title: Effect of limited ischemia time on the amount and function of mitochondria within human skeletal muscle cells Arm versus forearm tourniquet for carpal tunnel decompression – Which is better? A randomized controlled trial Impact of Phlebotomy Tourniquet Use on Blood Lactate Levels in Acutely Ill Patients. Evaluation of pain in bilateral total knee replacement with and without tourniquet; a prospective randomized control trial. Randomised controlled trial comparing marksmanship following application of a tourniquet or haemostatic clamp in healthy volunteers Postischemic conditioning does not reduce muscle injury after tourniquet-induced ischemia-reperfusion injury in rats. Analysis of Layperson Tourniquet Application Using a Novel Color-Coded Device. A comparison of live tissue training and high-fidelity patient simulator: A pilot study in battlefield trauma training Tourniquet-induced ischaemia during total knee arthroplasty results in higher proteolytic activities within vastus medialis cells: a randomized clinical trial Nerve compression and pain in human volunteers with narrow vs wide tourniquets. An evaluation of combat application tourniquets on training military personnel: changes in application times and success rates in three successive phases Training and Assessing Critical Airway, Breathing, and Hemorrhage Control Procedures for Trauma Care: Live Tissue Versus Synthetic Models The American Association for the Surgery of Trauma PROspective Observational Vascular Injury Treatment (PROOVIT) registry: Multicenter data on modern vascular injury diagnosis, management, and outcomes Systematic review of prehospital tourniquet use in civilian limb trauma
abstract: Abstract Introduction The clinical success of total knee arthroplasty ( TKA ) depends substantially on the quadriceps muscle function . A frequently applied thigh tourniquet during TKA may induce ischemia related injuries to quadriceps muscle cells . Animal limb muscles subjected to 2–5 h ischemia revealed dysfunctional mitochondria , which in turn compromised the cellular bioenergetics and increased the level of reactive oxygen species . The hypothesis of the present study was that tourniquet application during TKA for 60 min ( min ) affects the amount and function of mitochondria within musculus vastus medialis cells . Material s and methods In a r and omized clinical trial , 10 patients enrolled to undergo primary TKA . The patients were r and omly assigned to the tourniquet ( n = 5 ) or non-tourniquet group ( n = 5 ) after obtaining a written informed consent . For each of the groups , the first muscle biopsy was harvested immediately after performing the surgical approach and the second biopsy exactly 60 min later . All biopsies ( 5 × 5 × 5 mm ) 125 mm3 were harvested from musculus vastus medialis and snap-frozen in liquid nitrogen . The biochemical analysis of the prepared muscle tissues included the measurement of activities of mitochondrial respiratory chain enzyme complexes I – III and citrate synthase . Results Tourniquet-induced 60 min ischemia time did not significantly change the activities of the mitochondrial respiratory chain enzymes complexes I – III of the skeletal muscle cells . The citrate synthase activities found to be not significantly different between both groups . Conclusions The use of tourniquet during TKA within a limited time period of 60 min remained without substantial effects on the amount and function of mitochondria within human skeletal muscle cells Tourniquet pain is a common source of complaint for patients undergoing carpal tunnel decompression and practice varies as to the tourniquet position used . There is little evidence to suggest benefit of one position over another . Our aim was to compare patient and surgeon experience of forearm and arm tourniquets . Following a power calculation , 100 patients undergoing open carpal tunnel decompression under local anaesthetic  were r and omized to either an arm or a forearm tourniquet . Measurements of blood pressure , heart rate and pain were taken at 2.5 min intervals . The operating surgeon also provided a visual analogue scale rating for the extent of bloodless field achieved and for any obstruction caused by the tourniquet . There was no statistically significant inter-group difference in patient pain or physiological response , tourniquet time , bloodless field or length of procedure . The degree of obstruction caused by the tourniquet was significantly higher in the forearm group . Level of Evidence : I. Prospect i ve R and omized Controlled OBJECTIVE Lactate levels are increasingly used to guide resuscitation efforts . Some surgical literature suggests that tourniquet use during phlebotomy falsely elevates results , although studies in healthy volunteers have not demonstrated this . The purpose of this study was to determine in clinical practice whether tourniquet use during the drawing of a lactate results in significantly altered levels compared to the result of a level drawn without a tourniquet . METHODS A prospect i ve cohort study was carried out on emergency department patients whose clinical presentation led a physician to order a lactate level . Written informed consent was obtained from patients or their proxies . Study  lactates  were obtained using a tourniquet during the draw sequence of other laboratory studies . Lactate levels for clinical use were drawn per hospital protocol with no tourniquet . The time of lactate measurements and patient demographic information were recorded . Lactate levels for each patient were compared with the Wilcoxon Rank-Sum Test . RESULTS 40 patients were consented and enrolled . The median clinical lactate level was 1.9 ( interquartile range 1.5 - 2.6 ) , and the median study lactate level was 1.9 ( interquartile range 1.4 - 2.7 ) . There was no difference between paired lactate values ( p=0.95 ) . CONCLUSIONS Tourniquet use appears to have no impact on measured lactate levels . Our findings suggest that current practice s at many institutions regarding lactate collection are likely too stringent and should be changed AIM Thigh pain following tourniquet application is a common complaint in early post operative period following total knee arthroplasty . METHOD Post operative Thigh pain was evaluated in 30 consecutive simultaneous bilateral total knee arthroplasty patients between July 2013 and January 2014 . Patient thigh pain was evaluated with the VAS score . The scale was applied on first , second , third day & second and six weeks after surgery . RESULT There were statistically significant difference in VAS score  in non-tourniquet group on first , second , third post operative day . We did not find statistically significant difference at Second and Six weeks post operatively . CONCLUSION This R and omized trial demonstrates that non-tourniquet use in TKA has less early postoperative pain and leads to better recovery Background In a care under fire situation , a first line response to haemorrhage is to apply a tourniquet and return fire . However , there is little underst and ing of how tourniquets and other haemorrhage control devices impact marksmanship . Methods We compared the impact of the iTClamp and the Combat Application Tourniquet ( CAT ) on marksmanship . Following r and omisation ( iTClamp or CAT ) , trained marksmen fired an AR15 at a scaled silhouette target in prone unsupported position ( shooting task ) . Subjects then attempted to complete the shooting task at 5 , 10 , 15 , 30 and 60 min post-haemorrhage control device application . Results All of the clamp groups ( n=7 ) completed the 60 min shooting task . Five CAT groups ( n=6 ) completed the 5 min shooting task and one completed the 5 and 10 min shooting task before withdrawing . Four CAT groups were stopped due to unsafe h and ling ; two stopped due to pain . When examining hits on mass ( HOM ) for the entire shooting task , there was no significant difference between tourniquet and iTClamp HOM at 5 min ( p=0.18 ) . However , there was a significant difference at 10 min , p=0.003 with tourniquet having significantly fewer HOM ( 1.7±2.7 HOM ) than the iTClamp ( 8.1±3.3 HOM ) group . The total effective HOM for the entire 60 min shooting task showed that the iTClamp group achieved significantly ( p=0.001 ) more HOM than the tourniquet group . Over the entire 60 min shooting exercise , the iTClamp group achieved a median 72 % ( 52/72 ) of available HOM while the tourniquet group obtained 19 % ( 14/72 ) . Conclusions Application of a tourniquet to the dominant arm negates effective return of fire in a care under fire setting after a brief time window . Haemorrhage control devices that preserve function may have a role in care under fire situations , as preserving effectiveness in returning fire has obvious operational merits BACKGROUND The widespread application of tourniquets has reduced battlefield mortality related to extremity exsanguinations . Tourniquet-induced ischemia-reperfusion injury ( I/R ) can contribute to muscle loss . Postischemic conditioning ( PostC ) confers protection against I/R in cardiac muscle and skeletal muscle flaps . The objective of this study was to determine the effect of PostC on extremity muscle viability in an established rat hindlimb tourniquet model . METHODS Rats were r and omly assigned to  PostC-1 , PostC-2 , or no conditioning ischemic groups ( n = 10 per group ) .  Postischemic conditioning , performed immediately after tourniquet release , consisted of four 15-second cycles ( PostC-1 ) or eight 15-second cycles ( PostC-2 ) of alternating occlusion and perfusion of hindlimbs . Twenty-four hours later , muscles were excised . The primary end points were muscle edema and viability ; secondary end points were histologic and markers of oxidative stress . RESULTS Ischemia-reperfusion injury decreased viability in all tourniquet limbs , but viability was not improved in either PostC group . Likewise , I/R result ed in substantial muscle edema that was not reduced by PostC. The predominant histologic feature was necrosis , but no significant differences were found among groups . Markers of oxidative stress were increased similarly among groups after I/R , although myeloperoxidase activity was significantly increased only in the no conditioning ischemic group . A protective effect from PostC was not observed in our model suggesting that PostC was not effective in reducing I/R skeletal muscle injury or any benefits of PostC were not sustained for 24 hours when tissues were assessed . CONCLUSION These negative findings are pertinent as the military investigates different strategies to extend the safe time for tourniquet application OBJECTIVE To determine whether a color-coded tourniquet design ed for public use increases successful tourniquet application by laypeople . METHODS This was a r and omized study conducted on April 25 , 2015 . The study occurred during the Maryl and Day activity at the University of Maryl and in College Park , Maryl and . Investigators recruited participants with posters displayed at major crosswalks around a central testing area . A total of 157 volunteers aged 18 years or older and without prior military service or medical training were enrolled . A participant stood in front of a waist-down mannequin with an isolated leg injury while an investigator read aloud a mass causality scenario . The investigator then asked the participant to apply a tourniquet to the mannequin 's leg . All participants received a 4-step illustrated just-in-time ( JiT ) instruction card design ed to facilitate layperson tourniquet application . Test participants received a color-coded tourniquet design ed for layperson use with instructions printed on the device . Control participants received a black Combat Application Tourniquet ( C-A-T ; Composite Re sources , Rock Hill , SC ) . Participants were r and omized in a 1:1 ratio in blocks of 50 . The primary outcome was the proportion of successful tourniquet applications by those who received color-coded tourniquets compared to those who received black tourniquets . Secondary outcomes included validation of previous data analyzing layperson success with tourniquet application , time for successful placement , reasons for failed applications , and participant self-willingness and comfort using tourniquets . We also analyzed demographic data on the study population and inter-rater reliability regarding the assessment of successful tourniquet application . RESULTS Participants supplied with color-coded tourniquets  successfully placed the device 51.38 % of the time , compared to 44.71 % of the time for controls using a black tourniquet ( risk ratio : 1.15 ; 95 % confidence interval : 0.83 - 1.59 ; P=0.404 ) . Participants  ' self-reported willingness to use a tourniquet rose from 40.8 % before the study to 80.3 % after the study ( P<0.05 ) . CONCLUSIONS The color-coded device did not significantly increase laypeople 's proportion of successful tourniquet applications when compared with a st and ard black device . However , this study reproduced pilot study data showing that laypeople can successfully apply tourniquets about half the time if provided JiT instructions . Age , sex , race , income , and highest level of education were not found to impact one 's ability to properly apply a tourniquet . Laypeople 's willingness to apply tourniquets doubled to 80 % after brief exposure to the device . These results affirm the feasibility of engaging laypeople as immediate lifesavers of trauma victims and justify further efforts to boost rates of proper application BACKGROUND Trauma procedural and management skills are often learned on live tissue . However , there is increasing pressure to use simulators because their fidelity improves and as ethical concerns increase . We r and omized military medical technicians ( medics ) to training on either simulators or live tissue to learn combat casualty care skills to determine if the choice of modality was associated with differences in skill uptake . METHODS Twenty medics were r and omized to trauma training using either simulators or live tissue .  Medics were trained to perform five combat casualty care tasks ( surgical airway , needle decompression , tourniquet application , wound packing , and intraosseous line insertion ) . We measured skill uptake using a structured assessment tool . The medics also completed exit question naires and interviews to determine which modality they preferred . RESULTS We found no difference between groups trained with live tissue versus simulators in how they completed each combat casualty care skill . However , we did find that the modality of assessment affected the assessment score . Finally , we found that medics preferred trauma training on live tissue because of the fidelity of tissue h and ling in live tissue models . However , they also felt that training on simulators also provided additional training value . CONCLUSION We found no difference in performance between medics trained on simulators versus live tissue models . Even so , medics preferred live tissue training over simulation . However , more studies are required , and future studies need to address the measurement bias of measuring outcomes in the same model on which the study participants are trained . LEVEL OF EVIDENCE Therapeutic/care management study , level II Abstract Purpose Recent data suggest diminished post-operative quadriceps muscle strength after tourniquet application  during total knee arthroplasty ( TKA ) . The metabolic effects of the commonly utilized intraoperative tourniquet with consecutive ischaemia on the skeletal muscle cells were unknown . Ubiquitin proteasome system represents one of the main pathways involved in muscle protein breakdown contributing to muscle atrophy . Therefore , the purpose of the present study was to quantify the acute effects of the tourniquet application during TKA on the ( 1 ) concentrations of free/conjugated ubiquitin , ( 2 ) total ubiquitin-protein ligase activity , ( 3 ) proteasome-dependent and ( 4 ) proteasome-independent peptidase activities in the cells of vastus medialis . Methods The r and omized , controlled , monocentric trial included 34 patients scheduled to undergo primary TKA . Each patient was r and omly assigned to the tourniquet ( n = 17 ) or non-tourniquet group ( n = 17 ) after receiving a written consent . Muscle biopsies of ( 5 × 5 × 5 mm ) 125 mm3 were obtained from vastus medialis immediately after performing the surgical approach and exactly 60 min later . After preparation of the muscle tissue specimen , the concentrations of the free/conjugated ubiquitin ( Ub ) were measured by western blot analyses . The ubiquitination was determined as biotinylated Ub incorporated into the sum of the cytosolic proteins and expressed as total ubiquitin-protein ligase activity ( tUbPL ) . The quantification of the proteasome-dependent and proteasome-independent peptidase activities was performed with peptidase assays . Results Tourniquet application did not influence the concentration of the free/conjugated Ub . There were no differences in tUbPL activities between groups and time points . Tourniquet-induced ischaemia result ed in statistically significant higher proteasome-dependent ( caspase-like p = 0.0034 ; chymotryptic-like p = 0.0013 ; tryptic-like p = 0.0036 ) and proteasome-independent ( caspase-like p = 0.03 ; chymotryptic-like p = 0.0001 ; tryptic-like p = 0.0062 ) peptidase activities . Conclusion Tourniquet application did not affect the free/conjugated Ub as well as tUbPL significantly , emphasizing the sophisticated regulation of ubiquitination . The proteasome-dependent peptidase activities were significantly upregulated during tourniquet application , suggesting an increase in protein degradation , which in turn might explain the skeletal muscle atrophy occurring after TKA . These findings add further knowledge and should raise the awareness of surgeons about the effects of tourniquet-induced ischaemia at the molecular level . Additional high- quality research may be warranted to examine the short- and long-term clinical significance of the present data .Level of evidence AIM To assess the clinical effects and the morphological grade of nerve compression . METHODS In a prospect i ve single-center r and omized , open study we assessed the clinical effects and the morphological grade of nerve compression during 20 min of either a silicon ring ( group A ) or pneumatic tourniquet ( group B ) placement variantly on the upper non-dominant limb in 14 healthy human volunteers . Before and during compression , the median and radial nerves were visualized in both groups by 3 Tesla MR imaging , using high resolutional ( 2.5 mm slice thickness ) axial T2-weighted sequences . RESULTS In group A , Visual analog pain scale was 5.4 ± 2.2 compared to results of group B , 2.9 ± 2.5 , showing a significant difference ( P = 0.028 ) . FPS levels in group A were 2.6 ± 0.9 compared to levels in group B 1.6 ± 1 , showing a significant difference ( P = 0.039 ) . Results related to measureable effect on median and radial nerve function were equal in both groups . No undue pressure signs on the skin , redness or nerve damage occurred in either group . There was no significant difference in the diameters of the nerves without and under compression in either group on T2 weighted images . CONCLUSION Based on our results , no differences between narrow and wide tourniquets were identified . Silicon ring tourniquets can be regarded as safe for short time application Introduction Haemorrhage from the injured extremity is a significant cause of preventable death in military setting s. This study evaluated the effect of training on the efficacy of the combat application tourniquet ( CAT ) and to define st and ards for military personnel . Method Participants from a training tank battalion were r and omised . Data collected included age , body mass index , mean arterial pressure , h and dominance , femoral artery diameter and skin thickness . The study involved  tourniquet application times ( AT ) and application success rates in basic , after-training and eyes-closed phases . Doppler ultrasound was used to identify the presence or absence of popliteal , radial and ulnar artery pulses . Results A total of 102 trainees participated . In the after-training phase , the left and right upper extremity ATs were 35±13.1 s , and 34.8±13.5 s and the right and left lower extremity ATs were 20.6±6.0 s and 20.5±5.5 s , respectively . The overall tourniquet success rates in three successive study phases were 69.6 % , 82.4 % and 91.2 % , respectively . A negative significant relationship was found between extremity circumference and tourniquet success . Discussion The results show that the efficacy of CAT application  increases with training . Further studies are required to investigate the reasons underlying application failures . This single group prospect i ve r and omised study involves level of evidence 4 INTRODUCTION Optimal teaching and assessment methods and models for emergency airway , breathing , and hemorrhage interventions are not currently known . The University of Minnesota Combat Casualty Training consortium ( UMN CCTC ) was formed to explore the strengths and weaknesses of synthetic training models ( STMs ) versus live tissue ( LT ) models . In this study , we compare the effectiveness of best in class STMs versus an anesthetized caprine ( goat ) model for training and assessing seven procedures : junctional hemorrhage control , tourniquet ( TQ ) placement , chest seal , needle thoracostomy ( NCD ) , nasopharyngeal airway ( NPA ) , tube thoracostomy , and cricothyrotomy ( Cric ) . METHODS Army combat medics were r and omized to one of four groups : 1 ) LT trained-LT tested ( LT-LT ) , 2 ) LT trained-STM tested ( LT-STM ) , 3 ) STM trained-LT tested ( STM-LT ) , and 4 ) STM trained-STM tested ( STM-STM ) .  Participants trained in small groups for 3 to 4 hours and were evaluated individually . LT-LT was the " control " to which other groups were compared , as this is the current military predeployment st and ard . The mean procedural scores ( PSs ) were compared using a pairwise t-test with a Dunnett 's correction . Logistic regression was used to compare critical fails ( CFs ) and skipped tasks . RESULTS There were 559 subjects included . Junctional hemorrhage control revealed no difference in CFs , but LT-tested subjects ( LT-LT and STM-LT ) skipped this task more than STM-tested subjects ( LT-STM and STM-STM ; p < 0.05 ) , and STM-STM had higher PSs than LT-LT ( p < 0.001 ) . For TQ , both STM-tested groups ( LT-STM and STM-STM ) had more CFs than LT-LT ( p < 0.001 ) and LT-STM had lower PSs than LT-LT ( p < 0.05 ) . No differences were seen for chest seal . For NCD , LT-STM had more CFs than LT-LT ( p = 0.001 ) and lower PSs ( p = 0.001 ) . There was no difference in CFs for NPA , but all groups had worse PSs versus LT-LT ( p < 0.05 ) . For Cric , we were underpowered ; STM-LT trended toward more CFs ( p = 0.08 ) , and STM-STM had higher PSs than LT-LT ( p < 0.01 ) . Tube thoracostomy revealed that STM-LT had higher CFs than LT-LT ( p < 0.05 ) , but LT-STM had lower PSs ( p < 0.05 ) . An interaction effect ( making the subjects who trained and tested on different models more likely to CF ) was only found for TQ , chest seal , and Cric ; however , of these three procedures , only TQ demonstrated any significant difference in CF rates . CONCLUSION Training on STM or LT did not demonstrate a difference in subsequent performance for five of seven procedures ( junctional hemorrhage , TQ , chest seal , NPA , and NCD ) . Until STMs are developed with improved anthropomorphic and tissue fidelity , there may still be a role for LT for training tube thoracostomy and potentially Cric . For assessment , our STM appears more challenging for TQ and potentially for NCD than LT . For junctional hemorrhage , the increased " skips " with LT may be explained by the differences in anatomic fidelity . While these results begin to uncover the effects of training and assessing these procedures on various models , further study is needed to ascertain how well performance on an STM or LT model translates to the human model BACKGROUND There is a need for a prospect i ve registry design ed to capture trauma-specific , in-hospital , and long-term outcomes related to vascular injury . METHODS The American Association for the Surgery of Trauma PROspect i ve Vascular Injury Treatment ( PROOVIT ) registry was used to collect demographic , diagnostic , treatment , and outcome data on vascular injuries . RESULTS A total of 542 injuries from 14 centers ( 13 American College of Surgeons – verified Level I and 1 American College of Surgeons – verified Level II ) have been captured since February 2013 . The majority of patients are male ( 70.5 % ) , with an Injury Severity Score ( ISS ) of 15 or greater among 32.1 % . Penetrating mechanisms account for 36.5 % . Arterial injuries to the head/neck ( 26.7 % ) , thorax ( 10.4 % ) , abdomen/pelvis ( 7.8 % ) , upper extremity ( 18.4 % ) , and lower extremity ( 26.0 % ) were identified , along with 98 major venous injuries . Hard signs of vascular injury , including hypotension ( systolic blood pressure < 90 mm Hg , 11.8 % ) , were noted in 28.6 % . Prehospital tourniquet use for extremity injuries occurred in 20.2 % ( 47 of 233 ) . Diagnostic modalities included exploration ( 28.8 % ) , computed tomographic angiography ( 38.9 % ) , duplex ultrasound ( 3.1 % ) , and angiography ( 10.7 % ) . Arterial injuries included transection ( 24.3 % ) , occlusion ( 17.3 % ) , partial transection/flow limiting defect ( 24.5 % ) , pseudoaneurysm ( 9.0 % ) , and other injuries including intimal defects ( 22.7 % ) . Nonoperative management was undertaken in 276 ( 50.9 % ) , with failure in 4.0 % . Definitive endovascular and open repair were used in 40 ( 7.4 % ) and 126 ( 23.2 % ) patients , respectively . Damage-control maneuvers were used in 57 ( 10.5 % ) , including ligation ( 31 , 5.7 % ) and shunting ( 14 , 2.6 % ) . Reintervention of initial repair was required in 42 ( 7.7 % ) . Amputation was performed in 7.7 % of extremity vascular injuries , and overall hospital mortality was 12.7 % . Follow-up ranging from 1 month to 7 months is available for 48 patients via a variety of modalities , with reintervention required in 1 patient . CONCLUSION The PROOVIT registry provides a contemporary picture of the management of vascular injury . This re source promises to provide needed information required to answer questions about optimal diagnosis and management of these patients —including much needed long-term outcome data . LEVEL OF EVIDENCE Epidemiologic study , level BACKGROUND Military enthusiasm for limb tourniquet use in combat casualty care has result ed in acceptance by the trauma community for use in the prehospital care of civilian limb injuries . To date , there has been no report synthesizing the published data on civilian tourniquet use . The objective of this systematic review was to compile and analyze the content and quality of published data on the civilian use of tourniquets in limb trauma . METHODS The MEDLINE data base was search ed for studies on civilian limb tourniquet use in adults published between 2001 and 2017 . Search terms were tourniquet , trauma , and injury . Military reports and case series lacking systematic data collection were excluded . Counts and percentages were aggregated and weighted for analysis . RESULTS Reports were included from six regional trauma centers and one interregional collaboration ( total of 572 cases ) . One national prehospital data base report was included but analyzed separately ( 2,048 cases ) . All were retrospective cohort studies without prospect i ve data collection . Three reports defined a primary outcome , two had a nontourniquet control group , and no two articles reported the same variables . Limb injury severity and characteristics were inconsistently and incompletely described across reports , as were tourniquet indications and effectiveness . Arterial injury was reported in two studies and was infrequent among cases of tourniquet use . Mortality was low , and limb-specific complications were infrequent but variably reported . CONCLUSION The rapid increase in the civilian use of tourniquets for limb hemorrhage control has occurred without a large amount or high quality of data . Adoption of a multicenter registry with st and ardized data collection specific to limb trauma and tourniquet use can serve to improve the trauma community 's underst and ing of the safety and effectiveness of tourniquet use in civilian trauma setting s. LEVEL OF EVIDENCE Systematic review , level IV
target: The 50 original articles included in this qualitative , systematic review revealed that the recommendations " Tourniquet " of the DGAI published in 2016 are mostly still up to date despite an inhomogeneous study situation .
background: INTRODUCTION The effectiveness of a  tourniquet  in the case of life-threatening hemorrhages of the extremities is well recognized and led to the recommendations on " Tourniquet " of the German Society of Anaesthesiology and Intensive Care ( DGAI ) in 2016 .
  The aim of this systematic review was to re-evaluate the current medical literature in relation to the published DGAI recommendations .