Anesthesiology Ventilation

Physics and Anesthesiology

Page Back Page Forward

Return to Section Table of Contents

Return to Site Table of Contents

 

 

6Blood: gas partition coefficients

Sevoflurane (Sevorane, Ultane)

Desflurane (Suprane)

Isoflurane (Forane)

Enflurane (Ethrane)

Halothane (Fluothane)

Nitrous oxide

0.65

0.42

1.46

1.9

2.4

0.46

 

Factors that Increase or Decrease the Rate of Rise of FA/FI

Increase

Decrease

Comment

low B

high B

As the blood solubility decreases, the rate of rise in FA/FI increases.

low Q

high Q

The lower the cardiac output, the faster the rate of rise in FA/FI 

high A

low A

The higher the minute ventilation, the faster the rate of rise in FA/FI 

high (PA - PV)

low (PA - PV)

"At the beginning of induction, PV is zero but increases rapidly (thus [PA-PV] falls rapidly) and FA/FI increase rapidly.  Later during induction and maintenance, PV rises more slowly so FA/FI rises more slowly."

: blood solubility; Q = cardiac output; A = minute ventilation; PA , PV pulmonary alveolar & venous blood partial pressure

Page Back Page Forward

Return to Section Table of Contents

Return to Site Table of Contents