Objective—To determine tissue solubilities of desflurane,
sevoflurane, enflurane, and halothane in swine
and to evaluate the effects of freezing specimens on
Sample Population—Arterial blood samples and
specimens of brain, heart, liver, kidney, muscle, and
subcutaneous fat from 5 healthy female adult
Chinese Meishan pigs.
Procedure—Each tissue specimen was divided into 2
parts. One part was used to measure tissue-gas partition
coefficients immediately after collection. The
other part was frozen at –20 C for 6 days prior to
determination of tissue-gas partition coefficients.
Tissue-gas and blood-gas partition coefficients were
measured by use of gas chromatography, and tissueblood
partition coefficients were calculated.
Regression analysis was performed to determine
whether fat-gas partition coefficients were correlated
with lean tissue-gas partition coefficients.
Results—Tissue-gas and blood-gas partition coefficients
of halothane were greater than those of enflurane
followed by coefficients of sevoflurane and desflurane.
However, the order of anesthetic agents with
the greatest to smallest tissue-blood partition coefficients
was sevoflurane, halothane, enflurane, and
desflurane. Muscle-gas partition coefficients of
sevoflurane and enflurane, liver-gas partition coefficients
of desflurane and halothane, and the kidneygas
partition coefficient of enflurane were significantly
greater in frozen specimens, compared with fresh
specimens. Lean tissue-gas partition coefficients of
all 4 volatile anesthetics correlated directly with fatgas
Conclusion and Clinical Relevance—The fat content
of lean tissue is an important factor in determining
the tissue solubility of volatile anesthetics.
Freezing specimens before determination of tissuegas
partition coefficients may result in a false increase
in tissue solubility. (Am J Vet Res 2002;63:74–77)