How Misleading Data Could Change Tourniquet Protocols
A recent French article voiced a concern for overzealous pre-hospital tourniquet use; the data is not as supportive of their conclusions as the article makes it seem.
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During the December 2024 Committee for Tactical Emergency Casualty Care meeting, there was a brief discussion of a recently published French article1 which voiced a concern for overzealous pre-hospital tourniquet use in trauma patients with resulting tourniquet complications. My review of that article does not reflect the official position or views of the TECC Committee, and reflects my personal evaluation of the literature.
The authors1 described nine trauma patients over a three-month period, with severe upper extremity trauma, and tourniquet application pre-hospital by paramedics or EMS physicians; the patients were felt to have complications from the tourniquet application.
None of the patients were in shock, and bleeding was described as absent or moderate, suggesting that none of the patients needed tourniquets.
Four of the nine had tourniquets applied for an average of 80 minutes; the other five for 130 minutes.
Not surprisingly, those with longer tourniquet time had more complications.
The authors note that “under American influence, first-line tourniquet application is increasing,” and they expressed concern, particularly in upper extremities, that this is leading to tourniquet-related complications.1
Unfortunately, the description of their nine patients doesn’t provide much evidence for definitive tourniquet-related complications of those with tourniquet times of less than 2 hours.
In support of their argument, they cited complication data from numerous prior studies.
Looking at those studies, one by one, shows the data is not as supportive of their conclusions as their article makes it seem.
The authors1 noted nerve palsy from tourniquet application was 2.5 times more frequent in upper extremities compared to lower. They cited that statistic crediting an article by Bogdan2; However, the statistic is not original to Bogdan, and they credit that number to another article3 that does state that increased risk, but offers the statistic without any citation. Therefore, we have no source to support the assertion of 2.5 times increased nerve palsies from tourniquets.
To put the statistics in perspective, Lowe states it is estimated to occur in 1 of every 13,000 applications:
That is hardly a significant risk.
It is suggested that radial nerve injuries happen after operative tourniquet application to the forearm because of the reduced soft tissue overlying the nerves there.
In 1982, Dobner4 compared nerve electromyograms on 48 military males undergoing meniscectomy knee surgery. They randomized surgical patients between those where a 9.5 cm wide pneumatic tourniquet was used, and those where it was not. All other treatments were identical.
71% of those who had a tourniquet placed operatively had abnormal nerve conduction signals six weeks after surgery.
None of the knee surgery patients without a tourniquet did.
It took three to six months for the nerve conduction to return to normal in all patients. Is this decreased nerve function from tourniquet use significant or noticeable to the patient? Yes, it is. They also found the strength to single leg jump vertically on the operated leg, was about half the height of those operated on without tourniquets. Presumably, this normalized eventually, but they did not provide that data in the study.
However, in 2012, a prospective randomized comparison of 80 patients undergoing knee meniscectomy with or without an operative (18 cm) tourniquet inflated to 320 mmHg were studied regarding post-operative pain, knee range of motion, time to full weight bearing, return to light work, and sports showed no difference whether an operative tourniquet was used or not.5 This larger and more robust randomized comparison provides evidence against clinically significant nerve injury from operative tourniquets as a common occurrence.
Older research from 19726 concluded it was pressure on the nerve, not nerve ischemia that was to blame for tourniquet-related nerve damage. However, in the knee surgery study,4 tourniquet pressures (and mean tourniquet time 41 to 50 minutes) were the same between those with nerve injury and not, which would argue damage isn’t caused from pressure alone.
Jazottes1 cited a 7-fold increased risk of infection with tourniquet application per Clasper7 / British MOD. That study was a retrospective cohort comparison of prospectively collected data on 44 British military Global War on Terror casualties with lower extremity injuries associated with fractures.
Those with pre-hospital tourniquet application were matched to similarly injured controls (22 in each group) without tourniquets selected by one surgeon. 32% of pre-hospital tourniquet application casualties went on to deep space infections, whereas only 4% without tourniquets did.
Superficial infection rates were the same in both groups at 50%.
There was limited detail on how the patients were matched. Also, one could argue the groups weren’t sufficiently similarly matched, as IED blast was the mechanism of injury twice as often in the non-tourniquet group. Although this data is concerning, it is hardly definitive.
The authors of the French study did correctly cite prior literature showing a 6% rate of nerve palsies, higher infection rates, 8% compartment syndrome, and 8% ischemia / re perfusion syndrome.1,8
The study showing those complications was a retrospective, multi-center study of 197 trauma patients with extremity tourniquets applied and transported to level-1 trauma centers, between 2010 and 2013.8
Overall, 32.4% of the patients had had some form of complication.
The average tourniquet time was 48 minutes.
However, what the French authors didn’t say was the authors of the retrospective study themselves acknowledged they could not determine whether these complications were from tourniquet use.
They cited similar nerve palsy rates in military data.8 However, still other military data showed only a 1.7% rate of transient nerve palsies at the level of the tourniquet.9
A level-1 trauma center studied consecutive trauma patients with extremity injuries and compressible bleeding over an 8-year period. All extremity tourniquet placements for trauma were included. Case-control matching was used to compare similar extremity trauma patients, differing only as to whether they had tourniquets placed (127) or not (77).
Though the rate of nerve palsy was 6.3% in the tourniquet group and 2.6% in the non-tourniquet group, the difference was not statistically significant.
Additionally, on further review, it was determined when nerve palsy did occur, the level of nerve damage was at the point of injury, not where the tourniquet was placed.10
In yet another study, operative pneumatic tourniquet use in Norway showed the incidence of major neurovascular injury was estimated as one per 6,155 patients in the upper extremity and one in 3,752 in the lower extremity with an overall permanent injury rate of only 0.032%.11
In a systematic review and meta-analysis of 4095 trauma patients with concern for extremity vascular injury, pre-hospital application of a tourniquet decreased the odds of dying by 50% compared to no tourniquet or subsequent emergency department tourniquet application. There was no increase in complications in the tourniquet group in their study.12 However, scientifically, the evidence on which this study was based is considered low-quality as it was largely retrospective and had poorly controlled other variables in the patient groups.12
Finally, in a retrospective, single-center study of 192 adult trauma patients with pre-hospital commercial tourniquet placement, either by law enforcement officers or EMS, the LEO-placed tourniquets ultimately only required surgery to control bleeding in 6.4% after tourniquet removal. If EMS placed the tourniquet, 23.3% required surgical bleeding control.13
A named blood vessel injury (tiny blood vessels don’t have names and generally don’t cause life-threatening bleeding) was present in only 16% of LEO placements but 40% of EMS placements.
These findings indicate both LEO and EMS placed tourniquets frequently without the presence of massive hemorrhage. In many systems, tourniquet placement requires the patient be transported to a trauma center and activation of a high-level trauma team, regardless of the stability of the patient.13
In most cases, if you have a penetrating extremity injury, not requiring surgery, you don’t really need a trauma center or trauma team activation for your treatment. Trauma center resources are limited and expensive, even in the US.
What does all this mean?
Complications from wide pneumatic orthopedic surgical tourniquets are rare but do occur. There is no reason to believe that narrow commercial tourniquets used by law enforcement, pre-hospital providers, and the military would have lower complication rates, as narrower tourniquets generate more pressure under them to occlude extremity blood flow. Clearly, if enough tourniquets are applied, there will be some complications from their application.
Upper extremity application seems to be at more risk for causing nerve injury than lower extremity tourniquet application. The exact cause of nerve injury remains unclear, but might be related to decreased muscle mass over the nerves there.
When nerve and muscle injuries occur from tourniquet use, the vast majority are temporary and recover, although recovery can take six months.
Placement of tourniquets for extremity injuries without massive bleeding and for long periods of time, as we have seen in Ukraine, absolutely does cause devastating extremity complications.14
Nonetheless, in the event of massive hemorrhage from an extremity injury, tourniquet application for less than two hours remains an effective and safe option for short-term control, based on the current medical and scientific literature.
References
1Jazottes H, Chammas M, Lazerges C, Coulet B, Charbit J, Chammas PE. Morbidity associated with pre-hospital upper-limb tourniquet in civilian trauma: a case series. Hand Surg Rehabil. 2024 Oct;43(5):101752. doi: 10.1016/j.hansur.2024.101752. Epub 2024 Jul 15. PMID: 39019400.
2Bogdan Y, Helfet DL. Use of Tourniquets in Limb Trauma Surgery. Orthop Clin North Am. 2018 Apr;49(2):157-165. doi: 10.1016/j.ocl.2017.11.004. Epub 2017 Dec 9. PMID: 29499817.
3Lowe JB 3rd, Sen SK, Mackinnon SE. Current approach to radial nerve paralysis. Plast Reconstr Surg. 2002 Sep 15;110(4):1099-113. doi: 10.1097/01.PRS.0000020996.11823.3F. PMID: 12198425.
4Dobner JJ, Nitz AJ. Postmeniscectomy tourniquet palsy and functional sequelae. Am J Sports Med. 1982 Jul-Aug;10(4):211-4. doi: 10.1177/036354658201000404. PMID: 6896963.
5Tsarouhas A, Hantes ME, Tsougias G, Dailiana Z, Malizos KN. Tourniquet use does not affect rehabilitation, return to activities, and muscle damage after arthroscopic meniscectomy: a prospective randomized clinical study. Arthroscopy. 2012 Dec;28(12):1812-8. doi: 10.1016/j.arthro.2012.06.017. Epub 2012 Oct 22. PMID: 23089349.
6Ochoa J, Fowler TJ, Gilliatt RW. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J Anat. 1972 Dec;113(Pt 3):433-55. PMID: 4197303; PMCID: PMC1271414.
7Clasper JC, Brown KV, Hill P. Limb complications following pre-hospital tourniquet use. J R Army Med Corps. 2009 Sep;155(3):200-2. doi: 10.1136/jramc-155-03-06. PMID: 20397360.
8Schroll R, Smith A, McSwain NE Jr, Myers J, Rocchi K, Inaba K, Siboni S, Vercruysse GA, Ibrahim-Zada I, Sperry JL, Martin-Gill C, Cannon JW, Holland SR, Schreiber MA, Lape D, Eastman AL, Stebbins CS, Ferrada P, Han J, Meade P, Duchesne JC. A multi-institutional analysis of pre-hospital tourniquet use. J Trauma Acute Care Surg. 2015 Jul;79(1):10-4; discussion 14. doi: 10.1097/TA.0000000000000689. PMID: 26091308.
9Kragh JF Jr, Walters TJ, Baer DG, Fox CJ, Wade CE, Salinas J, Holcomb JB. Practical use of emergency tourniquets to stop bleeding in major limb trauma. J Trauma. 2008 Feb;64(2 Suppl):S38-49; discussion S49-50. doi: 10.1097/TA.0b013e31816086b1. PMID: 18376170.
10Smith AA, Ochoa JE, Wong S, Beatty S, Elder J, Guidry C, McGrew P, McGinness C, Duchesne J, Schroll R. Pre-hospital tourniquet use in penetrating extremity trauma: Decreased blood transfusions and limb complications. J Trauma Acute Care Surg. 2019 Jan;86(1):43-51. doi: 10.1097/TA.0000000000002095. PMID: 30358768.
11Odinsson A, Finsen V. Tourniquet use and its complications in Norway. J Bone Joint Surg Br. 2006 Aug;88(8):1090-2. doi: 10.1302/0301-620X.88B8.17668. PMID: 16877612.
12Ko YC, Tsai TY, Wu CK, Lin KW, Hsieh MJ, Lu TP, Matsuyama T, Chiang WC, Ma MH. Effectiveness and safety of tourniquet utilization for civilian vascular extremity trauma in the pre-hospital settings: a systematic review and meta-analysis. World J Emerg Surg. 2024 Mar 19;19(1):10. doi: 10.1186/s13017-024-00536-9. PMID: 38504263; PMCID: PMC10949629.
13Shukla D, Shapiro G, Smith ER, Sarani B. Comparison of law enforcement officer- versus emergency medical services-placed tourniquets. J Trauma Acute Care Surg. 2024 Oct 1;97(4):552-556. doi: 10.1097/TA.0000000000004349. Epub 2024 Apr 10. PMID: 38595271.
14Stevens RA, Baker MS, Zubach OB, Samotowka M. Misuse of Tourniquets in Ukraine may be Costing More Lives and Limbs Than They Save. Mil Med. 2024 Nov 5;189(11-12):304-308. doi: 10.1093/milmed/usad503. PMID: 38242075.
