Ketamine

KETAMINE

Q. 1

A child is taken to operation theatre for correction of right-to-left shunt in Tetralogy of Fallot. What is the anesthesia of choice in this child?

 A

Propofol

 B

Ketamine

 C

Thiopentone

 D

Sevoflurane

Q. 1

A child is taken to operation theatre for correction of right-to-left shunt in Tetralogy of Fallot. What is the anesthesia of choice in this child?

 A

Propofol

 B

Ketamine

 C

Thiopentone

 D

Sevoflurane

Ans. B

Explanation:

Ketamine is a ‘dissociative’ anaesthetic agent administered via the intravenous, intramuscular, and oral routes.

In view of its sympathomimetic effects, resulting in an increased heart rate, blood pressure, and cardiac output,

ketamine has been widely used in children with heart disease, particularly the younger age groups.

Because of its effects on systemic vascular resistance,

ketamine is considered a suitable choice in children with right-left-shunts because pulmonary blood flow would be enhanced.

 

Intravenous Anaesthetics

 

Anaesthetic agents used in Children

 


 

In older children intravenous induction is done using agents such as thiopentone, propofol, ketamine, midazolam and diazepam .

 

Desflurane and isoflurane are not used for induction because they have more pungent smell and is associated with increased coughing,
breath holding and laryngospasm during induction.

 

 

Ref: Synopsis of Pediatric Emergency Medicine By Gary Robert Fleisher 4th edition ,page 34; Textbook of Anesthesia for Postgraduates  By T. K. Agasti, page 799.



Q. 2

All of the following are correct about ketamine, EXCEPT:

 A

It  functionally “dissociates” the thalamus 

 B

It increases arterial blood pressure

 C

It is a potent bronchoconstrictor

 D

It inhibits polysynaptic reflexes in the spinal cord

Q. 2

All of the following are correct about ketamine, EXCEPT:

 A

It  functionally “dissociates” the thalamus 

 B

It increases arterial blood pressure

 C

It is a potent bronchoconstrictor

 D

It inhibits polysynaptic reflexes in the spinal cord

Ans. C

Explanation:

Ketamine functionally “dissociates” the thalamus (which relays sensory impulses from the reticular activating system to the cerebral cortex) from the limbic cortex (which is involved with the awareness of sensation).
 
Ketamine increases arterial blood pressure, heart rate, and cardiac output.
 
Racemic ketamine is a potent bronchodilator, making it a good induction agent for asthmatic patients.
 
It inhibits polysynaptic reflexes in the spinal cord as well as excitatory neurotransmitter effects in selected areas of the brain.
 
Ref: Butterworth IV J.F., Butterworth IV J.F., Mackey D.C., Wasnick J.D., Mackey D.C., Wasnick J.D. (2013). Chapter 9. Intravenous Anesthetics. In J.F. Butterworth IV, J.F. Butterworth IV, D.C. Mackey, J.D. Wasnick, D.C. Mackey, J.D. Wasnick (Eds), Morgan & Mikhail’s Clinical Anesthesiology, 5e.

Q. 3

Highest analgesic effect is a feature of –

 A

Ketamine

 B

Thiopentone

 C

Propofol

 D

Ethomidate

Q. 3

Highest analgesic effect is a feature of –

 A

Ketamine

 B

Thiopentone

 C

Propofol

 D

Ethomidate

Ans. A

Explanation:

Ans. is ‘a’ i.e., Ketamine

“Ketamine is different from most other anaesthetic induction agents in that it has significant analgesic action”.

Remember

o Amongst inhalation agents trilene (maximum), NO and ether have good analgesic action.


Q. 4

Emergence Delirium is characteristic of ?

 A

Midazolam

 B

Ketamine

 C

Thiopentone

 D

Opioids

Q. 4

Emergence Delirium is characteristic of ?

 A

Midazolam

 B

Ketamine

 C

Thiopentone

 D

Opioids

Ans. B

Explanation:

Ans. is ‘b’ i.e., Ketamine

o Ketamine produces emergence reaction during awakening from anaesthesia —> vivid dreaming, illusions, extracorporeal experiences, excitment, confusion, fear and euphoria —> contraindicated in psychiatric illness like schizophrenia.


Q. 5

Hallucinations are seen after ————————————–anaesthesia –

 A

Ketamine

 B

Thiopentonc

 C

Fentanyl

 D

Nitrous oxide

Q. 5

Hallucinations are seen after ————————————–anaesthesia –

 A

Ketamine

 B

Thiopentonc

 C

Fentanyl

 D

Nitrous oxide

Ans. A

Explanation:

Ans. ‘a’ i.e., Ketamine

o Ketamine cause emergence reaction which is manifested as hallucinations and illusions.


Q. 6

Ketamine produces –

 A

Emergence delirium

 B

Hypotension

 C

Bronchoconstriction

 D

Depression of cardiovascular system

Q. 6

Ketamine produces –

 A

Emergence delirium

 B

Hypotension

 C

Bronchoconstriction

 D

Depression of cardiovascular system

Ans. A

Explanation:

Ans. is ‘a’ i.e., Emergence delirium


Q. 7

Ketamine should be avoided in –

 A

The presence of increased arterial pressure

 B

Pregnancy

 C

Hypovolemic shock

 D

Asthmatic

Q. 7

Ketamine should be avoided in –

 A

The presence of increased arterial pressure

 B

Pregnancy

 C

Hypovolemic shock

 D

Asthmatic

Ans. A

Explanation:

Ans. is ‘a’ i.e., The presence of increased arterial pressure

`Ketamine increases BP and intracranial tension, it therefore should be avoided in hypertension and in the presence of raised ICT.’


Q. 8

Inducing agent of choice in shock ‑

 A

Isoflurane

 B

Desflurane

 C

Ketamine

 D

Thiopentone

Q. 8

Inducing agent of choice in shock ‑

 A

Isoflurane

 B

Desflurane

 C

Ketamine

 D

Thiopentone

Ans. C

Explanation:

Ans. is ‘c’ i.e., Ketamine

  • Inducing agent of choice in Asthma & COPD                Ketamine.
  • Inhalational agent of choice in Asthma & COPD —) Halothane.

Q. 9

Dose of Ketamine is

 A

0.5 mg/Kg l/m

 B

2 mg/kg I/v

 C

5mg/kg I/v

 D

10mg / kg I/m

Q. 9

Dose of Ketamine is

 A

0.5 mg/Kg l/m

 B

2 mg/kg I/v

 C

5mg/kg I/v

 D

10mg / kg I/m

Ans. B

Explanation:

B i.e. 2mg/Kg IV


Q. 10

Which drug of anesthetics causes delirium & hallucination

 A

Ketamine

 B

Trilene

 C

Halothane

 D

Trichloroethylenev

Q. 10

Which drug of anesthetics causes delirium & hallucination

 A

Ketamine

 B

Trilene

 C

Halothane

 D

Trichloroethylenev

Ans. A

Explanation:

A i.e. Ketamine 


Q. 11

Increased Cardiac Oxygen demand is caused by

 A

Halothane

 B

Thiopentone

 C

N20

 D

Ketamine

Q. 11

Increased Cardiac Oxygen demand is caused by

 A

Halothane

 B

Thiopentone

 C

N20

 D

Ketamine

Ans. D

Explanation:

D i.e. Ketamine


Q. 12

ICT is raised due to:

 A

Ketamine

 B

Scoline

 C

Halothane

 D

Ether

Q. 12

ICT is raised due to:

 A

Ketamine

 B

Scoline

 C

Halothane

 D

Ether

Ans. A

Explanation:

A i.e. Ketamine


Q. 13

Cerebral metabolism and 02 consumption are increased by:

 A

Propofol

 B

Ketamine

 C

Atracurium

 D

Fentanyl

Q. 13

Cerebral metabolism and 02 consumption are increased by:

 A

Propofol

 B

Ketamine

 C

Atracurium

 D

Fentanyl

Ans. B

Explanation:

B i.e. Ketamine


Q. 14

With regard to Ketamine, all of the following are true except:

 A

It is a direct myocardial depressant

 B

Emergence phenomenon are more likely if anticholinergic premedication is used

 C

It may induce cardiac dysarythmias in patients receiving tricyclic antidepressants

 D

Has no effect on intracranial pressure

Q. 14

With regard to Ketamine, all of the following are true except:

 A

It is a direct myocardial depressant

 B

Emergence phenomenon are more likely if anticholinergic premedication is used

 C

It may induce cardiac dysarythmias in patients receiving tricyclic antidepressants

 D

Has no effect on intracranial pressure

Ans. D

Explanation:

D i.e. Has no effect on intracranial pressure


Q. 15

All statements regarding ketamine are true except

 A

May be arrythmogenic

 B

Raised ICT do not respond to CO2 level

 C

Vasodialator and negative ionotropic effect

 D

Psychomimetic emergence

Q. 15

All statements regarding ketamine are true except

 A

May be arrythmogenic

 B

Raised ICT do not respond to CO2 level

 C

Vasodialator and negative ionotropic effect

 D

Psychomimetic emergence

Ans. B

Explanation:

B i.e. Raised ICT do not respond to CO2 level


Q. 16

Ketamine is safe in

 A

Raised ICT

 B

Open eye injury

 C

Ischemic heart disease

 D

Severe shock

Q. 16

Ketamine is safe in

 A

Raised ICT

 B

Open eye injury

 C

Ischemic heart disease

 D

Severe shock

Ans. D

Explanation:

D i.e. Severe Shock


Q. 17

Ketamine can be used in all of the situations except

 A

Status asthamaticus

 B

For analgesia & sedation

 C

Obstetric hemorrhage

 D

Ischemic heart disease

Q. 17

Ketamine can be used in all of the situations except

 A

Status asthamaticus

 B

For analgesia & sedation

 C

Obstetric hemorrhage

 D

Ischemic heart disease

Ans. D

Explanation:

D i.e. Ischemic heart disease

Ketamine causes profound analgesiaQ, disociative anesthesiaQ, and emergence psychomimetic hallucinations and delirium Q.

Ketamine increases cerebral metabolism, 02 consumption, blood flow & intracranial pressure.Q

Ketamine

– It causes profound analgesiaQ and dissociative anesthesiaQ (i.e. patient appears conscious e.g. eye opening, swallowing but unable to process or respond to sensory input). Ketamine causes Dissociative AnesthesiaQ by acting on cortex and subcortical areas (not on RAS) l/t feeling of dissociation from ones own body and surroundings. Post Operative Delirium and HallucinationQ is part of this Dissociative phenomenon. Drug of choice for post op. delirium & hallucination is Lorazepam.Q

– It is closest to being a complete anesthetic since it induces analgesia, amnesia & unconsciousness.

– It is associated with emergence psychotomimetic side effects (delirium, illusions, hallucination)Q. It is less common in children and pretreatment with lorazepam (drug of choice)Q.


Q. 18

An unconcious patient of head injury comes in casualty. On examination shows raised intracranial pressure. Which anesthetic agent is contraindicated:

 A

Thiopentone

 B

Propofol

 C

Ketamine

 D

Etomidate

Q. 18

An unconcious patient of head injury comes in casualty. On examination shows raised intracranial pressure. Which anesthetic agent is contraindicated:

 A

Thiopentone

 B

Propofol

 C

Ketamine

 D

Etomidate

Ans. C

Explanation:

C i.e. Ketamine

Ketamine causes increase in all pressure i.e. intracranial, intraocular, intragastric and intravascular (Blood) pressure. So it is not used in raised ICT/IOT & Hypertension as it may increase the pressure to morbid levels.


Q. 19

A 5 year old child is suffering from cyanotic heart disease. He is planned for corrective surgery. The induction agent of the choice would by:

 A

Thiopentone

 B

Ketamine

 C

Halothane

 D

Midazolam

Q. 19

A 5 year old child is suffering from cyanotic heart disease. He is planned for corrective surgery. The induction agent of the choice would by:

 A

Thiopentone

 B

Ketamine

 C

Halothane

 D

Midazolam

Ans. B

Explanation:

B i.e. Ketamine

  • Ketamine (intramuscular or intravenous) is a commonly used induction agent because it maintains or increases systemic vascular resistance and it does not appear to increase pulmonary vascular resistance and therefore does not aggravate the right to left shunting (in cyanotic heart disease)
  • Patients with milder degree of right to left shunting can also tolerate inhalational induction with halothane, because it tends to maintain systemic vascular resistance (due to minimal systemic arterial vasodilatation).
  • Halothane is not used in very young patients due to its pungent nature & slow action.
  • Halothane is also not preferred for patients with low cardiac output.
  • Important facts about cyanotic heart disease are‑

– Cyanotic heart disease has predominantly right to left shunt i.e. blood flows directly from right ventricle to left ventricle by-passing the pulmonary circulation

– Anaesthetic drugs and procedures which increase systemic vascular resistance & decrease pulmonary vascular resistance should be preferred.

–  R4L shunting tends to slow the uptake of inhalational anaesthetics. In contrast, it may accelerate the onset of intravenous agents.

– N20 is usually used with inhalational induction (does not T PVR).


Q. 20

Best anaesthesia for status asthamaticus

 A

Thiopentone

 B

Ketamine

 C

Ether

 D

N20

Q. 20

Best anaesthesia for status asthamaticus

 A

Thiopentone

 B

Ketamine

 C

Ether

 D

N20

Ans. B

Explanation:

B i.e. Ketamine


Q. 21

Which of the following anesthetic agents have analgesic property:

 A

Ketamine

 B

Nitrous oxide

 C

Thiopentone

 D

a and b

Q. 21

Which of the following anesthetic agents have analgesic property:

 A

Ketamine

 B

Nitrous oxide

 C

Thiopentone

 D

a and b

Ans. D

Explanation:

A i.e. Ketamine; B i.e. Nitrous oxide 


Q. 22

Which of the following drugs produces dissociative anaesthesia:        

March 2013 (g)

 A

Ketamine

 B

Propofol

 C

Thiopentone

 D

Enflurane

Q. 22

Which of the following drugs produces dissociative anaesthesia:        

March 2013 (g)

 A

Ketamine

 B

Propofol

 C

Thiopentone

 D

Enflurane

Ans. A

Explanation:

Ans. A i.e. Ketamine

Ketamine

  • Is a phencyclidine,
  • Causes dissociative anaesthesia,
  • Causes

–         Hallucination,

–         Delusion and

–         Illusion

  • Causes profound analgesia
  • Increases all pressures:

–         Intracranial Tension,

–         Intraocular pressure,

–         BP

  • C/I in: Intracerebral mass/hemorrhage etc

Q. 23

Anaesthetic of choice in asthma patients:

March 2007

 A

Halothane

 B

Thipentone

 C

Ketamine

 D

Fertanyl

Q. 23

Anaesthetic of choice in asthma patients:

March 2007

 A

Halothane

 B

Thipentone

 C

Ketamine

 D

Fertanyl

Ans. C

Explanation:

Ans. C: Ketamine

Ketamine is classified as an NMDA (N-methyl-D-aspartate) receptor antagonist, and at high, fully anesthetic level doses, ketamine has also been found to bind to opioid (mu) receptors and sigma receptors.

Like other drugs of this class such as tiletamine and phencyclidine (PCP), it induces a state referred to as “dissociative anaesthesia” and is used as a recreational drug.

Ketamine has a wide range of effects in humans, including analgesia, anaesthesia, hallucinations, elevated blood pressure, and bronchodilation.

It is primarily used for the induction and maintenance of general anaesthesia, usually in combination with some sedative drug.

Ketamine is usually injected intravenously or intramuscularly, but it is also effective when insufflated, smoked, or taken orally.

When used at anaesthetic doses, it will usually stimulate rather than depress the circulatory system, so I/ V anaesthetic of choice for shock.

Ketainine produces a dissociative state, characterised by a sense of detachment from one’s physical body and the external world which is known as depersonalization and derealization.

At sufficiently high doses users may experience what is coined the “K-hole”, a state of dissociation whose effects are thought to mimic the phenomenology of schizophrenia.


Q. 24

General anaesthetic agent causing sympathetic stimulation:  

September 2011

 A

Thiopental

 B

Ketamine

 C

Midazolam

 D

Etomidate

Q. 24

General anaesthetic agent causing sympathetic stimulation:  

September 2011

 A

Thiopental

 B

Ketamine

 C

Midazolam

 D

Etomidate

Ans. B

Explanation:

Ans. B: Ketamine

Ketamine stimulates sympathetic system causing tachycardia and hypertension so it is intravenous anaesthetic of choice for shock

Disadvantages of Midazolam: Incidence of apnea, respiratory depression and hypotension are higher and more profound than diazepam

Thiopentone causes hypotension which is more because of venodilatation

Ketamine:

  • It is phencyclidine
  • Causes dissociative anaesthesia
  • Increases all pressures (BP, intraocular tension, intracranial tension)
  • Causes profound analgesia
  • Causes hallucinations, illusions and delusions
  • Contraindicated in: Intracerebral mass or hemorrhage
  • Causes bronchodilation (used in asthmatics) and increases cardiac output (used in hypovolumic shock)

Q. 25

Ketamine produces‑

 A

Analgesia

 B

Allodynia

 C

Hyperpathia

 D

Dystonia

Q. 25

Ketamine produces‑

 A

Analgesia

 B

Allodynia

 C

Hyperpathia

 D

Dystonia

Ans. A

Explanation:

Ans. is ‘a’ i.e., Analgesia

Ketamine

  • The primary site of action is in the cortex and subcortical areas; not in the reticular activating system (site of action of barbiturates).
  • It acts on NMDA receptors.
  • Short duration of action (10-15 minutes) is due to redistribution from brain and blood to other tissues of the body.
  • Ketamine is different from most other anaesthetic induction agents in that it has significant analgesic action.
  • Ketamine increases IOT and cerebral metabolism → contraindicated in head injury.
  • It causes sympathetic stimulation with elevation of HR, CO & BP → contraindicated in hypertension and ischemic heart disease.
  • It also raises IOT → contraindicated in glaucoma.
  • It relieves bronchospasm intravenous anaesthetic of choice in asthmatics (inhalation anaesthetic of choice in asthmatic is halothane).
  • Injection is not painful (All other inducing agents cause pain on injection).
  • It is i.v. anaesthetic of choice in children (Sevoflurane is inhalation agent of choice).
  • Because it causes sympathetic stimulation it is intravenous anaesthetic of choice in patients with shock and hypovolumia.
  • It has no muscle relaxant property rather muscle tone is increased.
  • Airway reflexes (pharyngeal and laryngeal) are not depressed intravenous anaesthetic of choice for emergency anaesthesia (no starvation is required).
  • Ketamine produces emergence reaction during awakening from anaesthesia → vivid dreaming, illusions, extracorporeal experiences, excitment, confusion, fear and euphoria → contraindicated in psychiatric illness like schizophrenia.

Q. 26

A patient presented with blunt trauma to the abdomen to the emergency department. His pulse rate is 150/ min and his BP is 80/50 mm Hg. Scheduled to undergo an emergency laparotomy. Which of the following is the anesthetic of choice

 A

Thiopentone

 B

M i dazo lam

 C

Ketamine

 D

Propofol

Q. 26

A patient presented with blunt trauma to the abdomen to the emergency department. His pulse rate is 150/ min and his BP is 80/50 mm Hg. Scheduled to undergo an emergency laparotomy. Which of the following is the anesthetic of choice

 A

Thiopentone

 B

M i dazo lam

 C

Ketamine

 D

Propofol

Ans. C

Explanation:

Ans. c. Ketamine 


Q. 27

Which of the following intravenous anesthetic agent is contraindicated in epileptic patients posted for general anesthesia?

 A

Propofo

 B

Thiopentone

 C

Ketamine

 D

Midazolam

Q. 27

Which of the following intravenous anesthetic agent is contraindicated in epileptic patients posted for general anesthesia?

 A

Propofo

 B

Thiopentone

 C

Ketamine

 D

Midazolam

Ans. C

Explanation:

Ans. c. Ketamine

Ketamine should be avoided in patients with history of seizures as it further increases ICP and also causes delirium and hallucinations.

Midazolam is a benzodiazepine, which has anti-seizure potential and thus used in treating seizueres.

Both thiopentone and propofol decreases ICP and are neuroprotective.


Q. 28

Which of the following is contraindicated in head injury?

 A

Ketamine

 B

Halothane

 C

N,0

 D

Propofol

Q. 28

Which of the following is contraindicated in head injury?

 A

Ketamine

 B

Halothane

 C

N,0

 D

Propofol

Ans. A

Explanation:

Ans. is ‘a’ i.e., Ketamine


Q. 29

Ketamine contraindicated in all except‑

 A

Head injury

 B

Hypertension

 C

Asthma

 D

Glaucoma

Q. 29

Ketamine contraindicated in all except‑

 A

Head injury

 B

Hypertension

 C

Asthma

 D

Glaucoma

Ans. C

Explanation:

Ans. is `c’ i.e., Asthma

  • Ketamine increases cerebral blood flow, metabolism, oxygen consumption and intracranial tension, unlike thiopentone, propofol&etomidate, which have cerebroprotectiveeffect, therefore ketamine is contraindicated in head injury, intracranial space occupying lesions and for neuroanaesthesia.
  • Cerebrovascular responsiveness to CO2 is preserved, and reducing the arterial CO2 tension by hyperventilation attenuates the ketamine induced rise in ICT.
  • Ketamine has direct myocardial depressant (negative ionotropic) & vasodilator effect. However, ketamine also has
  • indirect sympathomimetic effect. Indirect sympathomimetic effect predominates over direct myocardial depressant &vasodilator effect; usual response is increased BP, cardiac output and heart rate-Cardiac 02 demand is increased. 
  • Ketamine is contraindicated in aortic aneurysm, hypertensive and ischemic heart disease. Ketamine also sensitizes
  • the heart to adrenaline – arrhythmias may occur.
  • As ketamine cause sympathetic stimulation, it is the intravenous anaesthetic of choice in patients with shock and hypovolemia.
  • Ketamine increases intra-ocular tension – Contraindicated in glaucoma & open eye surgery.
  • It is a potent bronchodilator and relieves bronchospasm – Intravenous anesthetic agent of choice in asthmatic (inhalational anaesthetic agent of choice in asthmatics is halothane)
  • It increases uterine tone and intensity of uterine contraction – agent of choice in patients with obstetric haemorrhage and flaccid uterus.
  • Injection of ketamine is not painful (all other i.v. inducing agents cause pain on injection).

Q. 30

Which of the following drugs is contraindicated in a patient with raised intracranial pressure?

 A

Thiopentone

 B

Propofol

 C

Midazolam

 D

Ketamine

Q. 30

Which of the following drugs is contraindicated in a patient with raised intracranial pressure?

 A

Thiopentone

 B

Propofol

 C

Midazolam

 D

Ketamine

Ans. D

Explanation:

Ans. is ‘d’ i.e., Ketamine

  • Cerebral blood flow, metabolism, oxygen consumption and ICT all are increased by ketamine —> ketamine is contraindicated in raised ICT.
  • Also see explanation- 5 of session 2.

Q. 31

Induction agent of choice in a child with cyanotic heart disease ‑

 A

Thiopentone

 B

Ketamine

 C

Halothane

 D

Midazolam

Q. 31

Induction agent of choice in a child with cyanotic heart disease ‑

 A

Thiopentone

 B

Ketamine

 C

Halothane

 D

Midazolam

Ans. B

Explanation:

Ans. is ‘b’ i.e., Ketamine

  • In cyanotic heart disease (right to left shunt), systemic vascular resistance should be increased by anaesthetics —> ketamine is the anaesthetic of choice.
  • In acyanotic heart disease (left to right shunt), systemic vascular resistance should be decreased –> volatile anaesthetics (isoflurane, sevoflurane or desflurane) should be used

Q. 32

Ketamine acts an which receptors

 A

GAGA

 B

Muscarinic

 C

5-HT4

 D

NMDA

Q. 32

Ketamine acts an which receptors

 A

GAGA

 B

Muscarinic

 C

5-HT4

 D

NMDA

Ans. D

Explanation:

Ans. is ‘d’ i.e., NMDA

  • See explanation- 5 of session- 2 of Anaesthesia of All India 2014-15 pattern of this book

Q. 33

Ketamine produces ‑

 A

Emergence delirium

 B

Pain on injection

 C

Bronchoconstriction

 D

Depression of cardiovascular system

Q. 33

Ketamine produces ‑

 A

Emergence delirium

 B

Pain on injection

 C

Bronchoconstriction

 D

Depression of cardiovascular system

Ans. A

Explanation:

Ans. is ‘a’ i.e., Emergence delirium

Ketamine

  • The primary site of action is in the cortex and subcortical areas; not in the reticular activating system (site of action of barbiturates).
  • It acts on NMDA receptors.
  • Short duration of action (10-15 minutes) is due to redistribution from brain and blood to other tissues of the body.
  • Ketamine is different from most other anaesthetic induction agents in that it has significant analgesic action.
  •  Ketamine increases IOT and cerebral metabolism –> contraindicated in head injury.
  • It causes sympathetic stimulation with elevation of HR, CO & BP —) contraindicated in hypertension and ischemic heart disease.
  • It also raises IOT —> contraindicated in glaucoma.
  • It relieves bronchospasm —> intravenous anaesthetic of choice in asthmatics (inhalation anaesthetic of choice in asthmatic is halothane).
  • Injection is not painful (All other inducing agents cause pain on injection).
  • It is i.v. anaesthetic of choice in children (Sevoflurane is inhalation agent of choice).
  • Because it causes sympathetic stimulation it is intravenous anaesthetic of choice in patients with shock and hypovolumia.
  • It has no muscle relaxant property rather muscle tone is increased.
  • Airway reflexes (pharyngeal and laryngeal) are not depressed —> intravenous anaesthetic of choice for emergency anaesthesia (no starvation is required).
  • Ketamine produces emergence reaction during awakening from anaesthesia —> vivid dreaming, illusions, extracorporeal experiences, excitment, confusion, fear and euphoria —> contraindicated in psychiatric illness like schizophrenia.

Q. 34

Inducing agent of choice in asthma

 A

Etomidate

 B

Ketamine

 C

Propofol

 D

Induction

Q. 34

Inducing agent of choice in asthma

 A

Etomidate

 B

Ketamine

 C

Propofol

 D

Induction

Ans. B

Explanation:

Ans. is ‘b’ i.e., Ketamine

  • Inducing agent of choice in Asthma & COPD —> Ketamine.
  • Inhalational agent of choice in Asthma & COPD —> Halothane.
  • Propofol and etomidate are alternates to ketamine for indcution in asthmatic patients.

Drugs considered safe for asthmatics

Induction                                  Propofol, etomidate, ketamine

Opioids                                     Pethidine, Fentanyl, alfentanil

Muscle relaxants                        Vecuronium, rocuronium, Pancuronium

Volatile agents                          Halothane, Isoflurane, Sevoflurane, Desflurane, N20

Other                                       Benzodiazepines (Amongst hypnotics, BZD are safe)


Q. 35

Anaesthetic agent causing analgesia‑

 A

 Ketamine

 B

Propofol

 C

 Etomidate           

 D

Thiopentone

Q. 35

Anaesthetic agent causing analgesia‑

 A

 Ketamine

 B

Propofol

 C

 Etomidate           

 D

Thiopentone

Ans. A

Explanation:

Ans. is ‘a’ i.e., Ketamine 


Q. 36

Intraocular pressure is increased by which anaesthetic‑

 A

 Ketamine

 B

 Propofol

 C

 N20

 D

Isoflurane

Q. 36

Intraocular pressure is increased by which anaesthetic‑

 A

 Ketamine

 B

 Propofol

 C

 N20

 D

Isoflurane

Ans. A

Explanation:

Ans. is ‘a’ i.e., Ketamine 


Q. 37

Disadvantage of ketamine is‑

 A

Increased heart rate

 B

 Increased ICT

 C

 Delirium

 D

 All of the above

Q. 37

Disadvantage of ketamine is‑

 A

Increased heart rate

 B

 Increased ICT

 C

 Delirium

 D

 All of the above

Ans. D

Explanation:

Ans. is ‘d’ i.e., All of the above 

  • When administered to adult patients as a sole anaesthetic agent, ketamine frequently cause emergence reaction characterized by anxiety, hallucination, delirium. Moreover, ketamine shows cardiovascular stimulant property (increases heart rate and BP), increases salivary and bronchial secretions, and may increase intracranial, intraocular and pulmonary pressure. All of these features have been advocated as limitations for its usefulness.

Q. 38

 Dissociative anaesthesia is produced by – (PGI 99)

 A

Ketamine

 B

Etomidate

 C

Propofol

 D

Thiopentone

Q. 38

 Dissociative anaesthesia is produced by – (PGI 99)

 A

Ketamine

 B

Etomidate

 C

Propofol

 D

Thiopentone

Ans. A

Explanation:

Ans. is ‘a’ i.e., Ketamine

  • Dissociative anaesthesia is characterized by profound analgesia, immobility, amnesia with light sleep and feeling of dissociation from once own body and the surroundings Cataleptic state.
  • Ketamine (phencyclidine) induces dissociative anaesthesia.

Q. 39

Ketamine produces ‑

 A

Emergence delirium

 B

Hypotension

 C

Bronchoconstriction

 D

Depression of cardiovascular system

Q. 39

Ketamine produces ‑

 A

Emergence delirium

 B

Hypotension

 C

Bronchoconstriction

 D

Depression of cardiovascular system

Ans. A

Explanation:

Ans. is ‘a’ i.e., Emergence delirium 

  • Ketamine cause emergence reaction which is manifested as hallucinations and illusions.

Ketamine

  • The primary site of action is in the cortex and subcortical areas; not in the reticular activating system (site of action of barbiturates).
  • It acts on NMDA receptors.
  • Short duration of action (10-15 minutes) is due to redistribution from brain and blood to other tissues of the body. 
  • Ketamine is different from most other anaesthetic induction agents in that it has significant analgesic action. 
  • Ketamine increases IOT and cerebral metabolism -3 contraindicated in head injury.
  • It causes sympathetic stimulation with elevation of HR, CO & BP→ contraindicated in hypertension and ischemic heart disease.
  • It also raises IOT -4 contraindicated in glaucoma.
  • It relieves bronchospasm intravenous anaesthetic of choice in asthmatics (inhalation anaesthetic of choice in asthmatic is halothane).
  • Injection is not painful (All other inducing agents cause pain on injection).
  • It is i.v. anaesthetic of choice in children (Sevoflurane is inhalation agent of choice).
  • Because it causes sympathetic stimulation it is intravenous anaesthetic of choice in patients with shock and hypovolumia.
  • It has no muscle relaxant property rather muscle tone is increased.
  • Airway reflexes (pharyngeal and laryngeal) are not depressed intravenous anaesthetic of choice for emergency anaesthesia (no starvation is required).
  • Ketamine produces emergence reaction during awakening from anaesthesia → vivid dreaming, illusions, extracorporeal experiences, excitment, confusion, fear and euphoria contraindicated in psychiatric illness like schizophrenia.


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