The microcirculation during enflurane and isoflurane anaesthesia in dogs.
The effects of enflurane and isoflurane of 0.75 and 1.5 MAC on capillary blood flow were studied by the microsphere (9 +/- 1 microns in diameter) method in two groups of seven dogs. Simultaneously, changes in the arteriolo-venular shunt were studied by collection of venous blood at a rate of 4.8 ml.min-1 for two minutes. Enflurane anaesthesia at 0.75 MAC decreased capillary blood flow in the thyroid glands (35% of control), left and right ventricular wall (59% and 50%), adrenal gland (59%), liver (63%), spleen (56%), pancreas (35%), omentum (20%), and small intestine (60%) and at 1.5 MAC it decreased further in the thyroid glands (15%), left and right ventricular wall (31% and 32%), adrenal gland (42%), liver (47%), spleen (31%), pancreas (23%), omentum (20%), stomach (45%), and small intestine (54%). No marked changes were noted in the brain, kidney, large intestine or skeletal muscle. The arteriolo-venular shunt was decreased in the kidney from an initial rate of 12.1 to 3.8% at 0.75 MAC and to 2.5% at 1.5 MAC enflurane. In contrast, during isoflurane anaesthesia, capillary blood flow remained unchanged, except for a decrease to the thyroid glands (43%) and right ventricular wall (74%) during 1.5 MAC anaesthesia. However, the arteriolo-venular shunt was increased in the brain from 12.0 to 29.7% and 33.0% during 0.75 and 1.5 MAC isoflurane anaesthesia, respectively. It also increased from 25.0 to 41.0% and 46.3% in the skeletal muscle, and from 8.9 to 19.9% and 17.4% in the whole systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS)
Yano
H
H
Department of Anesthesiology, Kawasaki Medical School, Kinki Central Hospital, Hyogo-ken, Japan.
Takaori
M
M
D000311:Adrenal Glands / Q000098:blood supply; D000769:Anesthesia, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002196:Capillaries / Q000187:drug effects / Q000503:physiopathology; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology; D004285:Dogs; D004737:Enflurane / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007530:Isoflurane / Q000008:administration & dosage / Q000494:pharmacology*; D007668:Kidney / Q000098:blood supply; D008099:Liver / Q000098:blood supply; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D010100:Oxygen / Q000097:blood; D013154:Spleen / Q000098:blood supply; D013961:Thyroid Gland / Q000098:blood supply
D002245:Carbon Dioxide; D004737:Enflurane; D007530:Isoflurane; D010100:Oxygen