***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Venous stasis caused by immobility is an important risk factor for deep vein thrombosis following surgery and lower limb trauma , in bed-ridden medical patients , and in high-risk long distance air travelers . A safe and convenient method for reducing venous stasis would be useful in patients while in hospital and after discharge during their rehabilitation . SUBJECTS AND METHODS 49 healthy subjects aged 51 - 76 were seated for 4 hours during which they received mild electrical stimulation of the calf , or sole of the foot ( plantar muscles ) .  Popliteal and femoral venous blood flow velocities were measured via doppler ultrasound . The non-stimulated lower extremity served as the simultaneous control . Subjects completed a question naire regarding their acceptance and tolerance of the electrical stimulation . RESULTS There was a significant increase in venous femoral and popliteal blood flow for both calf ( p < 0.035 , p < 0.003 ) , and plantar muscles ( p < 0.0001 , p < 0.009 ) on the stimulated side compared to the unstimulated side . The magnitude of the effect was similar for calf and plantar muscle stimulation . Subjects did not find the experience uncomfortable , and would use an electrical stimulator if told by their physician that they were at risk for developing blood clots . CONCLUSIONS Mild electrical stimulation of the feet , as well as the calf , is a safe effective and convenient method for counteracting venous stasis and therefore has the potential to reduce the risk of deep vein thrombosis and pulmonary embolism for subjects who are immobilized Bed rest poses an increased risk factor for a potentially fatal venous thromboembolism ( VTE ) . Lack of activation of the calf muscle pump during this resting period gives rise to venous stasis which may lead to deep vein thrombosis ( DVT ) development . Our aim was to investigate the effects that 4h of bed rest have on the lower limb hemodynamics of healthy subjects and to what extent electrically elicited contractions of the calf muscles can alleviate these effects . Outcome variables included popliteal vein blood flow and heart rate . Primary results indicated that the resting group experienced a significant decline in popliteal venous blood flow of approximately 47 % with approximately 13 % decrease in heart rate . The stimulated groups maintained a significantly higher venous blood flow and heart rate . Volume flow in the contralateral limb remained constant throughout the study and was comparable to that of the stimulated limb 's recovery flow . The results suggest that even short periods of bed rest can significantly reduce lower limb blood flow which could have implication s for DVT development . Electrically elicited calf muscle contractions significantly improve lower limb blood flow and can alleviate some debilitating effects of bed rest Background Deep vein thrombosis ( DVT ) is a major complication in critical care . There are various methods of prophylaxis , but none of them fully prevent DVT , and each method has adverse effects . Electrical muscle stimulation ( EMS ) could be a new effective approach to prevent DVT in intensive care unit ( ICU ) patients . We hypothesized that EMS increases the venous flow of the lower limbs and has a prophylactic effect against the formation of DVT . Methods This study included 26 patients admitted to a single ICU . We enrolled patients who could not move themselves due to spinal cord injury , head injury , central nervous system abnormalities , and sedation for mechanical ventilation . The patients were r and omly allocated to either the EMS group or the control group . Patients in the EMS group received 30-min sessions of EMS applied to the bilateral lower extremities on arbitrary days within 14 days after admission . The control patients received no EMS . The peak flow velocity and diameter of the popliteal vein ( Pop . V ) and common femoral vein ( CFV ) were measured by ultrasound and then the volumes of venous flow were calculated using a formula . Results There were no statistically significant differences in patient characteristics between the two groups except for the mortality rate . In the EMS group , the median and interquartile range ( IQR , 25th–75th percentile ) of velocities of the Pop . V and CFV were higher during EMS compared with at rest : 10.6 ( 8.0–14.8 ) vs 24.5 ( 15.1–37.8 ) cm/s and 17.0 ( 12.3–23.8 ) vs 24.3 ( 17.0–33.0 ) cm/s , respectively ( p < 0.05 ) . The median ( IQR ) of volumes of venous flow of the Pop . V and CFV at rest and during EMS were 4.2 ( 2.7–7.2 ) vs 8.6 ( 5.4–16.1 ) cm3/s and 12.9 ( 9.7–21.4 ) vs 20.8 ( 12.3–34.1 ) cm3/s , respectively ( p < 0.05 ) . There were no major complications related to EMS . Conclusions EMS increased the venous flow of the lower limbs . EMS could be one potential method for venous thromboprophylaxis . Trial registration Background : Lower deep venous thrombosis ( DVT ) is one of the major complications of patients with tumors or patients undergoing major surgery .  Electrical acupoint stimulation , an established technique of traditional Chinese medicine ( TCM ) , can be well combined with Western medicine to reduce the incidence of postoperative DVT , especially in elderly patients . Objective : The objectives of this study were to assess the efficiency of electrical acupoint stimulation in the prevention of postsurgery DVT in elderly patients with gastrointestinal malignant tumors and to vali date an effective and safe nursing approach that integrates TCM and Western medicine . Methods : A total of 120 patients ( none aged < 60 years ) who underwent malignant gastrointestinal tumor surgery between July 2005 and May 2007 were r and omly divided into 3 groups : routine nursing group ( group C1 ) , graduated compression stockings group ( group C2 ) , and electrical acupoint stimulation group ( group T ) . Hemorheological parameters ( blood viscosity , etc ) were measured and compared before and after surgery . Results : Compared with groups C1 and C2 , group T showed a significant difference in blood viscosity and blood flow velocity ( P < .05 ) . However , there were no statistical differences among groups C1 , C2 , and T in other hemorheological parameters . Conclusions : By speeding up the blood flow in patients ’ lower limbs , electrical acupoint stimulation showed a great potential to prevent symptomless DVT in elderly patients after malignant gastrointestinal tumor surgery . Implication s for Practice : Western medical care combined with TCM can reduce the occurrence of lower DVT in elderly patients suffering from gastrointestinal cancer . This approach may help nurses to plan effective care for elderly patients BACKGROUND Compression devices have been shown to prevent thromboembolic disease . However , the pressures generated may not be the same as the ones recommended by the manufacturer . The purpose of this study is to investigate a new sequential compression device with feedback to maintain optimal therapy , and to determine whether therapy is improved with this new device . PATIENTS AND METHOD A series of 50 patients undergoing elective total hip arthroplasty at a major tertiary-care hospital with a special interest in joint replacement were enrolled prospect ively . In addition to pharmacological prophylaxis for thromboembolic disease , all patients received compression from a modified device .  Maximum pressures generated and the rate of pressure rise in each of the 3 compartments within the device sleeves were measured and the results compared with data from historical controls . RESULTS We considered therapy to be ideal when in a particular compression cycle all chambers of both right and left sleeves reach within 10 % of their target pressures at within 10 % of their target pressure rise rates . The average patient received this ideal therapy 88 % of the time that the new trial sequential compression device was operating . This represents a dramatic improvement over previous devices . CONCLUSIONS The new device allows dramatically improved pressures within the device because of a feedback loop that allows dynamic control of each chamber 's pressure . Improved consistency of delivery should make it easier to accurately assess the true benefits of mechanical prophylaxis with a sequential compression device Background Patients post total hip arthroplasty ( THA ) remain at high risk of developing Deep Vein Thrombosis ( DVT ) during the recovery period following surgery despite the availability of effective pharmacological and mechanical prophylactic methods . The use of calf muscle neuromuscular electrical stimulation ( NMES ) during the hospitalised recovery period on this patient group may be effective at preventing DVT . However , the haemodynamic effectiveness and comfort characteristics of NMES in post-THA patients immediately following surgery have yet to be established . Methods The popliteal veins of 11 patients , who had undergone unilateral total hip replacement surgery on the day previous to the study , were measured using Doppler ultrasound during a 4 hour neuromuscular electrical stimulation ( NMES ) session of the calf muscles . The effect of calf muscle NMES on peak venous velocity , mean venous velocity and volume flow were compared to resting values . Comfort was assessed using a 100 mm non-hatched visual analogue scale taken before application of NMES , once NMES was initiated and before NMES was withdrawn . Results In the operated limb NMES produced increases in peak venous velocity of 99 % compared to resting . Mean velocity increased by 178 % compared to resting and volume flow increased by 159 % compared to resting . In the un-operated limb , peak venous velocity increased by 288 % , mean velocity increased by 354 % and volume flow increased by 614 % compared to basal flow ( p<0.05 in all cases ) . There were no significant differences observed between the VAS scores taken before the application of NMES , once NMES was initiated and before NMES was withdrawn ( p=.211 ) . Conclusions NMES produces a beneficial hemodynamic response in patients in the early post-operative period following orthopaedic surgery . This patient group found extended periods of calf-muscle NMES tolerable . Trial registration Clinical Trials.gov The aim of this study was to examine the effects of the sitting posture on the lower limb venous flow and to explore the beneficial effects of  neuromuscular electrical stimulation ( NMES )  and an ottoman-type seat on the venous flow . Healthy adult volunteers without a history of lower limb surgery or thromboembolism were recruited , and the flow velocity , cross-sectional area , and flow volume of the popliteal vein were measured using Doppler ultrasound . A posture change from the prone position to the sitting position on the ottoman-type seat decreased the flow velocity and increased the cross-sectional area of the popliteal vein , and the flow volume was not altered over 120 min . The flow velocity was further decreased , and the cross-sectional area was further increased by subjects sitting on a regular driving seat when compared with the values obtained with an ottoman-type seat . The popliteal flow velocity in the NMES leg was significantly higher than in the non-NMES leg throughout the 120-min testing in the sitting position , but no difference in the cross-sectional area was found between the NMES and the non-NMES legs . Thus lower limb venous stasis elicited by the sitting posture was improved by the ottoman-type seat and NMES AIM The aim of this pilot study was to evaluate the potential effect of electrical calf muscle stimulation ( EMS ) in the prevention of postoperative deep vein thrombosis ( DVT ) in high risk patients and to assess efficacy and safety of EMS in patients with calf DVT . METHODS This was a prospect i ve non-r and omized controlled study involving 80 patients over the age of 40 having major surgery ( 44 abdominal and 36 cranial or spinal surgery ; duration more than 60 min under general anesthesia ) . Patients were divided into 2 comparable groups : main ( N.=40 ) and control ( N.=40 ) . In both groups graduated middle stretch compression b and age with compression level 20 - 40 mmHg was applied and low dose unfractioned heparin ( LDUH ) injections ( 5000 U s.c . 3 t.i.d ) were started on 1st or 2 - 5th day after surgery and continued until discharge . The time of starting LDUH was comparable in both groups . In addition , electrical calf muscle stimulation ( EMS ) with Veinoplus device was performed for not less than 5 periods of 20 minutes per day ( total > 100 minutes ) in the main group . Control of venous patency was performed with duplex ultrasound obligatory at baseline ( first 24 h after surgery ) and then every 3 days until discharge . RESULTS The incidence of DVT was 2.5 % in the main group and 25 % in the control group ( P=0.007 ) . In patients without DVT at baseline it was 3 % versus 21 % ( P=0.025 ) . Patients with baseline thrombosis who underwent EMS did not have any new cases of DVT and PE , while in patients without EMS thrombosis progression was observed in 43 % cases also without pulmonary embolism ( not significant ) . CONCLUSION EMS with Veinoplus device at > 100 min per day ( > 5 sessions ) can decrease the rate of postoperative DVT in high risk patients . Using of EMS in patients with calf DVT does not increase the rate of PE . These findings need to be confirmed in a r and omized controlled trial BACKGROUND Current methods of posttraumatic thromboprophylaxis ( heparins and sequential compression devices ) are inadequate . New methods should be tested . Muscle electrostimulation ( MEST 
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None of the studies in this comparison reported bleeding .
None of the studies in this comparison reported bleeding .
Low- quality evidence shows no clear difference in the risk of DVT between NMES and alternative methods of prophylaxis but suggest that NMES may be associated with lower risk of DVT compared with no prophylaxis ( moderate- quality evidence ) and higher risk of DVT compared with low-dose heparin ( low- quality evidence ) .