Another cool book that should be on the ‘Recommended Texts for the Primary’ list

9781905237166-us

Most people don’t find pharmacokinetics particularly palatable. This book is arguably one of the most enjoyable ways you can learn about pharmacokinetics. This book doesn’t just entertain but it also gives you a sound understanding of PK concepts as they relate to the practising anaesthetist. It is under 200 pages and can be read in a day. It is fairly non PC which accounts for half its charm. Nothing in there about TCI sadly.

Addendum by woundedwildebeest… I got to see this post when it was a draft and bought the book. I definitely second this recommendation. Funny, educational, with even a dramatic twist on the last page. I’d suggest reading a chapter at a time and applying it in theatre before moving on to the next.

The Lower Oesophageal Sphincter

One of the body’s most under-rated sphincters…

BT_PO 1.107

Explain the:

  •   Physiology of swallowing
  •   Factors preventing reflux of gastric contents into the oesophagus
  •   Control of gastric motility and emptying
  •   Composition of gastric fluid
  •   Physiology of nausea and vomiting

General anaesthesia reduces lower oesophageal sphincter tone. TRUE/FALSE

Cricoid pressure reduces lower oesophageal sphincter tone. TRUE/FALSE

Suxamethonium reduces lower oesophageal sphincter tone. TRUE/FALSE

The lower oesophageal sphincter is a physiological sphincter, primarily due to the oblique gastro-oesophageal angle. TRUE/FALSE

Relaxation of the lower oesophageal sphincter after swallowing is neurally mediated. TRUE/FALSE

 

BT_PO 1.116 composition, indications and risks of blood products

These questions relate to Fibrinogen:

Q. Is designated by the Roman numeral II.  TRUE/ FALSE

Q. Is the predominant clotting factor found in Prothrombinex.  TRUE/ FALSE

Q. Is the predominant clotting factor found in the circulation.  TRUE/ FALSE

Q. Has a reduced concentration in the pregnant individual.  TRUE/ FALSE

Q. Is a Vitamin K dependent clotting factor.  TRUE/ FALSE

 

Methoxyflurane

BT_PM 1.9

Describe the pharmacology of the following agents applicable to pain management, including:

  •   Opioids
  •   Tramadol
  •   Local anaesthetic agents (also refer to the Regional and local anaesthesia clinical fundamental)
  •   NSAIDs
  •   Paracetamol
  •   NMDA antagonists
  •   Anticonvulsants
  •   Antidepressants
  •   Corticosteroids
  •   Inhalational analgesics – nitrous oxide, methoxyflurane

Methoxyflurane has a risk of nephrotoxicity and hepatotoxicity TRUE/FALSE

Methoxyflurane can be used in paediatric practice TRUE/FALSE

Methoxyflurane is safe in patients with Malignant Hyperpyrexia. TRUE/FALSE

The “Penthrox” inhaler dispenses 2-4% methoxyflurane. TRUE/FALSE

A large proportion of the inhaled methoxyflurane that is taken up by the body is removed from the body by exhalation. TRUE/FALSE

Queen’s Birthday Special

It seems serendipitous that last week’s posts were obstetric related and today is the Queen’s Birthday holiday…

Queen Victoria was a relatively early adopter of anaesthesia and received chloroform anaesthesia for the birth of her 8th and 9th children, Leopold in 1853 and Beatrice in 1857. The chloroform was administered via an open drop technique, during the second stage of labour, with the aim of achieving semi-consciousness. The Queen is quoted as saying the chloroform was “soothing, quieting and delightful beyond measure”

 


It was James Simpson who, in 1847, first suggested the use of anaesthesia for labour. Initially obstetricians were almost universally opposed to the use of anaesthesia for labour, citing it as unnecessary for a natural process and concerned for the safety aspects.

John Snow, who anaesthetised Queen Victoria on both occasions, was a physician with a career spanning interest in anaesthesia. He experimented widely, on animals, using different inhaled substances in an attempt to find superior anaesthetic agents. He realised that the volatility of an agent declined as it was vaporised , due to the drop in temperature. Consequently he developed and early vaporiser, with a brass chamber which was immersed in water, to minimise temperature fluctuations. He appears to have been a man of great scientific rigour, which likely inspired confidence amongst the Queen’s physicians and eased the path for her to receive anaesthesia, when she and Prince Albert requested it. He was also a strong proponent of a doctor separate to the surgeon administering the anaesthetic. One of his major works On Chloroform and Other Anaesthetics and their Administration was published following his death is 1858. If you click on the title it will take you to a copy of the book, with William Morton’s name handwritten across the top!

John Snow made another great contribution to medicine as an epidemiologist. He was a believer that cholera was transmitted by contaminated water, contrary to popular belief at the time. Following an outbreak in London in 1854, he conducted an extensive epidemiological investigation tracking the details of victims and non victims to identify where they sourced their water. He identified the likely source as a pump on Broad Street, Armed with his research, he went to town officials and convinced them to remove the pump handle, making it impossible to draw water from the pump. The outbreak stopped almost instantly! It wasn’t until 1883 that Vibrio cholerae was isolated by Robert Koch and the means of transmission confirmed.

John Snow died age 45. Just imagine what he might have contributed to our speciality ( and others) if he had lived a long life……

John_Snow

Labour physiology and pharmacology

SB_OB 1.9 and SB_OB 1.8

Describe the influence of pregnancy on the pharmacokinetics and pharmacodynamics of drugs commonly used in anaesthesia and analgesia

Describe the anatomy and physiology of pain in labour and childbirth

 

Paracetamol is a category A drug in pregnancy, but care should still be taken in patients with pre-eclampsia. TRUE/FALSE

The addition of lipid-soluble opioids to lumbar epidurals allows a reduction of local anaesthetic concentration. TRUE/FALSE

Visceral pain receptors located in the lower uterine segment and cervix extend to the spinal segments of S2-S4. TRUE/FALSE

Oxygen consumption increases by 40% during the first stage of labour. TRUE/FALSE

 

Entonox side effects include maternal sedation. TRUE/FALSE.

Wednesday is always a good day for primary revision.

SS_OB 1.4 … again.

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

The primary limitation to carbon dioxide transfer across the placenta is blood flow. TRUE/FALSE

Maternal-fetal exchange of most drugs and other substances occurs primarily by diffusion TRUE/FALSE

Foetal O 2 saturation does not exceed 40% even with 100% O 2 delivery to the mother. TRUE/FALSE

The placenta synthesises progesterone from cholesterol. TRUE/FALSE

O 2 delivery to the fetus is facilitated primarily because the fetal oxyhemoglobin dissociation curve is righ-shifted. TRUE/FALSE.

Obstetric Week

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.

Pregnant women have normal peripheral sympathetic nervous system activity. TRUE/FALSE

Uterine blood flow in the non pregnant state is 700mL/min. TRUE/FALSE

Increased maternal systemic resistance can lead to increased placental blood flow at term. TRUE/FALSE

A “normal” blood pressure reading in a supine (term) pregnant woman’s arm is a reliable indicator of uterine perfusion pressure. TRUE/FALSE

If there is no maternal hypotension then neuraxial blockade does not alter uterine blood flow. TRUE/FALSE

Obstetrics and the primary exam

SS_OB 1.1

Describe the physiological changes and their implications for anaesthesia that occur during pregnancy, labour and delivery, in particular the respiratory, cardiovascular, haematological and gastrointestinal changes.

SB_

Normal physiological changes begin in the first trimester of pregnancy. TRUE/FALSE

The largest increase in cardiac output in a pregnant woman occurs immediately after delivery. TRUE/FALSE

The closing capacity in normal pregnancy does not change. TRUE/FALSE

Gastrin is secreted by the placenta TRUE/FALSE

Progesterone from the gestational sac may cause changes in the renin-angiotensin-aldosterone system in the first trimester, promoting sodium absorption and water retention. TRUE/FALSE

Hats off to those of you who sit this exam pregnant!