Combat Application Tourniquet fares well in a chemical, biological, radiological or nuclear dress state.

INTRODUCTION: There is a need for a military tourniquet to control catastrophic haemorrhage in a chemical, biological, radiological or nuclear (CBRN) threat environment. No published data exist as to the efficacy of tourniquets while wearing British military CBRN individual protective equipment (IPE). METHODS: 12 volunteers from the counter CBRN instructors' course allowed testing on 24 legs. A Combat Application Tourniquet (C-A-T) was applied to all volunteers at the level of the midthigh. 12 legs were tested while wearing CBRN IPE (both operator and simulated casualty), and the control group of 12 legs was tested while wearing conventional combat dress state (both operator and simulated casualty). The order of leg laterality and dress state were sequenced according to a prerandomised system. Efficacy was measured via use of an ultrasound probe at the popliteal artery. Tourniquets were considered effective if arterial flow was completely occluded on ultrasound imaging. Data were collected on time to successful application, failure of tourniquets and pain scores as rated by the visual analogue scale (1-10). RESULTS: There were no failures of tourniquet application in the CBRN group, and two failures (17%) in the control group. Failures were pain threshold exceeded (n=1) and tourniquet internal strap failure (n=1). The mean application time for the CBRN group was 28.5 s (SD 11.7) and 23.7 s (SD 9.8) for the conventional combat group. There was no statistically significant difference (p=0.27). The median CBRN pain score was 2.0 (IQR 2.0-3.5). The median control pain score was 4.0 (IQR 3-6). This was a statistically significant difference (p=0.002). CONCLUSION: C-A-Ts applied to simulated casualties in CBRN IPE at the midthigh are at least as efficacious as those applied to the midthigh in a conventional combat dress state. The pain experienced was less in CBRN IPE than when in a conventional combat dress state.

The effects of tourniquet use on blood loss in primary total knee arthroplasty for patients with osteoarthritis: a meta-analysis.

BACKGROUND: The tourniquet is a common medical instrument used in total knee arthroplasty (TKA). However, there has always been a debate about the use of a tourniquet and there is no published meta-analysis to study the effects of a tourniquet on blood loss in primary TKA for patients with osteoarthritis. METHODS: We performed a literature review on high-quality clinical studies to determine the effects of using a tourniquet or not on blood loss in cemented TKA. PubMed, Web of Science, MEDLINE, Embase, and the Cochrane Library were searched up to November 2018 for relevant randomized controlled trials (RCTs). We conducted a meta-analysis following the guidelines of the Cochrane Reviewer's Handbook. We used the Cochrane Collaboration's tool for assessing the risk of bias of each trial. The statistical analysis was performed with Review Manager statistical software (version 5.3). RESULTS: Eleven RCTs involving 541 patients (541 knees) were included in this meta-analysis. There were 271 patients (271 knees) in the tourniquet group and 270 patients (270 knees) in the no tourniquet group. The results showed that using a tourniquet significantly decreased intraoperative blood loss (P < 0.002), calculated blood loss (P < 0.002), and the time of operation (P < 0.002), but tourniquet use did not significantly decrease postoperative blood loss (P > 0.05), total blood loss (P > 0.05), the rate of transfusion (P > 0.05), and of deep vein thrombosis (DVT) (P > 0.05) in TKA. CONCLUSIONS: Using a tourniquet can significantly decrease intraoperative blood loss, calculated blood loss, and operation time but does not significantly decrease the rate of transfusion or the rate of DVT in TKA. More research is needed to determine if there are fewer complications in TKA without the use of tourniquets.

Sweating the Little Things: Tourniquet Application Efficacy in Two Models of Pediatric Limb Circumference.

BACKGROUND: Current military recommendations include the use of tourniquets (TQ) in appropriate pediatric trauma patients. Although the utility of TQs has been well documented in adult patients, the efficacy of TQ application in pediatric patients is less clear. The current study attempted to identify physical constraints for TQ use in two simulated pediatric limb models. METHODS: Five different TQ (Combat Application Tourniquet (CAT) Generation 6 and Generation 7, SOFTT (SOF Tactical Tourniquet), SOFTT-W (SOF Tactical Tourniquet - Wide), SWAT-T (Stretch Wrap and Tuck - Tourniquet) and a trauma dressing were evaluated in two simulated pediatric limb models. Model one employed four cardiopulmonary resuscitation (CPR) manikins simulating infant (Simulaids SaniBaby), 1 year (Gaumard HAL S3004), and 5 years (Laerdal Resusci Junior, Gaumard HAL S3005). Model two utilized polyvinyl chloride (PVC) piping with circumferences ranging from 4.25" to 16.5". Specific end-points included tightness of the TQ and ability to secure the windlass (where applicable). RESULTS: In both models, the ability to successfully apply and secure the TQ depended upon the simulated limb circumference. In the 1-year-old CPR manikin, all windlass TQs failed to tighten on the upper extremity, while all TQs successfully tightened at the high leg and mid-thigh. With the exception of the CAT7 and the SOFTT-W at the mid-thigh, no windlass TQ was successfully tightened at any extremity location on the infant. The SWAT-T was successfully tightened over all sites of all CPR manikins except the infant. No windlass TQ was able to tighten on PVC pipe 5.75" circumference or smaller (age < 24 months upper extremity). All windlass TQs were tightened and secured on the 13.25" and 15.5" circumference PVC pipes (age 7-12 years lower extremity, age >13 years upper extremity). The SWAT-T was tightened on all PVC pipes. DISCUSSION: The current study suggests that commercial windlass TQs can be applied to upper and lower extremities of children aged 5 years and older at the 50%th percentile for limb circumference. In younger children, windlass TQ efficacy is variable. Further study is required to better understand the limitations of TQs in the youngest children, and to determine actual hemorrhage control efficacy.

Influence of tourniquet use in primary total knee arthroplasty with drainage: a prospective randomised controlled trial.

BACKGROUND: We aimed to compare the effect of tourniquet use or lack of it on recovery following uncomplicated primary total knee arthroplasty (TKA). METHODS: In a prospective randomised double-blinded study, 150 patients undergoing primary TKA were assigned to either a tourniquet or non-tourniquet group. At the early phase, 3 and 6 months after surgery, an independent observer assessed the primary outcome measure (i.e. total blood loss) and secondary outcome measures (i.e. wound complications, visual analogue scale pain score and knee range of motion). RESULTS: The tourniquet group exhibited reduced intraoperative blood loss (215.7 ± 113.7 ml vs. 138.6 ± 93.9 ml, P < 0.001) and shorter operating time (77.2 ± 14.5 min vs. 82.0 ± 12.7 min, P = 0.038). However, the non-tourniquet group showed less postoperative blood loss (180.2 ± 117.0 ml vs. 253.7 ± 144.2 ml, P = 0.001) and drainage volume (89.2 ± 66.3 ml vs. 164.5 ± 97.8 ml, P = 0.004), less thigh pain (all P < 0.001) in the initial 3 weeks, better knee range of motion (ROM) in the initial 3 days (day 1 81.6 ± 17.1 vs. 75.95 ± 14.55, P = 0.036; day 3 99.8 ± 13.7 vs. 93.95 ± 11.15, P = 0.005) and fewer wound tension vesicles (10.3 vs. 29.2%, P = 0.005). Earlier straight-leg raising (4.6 ± 3.8 h vs. 6.4 ± 4.3 h, P = 0.01) and shorter length of stay (6.3 ± 1.7 days vs. 7.1 ± 1.9 days, P = 0.001) were found in the non-tourniquet group. Similar total blood loss and blood transfusion rate were observed for both groups. All other parameters revealed no significant differences. CONCLUSIONS: Our study suggests that a non-tourniquet TKA would lead to early rehabilitation without increasing side effects. TRIAL REGISTRATION: Chinese Clinical Trials Registry, ChiCTR-IOR-16007851 , 1/29/2016.

Non-drainage versus drainage in tourniquet-free knee arthroplasty: a prospective trial.

BACKGROUND: It is still unknown whether drainage is necessary and non-drainage is safe and acceptable after tourniquet-free total knee arthroplasty (TKA). We aim to investigate whether non-drainage use is accepted in TKA that is performed without a tourniquet. METHODS: Clinical data of 80 adult patients who did or did not receive drainage in our centres from August 2015 to December 2015 were prospective investigated. RESULTS: The drainage group exhibited reduced hidden blood loss (47.6 ± 43.6 mL versus 151.1 ± 97.1 mL, P < 0.001), less calf swelling (d1: 3.2% versus 5.2%, P = 0.02) and milder knee active pain (d3: 4.9 ± 1.9 versus 5.9 ± 1.2, P = 0.01; d5: 3.2 ± 1.6 versus 4.2 ± 1.5, P = 0.003) than the non-drainage group. However, the non-drainage group had higher haemoglobin level (d1: 112.1 ± 10.6 g/dL versus 106.1 ± 12.4 g/dL, P = 0.026; d3: 99.5 ± 9.6 g/dL versus 92.7 ± 13.1 g/dL, P = 0.011) and less haematopoietic medication usage (42.1% versus 66.6%, P = 0.03) in the initial postoperative period following TKA. Earlier postoperative time to ambulation (22.4 ± 12.3 h versus 30.1 ± 14.6 h, P = 0.01) and shorter length of stay (5.5 ± 1.2 days versus 6.3 ± 1.7 days, P = 0.02) were found in the non-drainage group. CONCLUSION: It is practicable to abandon wound drainage in uncomplicated, primary, tourniquet-free TKA.

Two New Effective Tourniquets for Potential Use in the Military Environment: A Serving Soldier Study.

BACKGROUND: Limb tourniquets have been used extensively during modern Middle Eastern conflicts. Despite its undeniable successes, the combat applied tourniquet (C-A-T) has some shortfalls, principally its inability to reliably control lower limb bleeding when applied to the mid-thigh. We tested two tourniquets which may represent an improvement to the combat applied tourniquet; the tactical mechanical tourniquet and the tactical pneumatic tourniquet. METHODS: We recruited 12 healthy service personnel and applied the tactical mechanical tourniquet and tactical pneumatic tourniquet to both lower limbs in a randomly generated sequence. Tourniquets were tightened until popliteal artery occlusion. This was measured via a SonoSite portable ultrasound machine by a single consultant vascular radiologist familiar with its use. A longitudinal view of the popliteal artery was obtained, and Doppler waveform monitored. The tourniquets were tightened around volunteers' mid-thigh by a second researcher accustomed with their use. Time to complete occlusion, number of windlass revolutions, and pain scores were collected by a third researcher. Non-normally distributed data are present as median (interquartile range). Ordinal nonparametric data are analysed by Mann-Whitney U testing. RESULTS: Participants had a median age of 32.5 (28-35). Both tourniquets demonstrated complete occlusion of the popliteal artery in all limbs (n = 24). The mechanical tourniquet achieved arterial occlusion after a median of 3.8 (3-4) turns, and 16 (12-20) seconds. No participants dropped out of the study because of intolerable pain, or any cause. Median pain scores for the mechanical tourniquets were 4.5 (3-7) (maximum pain) and 4.0 (2-7) (pain when locked). Median pain scores for the pneumatic tourniquet were 5 (2-6) (maximum pain) and 5 (2-6) (pain when fully applied). There was no statistical difference in maximum pain scores between the tactical mechanical tourniquet and the tactical pneumatic tourniquet (p = 0.75). No participant had any tourniquet applied for longer than 80 seconds. CONCLUSION: Both tourniquets completely occluded the popliteal artery in all participants within an acceptable pain threshold. Further testing is required before the presented tourniquets can be taken to the battlefield; particularly measures of self-application, and use on other anatomical areas.

Slack Reducing Band Improves Combat Application Tourniquet Pressure Profile and Hemorrhage Control Rate.

BACKGROUND: The Combat Application Tourniquet (CAT) is the tourniquet of choice in the Israeli defense forces. Applying the device loosely before windlass twisting is a main pitfall in CAT application. This study objective is to assess the effectiveness of a novel design modification of the CAT, aiming to prevent loose applications, by minimizing the slack. METHODS: Using the HapMed leg tourniquet trainer, an above the knee traumatic amputation was simulated. Active duty combatants and Special Forces basic medics were randomly assigned to apply the modified (n = 67) or conventional CAT (n = 65) once. Applied pressure, hemorrhage control status, time to stop the bleeding, and estimated blood volume loss were measured. RESULTS: Using the modified CAT, the mean (±SD) pressure applied was significantly higher compared to the conventional one (231.49 ± 37.84 mm Hg vs. 213.31 ± 45.51 mm Hg, p < 0.05). Hemorrhage control rate was 86.6% in the modified CAT group versus 67.7% in the conventional CAT group (p < 0.05). Analyzing only the applications that succeeded in hemorrhage control, blood loss (171.12 ± 72.43 mL vs.187.75 ± 91.72 mL, p > 0.05) and time to stop bleeding (27.27 ± 13.15 seconds vs. 27.5 ± 11.25 seconds, p > 0.05) were similar. CONCLUSIONS: The modified CAT demonstrated an upgraded pressure profile and hemorrhage control rate, potentially indicating its improved efficacy.

Trends and Predictors of Limb Tourniquet Use by Civilian Emergency Medical Services in the United States.

BACKGROUND: Tourniquet use by Emergency Medical Services (EMS) can be life saving for severely injured patients. The adoption of this intervention is not well described in civilian settings. This study describes patterns and trends of tourniquet use by civilian EMS and identifies predictors of such use. METHODS: A retrospective study of four consecutive releases of the U.S. National Emergency Medical Services Information System (NEMSIS) public research dataset (2011-14) was conducted. Descriptive analysis was performed to compare two groups of EMS activations for injuries with or without tourniquet application. This was followed by multivariate logistic regression to identify predictors of tourniquet use. RESULTS: A total of 2,048 tourniquet applications were documented among all EMS activations for injured patients (N = 10,366,537) yielding a prevalence of 0.2 per 1,000 EMS activations. Tourniquets were mainly applied in young (mean age 44.0 ± 21.1 years) male patients (76.5%) in urban and suburban EMS activations (86.4%) and by advanced life support (ALS) EMS services (81.6%). Most common complaints reported by dispatch for EMS activations with tourniquet use were Traumatic injury (25.3%), Hemorrhage/laceration (23.5%), and Traffic accident (16.8%) with injuries mainly related to Stabbing/Accidental cutting (20.3%), Falls (17.1%), and Motor vehicle traffic accident (11.5%). Upper extremity injuries (39.6%) were more common than Lower extremity injuries (27.3%). The providers' primary impression was predominantly Traumatic injury (92.8%), and patients' primary symptoms were mainly Bleeding (50.4%) and Wound (28.7%). All prehospital time intervals except on-scene time interval were significantly shorter in the group with tourniquets compared to the group without tourniquets (p < 0.05). Reported prevalence of tourniquet use by EMS (per 1,000 EMS injury activations) increased from 2011 to 2012 then stabilized over the following years (2012-14). Significant predictors of tourniquet use reported by the provider were identified and included demographic characteristics, EMS agency type, specific complaints, injury cause, injury anatomic location, chief complaint organ system, and primary symptom. CONCLUSION: Reported tourniquet use by EMS for injured patients in the U.S. is low. Increasing adoption mainly by urban services was noted. Predictors for tourniquet use in civilian trauma were identified. Establishing the effectiveness of this intervention by comparing patient outcomes is needed. Key words: emergency medical services; prehospital; tourniquet; injury; NEMSIS; hemorrhage.

Transcriptional profiling and muscle cross-section analysis reveal signs of ischemia reperfusion injury following total knee arthroplasty with tourniquet.

Total knee arthroplasty (TKA) is the most common and cost-effective treatment for older adults with long-standing osteoarthritis. Projections indicate that nearly 3.5 million older adults will undergo this procedure annually by the year 2030. Thus, understanding the factors that lead to optimal outcomes is of great clinical interest. In the majority of cases, tourniquet is applied during surgery to maintain a clear surgical field, however, there is debate as to whether this intervention is completely benign. In particular, muscle atrophy is a significant factor in preventing full functional recovery following surgery, and some evidence suggests that tourniquet application and the associated ischemia-reperfusion injury that results contributes to muscle atrophy. For this reason, we examined tissue level changes in muscle in TKA patients following surgery and found that there was a significant increase in cross-sectional area of muscle fibers of all types. Furthermore, to detect changes not evident at the tissue level, we performed NextSeq analysis to assess the transcriptional landscape of quadriceps muscle cells following TKA with tourniquet and found 72 genes that were significantly upregulated. A large proportion of those genes regulate cell stress pathways, suggesting that muscle cells in our cohort of older adults were capable of mounting a significant response to cell stress. Furthermore, factors related to complement were upregulated, suggesting tourniquet may play a role in priming cells to ischemia reperfusion injury. Therefore, our analysis reveals potential harms of tourniquet during TKA, thus suggesting that surgeons should consider limiting its use.

Tourniquets in arterial bypass surgery.

BACKGROUND: successful infra-popliteal bypass depends on precise, atraumatic technique in performing the distal anastomosis. The use of a tourniquet facilitates the distal anastomosis, reducing dissection, avoiding traumatising clamping of the vessels and providing an "uncluttered" operating field. Despite these advantages the technique is under-used. OBJECTIVES: to review the use of tourniquets in arterial reconstruction, with particular reference to safety issues and complications. DESIGN, METHODS AND MATERIALS: a Medline search was performed (last search Feb. 2000), and keywords from relevant papers were used to perform subsequent searches. References were reviewed from each relevant paper. RESULTS: no randomised controlled trials were found. The review details reported use of tourniquets in arterial reconstruction, including techniques, outcomes and potential complications. CONCLUSION: the use of a tourniquet is a safe and effective technique to facilitate arterial reconstruction.