A tourniquet is a constricting or compressing device used to control venous and arterial circulation to an extremity for a period of time. In the Circulatory system, a vein is a Blood vessel that carries Blood back toward the Heart (as opposed to Artery, a blood vessel Arteries are Blood vessels that carry blood away from the Heart. 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. [1]
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History
In 1718 French surgeon Jean Louis Petit developed a screw device for occluding blood flow in surgical sites. Jean-Louis Petit (1674-1750 was a French surgeon He was first enthusiastic about anatomy received a master's certificate in surgery in Paris in 1700 He named this device after the French verb “tourner” (to turn), “tourniquet” as it is commonly known today. This would not have been possible without the prior work of William Harvey, an English surgeon who traced the human circulation in 1628. William Harvey ( April 1, 1578 – June 3, 1657) was an English Physician who is credited with being the first in
Joseph Lister is credited for being the first to use a tourniquet device to create a bloodless surgical field in 1864. Joseph Lister 1st Baron Lister, OM, FRS ( 5 April 1827 &ndash 10 February 1912) was an English surgeon He also recommended exsanguinations prior to tourniquet application by limb elevation. Exsanguination (also known colloquially as bleeding out) is the fatal process of total Hypovolemia (blood loss In 1873, Friedrich von Esmarch developed a rubber bandage that would both control bleeding and exsanguinate. Johannes Friedrich August von Esmarch ( January 9, 1823 &ndash February 23, 1908) was a German Surgeon. This device is known as Esmarch's bandage for surgical haemostasis or Esmarch's tourniquet. At the time this device was superior to Petit’s device as there were no screws to loosen or cloth to tear. In 1881 Richard von Volkmann showed that limb paralysis can occur from the use of the Esmarch tourniquet. Richard von Volkmann (1830 - 1889 was a prominent German surgeon and poet
In 1904 Harvey Cushing created a pneumatic tourniquet. Harvey Williams Cushing ( April 8, 1869 - October 7, 1939) was an American neurosurgeon and a pioneer of Brain surgery This type of tourniquet compressed the underlying blood vessels using a compressed gas source to inflate a cylindrical bladder. This was superior to the Esmarch tourniquet in two ways: (1) the tourniquet could be applied and removed quickly; and (2) this method of limb occlusion decreased the incidence of nerve paralysis.
August Bier used two tourniquets for administering segmental anesthesia in 1908. August Karl Gustav Bier ( 24 November 1861 - 12 March 1949) was German Surgeon and the pioneer of Spinal anaesthesia In this procedure circulation is isolated in a limb and the limb is then infused intravenously. In 1963 Hamilton E. Holmes reintroduced Bier’s method as a single tourniquet technique. Dr Hamilton E Holmes ( July 8, 1941 – October 26, 1995) was a Physician ( Orthopedist) who helped Desegregate Today, the two-tourniquet technique is used frequently and is called intra-venous regional anesthesia (IVRA). It is also commonly referred to as Bier block, or Bier’s method. Bier block anesthesia is an intravenous regional Anesthesia technique in which an extremity (generally an arm is made numb for Surgery by injecting a Local
In the early 1980’s microprocessor-controlled tourniquets were invented my James McEwen, PHD, a biomedical engineer in Vancouver, Canada. The first US patent for an electronic tourniquet system was awarded to Dr. McEwen in 1984 and to date he has been awarded many more US and foreign patents for tourniquet improvements. The use of automatic tourniquet systems has significantly improved tourniquet safety. Modern automatic tourniquets are self-calibrating and self-contained. These new tourniquet devices also provide a variety of safety features that are not possible in older mechanical tourniquets. [1]
Types
There are two types of tourniquets: surgical tourniquets and emergency tourniquets. Surgical tourniquets are frequently used in orthopedic surgery while emergency tourniquets are limited to emergency situations to control blood loss.
Surgical tourniquets
Surgical tourniquets prevent blood flow to a limb and enable surgeons to work in a bloodless operative field. Surgical tourniquets prevent blood flow to a limb and enable surgeons to work in a bloodless operative field This allows surgical procedures to be performed with improved precision, safety and speed. Tourniquets are widely used in orthopedic and plastic surgery, as well as in intravenous regional anesthesia (Bier block anesthesia) where they serve the additional function of preventing local anesthetic in the limb from entering general circulation. Bier block anesthesia is an intravenous regional Anesthesia technique in which an extremity (generally an arm is made numb for Surgery by injecting a Local
Emergency tourniquets
Emergency tourniquets are used in emergency bleeding control to prevent severe blood loss from limb trauma. An emergency tourniquet is a tightly tied band applied around a body part (an arm or a leg sometimes used in an attempt to stop severe traumatic Bleeding. Emergency tourniquets are a last resort, for all blood flow below the application of an emergency tourniquet is stopped, and can subsequently kill the tissue, leading to eventual loss of the limb below application. [2]
Current technology
In recent years there have been significant advancements in tourniquets. These advancements have vastly improved tourniquet safety.
Limb occlusion pressure
Limb occlusion pressure (LOP) is the minimum tourniquet pressure required to occlude blood flow to a specific patient's limb at a specific time and accounts for a patient’s limb and vessel characteristics, and the type and fit of the cuff. LOP can be determined by gradually increasing tourniquet pressure until distal arterial pulses cease, as indicated by a device sensing blood flow, such as a Doppler stethoscope. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species The stethoscope (from Greek στηθοσκόπιο, of στήθος stéthos - chest and σκοπή skopé - examination) is an acoustic Studies have shown that cuff pressure based on LOP measured immediately prior to surgery is generally lower than commonly used cuff pressures and is sufficient to maintain a satisfactory surgical field[3].
Automatic systems
Automatic tourniquet systems are capable of providing safety features that are not possible in older mechanical tourniquets. These systems can monitor the cuff inflation time as well as regulate the cuff pressure to a known pressure throughout the surgical procedure. Some microprocessor controlled tourniquets are capable of calculating LOP in about 30 seconds. [4] This assists the operating room staff in deciding what the tourniquet pressure should be set at on a per-patient basis.
Contoured and wide cuffs
Studies have shown that tourniquet cuff pressure can be substantially reduced by using wide, contoured cuffs. [5] A wider and contoured cuff has more contact with the limb's surface area and disperses the cuff's force. This concept is emerging from the surgical field into the emergency field with wider emergency tourniquets. [6]
See also
References
- ^ a b Tourniquets.org
- ^ Cyr, Dawna L; Johnson, Steven B (September 2006). For Tourniquet, see that article A tourniquet test (also known as a Rumpel-Leede Capillary-Fragility Test or simply a capillary fragility test Basic First Aid. The University of Maine. Retrieved on 2008-02-25. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 138 - The Emperor Hadrian adopts Antoninus Pius, effectively making him his successor
- ^ McEwen JA, Inkpen KB, Younger A. “Thigh tourniquet safety: Limb occlusion pressure measurement and a wide contoured cuff allow lower cuff pressure. ” Surg Tech. 2002; 34:8-18.
- ^ Zimmer Automatic Tourniquet Systems
- ^ Pedowitz RA, Gershuni DH, Botte MJ, et al. “The use of lower tourniquet inflation pressures in extremity surgery facilitated by curved and wide tourniquets and an integrated cuff inflation system. ” Clin Orthop Relat Res. 1993; 287:237-244.
- ^ Delfi Medical Specialty tourniquets
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