pharmaco

You plan to anaesthetize 2 year old boy plan for herniotomy with sevoflurane and nitrous oxide as it can fasten the induction time. Which is the best explanation of above choice?

• A Sevoflurane has Boiling point of 58.5 C

• Sevoflurane has 2% being metabolised in the liver

• Sevoflurane has  Blood gas partition coefficient BGPC of 0.7

• Sevoflurane has vapour pressure of 157mmHg at 20C

Bupivacaine 0.5% is deposited near brachial plexus proximity in achieving anaethesia for upper limb surgery.

Which mechanism best describe its use?

• Bupivacaine dissociates into unionised form

• Bupivacaine rapidly absorb into systemic circulation.

• Bupivacaine has high protein binding.

• Bupivacaine is metabolise in the liver.

Regarding non-competitive antagonist:

•   Binding occurs at the same receptor site as the agonist.

• Its effect is overcome by increasing the concentration of an agonist.

• It depresses the maximum obtainable response of the agonist

• It shifts the log dose-response curve of the agonist to the right

What is true about Ketamine?

• is the most protein bound among the intravenous induction agents.

•   in its racemic form, has been shown to block ATP-sensitive potassium channels.

• commonly induces arrhythmias

• has antanalgesic properties

     Which of the following is not true about sodium thiopentone?

           

• Its pKa of 7.6 means that 60% of free drug is unionized at physiological pH.

• It exhibits zero-order kinetic metabolism following a single induction dose.

• At hypnotic dose, it is also an anticonvulsant

• It decreases intracranial pressure by decreasing cerebral blood volume.

Which of the following about Desfluorane is not true?

• has a blood:gas partition coefficient of 0.45.

•   is less potent compared to sevoflurane

• degradation products include carbon dioxide.

• can cause laryngospasm during maintenance of anaesthesia

            Which of the following is not true regarding rocuronium:

         

• Its metabolite has no significant muscle relaxant activity

• It is mainly excreted unchanged in bile

• It is an aminosteroid.

• Its main mode of metabolism is ester hydrolysis.

Which of the following increase the placental transfer of local anaesthetic ?

•    it is highly protein bound.

• its pKa is high

• it is highly lipid soluble.

• there is foetal acidosis.

            All the following statement is true regarding local anaesthetic activity EXCEPT?

           

• Potency is determined by its lipid solubility.

• Onset of action is determined by its pKa.

• Duration of action is determined by its protein binding capacity.

• R-enantiomers produce less cardiotoxicity

            All the following is true regarding local anaesthetics EXCEPT:

•   The pKa of bupivacaine is higher than the pKa of lignocaine.

• At physiological pH, more than 30% of bupivacaine is unionised.

• Amides have a higher affinity for binding to a-I acid glycoprotein than albumin