Anaesthesia

Question 1

Adrenal suppression

Answer 1

Corticosteroid combined with anaesthesia can cause a dangerous fall in blood pressure

Question 2

Intravenous anasthesia

Answer 2

A topical anaesthetic can be used to reduce pain at the injection site e.g lidocaine (emlar)
Recommended dose as guide, depends on the patient
IV used to induce or maintain anaesthesia
Total intravenous anaesthesia - all drugs given IV

Question 3

Drugs used for IV anaesthesia

Answer 3

Propofol - most common not in neonates, rapid recovery, less hangover effect, can be used in intensive care

Thiopental sodium - barbiturate, no analgesia can have cardio and respiratory depression, dose related

Ketamine - side effects include hallucinations, nightmares and other psychotic effects

Question 4

Inhalation anaesthetics

Answer 4

Volatile liquids
Anaesthetics - induction or maintenance of anaesthesia then given IV

Question 5

Nitrous oxide

Answer 5

Entronox
Inhaled anaesthetic
Maintenance
Not as strong - not used alone
50/50 mix nitrous oxide and oxygen
Self administrated
Used in labour etc

Question 6

Malignant hyperthermia

Answer 6

Lethal complication, severe reaction
Rapid rise in temperature
Muscle rigidity
Tachycardia
Acidosis - acid in blood decreases pH
Most common if volatile liquid anaesthetic is used
Daritrolene used to treat

Question 7

Surgery and drugs that shouldn’t be stopped

Answer 7

Too many risks if taking meds and its easier to stop
Drugs that should normally NOT be stopped before surgery include
Anti-epileptics
Antiparkinsonian drugs
Antipsychotics
Anxiolytics
Bronchodilators
Cardiovascular drugs

Question 8

Drugs that should be stopped during surgery

Answer 8

If taking antiplatlet or oral anticoagulants STOP or switch to heparin/LMWH
Stop COC and HRT 4 weeks before major surgery
MAOI - to withdraw 2 weeks before
Lithium to be stopped before major surgery
Stop potassium sparing - risk of hyperkalaemia
ACEi / ARB or herbal meds
Diabetic drugs to be switched to insulin

Question 9

Sedation and resus in dental pain

Answer 9

Limited to conscious sedation
Diazepam or temazepam are effective anxiolytics for dental treatment in adults

Question 10

Pre medication and peri-operative drugs

Answer 10

Drugs that affect gastric pH regurgitation and aspiration of gastric contents
H2 receptor antagonists before surgery
Doesn’t affect pH, give 1-2 hours before
Pre-medicants give night before major surgery
A further, smaller dose may be required before surgery
- benzodiazepines, anxiety, sedation, short acting is best, night and morning before

Question 11

Benzodiazepines

Answer 11

Diazepam - mild sedation, drowsiness
Temazepam - shorter duration, more rapid than diazepam
Lorazepam - produces more prolonged sedation
Midazolam - water-soluble, better and quicker recovery than IV diazepam

Question 12

What is used to reverse respiratory depression in opioid use?

Answer 12

Naloxone

Question 13

What is benzodiazepine antagonist?

Answer 13

Flumazenil

Question 14

Local anaesthetic drug

Answer 14

Buphacain HCl - longer duration of action, slower onset
Levobupivacaine - isomer of bupivocapine, fewer adverse effects
Lidocaine HCl - lasts 90 mins if with adrenaline/epipherine
Phlocaine HCl - similar lidocaine
Ropivacine HCL - less toxic and effective than bupivacaine
Teracine - local for venepuncture or venous cannulation. Rapid absorption, don’t apply to inflammed surfaces

Question 15

Administration by injection

Answer 15

Dose depends on injection site, patient age, weight, physique, clinical conditions, duration
Uptake of local anaesthetics into the systemic circulation determines their duration of action and produces toxicity
NHS advice - prior to admin, draw injectable mass from ampules into syringe not be decanted to open containers. Reduce risk of contamination