Basic Sciences - Premedication

Question 1

Indications for pre-medication

Answer 1

Anxiolytics
Pre-emptive analgesia
Reduce acid aspiration risk
Continuing medication for chronic disease

Question 2

When to administer temazepam for pre-medication

Answer 2

1 - 2 hours prior to surgery

Question 3

Metabolism and excretion of temazepam

Answer 3

Metabolised in liver
Excreted by kidneys

Question 4

Usual dosing of temazepam

Answer 4

10-20 mg

Question 5

Usual dosing of lorazepam

Answer 5

1-2 mg

Question 6

Goal of pre-medication in reflux disease in elective surgical patients

Answer 6

Increase gastric pH
Reduce gastric volume

Question 7

Pre-medication options for acid aspiration risk

Answer 7

Antacids
PPIs / H2 receptor antagonist
Metoclopramide

Question 8

Role of antacids

Answer 8

Increase stomach pH but no effect on volume

Question 9

Duration of action of antacids

Answer 9

Limited duration of action
Therefore limited value during emergence when still aspiration risk

Question 10

Role of PPIs / H2 antagonists

Answer 10

Increase gastric pH and reduce volume of gastric acid

Question 11

Role of metoclopramide in premedication

Answer 11

Increases gastric emptying to reduce gastric volume

Question 12

Potential side effects of NSAIDs

Answer 12

GI irritation
Asthma exacerbation
Renal dysfunction
Platelet function

Question 13

NSAIDs effect on platelet function

Answer 13

Aspirin - irreversible platelet dysfunction

All other NSAIDs - only affect platelet function while their plasma concentrations are effective

Question 14

Mechanism of action and side effects of NSAIDs description

Answer 14

Cyclo-oxygenase (COX and COX-2) inhibition (plays role in inflammatory response and prostaglandin production)

Reduces prostaglandin production
Therefore lose their protective effects on stomach and kidneys

Question 15

Mechanism of action and side effects of NSAIDs flowchart

Answer 15

Question 16

Classification of thromboprophylaxis risk

Answer 16

Question 17

Thromboprophylaxis risk factors

Answer 17

Question 18

Medications to omit prior to surgery, timing and reason why

Answer 18

ACEi / ARBs - stop morning of surgery, profound refractory hypotension during GA (continue all other antihypertensives / anti-anginals)

Warfarin - stopped 5-7 days prior with INR check and may need heparin bridging

Clopidogrel - stop 5-7 days prior

Oral contraceptive, ideally 6 weeks prior due to VTE risk

Question 19

Options for diabetic insulin management perioperatively

Answer 19

VRII

Alberti regimen

Question 20

Alberti regimen for diabetic insulin control perioperatively

Answer 20

Addition of actrapid insulin to intravenous dextrose fluids.

The amount of insulin added can be varied. The standard is 10% dextrose with ten units of actrapid and 1 g of potassium in 500 ml.

Blood sugar and potassium is measured every two hours and either add more insulin or omit insulin in next bag

Question 21

Short acting oral hypoglycaemic agents

Answer 21

Gliclazide
Repaglinide

Question 22

Long acting oral hypoglycaemic agents

Answer 22

Glibenclamide
Metformin
Glipizide
Rosiglitazone