Complications and Preventive Measures
Pneumatic tourniquets are used in over 1 million surgical
cases annually in North America. The potential for injury assumes
startling proportions. Injuries resulting from pneumatic
tourniquet use are commonly pressurerelated, and can also
be caused by excessive tourniquet time. While the majority of
these problems may be transient, and perhaps even unnoticeable,
some are permanent or reversible only over extended time periods
with prolonged disability being experienced by the afflicted
person. This section of the self - study considers the most
common complications of tourniquet use, their causes, and
Nerve injury is the most common complication from the use of
tourniquets during upper - extremity surgery, and can also occur
in thigh and lower leg cuff applications. It was first recognized
more than 100 years ago. The extent of nerve injury can range
from a mild transient loss of function to permanent, irreversible
damage. Symptoms of nerve injury include an inability to detect
pain, heat, cold, or pressure over the skin along the source of
the nerve; and a sluggishness or inability to move large or small
muscles upon command.
Limb paralysis is also referred to as nerve paralysis or
tourniquet paralysis syndrome. When this occurs, all motor nerves
distal to the cuff are affected, resulting in a temporary or
permanent inability to move the extremity. The radial nerve is
the most common nerve affected. Symptoms of tourniquet paralysis
are: motor paralysis and loss of the sense of touch, pressure,
and proprioceptive responses.
Paralysis can produce considerable disability and
psychological stress in affected persons. Medical personnel may
be subject to legal action from the injured party.
The two most common causes of these nerve injuries are:
mechanical stress on the nerves under the cuff or at its edges
and anoxia or ischemia of nerves under or distal to the cuff,
which leads to a slowing or cessation of both sensory and motor
nerve conduction. Research has demonstrated that mechanical
pressure directly under the cuff leads to irreversible nerve
damage much sooner than ischemia or anoxia does. Tourniquet
paralysis may result from either excessive or insufficient
pressure, but the latter is considered more dangerous, resulting
in passive congestion with possible irreversible functional loss.
Persons with flaccid, loose skin (e.g., the elderly), or
persons with large amounts of subcutaneous tissue on cone -
shaped limbs are subject to nerve and tissue injury from a
shearing force mechanically created by an improperly fitting
cuff. Most often, shearing occurs at the proximal edge of the
cuff. Risk of shearing - related injury may be reduced by
selecting a contoured cuff (which fits the limb taper) and a
matching limb protection sleeve.
Because tourniquet - related neural injury has been linked to
mechanical rather than ischemic factors, mechanical stress merits
the most focus for preventing nerve injury. It is recommended
that the minimum tourniquet pressure that is necessary to obtain
a stable, bloodless field be employed in all circumstances.
Safety measures to prevent nerve injury and pressure - induced
complications can be summarized as follows:
- Never use a tourniquet for more than the recommended
period of time.
- Make sure that the pressure display accurately reflects
the pressure within the cuff bladder. Some nerve palsies
may be secondary to faulty pressure gauges causing
excessive tourniquet inflation pressures.
- Use only the minimal effective pressure required to
reliably maintain arterial occlusion throughout the
procedure. This is best achieved by the Limb Occlusion
Pressure technique outlined in Section 3.
- Use a cuff that properly fits the extremity and has the
maximum bladder width possible, as outlined in Section 1.
- Use a limb protection sleeve that matches the selected
- Apply the cuff to the limb with care and attention,
according to the manufacturer's instructions.
- Apply the cuff at the proper location on the limb.
Application of the cuff over the peroneal nerve (the knee
or ankle) or the ulnar nerve (the elbow) may produce
nerve/bone impingement resulting in nerve damage or
In addition, do not permit the tourniquet to slip or twist
during limb manipulation. Do not pinch or kink the connecting
tubing. Avoid wrinkling of loose, flaccid tissue and/or padding
under the cuff by using the proper limb protection sleeve for the
cuff, or 2 layer tubular stockinette which is stretched and
applies light compression to the limb when applied.
Post - Tourniquet
Post - tourniquet syndrome (PTS) is manifested by pronounced
and, at times, prolonged postoperative swelling of the extremity.
Approximately half of all post - tourniquet swelling is caused by
blood returning to the limb after the release of the tourniquet
(hyperemia). The remainder is the result of postischemic reactive
hyperemia, an additional increase of blood to restore normal acid
- base balance in tissue. Postischemic reactive hyperemia
reflects the body's attempt to cleanse the limb of the metabolic
products of anoxia. Later, additional swelling due to edema or a
postoperative hematoma may occur. Prolonged bleeding from the
surgical wound also significantly affects swelling. Post -
tourniquet syndrome is characterized by edema, stiffness, pallor,
weakness without paralysis, and subjective numbness without
Unlike nerve palsies, PTS is thought to be due primarily to
prolonged ischemia rather than the direct mechanical effect of
the tourniquet on the muscle. The tourniquet induces
neuromuscular injury by causing ischemia in the tissues distal to
the tourniquet, and by compression and ischemia in tissues
beneath the cuff.
Postoperative weakness, edema, stiffness, dysesthesia, and
pain may be falsely attributed to surgical trauma or to lack of
patient motivation if the clinician does not have an adequate
index of suspicion of tourniquet - related neuromuscular injury.
Randomized, prospective studies have demonstrated EMG
abnormalities in extremities treated with a routine pneumatic
tourniquet. These neurophysiologic changes may be associated with
weakness of the involved extremity and a longer clinical recovery
time; in fact, postoperative EMG abnormalities persist as long as
5 months in some cases.
Recent experimental studies suggest that the magnitude of
skeletal muscle injury beneath the tourniquet is related to a
complex interaction of the cuff pressure and duration.
The complication occurs in patients who have had tourniquets
applied for a prolonged time and also in patients whose
tourniquet cuff pressures were insufficient to prevent arterial
inflow while preventing venous outflow. Under inflation of the
tourniquet cuff is a particular risk for elderly patients who
frequently have extensive calcification of the major arteries,
which renders the vessels noncompliant to tourniquet pressure.
Rheumatoid arthritis patients on steroid treatment experience the
same problem in which a bloodless field cannot be obtained
because of steroid - induced vascular calcification. Because of
the significance of postoperative bleeding, patients with
prolonged clotting times also are at risk for post - tourniquet
Preventive measures for PTS are similar to those for nerve
injury complications. During the preoperative assessment, review
the patient's physiological status, including:
- Medication history. A patient's drug history should
detect the routine ingestion of any drug that will
influence clotting time or promote development of
atherosclerotic vascular disease. Among these are
steroids, aspirin, and birth control substances.
- History of hypertension.
- Clotting time.
- History of past thromboembolic occurrences.
- Evidence of arterial calcification.
Comply strictly with the recommended tourniquet time limit. A
higher than normal pressure may be required, particularly in
larger limbs, and it is particularly important with these at -
risk patients to use arterial occlusion pressure (see LOP section
above) rather than systolic blood pressure to determine the most
appropriate tourniquet cuff pressure and if possible to avoid
exceeding the recommended maximum cuff pressure limits (typically
recommended to be 300 - 350 mmHg for the thigh and 250 - 300 mmHg
for the arm and lower leg).
Intraoperative bleeding may be caused by:
- An underpressurized cuff. Underinflation of the
tourniquet cuff can result in venous pooling, leading to
passive venous congestion of the limb, hemorrhagic
infiltration of the nerve, and oozing of blood into the
- Blood remaining in the limb because of insufficient
- Too - slow inflation and deflation, both of which allow
arterial flow to enter while preventing venous return.
- Improper selection of the cuff, resulting in a poor or
- Excessive padding between the cuff and the limb, which
prevents a snug fit.
- A cuff that is applied too loosely.
- Blood entering through the intramedullary nutrient
vessels of the long bones (such as the humerus).
Theoretically, if breakthrough arterial bleeding does
occur, it does so less often than the venous ooze due to
medullary cavity bypass of venous blood.
To prevent intraoperative bleeding, take care to select the
proper style and size of tourniquet cuff, if limb protection is
to be used then use the matching limb protection sleeve or
similar stretched tubular stockinette rather than a thick buildup
of padding, apply the cuff snugly, and inflate it to the optimal
pressure. If the tourniquet cuff pressure selected is
insufficient to control bleeding into the operative field,
increase pressure in 25 mmHg increments until a satisfactory
bloodless field is achieved. Some surgeons may prefer to deflate
the cuff, re - exsanguinate the limb, and reinflate to a higher
pressure in order to prevent the blood from being trapped in the
distal part of the extremity.
Compartment syndrome is a condition in which external and
internal pressures on a confined space result in swelling of the
extremity. It is a relatively rare complication of tourniquet
use. The compartment is the area between the two tough fascia
layers of a muscle group. An infinitesimal amount of fluid in the
space normally allows contraction and relaxation of the muscle
group within its covering fascia. There is no room for additional
fluid. The first symptom of compartment syndrome is usually pain
that increases in severity and cannot be alleviated by narcotics.
Other symptoms include muscle weakness, paresthesia, decreased or
absent pulses, tense skin over the limb and, in some cases,
The combination of external compression and an increase in
compartment contents due to either trauma or surgery may cause a
compartment syndrome. Like PTS, this complication is due to
tourniquet ischemia time. Prolonged tourniquet times lead to a
fall in tissue pH, an increase in capillary permeability, and a
prolongation of clotting, all of which promote the development of
a compartment syndrome.
Patients at risk for tourniquet - related compartment syndrome
are those with a previous history of compartment syndrome
symptoms. Patients with McArdle's disease (a muscle phosphorylase
deficiency disease) exhibit compartment - like syndromes after
about 20 minutes of vigorous exercise. Use of a pneumatic
tourniquet on these patients, even for a short time, may lead to
Also at risk are patients who must have a cast placed on a
limb prior to tourniquet release. Post - tourniquet swelling, if
inhibited by a cast, can lead to compartment syndrome.
The following are preventive measures for compartment
- Preoperative evaluation of the patient's personal and
family history for any previous compartment syndrome -
like symptoms; patients with McArdle's disease are
- Limit tourniquet time to under 90 minutes before allowing
an aeration interval as outlined in Section 3.
- Avoid solid cast placement prior to tourniquet cuff
Sores and Chemical Burns
Pressure sores, skin blisters, and chemical burns are uncommon
consequences of pneumatic tourniquet use; however, when they do
occur, they cause considerable patient discomfort. Although
occasionally seen in adults, chemical burns beneath the cuff
occur most frequently in the sensitive skin of children.
Tourniquets can also cause skin damage due to shearing stresses.
These stresses tend to occur at the time of inflation and may be
a particular problem in older patients with delicate skin.
Surveys of clinicians show that skin injuries occur with and
without fluid accumulation under the cuff and can be attributed
to fluid leakage, excess pressure, excess tourniquet duration or
a combination of these factors. In one case report severe
friction burns were caused by a thigh cuff sliding distally off
the underlying padding during the procedure.
Pressure sores and skin blisters are the result of skin
breakdown, friction, or soft tissue folding under the tourniquet.
Pressure necrosis or shearing may be due to inadequate padding or
faulty cuff application in patients with loose or thin skin, such
as obese patients or elderly patients with loose, flabby skin.
Patients with compromised circulation, such as those who are
elderly or diabetic, are also at higher risk for pressure sores.
Chemical burns may be caused by antimicrobial prep solutions
seeping under the tourniquet cuff. When the cuff is inflated, the
solution is held tightly against the patient's skin. Chemical
burns are most likely to occur when prep solutions come in
contact with the rather delicate skin of young children.
The following measures will help prevent pressures sores and
- Use adhesive tape or an adhesive edged drape between the
distal edge of the cuff and limb to prevent prep solution
from leaking under the tourniquet; this also keeps the
cuff free from stains.
- Position the cuff properly on the limb. Apply the cuff
high on the limb and away from the joints; bony joints
prevent compression of blood vessels and proper fit.
- Use the correct limb protection technique as recommended
for the selected cuff. If available, use a limb
protection sleeve specifically designed for the cuff.
This will provide light compression and give a toning
effect to loose skin, reducing the tendency of the cuff
to gather up the skin into a wrinkle or pinch, and is
more likely to be smooth and wrinkle - free than loose,
wrapped padding. Use sufficient length of material to
extend distally beyond the cuff, and fold this material
back over the cuff to help prevent the cuff from sliding
distally off the material.
- For better cuff placement on the obese patient, draw the
subcutaneous tissue and skin distally before applying the
tourniquet. After the tissue is released, it will help
hold the cuff in place.
- Do not readjust an already positioned tourniquet cuff
using rotation. Rotation produces shearing forces which
may damage the underlying tissues.
Digital necrosis is the gangrenous destruction of a finger or
toe as a result of prolonged ischemia/anoxia.
The common practice of using a Penrose drain, rubber band, or
a rolled finger of the surgical glove as a tourniquet is
associated with this complication. Causes of digital necrosis
- Failure to remove the constricting device. This is more
prevalent when rubber bands or Penrose drains are used,
since they can be easily overlooked.
- Excessive, uncontrolled pressure. This is a potential
problem with all nonpneumatic tourniquets.
- Prolonged tourniquet time.
Patients at risk include those with impaired circulation
(i.e., Raynaud's syndrome, peripheral vascular disease, diabetes,
etc.), those with small limbs, and the elderly.
Digital necrosis can be prevented by taking the following
- Adhere strictly to a predetermined tourniquet time.
- Eliminate excessive, uncontrolled pressure from the
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.
The major cause of adverse effects of IVRA and/or failure of
the technique is technical error. A toxic reaction may result
- 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
- Under inflation of the tourniquet cuff. If complete
occlusion is not present, leakage of the anesthetic will
In general, high - risk patients have a hypersensitivity to
the anesthetic agent, a condition that makes arterial occlusion
difficult (i.e., obesity, hypertension, arterial calcification,
etc.), a chronic respiratory disease (e.g., chronic obstructive
pulmonary disease); congestive heart failure; or CNS impairments
(e.g., seizure disorders). Many of these problems are associated
with advanced age; thus, elderly patients with any of these
conditions are at high risk.
One study found detectable levels of anesthetic agent in the
general circulation even while the tourniquet was properly
inflated. The authors suggested that the hemodynamics in the
skeleton allowed endosteal (intraosseous, medullary) venous
outflow from the extremity, using the bone as a tourniquet bypass
while the tourniquet still effectively blocked extraosseous
arterial inflow and venous return. Thus, venous blood from the
extremity slowly entered the general circulation through this
intraosseous skeletal bypass.
The following preventive measures will reduce the possibility
of toxic reactions:
- Test the tourniquet system before each use.
- Obtain a complete allergy history when IVRA is being
contemplated. Of particular note is any allergic reaction
to any local anesthetic agent used for dental work or
another surgical procedure. Persons who have contact,
inhalation, and/or food allergies are also suspect
because of their hypersensitivity. Such an immunological
hypersensitivity may preclude the use of IVRA unless
other physical conditions rule out general anesthesia.
- Obtain a complete medical history to detect the presence
of cardiopulmonary or renal disease, seizure disorders,
vascular problems, morbid obesity, diabetes, and the
like. The severity of such problems may eliminate
administration of a general anesthetic and make IVRA the
better of two poor choices.
- Ensure proper size and fit of the tourniquet cuff. Use a
dual - bladder tourniquet for IVRA.
- Ensure that the limb is occluded at the selected cuff
pressure by confirming absence of a distal arterial
pulse. Limb Occlusion Pressure (LOP) is particularly
useful in setting the cuff pressure in IVRA procedures
due to the importance of maintaining occlusion.
- Use of the dual bladder tourniquet cuff provides a
measure of safety. If the distal bladder should
accidentally deflate, the proximal bladder can be
- Use intermittent deflation and reinflation of the
tourniquet cuff at the end of the procedure; this
releases the local anesthesia and waste chemicals into
general circulation in small amounts.
- Observe the patient's physiological status at all times
for any sign or symptom of a toxic reaction, beginning
immediately after injection of the anesthetic.
Deep venous thrombosis and the associated risk of pulmonary
embolism are a major cause of morbidity and mortality in lower
extremity orthopaedic surgery and have led to the use of various
prevention modalities. Lower extremity deep venous thrombosis has
been identified at autopsy as the source of pulmonary embolism in
several cases of tourniquet - related cardiac arrest. Less severe
episodes of venous embolism during surgery using tourniquets may
not be recognized by simple clinical observation.
To prevent dislodgement of thrombi, do not use an elastic
bandage for exsanguination in a patient with a traumatic injury
or in a patient who recently has been in a cast. Some experts
recommend subtherapeutic heparinization prior to the inflation of
Other complications of pneumatic tourniquet use might include:
- Tourniquet Pain.
- Thermal Damage to Tissues.
- Metabolic Changes.
Tourniquet pain is the most common complication seen in
clinical practice, Hypertension and a dull, aching pain
(tourniquet pain) throughout the limb may develop during and
following tourniquet use, despite otherwise adequate anesthesia.
The initial sensation of pressure at the tourniquet site is
replaced by a progressive numbness and paralysis, progressing to
complete paralysis. A severe, aching sensation at the site of the
tourniquet or distal extremity progressively develops. After
deflation of the tourniquet, a different pain sensation is noted,
associated with reperfusion of the limb. This sensation is
described as being equal to or greater than the intensity of the
discomfort caused by the tourniquet immediately before deflation.
The average time of pain tolerance after inflation of the
tourniquet seems to be about 30 minutes in unsedated patients.
Heat generated by surgical lights or powered surgical
instruments is not dissipated in limbs under tourniquet control,
and tissue may be subject to drying or trauma. Frequent
irrigation, special draping, and low - power surgical lights are
recommended to reduce the risk of thermal damage to tissues.
Limb tourniquets have been associated with a progressive
increase in central body temperature in pediatric patients, and
the increase is significantly greater when bilateral tourniquets
are used. It has been suggested that pediatric patients requiring
intraoperative tourniquets should not be aggressively warmed
Rhabdomyolysis has been described rarely as a complication of
prolonged ischemia time after tourniquet application. It is
defined as the release of the cellular contents after damage to
skeletal muscle and has a variable clinical presentation. Pyrexia
and tachycardia develop, and patients often complain of pain,
tenderness, edema, and hemorrhage of the limb. Classically, the
urine is dark and oliguria may develop. Prompt recognition and
early treatment prevent long term sequelae.
While the tourniquet is inflated, metabolic changes occur in
the ischemic limb, changes that include increased PaCO2,
lactic acid, and potassium, and decreased levels of PaO2
and pH. Pathophysiologic changes due to pressure, hypoxia,
hypercarbia, and acidosis of the tissue occur and become
significant after about 90 minutes of tourniquet use.
Deflation of the tourniquet results in the release of these
products of ischemia into the general circulation. The resultant
decreases in arterial pH and PaO2 and increases in
arterial lactic acid, potassium, PaCO2 and end tidal
carbon dioxide are associated with significant decreases in mean
arterial and central venous pressures and increases in heart
rate. The clinical significance of these changes is not yet
clear; in healthy individuals, no significant adverse effects
have been observed. However, the rapid increase in PaCO2
after thigh tourniquet release would be expected to result in a
corresponding increase in cerebral blood flow (CBF), which could
be dangerous in patients with increased intracranial pressure. It
may be prudent to monitor the increase in CO2 and
treat it promptly by hyperventilation.
Metabolic changes are generally more pronounced when bilateral
tourniquets are used, and it is also thought that the risk of Fat
Embolism Syndrome (FES) upon release of the tourniquet in
procedures such as bilateral total knee arthroplasty is reduced
if deflation times are separated by 30 - 45 minutes.
Use of a pneumatic tourniquet to produce a bloodless surgical
field places the patient at risk for complications. Certain
patients, because of their size, age, or physical condition, are
more likely to respond unfavorably to pneumatic tourniquet use
than others. Since most complications are pressure - related,
institute the following preventive measures:
- Conduct an adequate preoperative patient assessment.
- Assure an accurate pressure display.
- Use a tourniquet cuff that has the proper fit and size
and can maintain occlusion of arterial blood flow at the
minimum effective pressure.
- Accurately determine systolic blood pressure.
- Pay attention to tourniquet cuff pressure.
- Inform the surgeon regularly of elapsed tourniquet time.
Physicians are responsible for determining the correct cuff
pressure and tourniquet time, but nurses share responsibilities
for many of these measures. In addition, nurses assume
responsibility for maintenance of the cuff and accessories.