Spinal anesthesia reduces oxygen consumption in diabetic patients prior to peripheral vascular surgery.
OBJECTIVE
The purpose of this study was to evaluate the effect of spinal anesthesia in VO2 in a uniform high-risk patient population and also the relationship between dermatomal level of block and VO2, neither of which has been investigated previously.


METHODS
The effect of spinal anesthesia on VO2 was studied in 17 diabetic patients undergoing lower limb peripheral vascular surgery. Measurements were made before and 15 minutes after administration of a tetracaine spinal anesthetic. Values for VO2 and oxygen delivery (DO2) were derived from cardiac output as measured by thermodilution, hemoglobin concentration, and arterial and mixed venous blood gas analysis. The dermatomal level of the sensory block was determined by use of a hand-held nerve stimulator.


RESULTS
Mean VO2 decreased by 27.7% (P = .001) (95% confidence limits, decrease of 22.4-90.4%). Mean DO2 and arterial blood gases were unchanged, and the mean postspinal oxygen extraction ratio (VO2/DO2) decreased by 20.5% (P = .002) (95% confidence limits, decrease of 9.1-32.3%). There was a relationship between changes in VO2 and sensory block height (P = .029).


CONCLUSIONS
Spinal anesthesia in diabetic patients is associated with a reduction in VO2, the extent of which appears to be, at least in part, a function of the level of spinal sensory block.
Stanley
G D
GD
Department of Anaesthesia, Harvard Medical School, New England Deaconess Hospital, Boston, Massachusetts 02215, USA.
Pierce
E T
ET
Moore
W J
WJ
Lewis
K P
KP
Bode
R H
RH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000775:Anesthesia, Spinal; D003920:Diabetes Mellitus / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000378:metabolism; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects*; D014656:Vascular Surgical Procedures / Q000379:methods*
D010100:Oxygen