Proposed Clinical Guidelines for Large-Circumference Thighs
For large and obese thighs, conventional tourniquet cuffs may
not work: (1) the shape of the limb may be too tapered or conical
for a cuff designed to encircle a cylindrical limb; (2) the
presence of large amounts of fatty tissue may seriously impair
the ability of the cuff to stop blood flow when inflated to
typical tourniquet pressures; and (3) the limb circumference may
be sufficiently large so that the largest standard cuff may not
encircle the thigh.
For conical and tapered thighs typical of certain obese
patients, alternative cuffs are available if the best standard
tourniquet cuffs, such as Zimmer A.T.S. Cylindrical Cuffs, do not
fit well. For example, "Low Pressure" Thigh Cuffs are
available from Delfi Medical (www.delfimedical.com).
These specialty cuffs may provide a better fit to the highly
tapered limbs of some obese patients, and thus produce a better
tourniquet effect when inflated. Also, the Delfi Low Pressure
Cuffs are wider than standard tourniquet cuffs and the extra
width may allow a lower pressure to be used to occlude blood
flow.
A figure of the extended cuff is shown here.
To minimize the pressure required in a tourniquet cuff applied
to an obese thigh, a specialized technique of cuff application
may be worthy of consideration. Krakow, in a 1982 paper in
Clinical Orthopedics and Related Research (Vol 168) describes how
best to apply a tourniquet cuff to the thigh of an obese patient.
In essence, Krakow’s technique involves the following: (1)
the cuff is applied loosely on the proximal thigh by a first
person; (2) a second person grips the fatty tissue distal to the
thigh and retracts it distally; (3) while the tissue is being
retracted by the second person, the first person increases the
snugness of cuff application (typically, in Zimmer and Delfi
cuffs, by pulling on the ribbon tie straps with one hand and the
velcro securing strap with the other hand); and (4) the second
person releases the retracted tissue after the cuff has been
secured snugly around the limb. This technique usually results in
a cuff that stays fixed at the applied location, and that
transfers pressure well from the inflated cuff to underlying,
non-fatty tissue, thus reducing the pressure required to stop
blood flow past the cuff in the obese thigh.
To download a copy of Krakow's paper, click on the following
icon:
To estimate the minimum effective pressure required to stop
blood flow past a cuff applied to an obese thigh of an individual
patient, the use of a technique based on the measurement of the
individual patient’s "limb occlusion pressure
(LOP)" is recommended. A summary of this technique, together
with pertinent references from the clinical literature, is given here. The surgeon may wish to have
the LOP measured prior to surgery if desired.
For some extremely obese patients having fatty thighs up to 58
inches (147 cm) in circumference, special "extended
cuffs" are available from Delfi Medical; these cuffs will
encircle large-circumference thighs, but may not occlude blood
flow in all cases. Whenever such a cuff is used, is it strongly
recommended that LOP be measured by the surgeon prior to surgery,
to determine whether blood flow can be occluded by the cuff, and
if so to provide the basis for the surgeon’s determination
of the tourniquet pressure setting to be used.
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A Manoever for Improved Positioning of a
Tourniquet in the Obese Patient