Hazard [Health Devices Dec 1982;12(2):48-9]
In 1982, a British medical report (Health 1982) cited five deaths
associated with the use of pneumatic tourniquets during administration of regional
anesthesia by a technique known as intravenous regional anesthesia (IVRA) or Bier's block.
At least three of these accidents were caused by personnel deflating the tourniquet
prematurely. However, in some cases, equipment design and/or malfunction might have been
contributing factors. We also know that tourniquet malfunction leading to accidental
deflation has occurred in the United States. While nerve damage from tourniquet
overinflation has long been a recognized hazard with these devices, the risks of
underinflation or premature deflation (either deliberate or accidental) during regional
anesthesia are not widely recognized.
Surgical pneumatic tourniquets are frequently used on the extremities to
help maintain a bloodless operative field. During operations performed with IVRA, the
pneumatic tourniquet serves an additional role of preventing the infused local anesthetic
from flowing out of the limb. Deflation of the tourniquet soon after venous infusion of
the local anesthetic into a limb may result in the drug's entering the circulatory system
in a high concentration, which can cause serious adverse reactions (e.g., cardiovascular
collapse, respiratory depression, epileptic attack) or death.
IVRA is an alternative to general anesthesia for limb surgery and is
typically administered by an experienced anesthesiologist; in some cases, however, the
surgeon performs the anesthetizing procedure. First, blood is exsanguinated from the limb
(usually by wrapping it with an elastic bandage, beginning distally and squeezing and
wrapping toward the heart), and a tourniquet is inflated proximal to the operative site.
The elastic bandage is removed and the local anesthetic (e.g., bupivacaine) is injected
into the limb through an intravenous cannula. The local anesthetic remains in the limb as
long as the tourniquet is inflated. About 20 minutes after infusion, most of the
anesthetic has been absorbed into the limb tissues and deflation of the tourniquet will
not result in release of the drug in high concentration.
The pneumatic tourniquet plays a vital role in the safety and success of
IVRA; therefore, the tourniquet must be in good working order before use and must be
closely monitored for proper pressure and operation, especially just after local
Premature tourniquet deflation may result from the intentional action of
medical personnel who are not completely familiar with IVRA and its attendant risks, or
may be accidental due to equipment failure. The former problem must be addressed by
education; the latter, by effective equipment control, inspection, and preventive
maintenance, accompanied by adequate tourniquet monitoring during the operation.
Accidental tourniquet deflation due to equipment failure may result from
loose tubing connectors; deteriorated tubing (dry rot), especially over connector hose
barbs; stopcock leaks; cuff bladder leaks; and worn cuff closures (e.g., Velcro-type
Many pneumatic tourniquet cuffs contain two bladders side by side. If the
patient feels excessive pain due to the high inflation pressure (up to 600 mm Hg), the
second bladder is inflated. Then, the first bladder is deflated, thereby allowing the
tissue beneath to recover. Even if the patient experiences no pain, the anesthesiologist
may choose to alternate cuff bladders to lessen the possibility of nerve damage from
compression. However, a second cuff bladder also increases the chances of
equipment-related failure since additional tubing, connector, stopcocks, and cuff bladders
are present. It is important that the bladders be alternated using the proper
inflation/deflation sequence to ensure constant tourniquet application.
Other issues, such as the indications for use of IVRA, the comparative
toxicity from sudden intravenous injection of different regional anesthetics, and
emergency treatment for premature tourniquet deflation that results in a bolus of
anesthetic entering the circulatory system, are discussed in the articles cited in the
While the hazards of general anesthesia may be avoided by use of IVRA,
this technique also carries potentially fatal risks. Surgical and anesthesiology personnel
must be highly knowledgeable about the procedure and related equipment, including,
particularly, the risks of premature tourniquet deflation. Inform all appropriate
personnel of these recommendations.
- Inspect the tourniquet in the operating room before
each use for IVRA for proper operation and good general condition. Check the
condition of the cuff and tubing before placing the unit on the patient. The
cuff should not have torn stitching, and its closure should hold firmly. The
tubing should fasten securely to all connectors and be free of kinks,
cracks, and deteriorated material. Similarly, tubing connectors (frequently
luer taper fittings or luer locks) should mate securely.
- Verify that the unit maintains adequate pressure on
the patient's limb before injecting the regional anesthetic.
- Do not leave the tourniquet unattended during the
surgical procedure, especially during the first 20 minutes after infusion of
the anesthetic. Although the surgeon may deliver IVRA without assistance
from anesthesia personnel, once his or her attention is directed to the
operative procedure, a second person should be assigned to effectively
monitor and operate the pneumatic tourniquet.
- Be sure that the tubing that leads to the cuff from
the machine is protected from accidental contact by personnel near the
patient. Consider temporarily clamping the tubing leading to the inflated
cuff during the period immediately following infusion of the local
anesthetic. If clamping is used, place the clamp between the cuff and the
first tubing connection.
- Tourniquets are typically inflated with air
(supplied by a hand pump or from a compressed air outlet or cylinder),
nitrogen (from a compressed gas cylinder), or Freon (from a disposable
canister). On some pneumatic tourniquets, separate gauges are provided for
supply gas pressure and cuff pressure. Personnel responsible for monitoring
and/or operating the tourniquet should be especially aware of gauge
functions. Be sure to monitor the cuff pressure gauge, if present, for cuff
- When a double-bladder cuff is used, fully inflate
the second bladder and confirm its ability to maintain pressure before
deflating the first one.
- Ensure that surgical pneumatic tourniquets are included in a routine
equipment inspection and preventive maintenance program. Follow the
manufacturer's recommended procedures for inspection and repair. In
addition, be sure to check for the problems listed in this report and in
We have grouped the references by subject to aid in obtaining specific
Background information on regional
anesthesia and surgical pneumatic tourniquets
Chan KM, Ma GFY, Chow YN, et al. Intravenous regional anaesthesia in hand
surgery experience with 632 cases. Hand 1981;13:193-8.
Fitzgerald B. Intravenous regional anaesthesia in children. Br J
Heath ML. Deaths after intravenous regional anaesthesia. Br Med J
Inappropriate use of oxygen to inflate or power medical devices. Health
Inflating surgical pneumatic tourniquets. Health Devices
McEwen JA, Auchinleck. Advances in surgical tourniquets. AORN J
Rawlings ID, Staniforth P. Intravenous regional anaesthesia in upper limb
Ware RJ. Intravenous regional analgesia using bupivacaine: A double blind
comparison with lignocaine. Anaesthesia 1979;34:231-5.
Wildsmith JAW. Techniques of local anaesthesia. Update
Complications with regional anesthesia and
toxicity of anesthetics used
Albright GA. Cardiac arrest following regional anesthesia with etidocaine
or bupivacaine. Anesthesiology 1979;51(Oct):285-7.
Gooding JM, Tavakoli MM, Fitzpatrick WO, et al. Bupivacaine: Preferred
agent for intravenous regional anesthesia. South Med J 1981;74:1282-3.
Ware RJ, Caldwell J. Clinical and pharmacological studies of IV regional
analgesia using bupivacaine. Br J Anaesth 1976;48:1124-5.
Wildsmith JAW, Tucker GT, Cooper S, et al. Plasma concentrations of local
anaesthetics after interscalene brachial plexus. Br J Anaesth 1977;49:461-6.
Wildsmith JAW, Scott DHT, Brown DT. Intravenous regional analgesia using
bupivacaine. Anaesthesia 1979;34:919-20.
Wildsmith JAW, Scott DHT, Scott DB. Adverse reaction to bupivacaine.
Br Med J 1980;281(Nov):1287.
Treatment of toxic reactions to regional
Moore DC, Thompson, GE, Crawford RD. Long acting local anesthetic drugs
and convulsions with hypoxia and acidosis. Anesthesiology 1982;56(Mar):230-2.
Scott DB. Toxicity caused by local anaesthetic drugs. Br J Anaesth
- Tourniquets, Pneumatic [14-074]
- Tourniquets, Pneumatic, Automatic Rotating [10-234]
Cause of Device-Related Incident
Device factors: Device failure; Improper
maintenance, testing, repair, or lack or failure of incoming inspection
User error: Failure to perform pre-use inspection
Mechanism of Injury or Death