Recently Asked Questions
Question 1: How should an Esmarch bandage be
used for best exsanguination?
Answer 1:
When wrapping an Esmarch bandage it is
very important that tension in the elastic bandage be
maintained during the entire application of the bandage to
the limb.
In upper limb surgery, and especially for
hand surgery, one problem area can be in the region of the
patient's hand, specifically in the region of the fingers and
the palm. Generally, surgical staff will elongate
the fingers and have them positioned in a "bundle"
as the bandage is wound around the hand. This results
in excellent exsanguination within the fingers but produces
an area of low pressure in the region of the palm. To
eliminate this low pressure region and improve
exsanguination, it may be beneficial to first place a soft
ball (or some other round object) in the palm of the hand and
if possible wrap the fingers around the ball, then begin
exsanguination of the hand with the Esmarch bandage.
An area of concern, for lower limb surgery
and upper limb surgery, is that tension in the Esmarch
bandage may not be maintained uniformly around the limb
as the bandage is wrapped. Surgical staff
typically pull or tension the bandage in a single direction
away from the limb as they exsanguinate the patient's arm or
leg. This results in a higher degree of tension and
compression along one side of the limb and little to no
tension and compression along the opposite side of the limb
as the bandage is wrapped proximally up the limb. This
variation in compression results in poor exsanguination and
exposes the soft tissues of the limb to unnecessarily high
shear stresses.
To overcome this, a better approach is to
tension the bandage in "two" directions away from
the limb rather than a single direction as describe
above. For example, if we were to look at the limb in
cross section and using the face of a clock to assist in this
description, as the bandage is wrapped around the limb
tension is applied in a "3 o'clock" direction, the
tension is maintain and the bandage is wrapped around the
limb to the "9 o'clock" position. The
bandage is again tensioned and the tension is maintain as the
bandage is wrapped around the limb back to the "3
o'clock" position. The two direction technique is
repeated all the way up the limb resulting in a more uniform
compression in the soft tissues, reduced shear stresses
within the soft tissues and a superior exsanguination of the
limb.
For best exsanguination, the Esmarch
bandage should be wound up to, and over, the distal edge
of the tourniquet cuff. The Esmarch bandage
should remain in position until the tourniquet cuff is
pressurized. After the pressure in the cuff has reached
the desired level, the bandage may be removed from
the limb.
Question 2: Is there an ideal tourniquet deflation
rate?
Answer 2: Venous congestion occurs when the
pressure in a partially deflated cuff is below limb occlusion
pressure but above venous pressure. This condition blocks venous
outflow from the limb but allows arterial flow into the limb. If
this period of time becomes significant due to overly slow
deflation, then venous congestion will be considerable and that
is hazardous. Hemorrhagic infiltration of nerves may occur if the
cuff is deflated too slowly. Special considerations and
precautions apply for IVRA.
Question 3: Regarding tourniquet deflation rates and
deflation times associated with the use of Intravenous Regional
Anesthesia (also called IVRA or Bier block anesthesia), what are
the special considerations and precautions?
Answer 3: Special considerations and
precautions are given in relevant excerpts (below) from the AORN
2009 Recommended Practices on Pneumatic Tourniquets, and from
relevant sections of this educational website, as excerpted
below. See also the cited references for more detailed
information.
From 2009 AORN Recommended Practice XIII:
Potential patient injuries and complications
associated with intravenous regional anesthesia (IVRA,Bier
block) should be identified and safe practices should be
established.
The tourniquet should be deflated gradually as
determined by the physician to minimize the potential for an
adverse reaction. As the tourniquet cuff deflates, the
anesthetic agent is released into the circulatory system,
causing systemic effects.
The perioperative registered nurse circulator
should be aware of the patients physiological status.
Adverse reactions to local anesthetic agents are potential
complications of IVRA. A bolus of local anesthesia entering
the general circulation can occur when there is a sudden
deflation of the tourniquet, from deflation soon after
injection of local anesthetic, or if the bolus is released
too rapidly at the end of the procedure. The sudden rush of
anesthetic and metabolites into the circulatory system
affects the central nervous system (eg, ringing in the ears,
tingling, numbness, loss of consciousness, seizures) and the
heart.
From Complications and Preventive
Measures elsewhere in www.tourniquets.org:
Intraoperative Bleeding
may be caused by too slow inflation and deflation, both of
which allow arterial flow to enter while preventing venous
return.
Toxic Reactions to
local anesthetic agents are potential complications of IVRA.
Hypersensitive patients can exhibit generalized symptoms
almost immediately. The greatest danger is an inadvertent
bolus of local anesthetic entering the general circulation,
which can affect the central nervous system and the heart.
Early recognition and prompt treatment of early signs of
toxicity such as dizziness, drowsiness, respiratory
depression, tinnitus, and bradycardia may prevent progression
to more serious complications, like grand mal seizures, coma,
cardiorespiratory depression, and even cardiac arrest and
death.
Causes: The major cause of
adverse effects of IVRA and/or failure of the technique is
technical error. A toxic reaction may result from:
Accidental, sudden deflation of the
tourniquet.
Deflation of the tourniquet too soon after
injection of local anesthetic; prior to tourniquet
release, approximately 15 - 20 minutes is required to
maximize tissue binding of the local anesthetic, thus
removing the anesthetic from the circulatory system.
Single release of tourniquet pressure at the end
of IVRA procedures. This results in a sudden infusion of
metabolic waste products and local anesthetic into the
circulatory system.
Under-inflation of the tourniquet cuff.
If complete occlusion is not present, leakage of the
anesthetic will occur.
Safety considerations relating to
inflation/deflation rate and time during IVRA, from elsewhere in
www.tourniquets.org:
1. When IVRA is used, it has been suggested in
published literature that the tourniquet remain inflated for
a minimum of 20 minutes from the time of injection to ensure
that most of the anesthetic agent has been absorbed into the
limb tissue. For a procedure requiring only a few minutes,
too rapid a release of anesthetic agent can be prevented by
quickly deflating and reinflating the cuff several times, or
by slowly decreasing the cuff pressure.
2. Upon completion of the procedure, fully deflate the
tourniquet bladder, while the surgeon elevates the limb to
enhance venous return and exerts pressure over the incision
to prevent bleeding and hematoma formation. Deflation to zero
pressure each time is important to prevent venous distention,
which leads to bleeding and hematoma formation. A short (15 -
second) deflation period permits the wash of local anesthesia
and anaerobic waste products back into the general
circulation in small doses to minimize toxic reactions.
3. Observe the patient's mental status and cardiac monitor
carefully, as this is the time when complications are most
likely to occur.
4. Reinflate for 30 - 45 seconds to allow nourishment of the
tissue with oxygenated blood and diffusion of the anesthetic
agent and waste products back into venous circulation.
5. Apply the dressing and move the patient to the recovery
area.
6. The anesthetic effect recedes within 15 - 20 minutes, and
patients can be safely discharged from the post anesthesia
care unit more promptly than when other anesthetic techniques
are used.
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