3
•
Prolonged tourniquet time can also produce changes in the coagulability of the blood with increased
clotting time. Always minimize tourniquet time.
•
Tourniquet paralysis may result from excessive pressure. Insufficient pressure may result in passive
congestion of the limb with possible irreversible functional loss. Always use the minimum effective
tourniquet pressure, as described in the medical literature.
•
Inflation should be done rapidly to occlude arteries and veins as near simultaneously as possible.
•
Careful and complete exsanguination reportedly prolongs pain-free tourniquet time and improves the
quality of Intravenous Regional Anesthesia (Bier Block anesthesia). In the presence of infection and
painful fractures, after the patient has been in a cast, and in amputations due to malignant tumors,
exsanguination before tourniquet application may be done without the use of an elastic bandage by
elevating the limb for 3 to 5 minutes.
•
In case of failure, the tourniquet cuff must be fully deflated and the limb exsanguinated again before
reinflation. Reinflation over blood-filled vasculature may lead to intravascular thrombosis.
•
Tourniquet users must be familiar with the inflation-deflation sequence when using two tourniquet
cuffs and two P.T.S. units together for IVRA (Bier Block anesthesia), so that the wrong tourniquet will
not be released accidentally.
•
Test for hemoglobin type and level before using a tourniquet on patients with sickle-cell anemia.
When the tourniquet is used for these patients, the limb should be carefully exsanguinated and the
PO
2
and pH should be closely monitored.
•
Select the proper cuff size to allow for the overlap recommended by the cuff manufacturer. Too
much or too little overlap may cause cuff rolling and telescoping, unexpected release of the cuff from
the limb, inability to maintain a bloodless field at normal pressures, and/or undesired pressure
distribution on the limb.
•
The skin under the tourniquet cuff must be protected from mechanical injury by smooth, wrinkle-free
application of the cuff. If the tourniquet cuff is applied over any material that may shed loose fibers
(such as Webril) the fibers may become embedded in the contact closures and reduce their
effectiveness. Follow the cuff manufacturer’s recommendations for limb protection material under the
cuff. In general, a limb protection sleeve designed specifically for the cuff provides the best
protection.
•
If skin preparations are used preoperatively, they should not be allowed to flow nor collect under the
cuff where they may cause chemical burns.
•
Whenever the tourniquet cuff pressure is released, the wound should be protected from blood surging
back by applying pressure dressings and, if necessary, elevating the limb. Transient pain upon
tourniquet pressure release can be lessened by elevation of the limb. If full color does not return
within 3 to 4 minutes after release, the limb should be placed in a position slightly below body level.
•
The deflated cuff and any underlying limb protection material should be completely removed
as soon as tourniquet pressure is released. After the cuff has been fully deflated and removed
from the patient, the unit can be set to STANDBY. Even the slightest impedance of venous
return may lead to congestion and pooling of blood in the operative field.
•
Whenever IVRA (Bier Block anesthesia) is used, it is recommended that the tourniquet remain
inflated for at least 20 minutes from the time of injection.
1.4
ADVERSE EFFECTS
A dull aching pain (tourniquet pain) may develop throughout the limb following use. Stiffness, weakness,
reactive hyperemia, & skin discolouration may also occur to some degree in all patients after tourniquet use.
Pathophysiologic changes due to pressure, hypoxia, hypercarbia, and acidosis of the tissues occur and
become significant after about 1 1/2 hours of tourniquet use.
Symptoms of tourniquet paralysis are motor paralysis and loss of sense of touch, pressure, and proprioceptive
responses.
Intraoperative bleeding may be caused by:
•
The slight impeding effect exerted by an unpressurized cuff (and its limb protection material or
padding, if used), which prevents venous return at the beginning of the operation,
•
Blood remaining in the limb because of insufficient exsanguination,
•
Inadequate tourniquet pressure, or slow inflation and deflation, all if which allow arterial blood to enter
while preventing venous return,
•
Blood entering through the nutrient vessels of the long bones, such as the femur or humerus.
