SS_OB 1.4 Describe the utero-placental circulation and the principles of placental physiology as related to placental gas exchange and regulation of placental blood flow.

Uteroplacental blood flow at term is approximately 1125mL/min TRUE/FALSE

The utero-placental arteries have alpha-adrenergic receptors. TRUE/FALSE

The greatest driving force for diffusion of oxygen from maternal to foetal blood is the Bohr effect. TRUE/FALSE

The Haldane effect facilitates oxygen transfer from the mother to the foetus. TRUE/FALSE

The foetus has foetal haemoglobin which has a greater affinity for oxygen than adult haemoglobin. TRUE/FALSE

Aortocaval compression

SS_OB 1.5 Describe the mechanism and consequences of aorta-caval compression in pregnancy

In supine hypotensive syndrome, blood still returns to the right heart through the epidural, azygos and vertebral veins. TRUE/FALSE

Supine hypotension is compensated by an increase in peripheral sympathetic activity. TRUE/FALSE

The blood pressure measured in the arms, is a reliable predictor of uterine and placental blood flow, when the patient is supine. TRUE/FALSE

Aortocaval compression can reduce uterine perfusion due to reduced uterine venous pressure. TRUE/FALSE

General anaesthesia has no effect on supine hypotensive syndrome. TRUE/FALSE


Obs, Obs, Baby.

SS_OB 1.6 Describe the changes in the anatomy of the maternal airway and their impact on airway management during anaesthesia.

SS_OB 1.1 Describe the physiological changes and their implications for anaesthesia that occur during pregnancy, labour and delivery.

The increased risk of airway bleeding during manipulation is primarily due to platelet dysfunction in pregnancy. TRUE/FALSE

Lung compliance decreases in pregnancy. TRUE/FALSE

Closing capacity increases during pregnancy. TRUE/FALSE

Oxygen consumption is increased at term, regardless of whether the patient is in labour or not. TRUE/FALSE

Airway oedema can occur due to venous engorgement from labour. TRUE/FALSE

Neonatal circulation

SB_OB 1.3 Describe the transition from foetal to neonatal circulation and the establishment of ventilation.

At birth, the circulation changes from parallel to in series. TRUE/FALSE

Delivery of the neonate causes a reduction in flow through the IVC to the right atrium. TRUE/FALSE

The newborn’s ventricle is less compliant than an adult’s due to a lower proportion of non contractile proteins in the myocardial cells. TRUE/FALSE

Pulmonary vascular resistance falls at birth due to decreasing pH TRUE/FALSE

The neonatal circulation can revert back to the pattern of foetal circulation if there is pulmonary vasoconstriction. TRUE/FALSE


BT_PO 1.82a  Outline basic cellular physiology, in particular …. energy production by metabolic processes in cells

BT_PO 1.83  Describe the physiological consequences of starvation


T / F  ketones are produced from the oxidation of free fatty acids

T / F  the important role of ketones is as an alternative fuel source to glucose for the brain – this decreases the protein catabolism which occurs via gluconeogenesis

T / F  lipolysis is stimulated by insulin, adrenaline, and cortisol

T / F  ketones provide a source of acetyl-CoA for use directly in the TCA cycle (structurally, ketones consist of actetyl groups)

T / F  in poorly nourished patients (frail elderly, alcoholics etc), a short period of fasting can induce starvation ketoacidosis


I’m not sure that taking ketone pills is a good idea!!

Now that you have thought about ketones….
i) find out if any of the glucometers in your hospital can also measure ketones (if not, how else could you diagnose ketosis?) 
ii) how would you treat starvation ketoacidosis in a non-diabetic?


BT_PM 1.3 Pre-emptive and preventive analgesia


Glass poppies Andy Paiko


A few weeks ago I ran a series of posts on this LO.

I ran out of steam before reaching the last of the bullet points. This was partly because the area has held so much hope from a theoretical mechanistic viewpoint but there is little strong scientific evidence to support benefit from particular clinical practice – how disappointing….

I thought it might be timely to revisit now, just before the written exam. I wish there were a rapidly acting pre-emptive analgesic, I could prescribe, to make tomorrow less painful for those of you about to sit. However, the best prescription, to make the day easier, is to have studied well and practised lots – which I am sure all of you who read this blog will have done. BEST WISHES!!

The latest edition of Acute Pain Management: Scientific Evidence has a section on this topic (I hope that link takes you there. If it doesn’t, the book is freely available here [see section 1.5]).

BT_PM 1.3  Describe the basic physiological mechanisms of pain including:

· Pre-emptive and preventive analgesia

Pre-emptive analgesia, by definition, must be given before a noxious stimulus occurs TRUE/FALSE

The aim of pre-emptive and preventive analgesia is to reduce sensitisation   TRUE/FALSE

The NMDA receptor plays an important role in central sensitisation  TRUE/FALSE

Peri-operative ketamine infusions may have a role in preventing the development of chronic post-surgical pain    TRUE/FALSE

Outcomes in this area have been muddied by fraudulent research   TRUE?FALSE

Ventilation / Perfusion (V/Q) Relationships

BT_PO 1.26 Discuss normal ventilation-perfusion matching

BT_PO 1.29 Discuss ventilation-perfusion inequalities, venous admixture and the effect on oxygenation and carbon dioxide elimination


T / F   the V/Q ratio at the apex of the upright lung is 3.3, because the apex receives most of the alveolar ventilation

T / F   in a conscious person lying on their left side, the left lung will receive more ventilation AND perfusion than the right lung

T / F   in an anaesthetised ventilated patient lying on their left side, the left lung will receive more ventilation AND perfusion than the right lung

T / F   atelectasis results in an increase in alveolar dead space, which can cause hypercapnoea

T / F   a decrease in cardiac output can decrease mixed venous PO2 – this will magnify the hypoxaemia produced by any alveolar shunt


BT_SQ 1.5 Describe basic physics applicable to anaesthesia, in particular:
…. principles of humidification and use of humidifiers ….


T / F   during quiet breathing, air reaching the carina is close to 37 degrees C and 100% relative humidity

T / F   at 37 degrees C, air can hold a maximum of 44 mg/L of water vapour

T / F   during expiration, water vapour condenses onto the airway mucosa

T / F   absolute humidity depends upon both the temperature and the atmospheric pressure

T / F   a HME can warm inspired gases to about 30 degrees C, but this takes about 20 minutes

BT_GS 1.68 Describe the physiological responses to lowered and raised environmental temperature, and the effects of anaesthesia on these responses

I have been fortunate enough to have had a recent holiday on a Japanese ski field, where the temperature was consistently about -30°C with wind chill factor. Whilst we were away, (and unfortunately since my return) the temperature in my hometown of Adelaide was well above 40°C.

Humans have a range of adaptations to enable them to cope with these widely diverse environmental temperatures. Anaesthesia has an important effect on our ability to regulate out own body temperature and the theatre environment is often a cold one (although it is all relative 😉)


The hills beyond Nozawa Onsen, Japan

BT_GS 1.68  Describe the physiological responses to lowered and raised environmental temperature, and the effects of anaesthesia on these responses

The “thermoneutral zone” is the range of body temperatures at which metabolic rate is minimal  TRUE/FALSE

Cutaneous blood flow can increase 30 fold in heat stress  TRUE/FALSE

Shivering thermogenesis DOES NOT significantly increase adult metabolic rate TRUE/FALSE

In the neonate non-shivering thermogenesis can increase the metabolic rate to twice the resting rate TRUE/FALSE

General anaesthesia doubles the size of the interthreshold range   TRUE/FALSE

Carbon dioxide carriage in the blood

BT_PO 1.32   Discuss the carriage of carbon dioxide in blood, the carbon dioxide dissociation curve and their clinical significance and implications

Most of the dissolved carbon dioxide in the blood is in the erythrocytes     TRUE/FALSE

Carbonic anhydrase is found in erythrocytes   TRUE/FALSE

Carbonic anhydrase is found in pulmonary capillary endothelium   TRUE/FALSE

As temperature decreases, there is a lower pCO2 for a given mass of CO2 in the blood   TRUE/FALSE

Reduced Hb has a tenfold ability to carry CO2 over oxyhaemoglobin   TRUE/FALSE