NTA Level 4 • Semester 2 • PST04211

Description of General and Local Anaesthetics

Basic Pharmacology • Source Session/Topic 40

Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability.

Session 40: Description of General and Local Anaesthetics

Total Session Time: 120 minutes

Prerequisites

• None

Learning Tasks

By the end of this session students are expected to be able to:

• List indications of general and local anaesthetics

• List Contraindication of general and local anaesthetics

• Describe dose, dosage and course of general and local anaesthetics

• List side effects and adverse effects of general and local anaesthetics

• Describe interaction and precaution of general and local anaesthetics

Resources Needed:

• Flip charts, marker pens, and masking tape

• Black/white board and chalk/whiteboard markers

• Computer and overhead projector

SESSION OVERVIEW

Activity/

Step Time Content

Method

1 05 minutes Presentation Introduction, Learning Tasks

Presentation/

2 20 minutes Indications of General and Local Anaesthetics

Buzzing

Presentation/ Contraindication of General and Local

3 20 minutes

brainstorming Anaesthetics

Dose, Dosage and Course of General and

4 30 minutes Presentation

Local Anaesthetics

Presentation/ Side Effects and Adverse Effects of General

5 20 minutes

brainstorming and Local Anaesthetics

Interaction and Precaution of General and

6 15minutes

Presentation Local Anaesthetics

7 05 minutes Presentation Key Points

8 05 minutes Presentation Evaluation

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

253

SESSION CONTENTS

STEP 1: Presentation of Session Title and Learning Tasks (5 minutes)

READ or ASK students to read the learning objectives and clarify

ASK students if they have any questions before continuing.

STEP 2: Indications of General and Local Anaesthetics (20 Minutes)

Activity: Buzzing (5 minutes)

ASK students to pair up and buzz on the following question for 2 minutes

• What are the general and local anaesthetics?

• What are the indications of general and local anaesthesia?

ALLOW few pairs to respond and let other pairs add on points not mentioned

WRITE their response on the flip chart/board

CLARIFY and SUMMARIZE by using the content below

• General anaesthetics include; halothane, ketamine, isoflurane and thiopental while local

anaesthetic include lignocaine and bupivavaine

• Indication of General anaesthetics include:

o Halothane is occasionally used for inhalation induction of anaesthesia with careful

monitoring for cardiorespiratory depression and arrhythmias

o Ketamine is useful in induction and maintenance of anaesthesia it is used during

surgery and intubation

o Isoflurane is a volatile liquid anaesthetic, it is used in induction and maintenance of

anaesthesia, it is useful during surgery and intubation

o Thiopental is used in induction of general anaesthesia, anaesthesia of short duration

reduction during surgery and intubation

• Indication of Local anaesthetics include:

o Bupivacaine labour, surgery and local infiltration

o Lignocaine is used as infiltration anaesthesia, intravenous regional and nerve block,

surface anaesthesia and nerve block

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

254

STEP 3: Contraindications of General and Local Anaesthetics (20 minutes)

Activity: Brainstorming (5 minutes)

Ask students to brainstorm on the following question:

• What are the Contraindications of general and local anaesthetics?

ALLOW few students to respond

WRITE their responses on the flip chart/ board

CLARIFY and SUMMARISE by using the content below

• Contra indication of General anaesthetics;.

o Halothane is contraindicated if the anaesthetist is not confident of being able to

maintain the airway (e.g. in the presence of a tumour in the pharynx or larynx)

Extreme care is required in surgery of the mouth, pharynx, or larynx and in patients

with acute circulatory failure

o Ketamine is contraindicated if the anaesthetist is not confident of being able to

maintain the airway (e.g. in the presence of a tumor in the pharynx or larynx).

Extreme care is required in surgery of the mouth, pharynx, or larynx and in patients

with acute circulatory failure. Also in hypertension, pre-eclampsia or eclampsia,

severe cardiac disease, raised intracranial pressure, head trauma, acute and porphyria.

o Isoflurane is contraindicated to women who are breast feeding

o Thiopental is contraindicated if the anaesthetist is not confident of being able to

maintain the airway (e.g. in the presence of a tumor in the pharynx or larynx).

Extreme care is required in surgery of the mouth, pharynx, or larynx and in patients

with acute circulatory failure. Also in acute porphyria, myotonic dystrophy and

breast-feeding

• Contra indication of Local anaesthetics;

o Bupivacaine is contraindicated in hypovolemia, complete heart blockade should not

be used in solutions containing adrenaline for anaesthesia in appendages

o Lignocaine like bupivacaine, it is contraindicated in hypovolaemia, complete heart

blockade should not be used in solutions containing adrenaline for anaesthesia in

appendages

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

255

STEP 4: Dose, Dosage and Course of General and Local Anaesthetics

(30minutes)

• Dose, dosage, and course of General Anaesthetics are as follows.

o Halothane:

 Induction of anaesthesia: adult and child over 1 month are initially given 0.5%

then increased gradually according to response to 2–4%

 Using specifically calibrated vaporiser, in oxygen or nitrous oxide- oxygen

 Maintenance of anaesthesia: adult and child over 1 month, 0.5–2% using

specifically calibrated vaporiser, in oxygen or nitrous oxide–oxygen

o Ketamine:

 By intramuscular injection; For short procedures, initially 6.5–13 mg/kg, adjusted

according to response

 By intravenous injection; For short procedures, initially 1–4.5 mg/kg, adjusted

according to response

 By intravenous infusion; A solution containing 1 mg/Ml is used in longer

procedures for induction, a total dose of 0.5–2 mg/kg may be given. The

maintenance dose of 10–45 micrograms/ kg/minute is required and the rate may

be adjusted according to response

o Isoflurane:

 Induction of anaesthesia, the does is increased gradually from 0.5% to 3% using

specifically calibrated vaporiser, in oxygen or nitrous oxide–oxygen

 Maintenance of anaesthesia; is given at 1–2.5% in nitrous oxide–oxygen using

specifically calibrated vaporizer. Additional 0.5–1% may be required when given

with oxygen alone

o Thiopental:

 The dose for induction of general anaesthesia is usually 100–150 mg over 10–15

seconds as (25 mg/mL) solution by slow intravenous injection, for adult over 18

years. Children 1 month–18 years, initially up to 4 mg/kg, then 1 mg/kg repeated

as necessary (max. total dose 7 mg/kg)

• Indication of Local anaesthetics include

o Bupivacaine:

 The doses should be adjusted according to patient‘s physical status and nature of

procedure

 Local infiltration, max. 60 mL, using a 2.5 mg/mL solution

 Peripheral nerve block, max. 60 mL, using a 2.5 mg/ mL solution; max. 30 mL,

using a 5 mg/mL (0.5%) solution

 Epidural block Surgery and lumbar, max. 20 mL, using a 5 mg/mL Solution.

o Lignocaine:

 Infiltration anaesthesia, the drug is by injection according to patient‘s weight and

nature of procedure, max. 200 mg (or 500 mg if given in solutions containing

adrenaline

 The usual strength for surface anaesthesia, is 2–4%,

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

256

STEP 5: Side Effects and Adverse Effects of General and Local

Anaesthetics (20 Minute)

Activity: Brainstorming (5 minutes)

Ask students to brainstorm on the following question:

• What are the side effects and adverse effects of general and local anaesthetics?

ALLOW few students to respond

WRITE their responses on the flip chart/ board

CLARIFY and SUMMARISE by using the content below

• Side effects and adverse effects of general anaesthesia

o Halothane: Side effects include severe hepatotoxic which can be fatal in repeated uses

o Ketamine: Side effects include incidence of hallucinations, nightmares, and other

transient psychotic effects. Other side effects are tachycardia, hypertension,

arrhythmias, hypotension, bradycardia increased salivation, laryngospasm, anxiety,

insomnia, diplopia, nystagmus, raised intra-ocular pressure and rashes at injection-site

o Isoflurane: Side effects include irritation of mucous membranes causing cough,

breath-holding and laryngospasm

o Thiopental; Side effects include hypotension, arrhythmias, myocardial depression,

laryngeal spasm, cough, sneezing, hypersensitivity reactions, rash, injection-site

reactions. Excessive dose is associated with hypothermia and profound cerebral

impairment

• Side effects and adverse effects of local anaesthesia

o Bupivacaine Side effects include initially a feeling of inebriation and lightheadedness

followed by sedation, circumoral paraesthesia and twitching. convulsions can occur in

severe reactions. Also CNS effects which include confusion, respiratory depression

and convulsions hypotension and bradycardia (may lead to cardiac arrest)

o Lignocaine: same to those of bupivacaine

STEP 6: Interaction and precaution of general and local anaesthesia

(20minutes)

• Interaction

o General anaesthetics which include Halothane, Ketamine, Isoflurane and Thiopental

have the following interaction:

 Their hypotensive effect is enhanced when given with adrenergic blocker,

angiotensin ii receptor antagonists, monoamine oxidase inhibitors, tricyclic

antidepressants, beta blocker, and calcium channel blockers

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

257

 There is an increased chances of convulsion when they are given with theophyllin

especially Ketamine

 There is an increased chance of arrhythmias when given together with ocytocin

and theophyllin

• Local anaesthetics

o Bupivacaine has increased myocardial depression when given with antiarrhythmic

drugs, also bupivacaine toxicity is increased when given with beta blocker like

propranolol

o Lignocaine has no interaction or special pre caution

STEP 7: Key points (5 minutes)

• General anaesthetics are usually used in major surgical operations

• Local anaesthetics are usually used in minor surgical operations

• Ketamine should not be administered with aminophylline

• Bupivacaine and lignocaine dose should be adjusted according to length of procedure and

status of the patient

STEP 7: Evaluation (5 minutes)

• What are indications of halothane?

• Which drugs are used in general anaesthesia?

• Which drugs are used in local anaesthesia?

• What is the effects using calcium channel blocker with isoflurane?

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

258

References

Ministry Of Health and Social Welfare. (2013). Standard Treatment Guidelines & National

Essential Medicines List Tanzania Mainland (4th ed.). Dar es salaam, Tanzania

government printers.

Robert L. Talbert, Gary C. Yee, Gary R. Matzke, Barbara G. Wells, L. Michael. (2014).

Pharmacotherapy: A Pathophysiologic Approach (9th ed.). New York, McGraw-Hill

Education.

Sally S.R, Jeanne C.S. (2000). Introductory Clinical Pharmacology (6th ed) New York,

Lippincott Williams and Wilkins.

School of Pharmaceutical sciences. (2011).Tanzania Pharmaceutical Handbook (2nd ed.).

Dar es Salaam, ARDHI University press.

The Royal Pharmaceutical Society of Great Britain. (2007). Martindale, the Extra

Pharmacopoeia (5TH ed). London, pharmaceutical press.

The Royal Pharmaceutical Society of Great Britain. (2009). British National Formulary

(59th ed). London, BMJ Group and RPS Publishing.

PST 04211 Basic Pharmacology NTA Level 4 Semester 2 Facilitator Guide

259

← Previous Topic Next Topic →View all Basic Pharmacology topics Open Complete Full Notes

PDF / OFFLINE NOTES

Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP

WhatsApp: 255620339260