tourniquet

{{short description|Medical device}}

{{other uses}}

{{more citations needed|date=April 2019}}

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File:A black CAT tourniquet of the 7th generation.jpg

A tourniquet is a device that is used to apply pressure to a limb or extremity in order to create ischemia or stopping the flow of blood. It may be used in emergencies, in surgery, or in post-operative rehabilitation.

A simple tourniquet can be made from a stick and a rope, but the use of makeshift tourniquets has been reduced over time due to their ineffectiveness compared to a commercial and professional tourniquet. This may stem the flow of blood, but side effects such as soft tissue damage and nerve damage may occur.

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History

Image:Petit tourniquet - Savigny 1798.jpg

During Alexander the Great’s military campaigns in the fourth century BC, tourniquets were used to stanch the bleeding of wounded soldiers.{{cite news |date=January 19, 2014 |title=Reviving a Life Saver, the Tourniquet |work=New York Times |vauthors=Schmidt MS}} Romans used them to control bleeding, especially during amputations.{{cite web |date=July 2009 |title=Thigh tourniquet, Roman, 199 BCE-500 CE |url=https://collection.sciencemuseumgroup.org.uk/objects/co86342/thigh-tourniquet-roman-199-bce-500-ce-tourniquet |access-date=2009-06-19 |publisher=sciencemuseum.org.uk}} These tourniquets were narrow straps made of bronze, using only leather for comfort.

File:17850000-Tourniquet Use-GILBERT-BLANE.jpg advocates the issue of a tourniquet to each man in battle.]]

In 1718, French surgeon Jean Louis Petit developed a screw device for occluding blood flow in surgical sites. Before this invention, the tourniquet was a simple garrot, tightened by twisting a rod (thus its name tourniquet, from tourner = to turn).

In 1785, Sir Gilbert Blane advocated that, in battle, each Royal Navy sailor should carry a tourniquet:

It frequently happens that men bleed to death before assistance can be procured, or lose so much blood as not to be able to go through an operation. In order to prevent this, it has been proposed, and on some occasions practised, to make each man carry about him a garter, or piece of rope yarn, in order to bind up a limb in case of profuse bleeding. If it be objected, that this, from its solemnity may be apt to intimidate common men, officers at least should make use of some precaution, especially as many of them, and those of the highest rank, are stationed on the quarter deck, which is one of the most exposed situations, and far removed from the cockpit, where the surgeon and his assistants are placed. This was the cause of the death of my friend Captain Bayne, of the Alfred, who having had his knee so shattered with round shot that it was necessary to amputate the limb, expired under the operation, in consequence of the weakness induced by loss of blood in carrying him so far. As the Admiral on these occasions allowed me the honour of being at his side, I carried in my pocket several tourniquets of a simple construction, in case that accidents to any person on the quarter deck should have required their use.{{Cite book |title=Observations on the diseases incident to seamen |vauthors=Blane G |publisher=London: Joseph Cooper; Edinburgh: William Creech |year=1785 |pages=498–499}}{{cite journal |vauthors=Feldman V, Biadsi A, Slavin O, Kish B, Tauber I, Nyska M, Brin YS |date=December 2015 |title=Pulmonary Embolism After Application of a Sterile Elastic Exsanguination Tourniquet |journal=Orthopedics |volume=38 |issue=12 |pages=e1160-3 |doi=10.3928/01477447-20151123-08 |pmid=26652340}}{{cite journal |vauthors=Middleton RW, Varian JP |date=May 1974 |title=Tourniquet paralysis |journal=The Australian and New Zealand Journal of Surgery |volume=44 |issue=2 |pages=124–8 |doi=10.1111/j.1445-2197.1974.tb06402.x |pmid=4533458}}{{cite journal |vauthors=McLaren AC, Rorabeck CH |date=March 1985 |title=The pressure distribution under tourniquets |journal=The Journal of Bone and Joint Surgery. American Volume |volume=67 |issue=3 |pages=433–8 |doi=10.2106/00004623-198567030-00014 |pmid=3972869}}{{cite journal |vauthors=Klenerman L |date=November 1962 |title=The tourniquet in surgery |journal=The Journal of Bone and Joint Surgery. British Volume |volume=44-B |issue=4 |pages=937–43 |doi=10.1302/0301-620X.44B4.937 |pmid=14042193 |doi-access=free}}{{cite journal |vauthors=Richards RL |date=May 1951 |title=Ischaemic lesions of peripheral nerves: a review |journal=Journal of Neurology, Neurosurgery, and Psychiatry |volume=14 |issue=2 |pages=76–87 |doi=10.1136/jnnp.14.2.76 |pmc=499577 |pmid=14850993}}{{cite journal |vauthors=Fletcher IR, Healy TE |date=November 1983 |title=The arterial tourniquet |journal=Annals of the Royal College of Surgeons of England |volume=65 |issue=6 |pages=409–17 |pmc=2494408 |pmid=6357039}}{{cite journal |vauthors=Moldaver J |date=February 1954 |title=Tourniquet paralysis syndrome |journal=A.M.A. Archives of Surgery |volume=68 |issue=2 |pages=136–44 |doi=10.1001/archsurg.1954.01260050138002 |pmid=13123650}}{{Cite book |url=https://www.springer.com/gp/book/9781852337063 |title=The Tourniquet Manual — Principles and Practice {{!}} Leslie Klenerman {{!}} Springer |publisher=Springer |year=2003 |isbn=9781852337063 |language=en |doi=10.1007/b97532 |s2cid=26268006}}

In 1864, Joseph Lister created a bloodless surgical field using a tourniquet device.{{Cite journal |last1=Kragh |first1=John F. |last2=Swan |first2=Kenneth G. |last3=Smith |first3=Dale C. |last4=Mabry |first4=Robert L. |last5=Blackbourne |first5=Lorne H. |date=2011-07-22 |title=Historical review of emergency tourniquet use to stop bleeding |url=http://dx.doi.org/10.1016/j.amjsurg.2011.01.028 |journal=The American Journal of Surgery |volume=203 |issue=2 |pages=242–252 |doi=10.1016/j.amjsurg.2011.01.028 |pmid=21782152 |issn=0002-9610|url-access=subscription }}{{Cite journal |last1=Noordin |first1=Shahryar |last2=McEwen |first2=James A |last3=Kragh |first3=Colonel John F |last4=Eisen |first4=Andrew |last5=Masri |first5=Bassam A |date=December 2009 |title=Surgical Tourniquets in Orthopaedics |url=http://dx.doi.org/10.2106/jbjs.i.00634 |journal=The Journal of Bone and Joint Surgery-American Volume |volume=91 |issue=12 |pages=2958–2967 |doi=10.2106/jbjs.i.00634 |pmid=19952261 |issn=0021-9355|url-access=subscription }} In 1873, Friedrich von Esmarch introduced a rubber bandage that would both control bleeding and exsanguinate.{{Cite journal |last=Austin |first=M. |date=1963-05-01 |title=The Esmarch Bandage and Pulmonary Embolism |url=http://dx.doi.org/10.1302/0301-620x.45b2.384 |journal=The Journal of Bone and Joint Surgery. British Volume |volume=45-B |issue=2 |pages=384–385 |doi=10.1302/0301-620x.45b2.384 |issn=0301-620X|url-access=subscription }} This device is known as Esmarch's bandage. In 1881, Richard von Volkmann noted paralysis can occur from the use of the Esmarch tourniquet, if wrapped too tightly. Many cases of serious and permanent limb paralysis were reported from the use of non-pneumatic Esmarch tourniquets.

After observing considerable number of pressure paralysis with non-pneumatic, elastic, tourniquets, Harvey Cushing created a pneumatic tourniquet, in 1904.{{Cite journal |last=Prevoznik |first=Stephen J. |date=1970-02-01 |title=Injury from Use of Pneumatic Tourniquets |url=http://dx.doi.org/10.1097/00000542-197002000-00025 |journal=Anesthesiology |volume=32 |issue=2 |pages=177 |doi=10.1097/00000542-197002000-00025 |pmid=5414299 |issn=0003-3022}} Pneumatic tourniquets were superior over Esmarch’s tourniquet in two ways: (1) faster application and removal; and (2) decrease the risk of nerve palsy.

In 1908, August Bier used two pneumatic tourniquets with intravenous local anesthesia to anesthetize the limb without general anesthetics.{{Cite journal |last=Stevens |first=Donald S. |date=July 2005 |title=Bier Block With Steroid for CRPS |url=http://dx.doi.org/10.1097/00115550-200507000-00015 |journal=Regional Anesthesia and Pain Medicine |volume=30 |issue=4 |pages=409 |doi=10.1097/00115550-200507000-00015 |issn=1098-7339|url-access=subscription }}

In the early 1980s, microprocessor-based pneumatic tourniquet systems were invented by James McEwen.{{Cite journal |last=McEwen |first=J. A. |date=1981 |title=Complications of and improvements in pneumatic tourniquets used in surgery |url=https://pubmed.ncbi.nlm.nih.gov/7300701 |journal=Medical Instrumentation |volume=15 |issue=4 |pages=253–257 |issn=0090-6689 |pmid=7300701}}{{Cite journal |last1=Radulovic |first1=Aleksandar |last2=Cerovac |first2=Sonja |date=2023-10-26 |title=The history of tourniquet use in limb surgery |url=http://dx.doi.org/10.1007/s00264-023-06018-y |journal=International Orthopaedics |volume=48 |issue=2 |pages=603–609 |doi=10.1007/s00264-023-06018-y |pmid=37882842 |s2cid=264488005 |issn=0341-2695|url-access=subscription }} These modern electronic pneumatic tourniquet systems generally regulate the pressure in the tourniquet cuff within 1% of the target pressure and allows real-time monitoring of the inflation time. Modern pneumatic tourniquet systems include audiovisual alarms to alarm the user if hazardously high or low cuff pressures are present, automatic self-test and calibration, and backup power source.

In the 2000s, the silicon ring tourniquet, or elastic ring tourniquet, was developed by Noam Gavriely, a professor of medicine and former emergency physician.{{cite web |title=Unit of Physiology and Biophysics- Noam Gavriely |url=http://tx.technion.ac.il/~medicine/faculty/Gavriely.htm}}{{cite journal |vauthors=Tang DH, Olesnicky BT, Eby MW, Heiskell LE |date=6 December 2013 |title=Auto-transfusion tourniquets: the next evolution of tourniquets |journal=Open Access Emergency Medicine |volume=5 |issue=5 |pages=29–32 |doi=10.2147/OAEM.S39042 |pmc=4806816 |pmid=27147871 |doi-access=free}} The tourniquet consists of an elastic ring made of silicone, stockinet, and pull straps made from ribbon that are used to roll the device onto the limb. The silicone ring tourniquet exsanguinates the blood from the limb while the device is being rolled on, and then occludes the limb once the desired occlusion location is reached.{{cite journal |vauthors=Drosos GI, Ververidis A, Stavropoulos NI, Mavropoulos R, Tripsianis G, Kazakos K |date=June 2013 |title=Silicone ring tourniquet versus pneumatic cuff tourniquet in carpal tunnel release: a randomized comparative study |journal=Journal of Orthopaedics and Traumatology |volume=14 |issue=2 |pages=131–5 |doi=10.1007/s10195-012-0223-x |pmc=3667358 |pmid=23361654}} Unlike the historical mechanical tourniquets, the device reduces the risk of nerve paralysis.{{cite journal |vauthors=Mohan A, Baskaradas A, Solan M, Magnussen P |date=March 2011 |title=Pain and paraesthesia produced by silicone ring and pneumatic tourniquets |journal=The Journal of Hand Surgery, European Volume |volume=36 |issue=3 |pages=215–8 |doi=10.1177/1753193410390845 |pmid=21131688 |s2cid=31477205}}{{cite journal |vauthors=Gavriely N |date=May 2010 |title=Surgical tourniquets in orthopaedics |journal=The Journal of Bone and Joint Surgery. American Volume |volume=92 |issue=5 |pages=1318–22; author reply 1322–3 |pmid=20439692}} The surgical tourniquet version of the device is completely sterile, and provides improved surgical accessibility due to its narrow profile that results in a larger surgical field. It has been found to be a safe alternative method for most orthopedic limb procedures, but it does not completely replace the use of contemporary tourniquet devices.{{cite journal |vauthors=Demirkale I, Tecimel O, Sesen H, Kilicarslan K, Altay M, Dogan M |date=May 2014 |title=Nondrainage decreases blood transfusion need and infection rate in bilateral total knee arthroplasty |journal=The Journal of Arthroplasty |volume=29 |issue=5 |pages=993–7 |doi=10.1016/j.arth.2013.10.022 |pmid=24275263}}{{cite journal |vauthors=Drosos GI, Ververidis A, Mavropoulos R, Vastardis G, Tsioros KI, Kazakos K |date=September 2013 |title=The silicone ring tourniquet in orthopaedic operations of the extremities |journal=Surgical Technology International |volume=23 |pages=251–7 |pmid=23860930}} More recently the silicone ring tourniquet has been used in the fields of emergency medicine and vascular procedures.{{cite journal |vauthors=Ladenheim E, Krauthammer J, Agrawal S, Lum C, Chadwick N |date=April–June 2013 |title=A sterile elastic exsanguination tourniquet is effective in preventing blood loss during hemodialysis access surgery |journal=The Journal of Vascular Access |volume=14 |issue=2 |pages=116–9 |doi=10.5301/jva.5000107 |pmc=6159822 |pmid=23080335}} However, in 2015 Feldman et. al. reported two cases of pulmonary embolism after silicon ring exsanguination tourniquet application in patients with traumatic injuries. In one case of exsanguination tourniquet induced bilateral pulmonary emboli, after rapid intervention a 65-year-old woman was discharged in good condition 7 days after surgery. In a second case with multiple pulmonary emboli, despite extensive efforts of intervention a 53-year-old man’s condition quickly deteriorated after surgery, and was declared brain dead 2 days after. While Feldman et. al. discuss the potential risk of DVT for various types of tourniquets and exsanguination methods, the authors recommend extreme caution and suggest avoiding the use of an exsanguination tourniquet in patients with risk factors for DVT, including patients with traumatic injury of the extremities.

Most modern pneumatic tourniquet systems include the ability to measure the patient’s limb occlusion pressure (LOP) and recommend a tourniquet pressure based on the measured LOP to set safer and lower tourniquet pressures. Limb occlusion pressure is defined as "the minimum pressure required, at a specific time by a specific tourniquet cuff applied to a specific patient’s limb at a specific location, to stop the flow of arterial blood into the limb distal to the cuff.”

After World War II, the US military reduced use of the tourniquet because the time between application and reaching medical attention was so long that the damage from stopped circulation was worse than that from blood loss.

Since the beginning of the 21st century, US authorities have resuscitated its use in both military and non-military situations because treatment delays have been dramatically reduced. The Virginia State Police and police departments in Dallas, Philadelphia and other major cities provide tourniquets and other advanced bandages. In Afghanistan and Iraq, only 2 percent of soldiers with severe bleeding died compared with 7 percent in the Vietnam War, in part because of the combination of tourniquets and rapid access to doctors.{{citation needed|date=January 2015}} Between 2005 and 2011, tourniquets saved 2,000 American lives from the wars in Iraq and Afghanistan.{{cite news |date=12 October 2017 |title=Trauma medicine has learned lessons from the battlefield |url=https://www.economist.com/news/international/21730145-civilian-doctors-are-saving-more-lives-after-terrorist-attacks-copying-their-military |newspaper=The Economist}} In civilian use, emerging practices include transporting tourniquetted patients even before emergency responders arrive and including tourniquets with defibrillators for emergency use.

There are currently no standards for testing tourniquets although there have been several proposed devices to ensure that the appropriate pressures could be generated including many commercial systems and an open source system that can be largely 3D printed.{{Cite journal |last1=Liu |first1=Dawei |last2=Kulkarni |first2=Apoorv |last3=Jaqua |first3=Victoria F. |last4=Cole |first4=Christina A. |last5=Pearce |first5=Joshua M. |date=2023 |title=Distributed manufacturing of an open-source tourniquet testing system |journal=HardwareX |language=en |volume=15 |pages=e00442 |doi=10.1016/j.ohx.2023.e00442 |pmc=10338363 |pmid=37457304}} This would allow distributed manufacturing of tourniquets.{{Cite web |last=Stout |first=James |title=3D-printed tourniquets could save lives in conflict zones |url=https://www.newscientist.com/article/2322015-3d-printed-tourniquets-could-save-lives-in-conflict-zones/ |access-date=2023-12-20 |website=New Scientist |language=en-US}}{{Cite web |last=Loubani |first=Tarek |date=2022-03-25 |title=Reinventing 3D printed tourniquets for Ukraine is a mistake |url=https://trklou.medium.com/reinventing-3d-printed-tourniquets-for-ukraine-is-a-mistake-be2937f0ad65 |access-date=2023-12-20 |website=Medium |language=en}}

Risks

Risks and contraindications related to the use of a surgical tourniquet include: nerve injuries, skin injuries, compartment syndrome, deep venous thrombosis, and pain.Guideline for care of patients undergoing pneumatic tourniquet-assisted procedures. AORN. 2020. Risk of injury can be minimized by minimizing tourniquet pressure and pressure gradients. Tourniquet pressure and pressure gradients can be minimized by using a tourniquet pressure based on the patient’s limb occlusion pressure, and by using a wider, contoured pneumatic tourniquet cuff.

In some elective surgical procedures such as total knee arthroplasty, some research suggests tourniquet use may be associated with an increased risk of adverse events, pain, and a longer hospital stay, despite tourniquet use allowing shorter times in the operating room.{{cite journal |display-authors=6 |vauthors=Ahmed I, Chawla A, Underwood M, Price AJ, Metcalfe A, Hutchinson C, Warwick J, Seers K, Parsons H, Wall PD |date=December 2020 |title=Tourniquet use for knee replacement surgery |journal=The Cochrane Database of Systematic Reviews |volume=2020 |issue=12 |pages=CD012874 |doi=10.1002/14651858.cd012874.pub2 |pmc=8094224 |pmid=33316105}} However, such evidence (meta-analyses and reviews) often omit the analysis of key tourniquet parameters and their correlation to outcomes leading to limited, inconclusive, and conflicting results.{{Cite journal |last1=Neufeld |first1=Michael E. |last2=McEwen |first2=James A. |last3=Kerr |first3=Julie |last4=Sidhu |first4=Arsh |last5=Howard |first5=Lisa C. |last6=Masri |first6=Bassam A. |date=2023-04-17 |title=Optimization of surgical tourniquet usage to improve patient outcomes: Translational cross-disciplinary implications of a surgical practice survey |journal=Frontiers in Surgery |volume=10 |doi=10.3389/fsurg.2023.1104603 |doi-access=free |pmid=37139190 |pmc=10149658 |issn=2296-875X}}

A study by Pavao et al compared no tourniquet use to optimized tourniquet use in total knee arthroplasty and found no significant differences in surgical timing, blood loss, thigh and knee pain, edema, range of motion, functional scores, and complications, thus allowing surgery to occur with the benefits of a clean and dry surgical field from an optimized tourniquet without increase procedure-related comorbidities.{{Cite journal |last1=Pavão |first1=Douglas M. |last2=Pires eAlbuquerque |first2=Rodrigo S. |last3=de Faria |first3=José Leonardo R. |last4=Sampaio |first4=Yuri D. |last5=de Sousa |first5=Eduardo B. |last6=Fogagnolo |first6=Fabricio |date=April 2023 |title=Optimized Tourniquet Use in Primary Total Knee Arthroplasty: A Comparative, Prospective, and Randomized Study |url=http://dx.doi.org/10.1016/j.arth.2022.10.026 |journal=The Journal of Arthroplasty |volume=38 |issue=4 |pages=685–690 |doi=10.1016/j.arth.2022.10.026 |pmid=36280159 |s2cid=253075542 |issn=0883-5403|url-access=subscription }} Therefore, tourniquet use optimized to mitigate tourniquet related-risks while maintaining the benefits of a clear bloodless field and faster operating times may be achieved by minimizing tourniquet pressure and inflated tourniquet times.

Types

There are three types of tourniquets: surgical tourniquets, emergency tourniquets, and rehabilitation tourniquets.

= Surgical tourniquets =

Surgical tourniquets prevent blood flow to a limb and enable surgeons to work in a bloodless operative field.{{Cite journal |last1=Kumar |first1=Kamal |last2=Railton |first2=Craig |last3=Tawfic |first3=Qutaiba |date=2016 |title=Tourniquet application during anesthesia: "What we need to know?" |journal=Journal of Anaesthesiology Clinical Pharmacology |volume=32 |issue=4 |pages=424–430 |doi=10.4103/0970-9185.168174 |doi-access=free |pmid=28096570 |issn=0970-9185|pmc=5187604 }} This allows surgical procedures to be performed with improved precision, safety and speed. Surgical tourniquets can be divided into two groups: pneumatic tourniquets and non-pneumatic tourniquets.

== Surgical pneumatic tourniquets ==

Surgical pneumatic tourniquets are routinely and safely used orthopedic and plastic surgery, as well as in intravenous regional anesthesia (Bier block anesthesia) where they serve the additional function of preventing the central spread of local anesthetics in the limb. Modern pneumatic tourniquet systems consist of a pneumatic tourniquet instrument, tourniquet cuffs, pneumatic tubing, and limb protection sleeves.

=== Surgical pneumatic tourniquet instrument ===

Modern pneumatic tourniquet instruments are microcomputer-based with the following features:

  • Accurate pressure regulator to maintain cuff pressure within 1% of the target pressure,
  • Automatic timer to provide precise record of inflation time,
  • Audiovisual alarms to warn the operator if potential hazards are detected,
  • Automatic self test and self-calibration to ensure system hardware and software integrity, and
  • Backup power source to allow continued operation if unanticipated power outage occurs

Many studies published in the medical literature have shown that higher tourniquet pressures and pressure gradients are associated with higher risks of tourniquet-related injuries.{{Cite journal |last1=Masri |first1=Bassam A. |last2=Eisen |first2=Andrew |last3=Duncan |first3=Clive P. |last4=McEwen |first4=James A. |date=2020-05-28 |title=Tourniquet-induced nerve compression injuries are caused by high pressure levels and gradients – a review of the evidence to guide safe surgical, pre-hospital and blood flow restriction usage |journal=BMC Biomedical Engineering |volume=2 |issue=1 |page=7 |doi=10.1186/s42490-020-00041-5 |doi-access=free |pmid=32903342 |pmc=7422508 |issn=2524-4426}} Advances in tourniquet technology have reduced the risk of nerve-related injury by optimizing and personalizing tourniquet pressure based on the patient’s Limb Occlusion Pressure (LOP), rather than setting standard tourniquet pressures, which are generally higher and more hazardous.{{Cite journal |last1=Masri |first1=Bassam A. |last2=Day |first2=Brian |last3=Younger |first3=Alastair S. E. |last4=Jeyasurya |first4=Jeswin |date=October 2016 |title=Technique for Measuring Limb Occlusion Pressure that Facilitates Personalized Tourniquet Systems: A Randomized Trial |url=http://dx.doi.org/10.1007/s40846-016-0173-5 |journal=Journal of Medical and Biological Engineering |volume=36 |issue=5 |pages=644–650 |doi=10.1007/s40846-016-0173-5 |pmid=27853415 |issn=1609-0985|pmc=5083760 }} LOP is defined as “the minimum pressure required, at a specific time by a specific tourniquet cuff applied to a specific patient’s limb at a specific location, to stop the flow of arterial blood into the limb distal to the cuff.” LOP accounts for variables such as cuff design (bladder width), cuff application (snugness), patient limb characteristics (shape, size, tissues), and patient’s systolic blood pressure. After LOP is measured, personalized tourniquet pressure is set to LOP plus a safety margin to account for any increase in limb occlusion pressure normally expected during the surgery. The use of personalized pressures and wide contour tourniquet cuffs have been found to reduce average tourniquet pressure by 33%-42% from typical pressures.{{Cite journal |last1=Younger |first1=Alastair S. E |last2=McEwen |first2=James A |last3=Inkpen |first3=Kevin |date=November 2004 |title=Wide Contoured Thigh Cuffs and Automated Limb Occlusion Measurement Allow Lower Tourniquet Pressures |url=http://dx.doi.org/10.1097/01.blo.0000142625.82654.b3 |journal=Clinical Orthopaedics & Related Research |volume=428 |issue=428 |pages=286–293 |doi=10.1097/01.blo.0000142625.82654.b3 |pmid=15534554 |s2cid=12807792 |issn=0009-921X|url-access=subscription }} Setting the tourniquet pressure on the basis of LOP minimizes the pressure and related pressure gradients applied by a cuff to an underlying limb, which helps to minimize the risk of tourniquet-related injuries.

LOP may be measured manually by Doppler ultrasound. However, the method is time consuming and its accuracy is highly dependent on the skill and experience of the operator.{{Cite journal |last1=Hughes |first1=Luke |last2=McEwen |first2=James |date=2021-05-08 |title=Investigation of clinically acceptable agreement between two methods of automatic measurement of limb occlusion pressure: a randomised trial |journal=BMC Biomedical Engineering |volume=3 |issue=1 |page=8 |doi=10.1186/s42490-021-00053-9 |doi-access=free |pmid=33964963 |pmc=8105974 |issn=2524-4426}} LOP may also be measured automatically using a photoplethysmography distal sensor applied to the patient’s finger or toe of the operative limb to detect volumetric changes in blood in peripheral circulation as cuff pressure is gradually increased. Finally, most recently, LOP may be measured using a dual-purpose tourniquet cuff to monitor arterial pulsations in the underlying limb as the cuff pressure is gradually increased.

Pneumatic tourniquet instruments and cuffs are available in a single-line (single-port) or dual-line (dual-port) setup.{{Cite web |title=How to Choose a Tourniquet - Outpatient Surgery Magazine - November, 2 |url=https://www.aorn.org/outpatient-surgery/article/2013-November-how-to-choose-a-tourniquet |access-date=2024-02-09 |website=Outpatient Surgery Magazine |language=en}} Single-port configuration uses the same pneumatic line that connects the instrument to the cuff for both pressure regulation and pressure monitoring. Dual-port configuration uses one pneumatic line to regulate pressure and one pneumatic line to monitor pressure.McEwen, James A. US Patent No. 4,469,099, September 4, 1984, “Pneumatic Torniquet”.McEwen, James A. US Patent No. 7,771,453, August 10, 2010, “Occlusion detector for dual-port surgical tourniquet systems”. The dual-port configuration may facilitate faster cuff pressure regulation and the detection of occlusions in the hoses.

=== Surgical pneumatic tourniquet cuff ===

Compressed gas is introduced into a bladder within a pneumatic tourniquet cuff by the pneumatic tourniquet instrument through a pneumatic tubing. The inflated cuff exerts pressure on the circumference of the patient’s limb to occlude blood flow.

File:Cuff Technology - Application Handle Cuff.jpg

Compression by the inflated cuff can result in tissue injury.{{Cite journal |last1=Jensen |first1=Jacob |last2=Hicks |first2=Rodney W. |last3=Labovitz |first3=Jonathan |date=2019-01-29 |title=Understanding and Optimizing Tourniquet Use During Extremity Surgery |url=http://dx.doi.org/10.1002/aorn.12579 |journal=AORN Journal |volume=109 |issue=2 |pages=171–182 |doi=10.1002/aorn.12579 |pmid=30694553 |s2cid=59339160 |issn=0001-2092|url-access=subscription }} A good tourniquet cuff fit ensures even pressure distribution across the underlying soft tissues, whereas a poor tourniquet cuff fit can result in areas of higher pressure which can lead to soft tissue ischemia. Therefore, in order to safely and effectively occlude blood flow distal to the applied tourniquet cuff, proper selection and application of the tourniquet cuff should be followed.

The following should be considered when selecting a tourniquet cuff:

  • Cuff location,
  • Limb shape which determines the cuff shape (e.g. cylindrical or contour shaped),
  • Limb circumference which determines the cuff length,
  • Cuff width,
  • Single versus dual bladder design (e.g. whether an IVRA cuff is needed), and
  • Use sterile cuff when it will be very close to the sterile field

=== Surgical limb protection sleeve ===

It is recommended to protect the limb beneath the cuff by applying a low-lint, soft padding around the limb, prior to cuff application, according to the cuff manufacturer’s instructions for use.{{Cite journal |last=Spruce |first=Lisa |date=September 2017 |title=Back to Basics: Pneumatic Tourniquet Use |url=http://dx.doi.org/10.1016/j.aorn.2017.07.003 |journal=AORN Journal |volume=106 |issue=3 |pages=219–226 |doi=10.1016/j.aorn.2017.07.003 |pmid=28865632 |issn=0001-2092|url-access=subscription }} Matching limb protection sleeves matched to the cuff width and patient’s limb circumference has been shown to produce significantly fewer, less severe wrinkles and pinches in the skin surface than other padding types tested.{{Cite journal |last1=McEwen |first1=James A. |last2=Kelly |first2=Deborah L. |last3=Jardanowski |first3=Theda |last4=Inkpen |first4=Kevin |date=September 2002 |title=Tourniquet Safety in Lower Leg Applications |url=http://dx.doi.org/10.1097/00006416-200209000-00009 |journal=Orthopaedic Nursing |volume=21 |issue=5 |pages=61–62 |doi=10.1097/00006416-200209000-00009 |pmid=12432700 |issn=0744-6020|url-access=subscription }}

== Surgical non-pneumatic tourniquet ==

File:Prämeta tourniquet-4981.jpg

File:Phlebotomy-practice-university-of-delaware.jpg (venipuncture) using an elastic tourniquet.]]

In silicone ring tourniquets, or elastic ring tourniquets, the tourniquet comes in a variety of sizes. To determine the correct tourniquet size, the patient's limb circumference at the desired occlusion location should be measured, as well as their blood pressure to determine the best model. Once the correct model is selected, typically two sterile medical personnel will be needed to apply the device. Unlike with a pneumatic tourniquet, the silicone ring tourniquet should be applied after the drapes have been placed on the patient. This is due to the device being completely sterile.{{cite journal | vauthors = Thompson SM, Middleton M, Farook M, Cameron-Smith A, Bone S, Hassan A | title = The effect of sterile versus non-sterile tourniquets on microbiological colonisation in lower limb surgery | journal = Annals of the Royal College of Surgeons of England | volume = 93 | issue = 8 | pages = 589–90 | date = November 2011 | pmid = 22041233 | pmc = 3566682 | doi = 10.1308/147870811X13137608455334 }} The majority of the devices require a two-man operation (with the exception of the extra large model):

  1. One person is responsible for holding the patient's limb. The other will place the device on the limb (extra large models may require two people).
  2. Application:
  3. The elastic ring tourniquet is placed on the patient's limb. If placed on a hand or foot, all fingers or toes should be enclosed within the tourniquet.
  4. The handles of the tourniquet should be positioned medial-lateral on the upper extremity or posterior-anterior on the lower extremity.
  5. The person applying the device should start rolling the device while the individual responsible for the limb should hold the limb straight and maintain axial traction.
  6. Once the desired occlusion location is reached, the straps can be cut off or tied just below the ring.
  7. A window can be cut or the section of stockinet can be completely removed.
  8. Once the surgery is completed the device is cut off with a supplied cutting card.

The elastic ring tourniquet follows similar recommendations noted for pneumatic tourniquet use:

  1. It should not be used on a patient's limb for more than 120 minutes, as the interruption of blood flow may cause cell damage and necrosis.
  2. The tourniquet should not be placed on the ulnar nerve or the peroneal nerve.
  3. The silicone ring device cannot be used on patients with blood problems such as DVT, edema, etc.
  4. A patient suffering from skin lesions or a malignancy should use this type of tourniquet.{{cite journal | vauthors = Norman D, Greenfield I, Ghrayeb N, Peled E, Dayan L | title = Use of a new exsanguination tourniquet in internal fixation of distal radius fractures | journal = Techniques in Hand & Upper Extremity Surgery | volume = 13 | issue = 4 | pages = 173–5 | date = December 2009 | pmid = 19956041 | doi = 10.1097/BTH.0b013e3181b56187 | s2cid = 116895 }}

= Emergency tourniquets =

{{main|Emergency tourniquet}}Emergency tourniquets differ from surgical tourniquets as are they are used in military combat care, emergency medicine, and accident situations where electrical power is not available, and may need to be applied by an assisting person or self-applied by the injured person.{{Cite journal |last1=Lee |first1=C |last2=Porter |first2=K M |last3=Hodgetts |first3=T J |date=2007-08-01 |title=Tourniquet use in the civilian prehospital setting |journal=Emergency Medicine Journal |language=en |volume=24 |issue=8 |pages=584–587 |doi=10.1136/emj.2007.046359 |pmid=17652690 |pmc=2660095 |issn=1472-0205}} Emergency tourniquets are assessed for their effectiveness of hemorrhage control, pulse stoppage distal to the tourniquet, time to stop bleeding, total blood loss, and applied pressure.{{Cite journal |last1=Gibson |first1=Rudy |last2=Aden |first2=James K |last3=Dubick |first3=Michael A |last4=Kragh |first4=John F |date=2016 |title=Preliminary Comparison of Pneumatic Models of Tourniquet for Prehospital Control of Limb Bleeding in a Manikin Model |url=http://dx.doi.org/10.55460/tkbm-gs8o |journal=Journal of Special Operations Medicine |volume=16 |issue=2 |pages=21–27 |doi=10.55460/tkbm-gs8o |pmid=27450599 |issn=1553-9768|url-access=subscription }} However, their design and safe use should be considered as it relates to nerve injury, reperfusion injury, soft tissue injury, and pain.

Early implementation of non-pneumatic tourniquet use in the nineteenth century for non-amputation surgical procedures often resulted in reports of permanent and temporary limb paralysis, nerve injuries, and other soft-tissue injuries. As a result, pneumatic tourniquets were developed for surgery, where the applied pressure and pressure gradients can be controlled, minimized, and controlled, and thereby minimize the risk of tourniquet related injuries.

== Ratchet and Self Securing emergency tourniquet ==

A ratchet tourniquet is a type of tourniquet that employs a mechanical ratcheting system to achieve and maintain effective arterial compression during emergency bleeding control. Unlike traditional windlass or elastic band tourniquets, ratchet tourniquets use a lever-based or gear-driven mechanism to apply precise, incremental pressure with minimal user effort, making them particularly useful for self-application or one-handed use. These tourniquets are increasingly favored in military, law enforcement, and civilian emergency settings due to their reliability and ease of use under stress.

A prominent example is the XFORCE Tourniquet,{{Cite web|url=https://www.xforcetq.com/|title=X-FORCE TOURNIQUET|website=STAT X-FORCE}} developed by Auric Innovations.{{Cite web|url=https://www.auricinnovations.com/|title=Home|website=My Site 7}} The XFORCE features an intuitive ratcheting lever that allows for quick and secure tightening, with future concepts such as smart interchangeable adapters paired with Artificial Intelligence for specialized applications such as femoral artery compression, pressure sensing, or medicinal delivery.{{Cite web|url=https://www.medrxiv.org/content/10.1101/2025.03.15.25324011v1|title=The XForce Tourniquet: A Comparative Analysis with the CAT Tourniquet to Advance Efficacy and Establish Foundations for Smart Hemorrhage Control|first1=Altobelli|last1=Anthony|first2=Pai|last2=Esha|first3=Bandaru|last3=Aishwarya|first4=Yanamala|last4=Naveena|date=March 17, 2025|via=medRxiv|doi=10.1101/2025.03.15.25324011}} Designed for rapid response in high-pressure environments, the XFORCE Tourniquet provides users with a versatile and efficient life-saving tool that meets modern tactical and emergency medical needs.{{Cite web|url=https://www.teletq.com/|title=TELE-TQ | Auric Innovations|website=My Site 1}}

== Pneumatic emergency tourniquet ==

=== Emergency military tourniquet ===

The Emergency & Military Tourniquet (EMT) is an example of a pneumatic tourniquet developed for safe use in pre-hospital or military settings. In a study that evaluated 5 emergency tourniquet systems for use in the Canadian Forces, the EMT was one of the most effective tourniquets and caused the least pain.{{Cite journal |last1=King |first1=Roger B. |last2=Filips |first2=Dennis |last3=Blitz |first3=Sandra |last4=Logsetty |first4=Sarvesh |date=May 2006 |title=Evaluation of Possible Tourniquet Systems for Use in the Canadian Forces |url=http://dx.doi.org/10.1097/01.ta.0000215429.94483.a7 |journal=The Journal of Trauma: Injury, Infection, and Critical Care |volume=60 |issue=5 |pages=1061–1071 |doi=10.1097/01.ta.0000215429.94483.a7 |pmid=16688072 |issn=0022-5282|url-access=subscription }} In another study comparing the effectiveness of 3 emergency tourniquet systems, while all devices were effective in both hemorrhage control and stopping blood flow, the EMT also performed the best for shortest time to stop blood flow, lowest total blood loss, and required the least amount of pressure to stop blood flow.

== Non-pneumatic emergency tourniquet ==

=== Silicone ring auto-transfusion tourniquet ===

The silicone ring auto-transfusion tourniquet (SRT/ATT/EED), or surgical auto-transfusion tourniquet (HemaClear), is a simple to use, self-contained, mechanical tourniquet that consists of a silicone ring, stockinet, and pull straps that results in the limb being exsanguinated and occluded within seconds of application.{{YouTube|id=GdcSMsBkN7Q&list=UUYUdKv4V5SxsSTXglqnbSAg|title=HemaClear Instructional Video for the Orange Model (Large)}} The tourniquet can be used for limb procedures in the operating room, or in emergency medicine as a means to stabilize a patient until further treatment can be applied.{{Cite web|url=http://www.emergencyeed.com/|title=Emergency EED|website=Emergency EED}}

=== Combat application tourniquet ===

The combat application tourniquet (CAT) was developed by Ted Westmoreland. It is used by the U.S. and coalition militaries to provide soldiers a small and effective tourniquet in field combat situations. It is also used in the UK by NHS ambulance services, along with some UK fire and rescue services. The unit utilizes a windlass with a locking mechanism and can be self-applied. The CAT has been adopted by military and emergency personnel around the world.{{cite conference | title = Testing of Battlefield Tourniquets | vauthors = Walters T | publisher = US Army Institute of Surgical Research | conference = Advanced Technology Applications for Combat Casualty Care 2004 (ATACCC) Conference | date = 16–18 August 2004 | location = St. Petersburg, FL. | url = http://www.usaccc.org/ataccc/index.jsp }}

An open hardware-based 3D printing project called the Glia Tourniquet{{Citation |title=EXERCISE CAUTION WITH CLINICAL USE Tourniquet |date=2023-07-22 |url=https://github.com/GliaX/tourniquet |access-date=2023-07-29 |publisher=Glia Free Medical hardware}} (windlass type) enables emergency tourniquets to use distributed manufacturing to make them for $7 in materials.{{Cite web |title=The Glia Tourniquet Project |url=https://glia.org/pages/the-glia-tourniquet-project |access-date=2023-07-29 |website=Glia |language=en}} Concerns over quality control of distributed manufactured tourniquets was partially addressed with an open source testing apparatus.{{cite journal | vauthors = Liu D, Kulkarni A, Jaqua VF, Cole CA, Pearce JM | title = Distributed manufacturing of an open-source tourniquet testing system | journal = HardwareX | volume = 15 | pages = e00442 | date = September 2023 | pmid = 37457304 | pmc = 10338363 | doi = 10.1016/j.ohx.2023.e00442 }} The tourniquet tester costs less than $100 and once calibrated with a blood pressure monitor, the built-in LCD displays the measuring range of the tester (0 to 200 N), which can be used to test the validation of all tourniquets.

= Rehabilitation tourniquets =

== Personalized blood flow restriction ==

Recently, pneumatic tourniquets have been successfully used for a technique called Personalized Blood Flow Restriction Training (PBFRT) to accelerate the rehabilitation of orthopedic patients, injured professional athletes, and wounded soldiers.{{Cite journal |last1=McEwen |first1=Jim A. |last2=Jeyasurya |first2=Jeswin |last3=Owens |first3=Johnny |date=2016-05-24 |title=How Can Personalized Tourniquet Systems Accelerate Rehabilitation of Wounded Warriors, Professional Athletes and Orthopaedic Patients? |url=https://proceedings.cmbes.ca/index.php/proceedings/article/view/23 |journal=CMBES Proceedings |language=en |volume=39 |issn=2371-9516}}

Typically, to increase muscle size and strength, a person needs to lift loads at or above 65% of their one repetition maximum.{{Cite journal |date=March 2009 |title=Progression Models in Resistance Training for Healthy Adults |url=https://journals.lww.com/00005768-200903000-00026 |journal=Medicine & Science in Sports & Exercise |language=en |volume=41 |issue=3 |pages=687–708 |doi=10.1249/MSS.0b013e3181915670 |pmid=19204579 |issn=0195-9131 |author1=American College of Sports Medicine }} However, injured patients are often limited to low-load resistance exercise where strength and size benefits are limited compared to high-load resistance exercise.

Low-load resistance exercise combined with blood flow restriction (BFR) has been shown in literature to increase both muscle strength and size across different age groups. With BFR, exercise can be performed at substantially lower loads and intensities while generating similar muscular and physiological adaptations seen in high intensity resistance training.{{Cite journal |last1=Hughes |first1=Luke |last2=Rosenblatt |first2=Benjamin |last3=Haddad |first3=Fares |last4=Gissane |first4=Conor |last5=McCarthy |first5=Daniel |last6=Clarke |first6=Thomas |last7=Ferris |first7=Graham |last8=Dawes |first8=Joanna |last9=Paton |first9=Bruce |last10=Patterson |first10=Stephen David |date=2019-07-12 |title=Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled Trial |url=http://dx.doi.org/10.1007/s40279-019-01137-2 |journal=Sports Medicine |volume=49 |issue=11 |pages=1787–1805 |doi=10.1007/s40279-019-01137-2 |pmid=31301034 |s2cid=196350271 |issn=0112-1642}} For load compromised populations, this reduces the pain during the exercise protocol and leads to overall improvements in physical function.

To provide consistent BFR pressure stimulus to patients, it is recommended to (1) apply a restrictive pressure that is personalized to each individual patient based on the patient’s limb occlusion pressure,{{Cite journal |last1=Jessee |first1=Matthew B. |last2=Mattocks |first2=Kevin T. |last3=Buckner |first3=Samuel L. |last4=Dankel |first4=Scott J. |last5=Mouser |first5=J. Grant |last6=Abe |first6=Takashi |last7=Loenneke |first7=Jeremy P. |date=June 2018 |title=Mechanisms of Blood Flow Restriction: The New Testament |url=http://dx.doi.org/10.1097/bto.0000000000000252 |journal=Techniques in Orthopaedics |volume=33 |issue=2 |pages=72–79 |doi=10.1097/bto.0000000000000252 |s2cid=79572988 |issn=0885-9698|url-access=subscription }} and (2) utilize a BFR system that can provide surgical-grade tourniquet autoregulation.{{Cite journal |last1=Lai |first1=Tom |last2=Hughes |first2=Luke |last3=McEwen |first3=James |date=2023-05-14 |title=Blood flow restriction therapy: The essential value of accurate surgical-grade tourniquet autoregulation |url=https://proceedings.cmbes.ca/index.php/proceedings/article/view/1045 |journal=CMBES Proceedings |language=en |volume=45 |issn=2371-9516}}

See also

References

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