BT_RT 1.14 Discuss cerebral perfusion pressure

T/F  cerebral perfusion pressure = mean arterial pressure – intracranial pressure

T/F  cerebral perfusion pressure is the only determinant of cerebral blood flow

T/F  PEEP can decrease cerebral perfusion pressure

T/F  after traumatic brain injury, the recommended range for cerebral perfusion pressure is 60-70 mmHg (see reference 2)

T/F  sevoflurane may decrease CPP, but increase CBF

T/F  the cerebral circulation has minimal sympathetic innervation

References:

  1. Miller 8th edition, Chapter 17
  2. Brain Trauma Foundation. Guidelines for the management of severe traumatic brain injury, 4th edition. 2016, page 181

BT_PO 1.69 Describe the physiological effects and clinical assessment of renal dysfunction

Late, AND only 4 today. They range from a simple fact (in Hemmings and Egan), through to more complex statements. Statement 4 is TRUE, more important is that you know why.

Neonates have a higher serum potassium due to poor renal excretion  TRUE/FALSE

Urea concentration is a measure of renal function independent of hepatic function  TRUE/FALSE

Creatinine is a reliable indicator of renal function in an 80 year old TRUE/FALSE

Positive pressure ventilation contributes to intra-operative oliguria  TRUE/FALSE

 

BT_PO 1.115 Describe blood groups and methods of cross matching blood

I wish the weather here were a bit more like this today…..

I just noticed that there is no post for today – sorry. It may just be be that time of the year…

So you are not left high and dry, a quick one from me today. The Australian Red Cross has some excellent materials on this topic. Here is a section of pre transfusion compatibility testing. The Red Cross also has a good section on who can receive which products. This is clinically important stuff.

BT_PO 1.115 Describe blood groups and methods of cross matching blood

A serological crossmatch involves the patient’s serum being exposed to donor red blood cells T/F

Major ABO incompatibilities require only a short exposure between plasma and red cells to produce haemolysis T/F

In Australia, all crossmatching requires a sample of the patient’s serum to be exposed to the donor red blood cellsT/F

An O negative patient is a universal donor for red blood cellsT/F

An O negative patient is a universal donor for plasma components (eg FFP) T/F

The compatibility between donor platelets and the recipient is of no clinical significance T/F

BT_PO 1.103 Describe the storage, synthetic, metabolic, immunological and excretory functions of the liver and identify the physiological consequences of hepatic disease

T/F  liver failure can result in hypoglycaemia due to limited / absent –  (i) glycogen storage and (ii) gluconeogenesis

T/F  liver disease can result in coagulopathy, because the liver produces all of the clotting factors

T/F  Kupffer cells are macrophages which line the hepatic sinusoids – with severe liver disease these may be absent, placing the patient at risk of sepsis from GIT flora

T/F  biliverdin (from haem breakdown) undergoes active transport into hepatocytes where it is metabolised to bilirubin – this is why liver disease can produce jaundice

T/F  one cause of hepatic encephalopathy is high ammonia levels – this results from impaired conversion of nitrogenous compounds (derived from protein), to urea. Lactulose is used in patients with encephalopathy because it decreases intestinal ammonia production.

T/F  portal hypertension leads to intestinal wall oedema, which reduces the absorptive capacity of the GIT

T/F  (not in the primary exam) gynaecomastia occurs in men with chronic liver disease because the free oestrogen : testosterone ratio is altered by a reduction in sex-hormone binding globulin

References
1. Miller 8th edition, Chapter 22
2. Kam and Power 3rd edition, Chapter 6

BT_SQ 1.17 Discuss the safety of methods for maintaining body temperature during anaesthesia and sedation, including active warming of patients

T/F  patients being actively warmed during anaesthesia must have their core temperature continually monitored (see ANZCA PS 18)

T/F  a simple layer of insulation can reduce heat loss by approximately 30% – there is no clinically important difference between insulation types (cotton blanket, surgical drapes, plastic sheet, ‘space’ blanket)

T/F  mattresses containing circulating warm water are nearly ineffective, because there is very little capillary blood flow through the posterior skin surface

T/F  compared with an obese adult, in a frail thin adult, there is a greater risk of intraoperative hypothermia, and a greater risk of over-heating with forced air warming devices

T/F  forced air warmers cannot cause skin burns because the maximum air temperature is 43 degrees C

T/F  forced air warmers should not be turned on until after surgical draping is complete, because they blow germs around the theatre **

T/F  ‘space’ blankets are highly flammable (click here)

References
1. ANZCA PS 18
2. Miller 8th edition, Chapter 54

** is there any actual evidence for or against this statement?

BT_RT 1.6 Describe the physiological basis of anaphylactic and anaphylactoid reactions

Agasgal has previously posted on these topics.

https://primarydailylo.wordpress.com/2018/05/31/bt_rt-1-6-describe-the-physiological-basis-of-anaphylactic-and-anaphylactoid-reactions/

https://primarydailylo.wordpress.com/2018/09/11/bt_po-1-128-describe-the-immunological-basis-and-pathophysiological-effects-of-hypersensitivity/

She also mentioned NAP6 https://www.nationalauditprojects.org.uk/NAP6home

The UK National Audit Projects have provided us with some invaluable information courtesy of their size and widespread buy in by the UK anaesthetic community. This is particularly helpful when you look at important adverse outcomes which are quite uncommon. NAP6 looked at perioperative anaphylaxis and the results came out earlier this year. If you don’t look at anything else look at the one page infographic summary. NAP7 will look at perioperative cardiac arrest. Our College’s ANZAAG have developed an online module which can be done to complete the anaphylaxis activity for the emergency CPD module.

Although NAP6 is undoubtedly important it hasn’t made its way to any of the textbooks yet- but it will. I am going to be proactive and ask a few questions relating to its findings as well as the content of the ANZAAG module.

T/F anaphylaxis is the leading cause of death directly related to anaesthesia

T/F the incidence of anaphylaxis in NAP6 was 1 in 10,000 anaesthetics

T/F the single worst offender for causing anaphylaxis in the UK was teicoplanin

T/F IM adrenaline should be administered as first line therapy for low grade anaphylaxis responses

T/F tryptases should be taken at 1, 2 and 4 hours post event.

T/F Noradrenaline, vasopressin and glucagon are recommended for use in refractory anaphylaxis

The top three causes of anaphylaxis in Australasia are antibiotics, muscle relaxants and what?

 

BT_PO 1.84 Discuss the factors that influence metabolic rate

Palm Cove, QLD

Just a short one from me today…

Guyton and Hall Texbook of Medical Physiology Ch 73 has a good chapter on metabolic rate

BT_PO 1.84 Discuss the factors that influence metabolic rate

Males have a higher metabolic rate than females for a given weight T/F

Basal metabolic rate declines with advancing age T/F

Environmental conditions have no effect on basal metabolic rate T/F

Eating a carbohydrate rich meal increases metabolic rate more than eating a protein rich meal T/F

Growth hormone and thyroxine both increase metabolic rate T/F

BT_PO 1.24 Describe the alveolar exchange of oxygen and carbon dioxide

T/F  oxygen and carbon dioxide are exchanged on a 1:1 basis across the alveolar-capillary membrane *

T/F  the diffusion of oxygen from alveoli to blood occurs down an average partial pressure gradient of approximately 110 mmHg (150 – 40)

T/F  the diffusion gradient for oxygen is greater in basal alveoli, compared with apical

T/F  carbon dioxide diffuses less readily than oxygen through the alveolar-capillary membrane, because its molecular weight is higher

T/F  at altitude, or with lung disease, the transfer of oxygen can become diffusion limited when the cardiac output increases

T/F  If an aircraft at 36,000 ft depressurised, the alveolar PO2 would be below mixed venous PO2 (i.e. the diffusion gradient for O2 would be reversed), so breathing would actually excrete oxygen from the body. Therefore, you should hold your breath until your oxygen mask is on.

* this statement was confidently made by an SRMO at an ALS course I attended

BT_PO 1.72 Phosphate

I wonder whether any of these potions contain phosphate? (Warner Bros Studios, UK)

We can’t let the cations have all the fun! Interestingly, phosphate it the only anion singled out in the LOs ( I thought chloride may have been there too…)

Again Chapter 59 in Miller’s Anaesthesia is good for this topic.

BT_PO 1.72 Describe the function, distribution and physiological importance of sodium, potassium, magnesium, calcium and phosphate ions

Phosphate is the most abundant intracellular anion T/F

The majority of phosphate is found within bone T/F

Phosphate is essential for the production of 2,3 DPG T/F

Phosphate is freely filtered at the glomerulus T/F

High parathyroid hormone levels enhance renal phosphate reabsorption T/F

The phosphate buffer system is more important in extracellular fluid than intracellular fluid T/F

The phosphate buffer system has a pKa of 6.8 T/F

Magnesium

Daylesford, Victoria – a place with abundant mineral springs, some high in Magnesium

I’m on an electrolyte role! Today, Magnesium – important both physiologically and pharmacologically.

The therapeutic benefits of Magnesium have been known for at least 400 years, when Epsom Salts (MgSO4) were first discovered to have a laxative effect!

Miller’s Anaesthesia Ch59 is an excellent resource on electrolytes.

BT_PO1.72 Describe the function, distribution and physiological importance of sodium, potassium, magnesium, calcium and phosphate ions

BT_PO 1.57 Describe the pharmacology of antiarrhythmic agents and their clinical applications including magnesium (and lots more)

SS_OB1.12 Describe the pharmacology of agents used for the treatment of pre-eclampsia including magnesium, hydralazine and labetolol

Magnesium is largely an extracellular ion T/F

Magnesium acts as a physiological calcium antagonist T/F

Magnesium is a co-factor for the production of ATP during oxidative phosphorylation T/F

Hypermagnesaemia predisposes patients to Torsades de Pointes T/F

A Mg2+ ion blocks the open NMDA receptor channel at normal RMP preventing ion flux T/F

Magnesium causes smooth muscle relaxation throughout the body T/F

Magnesium has class I and class IV anti-arrhythmic effects T/F