Sevoflurane is not pungent and does not irritates respiratory tract

Question 22

Which of the following statement is wrong

a.       Sevoflurane has rapid onset and recovery

b.      Sevoflurane is pungent and irritates respiratory tract

c.       Desflurane has lower Blood Gas Partition Co Efficient than Sevoflurane

d.      Sevoflurane has lower MAC than Desflurane

Answer

b)      Sevoflurane is pungent and irritates respiratory tract

Reference

Katsung Page 403

QTDF :

Anaesthesia Books / Katsung

Quality

Thinker

Discussion

Anaesthetic	Blood : Gas Partition Co-efficient	Brain : Blood Partition Co-efficient	Minimal Alveolar Conc (MAC) (%)2	Remarks
Nitrous Oxide	0.47	1.1	> 100	Incomplete Anaesthetic. Rapid Onset and Recovery
Desflurane	0.42	1.3	6-7	Low Volatality. Poor Induction Agent. Rapid Recovery
Sevoflurane	0.69	1.7	2.0	Rapid Onset and Recovery. Unstable in Soda Lime
Isoflurane	1.40	2.6	1.4	Medium Rate of Onset and Recovery
Enflurane	1.80	1.4	1.7	Medium Rate of Onset and Recovery
Halothane	2.30	2.9	0.75	Medium Rate of Onset and Recovery
Methoxyflurane	12	2.0	0.16	Slow Onset and recovery

Explanation

a.       Sevoflurane (2,2,2-trifluoro-1-[trifluoromethyl]ethyl fluoromethyl ether), also called fluoromethyl hexafluoroisopropyl ether, has rapid onset and recovery

b.      Sevoflurane is a sweet-smelling, non-flammable, highly fluorinated methyl isopropyl ether which does not irriate the respiratory tract

c.       Desflurane has lower Blood Gas Partition Co Efficient (0.42) than Sevoflurane (0.67)

d.      Sevoflurane has lower MAC(2) than Desflurane(6-7)

Comments

Gas	Cylinder Colour		Pin Index	Pressure at 15oC
	In Other Countires	In USA		Lbf/in2	Bar
Oxygen(O2)	Black body with white shoulder	Green	2-5	1987	137
Nitrous Oxide (N2O)	French Blue	Blue	3-5	638	44
Cyclopropane	Orange	Orange	3-6	73	5
Carbon Di Oxide(CO2)	Grey	Grey	1-6	725	50
Halothane bottle	Amber
Ethylene bottle	Red
Helium (He)	Brown	Brown		1987	137
Entonoc	Blue body with white shoulder	Blue / Green	7	1987	137
Air	Grey body with B & White shoulder	Yellow	1-5	1987	137
O2/Helium	Black	Green / Brown	4-6,2-4	1987	137
O2/CO2	Black	Green / Grey	2-6,1-6	1987	137
Nitrogen			1-4

Tips

Few agents are in bottles rather than in cylinders

Gases	Bottle Colour
Halothane	Amber
Ethylene	Red

Sometimes the supply is through pipes and we have a few details here also

Gas	Hose Colour	Socket Colour	Pressure
Oxygen(O2)	White	White	4 Bar
Nitrous Oxide (N2O)	Blue	Blue	4 Bar
Air	Black	Black	7 Bar
Suction	Yellow	Yellow

The boiling points of the Anaesthetic agents also are worth remembering

Gas	Boiling Point
Ethylene Chloride	12.5 oC
Desflurane	23 oC
Ether	34.6 oC
Isoflurane	45.5 oC
Halothane	50 oC
Enflurane	56.5 oC
Sevoflurane	58.5 oC
Tricholoroethylene	86 oC
Nitrous Oxide	89 oC
Methoxyflurane	104 oC