ignore obvious answers. There is probably a mark for stating¬†them.

Don’t be vague. Almost every drug is metabolised in the liver.¬†If there is something important about its liver metabolism, then say so: Is the enzyme inducible, does it show genetic variability, are the metabolites active?

Don’t define standard abbreviations. Do define non standard ones.

Useenoughwhitespacethattheexaminercanfindyouranswer. Remember that the examiner is¬†looking for the points in the marking scheme. Don’t camouflage them.

These are¬†not essay questions. Write enough that it is obvious that you have made the point, and try to set the points out in such a fashion that the points¬†are easy to find. Don’t waste too much time on formatting though.

You often find people writing bizarre sweeping¬†statements such as, “Sevoflurane is too dangerous to use, better to use propofol”. Be guided by what you see in clinical practice. If a drug is in use, there is obviously a reason for it. If it is no longer used, again there will also be a reason.

What to do if you are really stuck

If a question has caught you out, try this approach.

  1. Write down a fact that relates to the question.
  2. Look at the question, and check that the fact is actually relevant.
  3. Repeat
  4. When you get to 15 facts, move onto the next question.

 

Tips for practising

Realising that the questions are marked using a marking scheme:

  1. Go through the past questions, and make up a marking scheme for each question.
  2. Write this scheme down on a card, so you can easily revise it.
  3. You should have at least 15 points in your scheme. Most marking schemes will have several times this. If the topic is in the detailed knowledge group, look for at least 30-40 points.
  4. Not all points will be equally important, and probably won’t¬†have time to write all the points in 10 minutes. Make sure you know which are the vital ones that you must include. You can always leave space to fill in the minutiae if you have time at the end.
  5. The question you get in the exam may be slightly different to the one you have practised. In this case, make sure you get down the points most relevant to answering the question.
  6. Once you have finished this process, look for variations on past questions. If you have seen a question on functions of the liver, consider related ones, such as functions of the lung or the kidney.
  7. Look through all the past viva opening questions, think about how they could be made into an SAQ, and write a relevant marking scheme.

Make sure you also practise answering the questions under exam conditions!

BT_SQ 1.6 CO2 Analysis

Back to an old favourite LO ūüėČ

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

TRUE/FALSE The 90-95% response time for a CO2 analyser should be less than 150ms
TRUE/FALSE Volatile agents can be distinguished from each other by measuring infrared absorbance at 3.3¬Ķm
TRUE/FALSE Collision broadening means that the absorption peak for CO2 at 4.3¬Ķm is made wider in the presence of Nitrous Oxide
TRUE/FALSE Infrared analysers measure gas concentration rather than partial pressure
TRUE/FALSE Water is a powerful absorber of infrared light

A couple of follow on questions:

  1. Why is the 90% response time important in a CO2 analyser? The answer is related to what you have learned about requirements for invasive pressure monitoring.
  2. What is the device in the picture below? What is it used for? How does it work?

img_4087

BT_PO 1.60 : Digoxin

Describe the pharmacology of drugs used to manage acute or chronic cardiac failure, including: sympathomimetics, phosphodiesterase inhibitors, digoxin, diuretics, ACE inhibitors, nitrates and beta blockers

 

A guest post from an ex PEX chair :

Agatha Christie knew a lot about poisoning, probably as a result of working with a pathologist.  (https://bookshop.theguardian.com/catalog/product/view/id/323440/).  After reading this book, you would have to be brave to go into an English garden.
   
One of her garden poisons was foxglove, which made me think of digoxin.   As did the recent death of Miles Vaughan Williams, who classified anti arrhythmics.   So often we see digoxin toxicity in clinical practice.     An old drug, but one that continues to be used, and is loved by examiners because it allows for candidates to demonstrate  an understanding of many different facets of pharmacology.    

TRUE/FALSE  Digoxin is highly protein bound, hence the introduction of another highly protein bound drug is likely to precipitate toxicity

TRUE/FALSE  Digoxin is primarily excreted renally, and frequently patients who are prescribed digoxin may have borderline or impaired renal function which may precipitate toxicity

TRUE/FALSE  Overdosage of digoxin may be treated using Digibind (R)  which is an example of an immunoglobulin which binds to digoxin to cease its therapeutic effect

TRUE/FALSE ¬†Hypokalaemia is frequently seen in digoxin toxicity, reflecting digoxin’s inhibition of the Na/Ca pump

TRUE/FALSE  The bioavailability of digoxin is reasonably high (approx 70%) allowing for oral loading doses to be only slightly slower in reaching therapeutic effects compared with intravenous loading doses

BT_SQ 1.6 : measurement of blood pressure

And another guest post (yesterday’s post by this guest accidentally came up on 13 December – scroll back for more on resonance and damping if you missed it) :

Once again I was with my registrar with the expert knowledge of physics waiting for the cardiothoracic registrar to take down the mammary.¬† It was as though time stood still.¬†¬† We were both looking at the clock, and reminiscing on the wonderful mechanics of (non digital) clocks.¬† She commented to me in passing “I do miss the slow natural frequency of the pendulum of a grandfather clock” which made me consider the fast swinging pendulum of a cuckoo clock.¬†¬† Needless to say, my mind turned to the concept of natural resonance frequencies in invasive pressure monitoring systems, and I thought back to the days of my music lessons…

TRUE/FALSE  The natural resonant frequency of a system is proportional to the stiffness or tension in the system, and inversely proportional to the mass.

TRUE/FALSE  As in tightening a violin or guitar string, increasing the stiffness or tension will lead to an increase in the natural resonant frequency (a higher note on the instrument)

TRUE/FALSE  Like the pendulum of a grandfather clock being slower than that of a cuckoo clock on the wall, the pulmonary artery tracing on the monitor is not as good as the arterial system, as the pulmonary artery system has a much longer system and as such more mass and a lower natural frequency

TRUE/FALSE  The ideal system for an arterial monitoring system has a large length and very stiff tubing to ensure that its natural frequency is close to the frequency of the system being monitored

TRUE/FALSE  The ideal frequency for a pressure monitoring system is determined by the pressure range being measured, rather than by the frequency of the system.