Intra venous anaesthetic drugs

1. TOPIC: IV ANAESTHESIA DRUGS
INTERNAL EXAMINER:
LT.COL.Dr.Ashok
Professor
PSIMS,Gannavaram
POSTGRADUATES:
Dr.Vara lakshmi
Dr.Shashank
Dr.Jane Ramya

2. INTRAVENOUS ANAESTHETICS
Post Graduates and
The Faculty of
Dr. PSIMS & RF

3. Thiopentone Sodium
1) What are the commonly used IV induction agents?
a) Thiopentone sodium
b) Propofol
c) Ketamine
d) Etomidate.

4. 2) Thiopentone sodium belongs to which group
pharmacologically?
A) Thiopentone sodium is ultra-short acting barbiturate
which can be administered only in an IV route.

5. 3) What is the pH of Thiopentone and where is it
significant in anaesthesia ?
A) Thiopentone sodium is highly alkaline with a pH of
10.6.
Hence it should not be given just prior to the
administration of drugs with different pH, like Scoline.
• There should be adequate saline flush between the
two drugs.

6. 4) How is Thiopentone sodium available and how do you
prepare it for induction?
A) Thiopentone sodium is available as crystalline powder
in a vial with a strength of 500 mg or 1 gm. I will dilute
with normal saline to make it 25 mg per ml solution for
slow IV administration.

7. 5) What is the dose of Thiopentone sodium for
induction of anaesthesia ?
A) In a healthy adult the dose is 3-5 mg/Kg body
weight for normal induction.
• Sleep dose of Thiopentone sodium is 100mg/min
(4ml/min of a 2.5% solution). Till the patient goes to
sleep.

8. 6) What are the contraindications of Thiopentone
sodium ?
A) Bronchial asthma , Acute bronchitis , and atopic
individuals are relative contraindications in addition to
severe hypotension.
Acute Intermittent Porphyria and known allergy to
sulpha drugs are the absolute contraindications.

9. 7) What severe damage can occur by wrong
administration of Thiopentone sodium ?
A) Accidental intra-arterial administration of
thiopentone results in the following :
1.Severe pain in the area supplied by the artery.
2. Spasm of artery leading to decreased blood supply.
3.Burning sensation of the area involved.
4. Spasm of the muscles involved.
5. Cyanosis and gangrene of the distal areas.
6. Systemic hypotension leading to shock.

10. 8) What is the management of such incident?
a- Do not remove the culprit needle from the artery.
b- Inject preservative free 1% Lignocaine 5ml (50 mg) +
phenoxybenzamine (a blocker) 0.5 mg bolus or 50-
200mcg/min infusion into the artery.
c- Infuse plenty of normal saline into the site.
d- Keep the arm elevated.

11. 9) What are the non-induction uses of Thiopentone
sodium clinically ?
A)
• It is a powerful agent to reduce the raised ICP.
• It is administered to manage Status Epilepticus.
• It is administered as Truth Serum in criminal cases.
• It is used as one of the drugs in TIVA for short
surgical procedures.

12. 10) What was the historical connection between
Thiopentone sodium and Pearl Harbor attack?
A) After the Pearl Harbor attack the casualties were
induced with standard doses of Thiopentone sodium
which resulted in multiple intra-op deaths due to
severe hypotension. The drug went into disrepute for
almost a decade. Later the reason for death was
identified as pre-operative hypotension and the drug
was brought back to clinical usage.

13. 11) What are the special precautions while administering
Thiopentone sodium ?
A) Thiopentone sodium should be administered very
slowly in extremes of age and the dose to be
minimized in elderly patients.

14. 12) What is the effect of Thiopentone sodium on the
fetus when administered to the pregnant mother ?
A) The effect is minimal because of the multiple
dilutions of the drug before it reaches fetal
circulation.

15. Propofol
1) What is the pharmacological composition of Propofol ?
A) Propofol is a milky white emulsion with following
composition.
• Propofol
• Egg lecithin (purified)
• Soya bean oil
• Isopropyl phenol
• Glycerol.

16. 2) What are the unique pharmacological features of
Propofol ?
A) Propofol can be administered only through IV route.
• It produces peripheral vasodilation leading to
systemic hypotension.
• Onset of action is fast and recovery time is also
short making it a very useful drug in day care
anaesthesia.

17. 3) What are the advantages of Propofol ?
A)
• Safe induction agent in known hypertensive patients.
• Very useful drug in day care anaesthesia due to its
fast in & fast out property.
• Useful in ICU sedation for short periods.
• Useful in irritable airway diseases.

18. 4) What are the precautions to be taken in Propofol
administration ?
A)
• To be administered with care in hypotensive patients.
• To be administered carefully in atopic individuals and
in patients with egg allergy.
• IV injection is painful, hence prior injection of
lignocaine is advised.

19. 5) What is Propofol infusion syndrome ?
A) It is a syndrome seen usually in ICUs , when the
Propofol is used as an infusion for sedation for
prolonged periods at 4mg/kg/hr, usually more than
48hrs. The signs and symptoms are the result of
muscle injury and release of intracellular toxic
content
Acute refractory bradycardia leading to asystole in the
presence of one or more of the following
Metabolic acidosis ( base defecit > 10mmol/litre)
Rhabdomylosis Hypotension
Hyperlipidemia Tachypnea

20. 6) How do you manage this syndrome ?
A)
• Stop Propofol infusion immediately.
• Rapid fluid resuscitation with normal saline.
• Inj. Furosemide to flush out the excessive drug.
• Inj. Hydrocortisone IV NOT to be given.
• Inotropic support if required.
• Hemodialysis if indicated.

21. 7) What do you know about Propofol induced sepsis ?
A) Propofol may be a potential source of systemic
sepsis as it is a favorable medium for bacterial
growth. This is commonly seen in opened and reused
Propofol vials.

22. 8) How do you prevent this sepsis ?
A)
EDTA added Propofol preparations are available in the
market which will prevent the growth of bacteria in the
vials.
Not using the partially used vials next day is a safe
practice to prevent Propofol induced sepsis.

23. KETAMINE
1) What is the pharmacological precursor for Ketamine?
Say a few words about its history?
A)
• Ketamine is phencyclidine derivative and the latter
drug was used initially as a recreational drug.
• Ketamine was introduced into clinical practice in 1970
by Corssen and Domino.

24. 2) What are the unique pharmacological actions of Ketamine?
A)
• Ketamine is a powerful analgesic agent.
• It produces rapid dissociative anaesthesia.
• It increases the heart rate and blood pressure.
• It increases IOP , ICP and IGP.
• It reduces the seizure threshold, sometimes precipitating
imminent Seizures.
• It produces hallucinations- visual, auditory and tactile- both
positive and negative also.
• Ketamine partially suppresses the pharyngeal and laryngeal
reflexes.
• Ketamine is a bronchodilator and so useful drug in bronchial
spasm or asthma.
• Ketamine increases the oral secretions , which may sometimes
lead to laryngospasm.
• Ketamine increases the skeletal muscle tone.

25. 3) What is the role of Ketamine in day-care
anaesthesia?
A) Very useful drug in TIVA because of its unique
analgesic and CVS stabilizing properties . Quick
elimination - half time is also a favorable character.

26. ETOMIDATE
1) What are the physical and pharmacological
properties of Etomidate?
A) Etomidate is usually supplied in vials as a milky white
solution or transparent liquid. It is a powerful
induction agent.

27. 2) What is the dose of Etomidate for induction?
A) 0.2 to 0.6 mg/kg, IV is the standard induction dose
of Etomidate.

28. 3) What are the advantages of Inj. Etomidate?
A) Etomidate is a drug with cardiac stability. So, can be
safely administered in cardiac patients without any
unwanted changes in blood pressure or pulse rate.

29. 4) What are the limitations of Etomidate usage?
A)
a) Etomidate is known to disturb the hypothalamus
pituitary adrenal axis.
b) It causes involuntary muscle movements and also
reduces the threshold of seizures in patients.

30. 5. What are the relative contraindications for the usage
of Etomidate in anaesthesia?
A) Hypopituitarism, Addison’s disease and known cases
of epilepsy are the relative contraindications of
Etomidate.

31. ANTI-CHOLINERGICS
1. What are the commonly used anticholinergics in
anaesthetic practice?
A) Inj Atropine or Inj Glycopyrrolate are the two
commonly used anticholinergic drugs in Anaesthesia.

32. 2. What are the indications of usage of
anticholinergics?
A)
They are used to:
• Reduce the salivary and bronchial secretions.
• To reduce the vagal tone and thus preventing the
unwanted bradycardia during anaesthesia.
• They are mild bronchodilators and hence are useful in
irritable respiratory system disorders.

33. 3. What are the disadvantages of Anticholinergics?
A)
• They produce unwanted tachycardia and hence they
must be used with caution in Tachyarrythmias,
Phaeochromocytoma or hyperthyroidism.
• They block the sweat glands, so must be avoided in
patients running high temperatures.
• They create dry mouth and dry respiratory tract
which may cause great discomfort to patients.
• Atropine being tertiary amino compound crosses the
blood brain barrier and may cause cerebral
anticholinergic syndrome especially in elders.

34. 4. What are the dosages and preparation of
anticholinergics?
A)
• Atropine is available as 1ml ampoule containing 0.6 or
0.5 mg of Atropine sulphate.
• 1mg/ml preparation is also available for ICU usage for
treatment of OP poisoning
• Dose is 0.6 – 2 mg IM/IV, not more than 10 µg/kg in
children.
• Glycopyrrolate is available as 1ml ampoule containing
0.2 mg.

35. BENZODIAZEPINES
1. What are the commonly used Benzodiazepines in the
anaesthesiology and for what purpose?
A) Midazolam, Diazepam and Clonazepam are the
frequently used benzodiazepines in anaesthesia.
Midazolam is used as an anxiolytic agent before
induction.
Diazepam is used as an anticonvulsant during an attack
of epilepsy or eclampsia.
Alprazolam is used as a mild sedative on the night
before surgery for a peaceful sleep.

36. 2. What are the pharmacological differences between
Diazepam and Midazolam?
A) Onset of action is faster, duration of action is
shorter and the elimination half life is shorter with
midazolam compared to diazepam.
Midazolam is water soluble and hence less painful
when administered intravenously, where as Diazepam is
a thick viscous liquid that causes pain in IV injection.
Diazepam is more potent anticonvulsant than
midazolam and hence it is a preferred drug in an attack
of epilepsy, but its duration of action may extend upto ~
72 hrs.

37. 3. What are the limitations of Midazolam?
A) Benzodiazepines are not analgesic drugs and if
administered in the presence of acute pain, will cause
delirium in the patient with severe pain as they act
as antanalgesics.

38. FENTANYL
1. Why is Inj Fentanyl is a preferred Opioid chosen for
intra-op analgesia?
A) Fentanyl is a powerful synthetic opioid drug which
produces prompt and profound analgesia,is 100 times
more potent than Inj Morphine.
B) Onset of action is within 5 min and effect lasts for
4-6 hrs. Release of Histamine is minimal and hence
appearance of rash, hypotension or bronchospasm
are rare events with fentanyl.

39. 2. What is the dose of Fentanyl? Which are the chief
side effects of Fentanyl?
A) Analgesic dose of Fentanyl is 1-2 µg/kg body weight
given in IV route. Onset of action is after five
minutes and peak action is at 45 min after
administration. The chief side effect after Fentanyl
is the chest wall rigidity, hypotension and over-
sedation. The side effects can be minimized by slow
administration of Fentanyl.

40. 3. What are the non anaesthetic uses of Fentanyl?
A) Fentanyl can also be used for:
• Post op analgesia.
• Post traumatic analgesia in emergency room.
• To manage acute MI.
• ICU sedation and analgesia

41. DEXMEDETOMIDINE
1.Dexmedetomidine belongs to which group
pharmacologically?
A) Dexmedetomidine belongs to α2-adrenergic agonist
group and it is different from Clonidine in the
following way: α2 stimulant 1600 times more selective
(α2/α1=1600:1) compared to Clonidine (α2/α1=220:1).

42. 2.What are the pharmacological actions of
Dexmedetomidine?
• It is mild sedative.
• It is an anti-hypertensive drug.
• It is a mild analgesic.
• It is a tranquilizer during analgesic.
• It reduces the pressor response of the laryngoscopy
and intubation in general anaesthesia.
• It maintains the heart rate.

43. 3. What are the advantages of Dexmedetomidine in
clinical use ?
A) 1. Rapid onset of action.
2. Rapid recovery from the action.
3.Arousable sedation.
4. Mild analgesia present.
5. Maintains cardiovascular stability.
6. Can be administered by IV infusion.

44. 4. What are the precautions to be taken during
administration of Dexmedetomidine?
A)
• Dexmedetomidine administration is contraindicated in
patients with severe hypotension and bradycardia.
• Sporadically few patients will develop unexpected
hypertension and tachycardia immediately after starting
the Dexmedetomidine infusion. The reason for this is the
disturbance in Nor-epinephrine re-uptake mechanism. In
such patients Dexmedetomidine to be terminated
immediately and IV Esmolol or IV Labetalol to be given to
correct the situation
• Unwanted hypotension and severe bradycardia may be seen
in certain sensitive patients. Reduction of infusion rate is
indicated in such patients.

45. 5. What is the role of Dexmedetomidine in ICU care?
A) Dexmedetomidine can be administered as an infusion
for sedation in ICU with minimum side-effects. The
context sensitivity half-life of the drug is short and
hence it is a safer alternative.