BT_RT 1.17 and 1.18 Adrenaline in shock and resuscitation

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Not sure that these fit the topic, but they were beautiful and I am a sucker for a rainbow (viewed at the V&A). I think these would give you a surge of dopamine rather that adrenaline, but we will save that for another day…

The current ARC guidelines (see 11.5) provide a very minimalist approach to drug therapy in cardiopulmonary resuscitation, emphasising the importance of high quality and minimally interrupted CPR. However of the couple of drugs left, adrenaline in front and centre.

BT_RT 1.17 With reference to the management of shock, describe the pharmacology of vasopressors and inotropes, including:

adrenaline,

and lots of other drugs (click on the link to view them)

BT_RT 1.18 With reference to cardiopulmonary resuscitation, describe the pharmacology of

adrenaline,

vasopressin,

amiodarone and

lignocaine

 

During cardiac arrest, adrenaline has a role in the treatment of both shockable and non shockable rhythms     TRUE/FALSE

Adrenaline has been shown to improve the chances of return of spontaneous circulation in arrest situations   TRUE/FALSE

Adrenaline is useful in the treatment of anaphylactic shock, in part, because it prevents further mast cell degranulation  via a beta mediated response TRUE/FALSE

Adrenaline may improve myocardial blood flow in low flow states as it causes aortic diastolic pressure to rise   TRUE/FALSE

If giving adrenaline via the endotracheal tube, the dose should be increased by 10 fold TRUE/FALSE

 

BT_RT 1.2 Integrate knowledge of factors determining cardiac output to classify causes of shock

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To fit with today’s theme is this photo of Tippoo’s Tiger, on display at the V&A Museum, London. This wind-up piece has an organ inside and when the handle was turned it supposedly “imitated the European victim’s dying wails of agony” – delightful! It was found in the music room of Tipu Sultan after his death in 1799

Let’s knock off another LO before we get started on the core business of today –

BT_RT 1.1  Define shock

Shock is defined as a state where tissue perfusion is inadequate to meet the metabolic requirements of that tissue     TRUE/FALSE

Ok, now for the main event. This topic is covered quite well in Oh’s Intensive Care Manual  and Guyton and Hall Textbook of Medical Physiology – details here. I suspect it is well covered in lots of places actually 😉

BT_RT 1.2 Integrate knowledge of factors determining cardiac output to classify causes of shock

All causes of shock are associated with an absolute reduction in cardiac output    TRUE/FALSE

Cardiogenic shock occurs when the heart is unable to pump blood sufficiently to maintain perfusion      TRUE/FALSE

Neurogenic shock and anaphylaxis are both examples of distributive shock  TRUE/FALSE

Anaesthesia may cause neurogenic shock     TRUE/FALSE

Hypovolaemic shock can be used to describe any form of shock where there is inadequate venous return   TRUE/FALSE

 

And finally one last photo of the tiger and its hapless victim…

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BT_SQ 1.13 Describe and classify breathing systems used in anaesthesia (episode 2).

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I photographed this little guy in Hong Kong – he’s (or perhaps she’s??) looking bit ragged. Following yesterday’s post I did a bit of research. It tuns out that sea jellies have no breathing system at all. They meet their oxygen requirements through diffusion across their bodies….

Today we will turn our focus to the circle system. This is something most of us use every day. I asked a viva on it in the last exam and was surprised by many of the answers I was given.

The circuit is circular with unidirectional valves – does that mean that gas flows in only one direction throughout the entire system?

BT_SQ 1.13  Describe and classify breathing systems used in anaesthesia. Evaluate their clinical utility and hazards associated with their use

The circle circuit, as commonly used in current anaesthetic practice, is a closed system  TRUE/FALSE

With the standard circle arrangement, fresh gas commonly flows through the CO2 absorber   TRUE/FALSE

Placing the APL valve before the CO2 absorber (on the expiratory limb) helps to conserve the CO2 absorbent  TRUE/FALSE

When running the circle as a closed circuit, minimal gas monitoring is required, as it is a stable system        TRUE/FALSE

A safe circle system requires the fresh gas flow to be placed between the patient and the expiratory valve  TRUE/FALSE

BT_SQ 1.13 Describe and classify breathing systems used in anaesthesia.

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What sort of  breathing system do those guys have? Certainly none of the ones we will be discussing today…

Today I will focus on the Mapleson classification of breathing systems. Here is an article written about them by Mapleson himself. He is still alive and in his 90s. You can read a little more about him here. Textbooks on the ANZCA primary exam reading list generally cover this topic adequately too.

BT_SQ 1.13 Describe and classify breathing systems used in anaesthesia. Evaluate their clinical utility and hazards associated with their use

The Mapleson A circuit is more efficient for a spontaneously ventilating patient compared with Mapleson D    TRUE/FALSE

A Mapleson E circuit is also referred to as classic T-piece     TRUE/FALSE

In the Mapleson D circuit the reservoir bag is located off the expiratory limb    TRUE/FALSE

The Mapleson D circuit is more efficient for controlled ventilation (CV) compared with spontaneous ventilation, due to the longer expiratory phase with CV    TRUE/FALSE

The Mapleson C circuit is the most efficient of these systems for spontaneous ventilation TRUE/FALSE

 

SS_OB 1.12 Labetolol

At least where I work we have to fill out the Special Access Scheme form to use IV labetolol, but worldwide it is a commonly drug for blood pressure control in pre-eclampsia, and it has many advantages over hydralazine.

SS_OB 1.12 Describe the pharmacology of agents used for the treatment of pre-eclampsia including magnesium, hydralazine and labetolol

 

T/F Labetolol is a non specific alpha antagonist

T/F Labetolol is a non specific beta antagonist

T/F A beta blocker with Intrinsic Sympathomimetic Activity is particularly useful for prevention of myocardial infarction

T/F Labetolol may cause profound foetal bradycardia

T/F Cardiac output rises after intravenous but not oral Labetolol

 

BT GS 1.12 Explain and describe the clinical application of concepts related to intravenous and infusion kinetics

Admittedly, this is a rather dry topic.  It is of unequivocal importance to anaesthetists however as our practice revolves around giving drugs that have potent pharmacodynamics effects with rapid onset and offset of action.

Regarding the time to peak effect (TTPE):

Is indicated on a plasma time curve for a bolus dose where the effect site curve crosses the plasma concentration curve TRUE/FALSE

Will be relatively short for any drug that rapidly redistributes TRUE/FALSE

Will be relatively short for drugs with a large keo TRUE/FALSE

Will always be longer than the t ½ keo TRUE/FALSE

Is considered to be a dose insensitive parameter TRUE/FALSE

BT PO 1.91 Outline the pharmacology of glucagon (& other things)

glucagon

Coming in an aesthetically pleasing little orange container, glucagon is a drug anaesthetists administer infrequently. Funnily enough the most common indication that we give glucagon for has nothing to do with hypoglycaemia. Rather it is given to treat suspected spasm of the sphincter of Oddi demonstrated on an intraoperative cholangiogram when performed during a lap chole. The second most common indication in our sphere of influence is probably the management of impacted food boluses. Both of these indications relate to the smooth muscle relaxant action of glucagon.

 

Glucagon is an anabolic hormone TRUE/FALSE

Glucagon is synthesized by the alpha cells of the islets of Langerhans TRUE/FALSE

Glucagon is effective in the management of beta blocker overdose because it  firmly binds to adrenoceptors TRUE/FALSE

Glucagon is an inotrope and chronotrope TRUE/FALSE

Glucagon binds to a G protein coupled receptor and inhibits adenylate cyclase activity and thus reduces cAMP TRUE/FALSE

BT PO 1.90 Describe the pharmacology of insulin preparations

Regarding insulin:CRw26neXIAA8kW7

Insulin preparations are synthesized using recombinant technology TRUE/FALSE

If injected intravenously, long acting insulins will still have a long duration of action TRUE/FALSE

Insulins are metabolized by the liver TRUE/FALSE

Measurement of C-peptide levels can differentiate endogenous from exogenous insulin TRUE/FALSE

Glargine insulin (Lantus) forms microprecipitates when injected subcutaneously* TRUE/FALSE

 

* Lantus commonly stings when injected- my diabetic father will attest to this! This is related to its formulation. Can you hazard a guess at its pH and why it is formulated like that?

Although insulin will degrade at room temperature, it is similar to suxamethonium in that it will be retain adequate activity for well over a month if left out on your anaesthetic trolley.

BT PO 1.85 Explain the control of blood glucose

Mars-reaches-reformulation-limits-and-calls-downsizing-the-only-option_strict_xxl

A standard Mars bar (53g) contains 30g of glucose. They used to be given to pregnant women as a component of the glucose challenge test for gestational diabetes. I don’t know if this is still the case.

The glucose transporter, GLUT-4, is ubiquitous and found in most cells in the body TRUE/FALSE

Hepatic uptake of glucose is dependent on the presence of insulin TRUE/FALSE

Glucokinase phosphorylates glucose and is a pivotal enzyme in the glycolysis pathway TRUE/ FALSE

Alterations in glucose transport occur within seconds of insulin release TRUE/FALSE

Insulin has trophic and mitogenic actions TRUE/FALSE

 

A bonus question- are glucose and dextrose the same thing?

Study tip: sit the exam when you’re ready

That may seem like a ridiculously obvious statement.

However, speaking with registrars who have failed the exam, sometimes multiple times, they often say they should not have attempted the exam when they initially did.

I realise that there is an imperative, real or implied, to sit the exam as soon as possible in your training. For the majority of people it is completely feasible to prepare for, and sit the exam within the first two years of Basic Training. However as far as I can see in Regulation 37, which details the requirements for training,  you actually have at least 4 yrs to attempt it.

If you end up at a point where you really don’t think that you are ready to sit the exam, please think twice (or three or four times) before “just giving it a go”.

Now I am not talking about the feeling we all get, where you don’t feel 100% ready to sit the exam. However, you have: put in a very concerted effort with your studies; covered the syllabus; done lots of exam practice; had people review your questions and all the signs are looking good. It is normal to have the heebie jeebies.

I am talking about the situation where, for one reason or another, your exam preparation has been significantly compromised. Perhaps there was more work to do that you realised and you just didn’t leave yourself enough time. There are a myriad of other social and work related issues which can derail an attempt. You may have been avoiding giving people practice questions to look because you don’t want to look silly ( that to me is a sign you are not quite ready – much, much better to get the feedback which helps you improve before you sit the exam, not after you fail)

I would counsel you to NOT just give it a go for the experience. Wait until you are properly prepared.

We are all highly achieving individuals. It is not in our nature to fail and a lot of you will never have failed anything up until this point of your lives. Do not underestimate how psychologically devastating it is to fail something, even when you have convinced yourself you were not going to pass in the first place. I do not know one person who has felt ok with it….

Statistically, your first attempt at the exam is the one where you have by far the greatest likelihood of passing. Make it you best posssible shot – sit the exam when you are ready.

( A little birdie told me that the applications for the next exam open on Monday ……)

And finally, today’s photo is from my garden. Hope you have a lovely weekend….