Tourniquet Guide Issue 2.0 May 2009

8.

9.

Intraoperative monitoring

14-15

8.1 8.2 8.3 8.4

14 14 14-15 15

Blood pressure Tourniquet pressure Tourniquet time Cuff deflation

Possible complications and preventive measures

15-18

9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8

16 16 16 17 17 17 18 18

Cardiovascular Temperature Skin Nerve injury Muscle / Post Tourniquet Syndrome (PTS) Intraoperative bleeding Toxic reactions Congestion and pooling of blood in the operative field

10. Summary

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1. Definition of a Tourniquet A Tourniquet can be defined as a compressing device used to control venous and arterial circulation to the upper or lower extremity for a period of time. Pressure is applied circumferentially upon the skin and underlying tissues of a limb; this pressure is transferred to the walls of vessels, causing them to become temporarily occluded. In surgical settings, the purpose of a Tourniquet is to exert enough pressure on the arterial blood flow in a limb following exsanguination to produce a relatively bloodless operative field.

2. Brief history 1628:

William Harvey, an English surgeon discovers and traces the human circulation.

1718:

Jean Louis Petit, a French surgeon, develops the mechanical twisting device. He names the device “Tourniquet” (which derives from the French word “tourner” meaning to turn).

1864:

Joseph Lister is credited with being the first to use a Tourniquet to create a bloodless surgical field. For exsanguination, he recommends elevation of a limb for 4 minutes before applying the Tourniquet.

1873:

Johann von Esmarch develops a rubber bandage for exsanguination and Tourniquet use. The device is superior to Petit's screw device, because Petit's cloth bandages tore and the screw could untwist.

1881:

Volkmann demonstrates that limb paralyis might result from use of the Esmarch Tourniquet.

French mechanical twisting device

Modern Esmarch Bandage

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1904:

1908:

An inflatable (pneumatic) Tourniquet is developed by Harvey Cushing. To constrict the blood vessels, compressed air is introduced into a cylindrical bladder. This device has two advantages over the Esmarch Tourniquet: (1) rapid application and removal; and (2) decreased incidence of nerve paralysis. August Bier introduces the use of two Tourniquets for administering segmental anesthesia. In this two-Tourniquet procedure, circulation is isolated in a portion of the extremity and anesthesia is infused intravenously. The procedure does not become popular at that time.

1980:

Modern pneumatic Tourniquet systems were invented.

Nowadays:

Modern pneumatic Tourniquet systems are invented.

VBM Manual Tourniquet

VBM Double Cuff

1982: First Generation VBM Tourniquet

2006: VBM Digital Tourniquet

3. Two distinct types of Tourniquets 3.1

Non-inflatable (non-pneumatic) Tourniquets

These Tourniquets are usually made of rubber or elastic cloth. Nowadays, the surgical use of non-inflatable Tourniquets is very limited as they have been replaced by modern Tourniquet systems connected to inflatable cuffs. For phlebotomy or intravenous infusion, simple elastic Tourniquets may be utilized. Roll-On Cuffs or elastic bandages are used to control bleeding following procedures such as vein stripping. For prehospital care of a patient with trauma to an extremity, a non-pneumatic tourniquet may be employed as a last resort to control hemorrhage.

Non-inflatable Tourniquet “Tourny”

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3.2

Pneumatic Tourniquet VBM compressed air Tourniquet

A pneumatic Tourniquet uses an air-inflated cuff to constrict blood flow. A regulating device on the Tourniquet machine can control the amount of cuff pressure exerted on the limb. Pneumatic Tourniquets are available electrically driven (by an integrated pump) or for central compressed air supply.

4. Indications pneumatic Tourniquets There is a large variety of different indications for the use of a pneumatic Tourniquet. Following are possible indications:  Reduction of certain fractures  Arthroscopy of knee, wrist, digits, hand or elbow  Bone grafts  Kirschner wire removal  Traumatic or nontraumatic amputations  Tumor and cyst excision  Subcutaneous fasciotomy  Nerve injuries  Tendon repair  Replacement or revision of the joints of the knee, wrist, digits, hand or elbow  Correction of a hammer toe  Podiatry This list is not exhaustive and other indications could be possible.

5. Contraindications pneumatic Tourniquets Following is a list of possible contraindications:  Open fractures of the leg  Post-traumatic lengthy hand reconstruction  Severe crushing injuries  Elbow surgery (with concomitant excess swelling)  Severe hypertension  Skin grafts (to help distinguish all bleeding points) 7

 Compromised circulation (e.g. peripheral artery disease)  Diabetes mellitus There are other cases where special attention will be required when a Tourniquet is applied. This will be described in the following sections.

6. Tourniquet cuffs 6.1

Cuff position (location)

Different cuffs are designed to be placed on different extremities. VBM produces the largest available variety of cuffs, to ensure that the right cuff can be used for all different procedures. Make sure to apply the correct cuff size, which depends on shape, length and width of the limb. The cuffs should be applied to the verified operative extremity in location with adequate muscle mass to protect nerves and vessels.  Upper arm and thigh Tourniquet Cuffs should be positioned on the limb at the point of maximum circumference proximal to the incision.

 Forearm Tourniquet Cuffs should be positioned mid-forearm.

 Lower leg Tourniquet Cuffs should be placed with the proximal edge on the largest area of calf circumference.

 Ankle Tourniquet Cuffs should be placed over the lower third of the lower leg, with the distal edge proximal to the malleoli.

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To improve cuff positioning on an obese patient's extremity, an assistant should manually grasp the adipose tissue of the extremity and gently apply and hold traction distal to the Tourniquet site until the cuff is placed. Traction should be maintained until the cuff is secured. The patient's skin under the cuff should be protected to prevent fluid accumulation (e.g., skin prep solutions, irrigation) under the cuff, which may cause skin injury. Also, reusable cuffs should be protected from contamination by fluid, blood and other potentially infectious material during surgery. VBM offers a disposable cuff protection cover for these purposes.

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VBM Cuff Cover

The cuff tubing should be positioned on or near the lateral part of the extremity to avoid pressure on nerves and kinking of the tubing. Also it should direct away from the operative field to avoid any complications.

6.2

Single bladder vs. double bladder design

Depending on the surgical procedure a single or double cuff will be necessary. For general-, spinal- or plexus anesthesia a single cuff is usually used. For intravenous regional anesthesia (IVRA also known as Bier’s Block) a double cuff is usually applied. Inflation and deflation of each bladder can be controlled separately to permit switching cuff inflation from the proximal to the distal bladder after injection of the local anesthetic. Under the distal bladder the local anesthetic is effective to avoid pain caused by the inflated cuff. This enhances safety and patient comfort, particularly for longer procedures. Consider that the bladder of a double cuff is usually narrower than that of a single cuff and therefore higher pressures might be necessary for a safe limb occlusion.

VBM Single Cuff

VBM Double Cuff

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6.3

Cuff shape

Standard straight (or cylindrical) Tourniquet Cuffs are designed to fit optimally on cylindrically shaped limbs. However, human limbs may be conical in shape (particularly in extreme muscular or obese patients) which can result in poor fit, sliding of the cuff distally on the limb during the procedure and inability to achieve a proper bloodless field at normal pressures if standard straight cuffs are used. Therefore VBM offers a variety of Contour Cuffs. Contour Cuffs have an arced design that gives them a smaller diameter distally than proximally when wrapped. Contour Cuffs enhance comfort in patients and ensure a snuggish fit with conically shaped limbs and thus reduce the risk of mechanical shearing. Also they are ideal for obese or very muscular patients as they require lower pressures than straight cuffs, which may be attributable to better cuff fit and more efficient transmission of pressure to deep tissues.

6.4

Contour Cuff for conical shaped limb

Cuff length

The cuff length is usually chosen by a perioperative nurse. The important measure when choosing a cuff length is the length of the bladder inside of the cuff. On VBM Tourniquet cuffs, the inflatable bladder extends the full length of the cuff. A cuff that is too long or too short can cause problems. If a cuff is too long (excessive overlap) it may be difficult to apply snugly and it may be less stable. Both problems may prevent efficient occlusion of the extremity at normal cuff pressures which can lead to loss of occlusion during the procedure and skin injury.

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Excessive overlap

If a cuff is too short (too little / no overlap) it will produce uneven distribution of pressure and it can lead to loosening of the cuff or an inefficient occlusion.

Too little / no overlap

VBM cuffs are color coded and a corresponding measuring tape is available to assist the user in selecting the most appropriate cuff for the patient. To determine the appropriate cuff length, measure the circumference of the limb near the middle of the location chosen for the cuff.

RX EF 20

- X-7 11

VBM measuring tape

The maximum overlap with VBM Tourniquet Cuffs should not exceed ¼ to ⅓ of the overall cuff length.

Correct overlap

6.5

Cuff width

Wide Tourniquet Cuffs require lower inflation pressures than narrow Tourniquet Cuffs to ensure a safe occlusion. This may be related to more efficient pressure transmission to the deeper tissues with a wider cuff. The lower pressure may reduce the risk of pressure related injury to the patient. Therefore the widest possible cuff should be selected.

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6.6

Disposable vs. reusable Cuffs

VBM offers sterile, disposable cuffs for situations that require placement of a sterile Tourniquet Cuff near the operative site, or for use in contaminated surgical cases. The design and material of VBM Disposable Tourniquet Cuffs are suitable for single use only and therefore these cuffs must not be resterilized or reused and must be discarded at the end of the procedure. VBM also offers reusable Silicone Cuffs which can be sterilized in an autoclave at 134°C (273°F) to allow sterile application.

6.7

Limb protection beneath Tourniquet Cuffs

It has been suggested in published literature to use underpadding below the Tourniquet Cuff. It can help reduce wrinkling, pinching and shearing of the soft tissues. Too thick layer of underpadding should be avoided as it will increase the required pressure for safe limb occlusion.

7. Tourniquet Cuff Pressure The pressure to which a Tourniquet Cuff should be inflated depends on a number of variables, including the patient's age, skin, blood pressure and the shape and size of the extremity in question, as well as the dimensions of the cuff. Different approaches to calculate the ideal cuff pressure do exist. It has been suggested in published literature that for normal patients, effective tourniquet operation may be achieved at pressure settings of 75-100 mmHg above the preoperative systolic pressure for upper limbs, and two times the preoperative systolic blood pressure for lower limbs when using single bladder cuffs.

7.1

Patient assessment

Every patient should be assessed before applying a Tourniquet Cuff. Ideally the preoperative assessment is conducted the day before surgery is scheduled. The preoperative assessment should include the review of the patient's physical status and medical history since allergies, medications or preexisting disease like for instance arterial calcification or diabetes could complicate the Tourniquet use. Lower cuff pressures to achieve occlusion may be tolerated in younger patients due to youthful vessel compliance. 12

During the patient assessment, the operative limb should be measured for the selection of the proper size Tourniquet Cuff and the patient's blood pressure should be recorded.

7.2

Blood pressure

The patient's systolic blood pressure is the most important criterion for determining the lowest cuff pressure required to achieve a safe occlusion of a limb. The patient's systolic blood pressure can increase during the operation and in average the increase has been measured to be approx. 50 mmHg.

7.3

Cuff design, fit and snugness of application

Tourniquet Cuff design also affects the minimum cuff pressure needed to occlude arterial flow. With dual bladder cuffs, a higher pressure is often required to achieve occlusion and ensure a bloodless operative field because the individual bladders are narrower. It has been reported that curved and wider Tourniquet Cuffs occlude blood flow at a lower inflation pressure than straight narrow cuffs. Contour Cuffs also enhance comfort in patients with conically shaped limbs and reduce the risk of mechanical shearing. If a cylindrical cuff is used on a significantly tapered limb, the effective width of the bladder is reduced due to the loose distal portion of the cuff and the required pressure may be higher than normal. Similarly, if a cuff of any design is applied too loosely or applied over a thick layer of loose padding, higher pressures may be required to occlude the limb.

7.4

Limb circumference

The circumference of the limb at the site of cuff application also affects the cuff pressure required to occlude the limb. Circumference is also an external indicator of the depth of soft tissue through which Tourniquet Cuff pressure must be exerted. Research has demonstrated that soft tissue pressure is lower than Tourniquet Cuff pressure and decreases with the depth of the tissue. For a slender, thin limb, the cuff pressure indicated on the pressure display is very close to the pressure actually exerted on the deep artery. Limbs with a large mass of fatty or muscular subcutaneous tissue require a higher Tourniquet Cuff pressure to ensure sufficient pressure to occlude the limb. Similarly the lower extremities (legs) have a higher tissue mass than the upper extremities (arms);

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therefore, a higher Tourniquet Cuff pressure is necessary to transmit sufficient pressure through the tissue to occlude the deep vessels.

7.5

State of the tissue

The state of the tissue (its flaccidity or tenseness) at the site of cuff application also has an effect on the pressure exerted. Folds and puckers in underlying flabby tissue can cause skin injury and uneven pressure on vessels. Tense, strong muscle resists pressure more readily than soft muscle.

7. 6

Vascular status

Usually the presence of atherosclerotic vascular disease or similar diseases that occlude the artery demands higher Tourniquet Cuff pressure. Atherosclerotic vascular disease is a common condition in older patients.

8. Intraoperative monitoring Intraoperative monitoring of blood pressure, Tourniquet pressure and Tourniquet time reduces the risk of complications.

8.1

Blood pressure

Monitor the patient's blood pressure for fluctuations during the procedure and pass on this information to the surgeon.

8.2

Tourniquet pressure

Monitor and adjust the Tourniquet pressure during the procedure if necessary.

8.3

Tourniquet time

There is general agreement that for reasonably healthy adults 120 minutes should not be exceeded without releasing the Tourniquet for a short time. If the surgeon decides on performing a reperfusion to allow for removal of metabolic waste products from the limb and nourishment of the tissue with oxygenated blood after 14

a certain time the limb should be elevated and a steady pressure should be applied on the incision with a sterile dressing. Unfortunately the time limits for subsequent ischemia are unknown. The suggested reperfusion time between successive ischemic periods has ranged from three minutes to twenty minutes. Therefore a reperfusion time of 10-15 minutes for the first reperfusion and 15-20 minutes for every subsequent reperfusion are suggested. In any case the surgeon should be informed after 60 minutes of elapsed operation time and after all subsequent 30 minutes. VBM Digital Tourniquets have a visual and acoustic warning signal that automatically activates after the first 30 minutes of elapsed operation time and after every subsequent 30 minutes.

8.4

Cuff deflation

The final deflation of the Tourniquet Cuff should be done after wound closure. Tourniquet release prior to wound closure is associated with significantly greater blood loss and demands in blood transfusion, suggesting release following wound closure would offer better control. VBM Tourniquets have a unique feature due to the incorporated flush valve. The flush valve permits to check the seam for bleedings by pressing the valve for a few seconds. During IVRA (Bier’s Block) the valve permits to release the anesthetic gradually into the circulation and therefore avoids possible intoxications. Immediately remove the deflated cuff and any underlying limb protection following cuff deflation. Even the slightest impedance of venous return by the deflated cuff or padding may lead to congestion and pooling of blood in the operative field.

9. Possible complications and preventive measures All Tourniquets can cause complications ranging from minor and self limiting to severe, and even fatal. Injuries resulting from pneumatic Tourniquet use are commonly pressure related, and can also be caused by excessive Tourniquet time. Also Tourniquets are often misused and therefore a list of the most common possible complications, their causes and preventive measures is provided.

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a) 9.1

Systemic complications Cardiovascular

While the vast majority of patients tolerate inflation of the Tourniquet Cuff around an extremity, mobilization of blood volume at Tourniquet placement and release may have detrimental effects on those with coronary or cardiac insufficiency. Exsanguination of both lower limbs can account for a 15 % increase in circulating blood volume. This fluid shift accounts for the transient rise in central venous pressure and systolic blood pressure that occur in two thirds of patients having Tourniquets applied under general anesthesia, while occurring in only 2.7 % of patients undergoing spinal anesthesia.

9.2

Temperature

Core body temperature increases during Tourniquet inflation, and decreases following Tourniquet release. The particular body habitus of children causes a greater increase in core temperature and they should not be actively warmed during surgery.

b)

Local complications

9.3

Skin

Excessive Tourniquet time or poorly placed Tourniquets may result in cutaneous abrasions, blisters and even pressure necrosis. Chemical burns can occur with alcohol based skin preparation, while friction burns arise if the Tourniquet Cuff is unpadded or telescopes away from its padding during surgery. Children, obese and older patients with delicate loose and flabby skin are at higher risk of skin injuries. Patients with compromised circulation, such as those who are elderly or diabetic, are also at higher risk for pressure sores. Use VBM Tourniquet protection covers and padding to avoid skin injuries. Use adhesive tape or tape between the distal edge of the cuff and limb to prevent prep solution from leaking under the Tourniquet Cuff.

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9.4

Nerve injury

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. 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 cuffs while mechanical stress merits the most focus for preventing nerve injury. Persons with flaccid (flabby), loose skin, e.g. elderly or obese patients are subject to nerve and tissue injury from a shearing force mechanically created by an improperly fitted cuff. Risk of shearing may be reduced by selecting a Contour Cuff (which fits the limb taper). Never exceed the recommended Tourniquet time and always use the minimal effective pressure required to ensure a safe occlusion of the limb. Use a cuff that properly fits the extremity and has the maximum possible width. 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 paralysis.

9.5

Muscle / Post Tourniquet Syndrome (PTS)

Application of a Tourniquet Cuff causes tissue ischemia both beneath the cuff and distal to the occluded area. Ischemic necrosis may occur beneath the cuff after only two hours of tourniquet inflation of 200 mmHg to 350 mmHg. The combined effects of muscle ischemia, edema and microvascular congestion, leads to the Post Tourniquet Syndrome, the most common and least appreciated morbidity associated with Tourniquet use. This syndrome is characterized by stiffness, pallor, paresis and paraesthesia.

9.6

Intraoperative bleeding

To prevent intraoperative bleeding, take care to select the proper style and size of Tourniquet Cuff, apply the cuff snugly, and inflate it to the optimal pressure (see section 6 “Tourniquet Cuffs” and section 7 “Tourniquet Cuff 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.

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9.7

Toxic reactions

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. Therefore it is recommended to 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. VBM Tourniquets offer a unique feature due to the incorporated flush valve. The flush valve permits to release the anesthetic gradually into the circulation and therefore avoids possible intoxications.

9.8

Congestion and pooling of blood in the operative field

Immediately remove the deflated cuff and any underlying limb protection following cuff deflation. Even the slightest impedance of venous return by the deflated cuff or padding may lead to congestion and pooling of blood in the operative field.

10. Summary Use of pneumatic Tourniquets 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, consider the following preventive measures:  Conduct an adequate preoperative assessment.  Use a Tourniquet Cuff that has the proper fit and size and can maintain occlusion 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.

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VBM Medizintechnik GmbH Einsteinstrasse 1 DE-72172 Sulz a.N. Germany Tel.: +49 74 54 / 95 96 10 Fax: +49 74 54 / 95 96 33 e-mail: info@vbm-medical.de www.vbm-medical.de

VBM USA VBM Medical Inc. 524 Herriman Court Noblesville IN 46060 USA Tel.: 317 776 1800 Fax: 317 776 1881 e-mail: info@vbm-medical.com

VBM France VBM France sarl ZAC de la Ferrage 13980 Alleins France Tel.: 04.42.46.79.53 Fax: 04.42.46.79.54 e-mail: info@vbm-medical.fr

VBM Czech Republic VBM Lékarská technika, spol.s.r.o. Komenského 1313 66434 Kurim Czech Republic

2.0/05.09-GB

Tel.: 5 4123 1191 Fax: 5 4123 1191 e-mail: vbm@volny.cz