General Anaesthesia Short Answers
Question 1. Actions of nitrous oxide.
Answer:
Nitrous oxide is a colourless, odourless, non-inflammable gas.
Nitrous oxide Actions:
- A moderate increase in pain threshold.
- Slight amnesia effect
- Euphoria is frequent
- Decreased sense of Smell.
- improved hearing.
- Slight myocardial depression.
- Minimal effect on respiration.
Pharmacology II Short Answer Questions
Question 2. Diazepam. Diazepam uses.
Answer:
- To induce conscious sedation in small repeated doses or by slow infusion.
- Sedative hypnotic.
- Anxiety.
- Centrally acting skeletal muscle relaxant
- Combined with analgesic for the treatment of rheumatic disorders.
- Antiepileptic drugs.
Question 3. Ketamine.
Answer:
Ketamine induces dissociative anaesthesia characterized by profound analgesia, immobility, amnesia, light sleep and a feeling of dissociation from one’s own body and surrounding.
Ketamine Site of action:
- Cortex and subcortical areas.
Ketamine Dose:
- 1-2 mg/kg slow IV or
- 10 mg/kg IM
- The onset of action -1 – 3 min.
- Recovery – After 10-15 min.
Pharmacology II Short Answer Questions
Ketamine Indications:
- Surgery of head and neck.
- Children.
- Asthmatic patients.
- For short operations.
- in patients who do not want to lose consciousness.
Ketamine Contra-indications:
- Hypertensives.
- ischaemic heart disease.
- Pregnancy.
- increased intracranial tension.
- Psychiatric disorders.
Question 4. Methohexitone.
Answer:
Methohexitone is a more potent and shorter-acting thiopentone congener.
- It is more rapidly metabolized.
- It has quick and brief actions.
- Induction – in 15 – 30 sec.
- Recovery – within 2 – 3 min.
Methohexitone Actions:
- Less hypotensive
- Slight increase in heart rate
- Moderate hypoventilation.
Methohexitone Contra/Indication:
- Epileptic patients.
Question 5. Thiopentone sodium.
Answer:
Thiopentone sodium is ultra short-acting thiobarbiturate.
Thiopentone sodium The onset of action:
- 15-20 sec when given intravenously.
Thiopentone sodium Duration of action:
- 4 – 7 min.
Pharmacology II Short Answer Questions
Thiopentone sodium Properties:
- Highly soluble in water.
- Prepared freshly before injection.
- Highly lipid soluble.
- Poor analgesic.
- Weak muscle relaxant
- Extravasation of solution causes intense pain, necrosis and gangrene.
Thiopentone sodium Adverse effects:
- Laryngospasm.
- Shivering and delirium.
Question 6. Propofol.
Answer:
it is an oily liquid employed as a 1% emulsion
Propofol Pharmacokinetics:
- Unconsciousness occurs in 15-45 sec and lasts approximately 10 minutes
- Distributes rapidly
- Plasma half-life – 2-4 min
Propofol Advantages:
- Faster onset
- Quick recovery
- Antiemetic
- Safer in pregnancy
Pharmacology II Short Answer Questions
Propofol Uses:
- IV induction
- Shorter duration procedures like endoscopies, bums dressings
Propofol Adverse Effects:
- Pain at the injection site
- Fall in BP
- CVS and respiratory depression