Elastic compression in the prevention of venous stasis. A critical reevaluation

Compression for preventing recurrence of venous ulcers

BACKGROUND

Up to 1% of adults will have a leg ulcer at some time. Most leg ulcers are venous in origin and are caused by high pressure in the veins due to blockage or damaged valves. Venous ulcer prevention and treatment typically involves the application of compression bandages/stockings to improve venous return and thus reduce pressure in the legs. Other treatment options involve removing or repairing veins. Most venous ulcers heal with compression therapy, but ulcer recurrence is common. For this reason, clinical guidelines recommend that people continue with compression treatment after their ulcer has healed. This is an update of a Cochrane review first published in 2000 and last updated in 2014.

OBJECTIVES

To assess the effects of compression (socks, stockings, tights, bandages) for preventing recurrence of venous leg ulcers.

SEARCH METHODS

In August 2023, we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, three other databases, and two ongoing trials registries. We also scanned the reference lists of included studies and relevant reviews and health technology reports. There were no restrictions on language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated compression bandages or hosiery for preventing the recurrence of venous ulcers.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected studies, assessed risk of bias, and extracted data. Our primary outcome was reulceration (ulcer recurrence anywhere on the treated leg). Our secondary outcomes included duration of reulceration episodes, proportion of follow-up without ulcers, ulceration on the contralateral leg, noncompliance with compression therapy, comfort, and adverse effects. We assessed the certainty of evidence using GRADE methodology.

MAIN RESULTS

We included eight studies (1995 participants), which were published between 1995 and 2019. The median study sample size was 249 participants. The studies evaluated different classes of compression (UK class 2 or 3 and European (EU) class 1, 2, or 3). Duration of follow-up ranged from six months to 10 years. We downgraded the certainty of the evidence for risk of bias (lack of blinding), imprecision, and indirectness. EU class 3 compression stockings may reduce reulceration compared with no compression over six months (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.27 to 0.76; 1 study, 153 participants; low-certainty evidence). EU class 1 compression stockings compared with EU class 2 compression stockings may have little or no effect on reulceration over 12 months (RR 1.70, 95% CI 0.67 to 4.32; 1 study, 99 participants; low-certainty evidence). There may be little or no difference in rates of noncompliance over 12 months between people using EU class 1 stockings and people using EU class 2 stockings (RR 1.22, 95% CI 0.40 to 3.75; 1 study, 99 participants; low-certainty evidence). UK class 2 hosiery compared with UK class 3 hosiery may be associated with a higher risk of reulceration over 18 months to 10 years (RR 1.55, 95% CI 1.26 to 1.91; 5 studies, 1314 participants; low-certainty evidence). People who use UK class 2 hosiery may be more compliant with compression treatment than people who use UK class 3 hosiery over 18 months to 10 years (RR for noncompliance 0.69, 95% CI 0.49 to 0.99; 5 studies, 1372 participants; low-certainty evidence). There may be little or no difference between Scholl UK class 2 compression stockings and Medi UK class 2 compression stockings in terms of reulceration (RR 0.77, 95% CI 0.47 to 1.28; 1 study, 166 participants; low-certainty evidence) and noncompliance (RR 0.97, 95% CI 0.84.1 to 12; 1 study, 166 participants; low-certainty evidence) over 18 months. No studies compared different lengths of compression (e.g. below-knee versus above-knee), and no studies measured duration of reulceration episodes, ulceration on the contralateral leg, proportion of follow-up without ulcers, comfort, or adverse effects.

AUTHORS' CONCLUSIONS

Compression with EU class 3 compression stockings may reduce reulceration compared with no compression over six months. Use of EU class 1 compression stockings compared with EU class 2 compression stockings may result in little or no difference in reulceration and noncompliance over 12 months. UK class 3 compression hosiery may reduce reulceration compared with UK class 2 compression hosiery; however, higher compression may lead to lower compliance. There may be little to no difference between Scholl and Medi UK class 2 compression stockings in terms of reulceration and noncompliance. There was no information on duration of reulceration episodes, ulceration on the contralateral leg, proportion of follow-up without ulcers, comfort, or adverse effects. More research is needed to investigate acceptable modes of long-term compression therapy for people at risk of recurrent venous ulceration. Future trials should consider interventions to improve compliance with compression treatment, as higher compression may result in lower rates of reulceration.

Responses of low and high compression during recovery after repeated sprint training in well-trained handball players

The aim of the study was to investigate the effects of wearing various levels of compression following repeated and exhausting sprint exercise on variables related to recovery. Twelve well-trained handball players performed three sessions of repeated and exhausting sprint exercise (30 × 30m). Directly after each session the participants wore tights extending from below the hip to the foot with either 0, 10, or 25 mm Hg of compression onto the thigh and calf muscles. 48 h after the training session all participants performed 5 × 30m sprints and counter movement jumps. Before, directly after, 24 h, and 48 h after the training session venous blood samples were drawn for the determination of creatine kinase (CK), urea, C-reactive protein (CRP). At the same time points, subjective ratings of the Acute Recovery and Stress Scale (ARSS) questionnaires were obtained. The results for plasma concentrations of CK and urea showed 'likely' to 'very, very likely' beneficial effects for compression garments exerting 10 mm Hg of compression (p = 0.06-1.0). With regard to sprint and jump performance no differences were evident between 0, 10, and 25 mm Hg (p = 0.07-1.0). In addition, subjective scores from the ARSS did not differ between conditions over time (p > 0.05). We conclude that the application of 10 mm Hg leg compression compared to 0 and 25 mm Hg of compression during 48 h of recovery from repeated and exhausting sprints lowered the plasma concentrations of CK and urea with no improvements in recovery for performance.

Compression therapy for prevention of post-thrombotic syndrome

BACKGROUND

Post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) that is characterised by chronic pain, swelling, and skin changes in the affected limb. One of every three people with DVT will develop post-thrombotic complications within five years. Several non-pharmaceutical measures are used for prevention of post-thrombotic syndrome during the acute phase of DVT. These include elevation of the legs and compression therapy. Clinicians and guidelines differ in their assessment of the utility of compression therapy for treatment of DVT. This is an update of a review first published in 2003.

OBJECTIVES

To determine relative effectiveness and rate of complications when compression therapy is used in people with deep vein thrombosis (DVT) for prevention of post-thrombotic syndrome (PTS).

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist (CIS) searched the Cochrane Vascular Specialised Register (20 March 2017) and CENTRAL (2017, Issue 2). The CIS also searched trial registries for details of ongoing or unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of compression therapy, such as bandaging and elastic stockings, in people with clinically confirmed DVT. The primary outcome was the occurrence of PTS.

DATA COLLECTION AND ANALYSIS

Two review authors (DK and EvL) identified and assessed titles and abstracts for relevance, and a third review author (DA) verified this assessment independently. Review authors imposed no restrictions on date or language of publications. Three review authors (DA, DK, EvL) used data extraction sheets to independently extract study data. We resolved disagreements by discussion.

MAIN RESULTS

We identified 10 RCTs with a total of 2361 participants that evaluated compression therapy. The overall methodological quality of these trials was low. We used only five studies in meta-analysis owing to differences in intervention types and lack of data. Three studies compared elastic compression stockings (pressure of 30 to 40 mmHg at the ankle) versus no intervention. Two studies compared elastic compression stockings (pressure 20 to 40 mmHg) versus placebo stockings. Overall, use of elastic compression stockings led to a clinically significant reduction in the incidence of PTS (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.01; P = 0.05; 1393 participants; 5 studies; low-quality evidence); no reduction in the incidence of severe PTS (RR 0.78, 95% CI 0.53 to 1.15; P = 0.21; 1224 participants; 4 studies; low-quality evidence); and no clear difference in DVT recurrence (RR 0.94, 95% CI 0.69 to 1.28; 1212 participants; 4 studies; P = 0.69; low-quality evidence). We did not pool data on the incidence of pulmonary embolism because this information was poorly reported, but we observed no differences between groups included in individual studies (low-quality evidence).Two studies evaluated effects of compression in the acute phase versus no compression treatment and found no differences in the incidence of PTS (RR 0.76, 95% CI 0.49 to 1.16; P = 0.2; 101 participants). One study reported that thigh-length stockings did not provide better protection against development of PTS than knee-length stockings (RR 0.92, 95% CI 0.66 to 1.28; P = 0.6; 267 participants). Another trial reported that wearing compression stockings for two years seemed to be superior to wearing them for one year in terms of PTS incidence.Two of the 10 included studies described patient satisfaction and quality of life (moderate-quality evidence), using different measurement systems. The first study showed significant improvement in well-being and DVT-related quality of life with compression treatment (P < 0.05) compared with bed rest, and the second study showed no differences in quality of life scores between compression and placebo groups. Four studies poorly reported side effects (low-quality evidence) that included itching, erythema, and other forms of allergic reaction and described no serious adverse events. Compliance with wearing of compression stockings was generally high but varied across studies.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that elastic compression stockings may reduce the occurrence of PTS after DVT. We downgraded the quality of evidence owing to considerable heterogeneity between studies and lack of or unclear risk of blinding due to clinical assessment scores. No serious adverse effects occurred in these studies. Large randomised controlled trials are needed to confirm these findings because of current lack of high-quality evidence and considerable heterogeneity.

Graduated compression stockings for the prevention of deep-vein thrombosis in postoperative surgical patients: a systematic review and economic model with a value of information analysis

BACKGROUND

Deep-vein thrombosis (DVT) can occur in surgical patients. Routine prophylaxis can be pharmacological and/or mechanical [e.g. graduated compression stockings (GCSs)]. GCSs are available in knee length or thigh length.

OBJECTIVE

To establish the expected value of undertaking additional research addressing the relative effectiveness of thigh-length GCSs versus knee-length GCSs, in addition to pharmacoprophylaxis, for prevention of DVT in surgical patients.

DESIGN

Systematic review and economic model, including value of information (VOI) analysis.

REVIEW METHODS

Randomised controlled trials (RCTs) assessing thigh- or knee-length GCSs in surgical patients were eligible for inclusion. The primary outcome was incidence of DVT. DVT complications and GCSs adverse events were assessed. Random-effects meta-analysis was performed. To draw on a wider evidence base, a random-effects network meta-analysis (NMA) was undertaken for the outcome DVT. A review of trials and observational studies of patient adherence was also conducted. A decision-analytic model was developed to assess the cost-effectiveness of thigh- and knee-length GCSs and the VOI.

RESULTS

Twenty-three RCTs were included in the review of effectiveness. There was substantial variation between trials in terms of the patient characteristics, interventions and methods of outcome assessment. Five trials comparing knee-length with thigh-length GCSs with or without pharmacoprophylaxis were pooled; the summary estimate of effect indicated a non-significant trend favouring thigh-length GCSs [odds ratio (OR) 1.48, 95% confidence interval (CI) 0.80 to 2.73]. Thirteen trials were included in the NMA. In the base-case analysis, thigh-length GCSs with pharmacoprophylaxis were more effective than knee-length GCSs with pharmacoprophylaxis (knee vs. thigh OR 1.76, 95% credible interval 0.82 to 3.53). Overall, thigh-length stockings with pharmacoprophylaxis was the most effective treatment, with a 0.73 probability of being the most effective treatment in a new trial of all the treatments. Patient adherence was generally higher with knee-length GCSs, and patients preferred knee-length GCSs. Thigh-length GCSs were found to be cost-effective in all but the subgroup with the lowest baseline risk, although the absolute differences in costs and effects were relatively small. The expected value of perfect information ranged from £0.2M to £178.0M depending on the scenario and subgroup. The relative effect parameters had the highest expected value of partial perfect information and ranged from £2.0M to £39.4M. The value of further research was most evident in the high-risk subgroups.

LIMITATIONS

There was substantial variation across the included trials in terms of patient and intervention characteristics. Many of the included trials were old and poorly reported, which reduces the reliability of the results of the review.

CONCLUSIONS

Given that the results from both the standard meta-analysis and the NMA lacked precision (CIs were wide) owing to the heterogeneous evidence base, a new definitive trial in high-risk patients may be warranted. However, the efficiency of any further research (i.e. whether this represents value for money) is dependent on several factors, including the acquisition price of GCSs, expected compliance with thigh-length GCSs wear, and whether or not uncertainty can be resolved around possible effect modifiers, as well as the feasibility and actual cost of undertaking the proposed research.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014007202.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The Physiological Effect of Graded Compression Stockings on Blood Flow in the Lower Limb: An Assessment with Colour Doppler Ultrasound

Objectives:

To assess the physiological effect of low-pressure graded compression stockings (GCS) on the blood flow of the lower limb with the use of colour Doppler.

Design:

A randomised controlled study.

Setting:

X-ray Department in a teaching hospital.

Patients:

Forty-five healthy, adult, voluntary subjects.

Method:

Subjects were randomised into three groups to either wear thigh- or knee-length GCS of the same type or no stockings. The diameter and cross-sectional area of the femoral and popliteal veins and the peak venous velocities were measured with colour Doppler before the application of GCS and after 20 min bed rest with the stockings in situ.

Results:

Measurements showed a significant increase of the peak velocity in the femoral vein with thigh-length GCS ( p<0.002). There was a significant decrease of the popliteal vein diameter and cross-sectional area with thigh-length GCS ( p<0.05). There was no significant change in the knee-length GCS group and the control group, in which patients did not wear stockings. A paired t-test was used to determine the significance of the changes.

Conclusions:

Thigh-length GCS have an effect of increasing venous peak velocity in the femoral vein, hence decreasing venous stasis. Furthermore, they decrease the dilatation of the popliteal vein, which may reduce the risk of intimal tears occurring, which may contribute to venous thrombogenesis. Other methods can given more information in assessing the effect of various lengths of stocking on venous stasis.

Compression Stockings and their Effect on the Venous Pump — A Comparative Study

A prospective study of 45 patients with venous insufficiency. The patients were divided into four different groups that were comparable in venous function, age and sex distribution. The effect of four different conventional compression stockings was evaluated by their clinical effect and the effect upon the musculo-venous pump as assessed by ambulatory strain-gauge plethysmography, over a 6-week treatment period. In this patient category, there could not be demonstrated any additional benefit of increasing compression, and patient acceptability was concomitantly reduced with increasing pressure. The pressure exerted by the stockings was assessed by the Borgnis Medical Stocking Tester, and pressures were found to increase in the upright position with an increase in the concomitant pressure gradient between ankle and knee.

The Effect of Graduated Compression Stockings on Lower Limb Venous Haemodynamics

Objectives:

To compare the effect of four types of thigh-length graduated compression stockings (GCS) on lower limb venous blood flow using strain-gauge Plethysmography (SGP).

Design:

A randomized controlled study.

Setting:

Inpatient Orthopaedic Centre.

Patients:

200 preoperative patients admitted for elective lower limb orthopaedic surgery.

Interventions:

Patients were randomized to five groups to wear one of four types of GCS or no stocking (control). Resting venous flow parameters were measured prior to application of GCS and after 20 min bed rest with the stockings in situ.

Main outcome measures:

Effects on resting venous capacitance (Vc) and venous outflow (Vo).

Results:

In the control group 20 min bed rest had no effect on the parameters studied. Both Vc and Vo were significantly increased ( p<0.001) in all the groups wearing stockings. There was a significant variation in the changes in outflow produced by the different stocking types ( p<0.05).

Conclusions:

GCS have a beneficial effect on lower limb venous outflow, preventing venous stasis, an important factor in the development of deep venous thrombosis. This effect varies depending on which type of stocking is used.

Low Compression, High Gradient Stockings in Patients with Venous Insufficiency: Effect on the Musculo-Venous Pump, Evaluated by Strain Gauge Plethysmography

In a prospective study 17 patients with superficial venous insufficiency were treated with a high gradient low compression stocking for a period of 6 weeks. The effect upon the musculo-venous pump was evaluated by ambulatory calf strain gauge plethysmography and compared to improvements in symptoms and clinical findings. The immediate effect of the stockings was a significant 22% reduction in venous reflux and 43% increase of the expelled volume. Moreover, an effect after 6 weeks (with the stockings applied during all daytime hours) was found even after the stockings were removed. This reduction of venous reflux of 30% and increase in expelled volume of 29% were statistically significant. Symptoms and objective findings were simultaneously improved. Finally the stockings were found to increase the maximal venous outflow by 27%.

Graduated compression stockings for prevention of deep vein thrombosis

BACKGROUND

One of the settings where deep vein thrombosis (DVT) in the lower limb and pelvic veins occurs is in hospital with prolonged immobilisation of patients for various surgical and medical illnesses. Using graduated compression stockings (GCS) in these patients has been proposed to decrease the risk of DVT. This is an update of a Cochrane review first published in 2000 and updated in 2010.

OBJECTIVES

To evaluate the effectiveness and safety of graduated compression stockings in preventing DVT in various groups of hospitalised patients.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched March 2014) and CENTRAL (2014, Issue 2).

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving GCS alone; or GCS used on a background of any other DVT prophylactic method. Results from both these groups of trials were combined in this update.

DATA COLLECTION AND ANALYSIS

For this update one review author (AS) extracted the data. These were cross-checked and authenticated by a second author (MJD). Two review authors (AS and MJD) assessed the quality of trials. Disagreements were resolved by discussion.

MAIN RESULTS

Nineteen RCTs were identified involving 1681 individual patients and 1064 individual legs (2745 analytic units). Of these 19 trials, nine included patients undergoing general surgery, six included patients undergoing orthopaedic surgery, and only one trial included medical patients. Graduated compression stockings were applied on the day before surgery or on the day of surgery and were worn up until discharge or until the patients were fully mobile. In the majority of the included studies DVT was identified by the radioactive I(125) uptake test. Overall, included studies were of good quality.In the treatment group (GCS) of 1391 units 126 developed DVT (9%) in comparison to the control group (without GCS) of 1354 units where 282 (21%) developed DVT. The Peto odds ratio (OR) was 0.33 (95% confidence interval (CI) 0.26 to 0.41) with an overall effect favouring treatment with GCS (P < 0.00001).Based on results from eight included studies, the incidence of proximal DVT was 7 of 517 (1%) units in the treatment group and 28 of 518 (5%) units in the control group. The Peto OR was 0.26 (95% CI 0.13 to 0.53) with an overall effect favouring treatment with GCS (P = 0.0002). Based on results from five included studies, the incidence of PE was 5 of 283 (2%) participants in the treatment group and 14 of 286 (5%) in the control group. The Peto OR was 0.38 (95% CI 0.15 to 0.96) with an overall effect favouring treatment with GCS (P = 0.04). Limited data were available to accurately assess the incidence of adverse effects and complications with the use of GCS.

AUTHORS' CONCLUSIONS

GCS are effective in diminishing the risk of DVT in hospitalised patients, with strong evidence favouring their use in general and orthopaedic surgery. However, evidence for their effectiveness in medical patients is limited to one trial.

Compression for preventing recurrence of venous ulcers

BACKGROUND

Up to 1% of adults will have a leg ulcer at some time. The majority of leg ulcers are venous in origin and are caused by high pressure in the veins due to blockage or weakness of the valves in the veins of the leg. Prevention and treatment of venous ulcers is aimed at reducing the pressure either by removing/repairing the veins, or by applying compression bandages/stockings to reduce the pressure in the veins.The majority of venous ulcers heal with compression bandages, however ulcers frequently recur. Clinical guidelines therefore recommend that people continue to wear compression, usually in the form of hosiery (tights, stockings, socks) after their ulcer heals, to prevent recurrence.

OBJECTIVES

To assess the effects of compression (socks, stockings, tights, bandages) in preventing the recurrence of venous ulcers. If compression does prevent ulceration compared with no compression, then to identify whether there is evidence to recommend particular levels of compression (high, medium or low, for example), types of compression, or brands of compression to prevent ulcer recurrence after healing.

SEARCH METHODS

For this second update we searched The Cochrane Wounds Group Specialised Register (searched 4 September 2014) which includes the results of regular searches of MEDLINE, EMBASE and CINAHL; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 8).

SELECTION CRITERIA

Randomised controlled trials (RCTs)evaluating compression bandages or hosiery for preventing the recurrence of venous ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors undertook data extraction and risk of bias assessment independently.

MAIN RESULTS

Four trials (979 participants) were eligible for inclusion in this review. One trial in patients with recently healed venous ulcers (n = 153) compared recurrence rates with and without compression and found that compression significantly reduced ulcer recurrence at six months (Risk ratio (RR) 0.46, 95% CI 0.27 to 0.76).Two trials compared high-compression hosiery (equivalent to UK class 3) with moderate-compression hosiery (equivalent to UK class 2). The first study (n=300) found no significant reduction in recurrence at five years follow up with high-compression hosiery compared with moderate-compression (RR 0.82, 95% CI 0.61 to 1.12). The second study (n = 338) assessed ulcer recurrence at three years follow up and found that high-compression hosiery reduced recurrence compared with moderate-compression (RR 0.57, 95% CI 0.39 to 0.81). Statistically significant heterogeneity precluded meta-analysis of the results from these studies. Patient-reported compliance rates were reported in both trials;,there was significantly higher compliance with medium-compression than with high-compression hosiery in one and no significant difference in the second.A fourth trial (166 patients) found no statistically significant difference in recurrence between two types of medium (UK class 2) compression hosiery (Medi versus Scholl: RR 0.74, 95% CI 0.45 to 1.2).No trials of compression bandages for preventing ulcer recurrence were identified.

AUTHORS' CONCLUSIONS

There is evidence from one trial that compression hosiery reduces rates of reulceration of venous ulcers compared with no compression. Results from one trial suggest that recurrence is lower in high-compression hosiery than in medium-compression hosiery at three years whilst another trial found no difference at 5 years. Rates of patient intolerance of compression hosiery were high. There is insufficient evidence to aid selection of different types, brands, or lengths of compression hosiery.

Venous thromboembolism prophylaxis

Venous thromboembolism (VTE) can occur after major general surgery. Pulmonary embolism is recognized as the most common identifiable cause of death in hospitalized patients in the United States. The risk of deep venous thrombosis (DVT) and pulmonary embolism (PE) is higher in colorectal surgical procedures compared with general surgical procedures. The incidence of venous thromboembolism in this population is estimated to be 0.2 to 0.3%. Prevention of VTE is considered a patient-safety measure in most mandated quality initiatives. The measures for prevention of VTE include mechanical methods (graduated compression stockings and intermittent pneumatic compression devices) and pharmacologic agents. A combination of mechanical and pharmacologic methods produces the best results. Patients undergoing surgery should be stratified according to their risk of VTE based on patient risk factors, disease-related risk factors, and procedure-related risk factors. The type of prophylaxis should be commensurate with the risk of VTE based on the composite risk profile.

Venous thromboembolism prophylaxis

Venous thromboembolism (VTE) can occur after major general surgery. Pulmonary embolism is recognized as the most common identifiable cause of death in hospitalized patients in the United States. The risk of deep venous thrombosis (DVT) and pulmonary embolism (PE) is higher in colorectal surgical procedures compared with general surgical procedures. The incidence of venous thromboembolism in this population is estimated to be 0.2 to 0.3%. Prevention of VTE is considered a patient-safety measure in most mandated quality initiatives. The measures for prevention of VTE include mechanical methods (graduated compression stockings and intermittent pneumatic compression devices) and pharmacologic agents. A combination of mechanical and pharmacologic methods produces the best results. Patients undergoing surgery should be stratified according to their risk of VTE based on patient risk factors, disease-related risk factors, and procedure-related risk factors. The type of prophylaxis should be commensurate with the risk of VTE based on the composite risk profile.

Bringing light into the dark: effects of compression clothing on performance and recovery

To assess original research addressing the effect of the application of compression clothing on sport performance and recovery after exercise, a computer-based literature research was performed in July 2011 using the electronic databases PubMed, MEDLINE, SPORTDiscus, and Web of Science. Studies examining the effect of compression clothing on endurance, strength and power, motor control, and physiological, psychological, and biomechanical parameters during or after exercise were included, and means and measures of variability of the outcome measures were recorded to estimate the effect size (Hedges g) and associated 95% confidence intervals for comparisons of experimental (compression) and control trials (noncompression). The characteristics of the compression clothing, participants, and study design were also extracted. The original research from peer-reviewed journals was examined using the Physiotherapy Evidence Database (PEDro) Scale. Results indicated small effect sizes for the application of compression clothing during exercise for short-duration sprints (10-60 m), vertical-jump height, extending time to exhaustion (such as running at VO2max or during incremental tests), and time-trial performance (3-60 min). When compression clothing was applied for recovery purposes after exercise, small to moderate effect sizes were observed in recovery of maximal strength and power, especially vertical-jump exercise; reductions in muscle swelling and perceived muscle pain; blood lactate removal; and increases in body temperature. These results suggest that the application of compression clothing may assist athletic performance and recovery in given situations with consideration of the effects magnitude and practical relevance.

Effect of Graduated Compression Stockings on Venous Blood Velocity in Supine Resting Hospitalized Patients

The effects of graduated compression stockings (GCSs) on venous blood velocity were measured in 26 hospitalized medical patients while supine at rest. Peak blood velocity in the right femoral vein was 21.6 cm/s without GCS and 23.0 cm/s with GCS [not significant (NS)]. Peak blood velocity in the right popliteal vein was 12.5 cm/s without GCS and 15.0 cm/s with GCS (NS). Mean blood velocity in the right femoral vein did not increase significantly with GCS, but mean blood velocity in the right popliteal vein increased marginally from 5.0 cm/s to 5.8 cm/s ( P = .05). Among 11 patients with venous insufficiency (refilling time ≤19 s), neither peak nor mean blood velocity in the femoral or popliteal veins increased significantly with GCS. In conclusion, thigh-length GCS in hospitalized patients had little or no effect on popliteal or femoral vein blood velocity while supine at rest, irrespective of whether the patients had venous insufficiency.

Compression for preventing recurrence of venous ulcers

BACKGROUND

Up to 1% of adults will have a leg ulcer at some time. The majority of leg ulcers are venous in origin and are caused by high pressure in the veins due to blockage or weakness of the valves in the veins of the leg. Prevention and treatment of venous ulcers is aimed at reducing the pressure either by removing/repairing the veins, or by applying compression bandages/stockings to reduce the pressure in the veins.The majority of venous ulcers heal with compression bandages, however ulcers frequently recur. Clinical guidelines therefore recommend that people continue to wear compression, usually in the form of hosiery (tights, stockings, socks) after their ulcer heals, to prevent recurrence.

OBJECTIVES

To assess the effects of compression (socks, stockings, tights, bandages) in preventing the recurrence of venous ulcers. If compression does prevent ulceration compared with no compression, then to identify whether there is evidence to recommend particular levels of compression (high, medium or low, for example), types of compression, or brands of compression to prevent ulcer recurrence after healing.

SEARCH METHODS

For this update we searched The Cochrane Wounds Group Specialised Register (searched 1 March 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 2); Ovid MEDLINE (1950 to February Week 4 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, February 29, 2012); Ovid EMBASE (1980 to 2012 Week 08); and EBSCO CINAHL (1982 to 1 March 2012).

SELECTION CRITERIA

Randomised controlled trials evaluating compression bandages or hosiery for preventing the recurrence of venous ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors undertook data extraction and risk of bias assessment independently.

MAIN RESULTS

Four trials (979 participants) were eligible for inclusion in this review. One trial in patients with recently healed venous ulcers (n = 153) compared recurrence rates with and without compression and found that compression significantly reduced ulcer recurrence at six months (Risk ratio (RR) 0.46, 95% CI 0.27 to 0.76).Two trials compared high-compression hosiery (equivalent to UK class 3) with moderate-compression hosiery (equivalent to UK class 2). The first study (n=300) found no significant reduction in recurrence at five years follow up with high-compression hosiery compared with moderate-compression (RR 0.82, 95% CI 0.61 to 1.12). The second study (n = 338) assessed ulcer recurrence at three years follow up and found that high-compression hosiery reduced recurrence compared with moderate-compression (RR 0.57, 95% CI 0.39 to 0.81). Statistically significant heterogeneity precluded meta-analysis of the results from these studies. Patient-reported compliance rates were reported in both trials;,there was significantly higher compliance with medium-compression than with high-compression hosiery in one and no significant difference in the second.A fourth trial (166 patients) found no statistically significant difference in recurrence between two types of medium (UK class 2) compression hosiery (Medi versus Scholl: RR 0.74, 95% CI 0.45 to 1.2).No trials of compression bandages for preventing ulcer recurrence were identified.

AUTHORS' CONCLUSIONS

There is evidence from one trial that compression hosiery reduces rates of reulceration of venous ulcers compared with no compression. Results from one trial suggest that recurrence is lower in high-compression hosiery than in medium-compression hosiery at three years whilst another trial found no difference at 5 years. Rates of patient intolerance of compression hosiery were high. There is insufficient evidence to aid selection of different types, brands, or lengths of compression hosiery.

Elastic compression stockings for prevention of deep vein thrombosis

BACKGROUND

One of the settings where deep vein thrombosis (DVT) in the lower limb and pelvic veins occurs is in hospital with prolonged immobilisation of patients for various surgical and medical illnesses. Using graduated compression stockings (GCS) in these patients has been proposed to decrease the risk of DVT. This is an update of a Cochrane review first published in 2000 and updated in 2003.

OBJECTIVES

To determine the magnitude of effectiveness of GCS in preventing DVT in various groups of hospitalised patients.

SEARCH STRATEGY

For this update the Cochrane Peripheral Vascular Diseases Group searched their Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 4) for randomised controlled trials of elastic or graduated compression stockings for prevention of DVT.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving GCS alone; or GCS used on a background of any other DVT prophylactic method.

DATA COLLECTION AND ANALYSIS

One author extracted the data, assessed the quality of trials and analysed the results; which were cross-checked and authenticated by a second author.

MAIN RESULTS

Eighteen RCTs were identified. GCS were applied on the day before surgery or on the day of surgery and were worn up until discharge or until the patients were fully mobile. In the majority of the included studies DVT was identified by the radioactive I(125) uptake test.For GCS alone, eight RCTs were identified involving 1279 analytic units (887 patients). In the treatment group (GCS), of 662 units, 86 developed DVT (13%) in comparison to the control group (without GCS) of 617 units where 161 (26%) developed DVT. The Peto's odds ratio (OR) was 0.35 (95% confidence interval (CI) 0.26 to 0.47) with an overall effect favouring treatment with GCS (P < 0.00001). For GCS on a background of another prophylactic method, 10 RCTs were identified involving 1248 analytic units (576 patients). In the treatment group (GCS plus another method), of 621 units, 26 (4%) developed DVT, in the control group (the other method alone), of 627 units, 99 (16%) developed DVT (OR 0.25, 95% CI 0.17 to 0.36). The overall effect also favoured treatment with GCS on a background of another DVT prophylactic method (P < 0.00001).

AUTHORS' CONCLUSIONS

GCS are effective in diminishing the risk of DVT in hospitalised patients. Data examination also suggests that GCS on a background of another method of prophylaxis is more effective than GCS on its own.

Physiological effects of wearing graduated compression stockings during running

This study examined the effect of wearing different grades of graduated compression stockings (GCS) on physiological and perceptual measures during and following treadmill running in competitive runners. Nine males and one female performed three 40-min treadmill runs (80 +/- 5% maximal oxygen uptake) wearing either control (0 mmHg; CON), low (12-15 mmHg; LO-GCS), or high (23-32 mmHg; HI-GCS) grade GCS in a double-blind counterbalanced order. Oxygen uptake, heart rate and blood lactate were measured. Perceptual scales were used pre- and post-run to assess comfort, tightness and any pain associated with wearing GCS. Changes in muscle function, soreness and damage were determined pre-run, immediately after running and 24 and 48 h post-run by measuring creatine kinase and myoglobin, counter-movement jump height, perceived soreness diagrams, and pressure sensitivity. There were no significant differences between trials for oxygen uptake, heart rate or blood lactate during exercise. HI-GCS was perceived as tighter (P < 0.05) and more pain-inducing (P < 0.05) than the other interventions; CON and LO-GCS were rated more comfortable than HI-GCS (P < 0.05). Creatine kinase (P < 0.05), myoglobin (P < 0.05) and jump height (P < 0.05) were higher and pressure sensitivity was more pronounced (P < 0.05) immediately after running but not after 24 and 48 h. Only four participants reported muscle soreness during recovery from running and there were no differences in muscle function between trials. In conclusion, healthy runners wearing GCS did not experience any physiological benefits during or following treadmill running. However, athletes felt more comfortable wearing low-grade GCS whilst running.

A pilot evaluation of a neuromuscular electrical stimulation (NMES) based methodology for the prevention of venous stasis during bed rest

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 implications for DVT development. Electrically elicited calf muscle contractions significantly improve lower limb blood flow and can alleviate some debilitating effects of bed rest.

Graduated compression stockings: physiological and perceptual responses during and after exercise

The aim of this study was to examine the effect of wearing graduated compression stockings on physiological and perceptual variables during and after intermittent (Experiment 1) and continuous (Experiment 2) running exercise. Fourteen recreational runners performed two multi-stage intermittent shuttle running tests with 1 h recovery between tests (Experiment 1). A further 14 participants performed a fast-paced continuous 10-km road run (Experiment 2). Participants wore commercially available knee-length graduated compression stockings (pressure at ankle 18 - 22 mmHg) beneath ankle-length sports socks (experimental trials) or just the latter (control trials) in a randomized counterbalanced design (for both experiments). No performance or physiological differences were observed between conditions during intermittent shuttle running. During the 10-km trials, there was a reduction in delayed-onset muscle soreness 24 h after exercise when wearing graduated compression stockings (P < 0.05). There was a marked difference in the frequency and location of soreness: two participants in the stockings trial but 13 participants in the control trial indicated soreness in the lower legs. Wearing graduated compression stockings during a 10-km road run appears to reduce delayed-onset muscle soreness after exercise in recreationally active men.

Compression modalities and dressings: their use in venous ulcers

Among the standard of care for venous ulcer treatment are the use of compression therapy to reverse the effect of venous hypertension and the use of occlusive dressings to maintain a moist wound-healing environment and for treatment of abnormalities of the ulcer bed. The use of multilayered elastic bandages for compression in patients with normal arterial flow currently provides the treatment with the highest level of evidence for treatment of venous ulcers. Additionally, treatment of the ulcer bed, especially with cadexemer iodine dressings, is also supported by evidence from randomized controlled trials, whereas newer dressings provide less well proven alternative opportunities to speed the healing of venous ulcers.

Graduated compression stockings as prophylaxis for flight-related venous thrombosis: systematic literature review

AIM

This paper reports a systematic review whose objective was to evaluate the effectiveness of graduated compression stockings as prophylaxis for flight-related venous thrombosis, including deep vein thrombosis and superficial venous thrombosis, after air travel in the general population.

BACKGROUND

Despite the extended history of the use of graduated compression stockings, their application to prevent flight-related thrombosis was not explored until flight-related thrombosis was perceived as a preventable illness. Even now, their effectiveness in preventing flight-related thrombosis remains unresolved.

METHODS

Generic terms including stocking/s, sock/s, or hosiery/hosieries were used to search a variety of electronic databases. Based on the selection criteria, decisions regarding inclusion and exclusion of primary studies were made. Using a meta-analysis software program, relative risk for the incidence of deep vein thrombosis, superficial venous thrombosis, and intention-to-treat analysis was calculated.

RESULTS

A total of nine randomized controlled trials were included. In the treatment group, two of 1237 participants developed deep vein thrombosis in comparison with 46 of 1245 in the control group. The weighted relative risk for deep vein thrombosis was 0.08, with fixed 95% confidence interval 0.03-0.23. In the treatment group, four of 826 participants developed superficial venous thrombosis in comparison with seven of 823 in the control group. The weighted relative risk for superficial venous thrombosis was 0.67. with fixed 95% confidence interval 0.24-1.87 (non-significant difference). Using intention-to-treat analysis, the risk for participants in the treatment group was 0.53 times as great as that for those in the control group.

CONCLUSIONS

This review demonstrates the effectiveness of medium compression pressure, below-knee graduated compression stockings in preventing flight-related deep vein thrombosis but not superficial venous thrombosis in low-medium- or high-risk participants.

DVT prophylaxis and anticoagulation in the surgical patient

One of the most common postoperative complications is venous thromboembolism, a term encompassing deep vein thrombosis and pulmonary embolism. This article reviews the epidemiology, natural history, difficulties in diagnosis, and strategies for the prevention of postoperative venous thromboembolism. We thoroughly review the currently available methods for thromboprophylaxis including: early ambulation, elastic compression stockings, pneumatic compression devices, inferior vena cava filters, and a variety of pharmacologic agents such as unfractionated heparin, warfarin, aspirin, low molecular weight heparin, and pentasaccharides. Finally, we review the perioperative management of patients on long-term oral anticoagulation.

Venous haemodynamics and the effects of compression stockings

Over the years, graduated compression stockings exerting varying ankle pressures have been used with differing degrees of effectiveness in the prevention of deep venous thrombosis and ulcer recurrence, and the treatment of venous ulceration (Stemmer et al, 1980; Partsch and Horakova, 1994; Veraart et al, 1997). Whether in the hospital or community setting, nurses often have the responsibility of measuring the limb and fitting the compression stocking on the patient and it is he/she who often influences the patient on the type of stocking and level of compression required. Understanding the influence of graduated compression on the venous haemodynamics of the lower limb and having a good working knowledge of the claims of the manufacturers as to expected levels of compression from each garment will aid the nurse and patient in decision making. An awareness of the hazards of inappropriate use of compression therapy should ensure that the nurse is a safe practitioner.

Compression for preventing recurrence of venous ulcers

BACKGROUND

Up to 1% of adults will suffer from leg ulceration at some time. The majority of leg ulcers are venous in origin and are caused by high pressure in the veins due to blockage or weakness of the valves in the veins of the leg. Prevention and treatment of venous ulcers is aimed at reducing the pressure either by removing / repairing the veins, or by applying compression bandages / stockings to reduce the pressure in the veins. The vast majority of venous ulcers are healed using compression bandages. Once healed they often recur and so it is customary to continue applying compression in the form of bandages, tights, stockings or socks in order to prevent recurrence. Compression bandages or hosiery (tights, stockings, socks) are often applied for ulcer prevention.

OBJECTIVES

To assess the effects of compression hosiery (socks, stockings, tights) or bandages in preventing the recurrence of venous ulcers. To determine whether there is an optimum pressure/type of compression to prevent recurrence of venous ulcers.

SEARCH STRATEGY

Searches of 19 databases including the Cochrane Wounds Group trials register and the Cochrane Controlled Trials Register, handsearching of journals, conference proceedings, and bibliographies up to June 2000.

SELECTION CRITERIA

Randomised controlled trials evaluating compression bandages or hosiery for prevention of venous leg ulcers.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of study quality were undertaken by two reviewers independently.

MAIN RESULTS

No trials compared recurrence rates with and without compression. One trial (300 patients) compared high (UK Class 3) compression hosiery with moderate (UK Class 2) compression hosiery. A intention to treat analysis found no significant reduction in recurrence at five years follow up associated with high compression hosiery compared with moderate compression hosiery (relative risk of recurrence 0.82, 95% confidence interval 0.61 to 1.12). This analysis would tend to underestimate the effectiveness of the high compression hosiery because a significant proportion of people changed from high compression to medium compression hosiery. Compliance rates were significantly higher with medium compression than with high compression hosiery. One trial (166 patients) found no difference in recurrence between two types of medium (UK Class 2) compression hosiery (relative risk of recurrence with Medi was 0.74, 95% confidence interval 0.45 to 1.2). Both trials reported that not wearing compression hosiery was strongly associated with ulcer recurrence and this is circumstantial evidence that compression reduces ulcer recurrence. No trials were found which evaluated compression bandages for preventing ulcer recurrence.

REVIEWER'S CONCLUSIONS

No trials compared compression with vs no compression for prevention of ulcer recurrence. Not wearing compression was associated with recurrence in both studies identified in this review. This is circumstantial evidence of the benefit of compression in reducing recurrence. Recurrence rates may be lower in high compression hosiery than in medium compression hosiery and therefore patients should be offered the strongest compression with which they can comply. Further trials are needed to determine the effectiveness of hosiery prescribed in other settings, i.e. in the UK community, in countries other than the UK.

Compression wraps for venous ulcer healing: a review

Compression to the lower extremities is used to increase healing of venous stasis ulcers by improving the blood supply and reducing edema and distension. Compression wraps are available in elastic or non-elastic and in single to multilayer systems requiring varying types of application and exerting different levels of compression. Elimination of edema is so basic and important to venous ulcer healing that the most effective level of compression should be used. Controversy exists regarding the most effective sub-bandage pressure (ranging from 20 mm Hg to 45 mm Hg) for timely healing. Because of differences in compression wraps, selection of the most effective and efficient wrap can be difficult. The purpose of this integrated review was to determine healing rates of venous ulcers with various wraps. The studies reviewed provide reasonable evidence that venous ulcers can be healed with the use of compression wraps and that various wraps are effective when used with correct assessment, application, and fit by the caregiver, along with compliance and mobility of the patient.

Graduated compression stockings in the prevention of venous thromboembolism

BACKGROUND

Surveys still show a wide variation in routine use of deep vein thrombosis (DVT) prophylaxis despite its established place in current patient management. This article reviews the mechanism of action, efficacy and complications of stockings in preventing DVT.

METHODS

Relevant publications indexed in Medline (1966-1998) and the Cochrane database were identified. Appropriate articles identified from the reference lists of the above searches were also selected and reviewed.

RESULTS AND CONCLUSION

Graduated compression stockings reduce the overall cross-sectional area of the limb, increase the linear velocity of venous flow, reduce venous wall distension and improve valvular function. Fifteen randomized controlled trials of graduated compression stockings alone were reviewed. Stockings reduced the relative risk of DVT by 64 per cent in general surgical patients and 57 per cent following total hip replacement. The effect of stockings was enhanced by combination with pharmacological agents such as heparin; the combination is recommended in patients at moderate or high risk of DVT. Knee-length stockings are as effective and should replace above-knee stockings. Complications are rare and avoidable.

Graduated compression and the prevention of deep vein thrombosis (Part 2)

The second of this three-part literature review discusses the effects of external compression on blood flow.

Pulmonary embolism in rehabilitation patients: relation to time before return to physical therapy after diagnosis of deep vein thrombosis

OBJECTIVE

There is increased risk of a pulmonary embolism (PE) after a deep vein thrombosis (DVT). The effect of mobilizing the affected lower extremity has not been well studied. The purpose of this study was to detect any change in the rate of PE occurrence dependent on time to mobilization in patients diagnosed with a DVT in a rehabilitation hospital.

DESIGN

Retrospective case-control study.

SETTING

Urban rehabilitation hospital.

PATIENTS

Data were collected from charts of 190 patients with a discharge diagnosis of PE or DVT at an urban rehabilitation hospital from January 1991 to June 1995; 127 patients met inclusion criteria in the study.

INTERVENTIONS

Measurement of time to return to physical therapy after diagnosis of DVT.

MAIN OUTCOME MEASURES

A DVT was diagnosed with either Doppler ultrasound or venogram testing, a PE by ventilation/perfusion (V/Q) scan, and time to mobilization in hours until return to physical therapy.

RESULTS

One hundred twenty-one patients had a DVT without a subsequent PE and a mean time of 123.2 hours until mobilization. Six patients had a subsequent PE and a mean time of 48.3 hours until mobilization (p = .021). A Fischer exact test comparing patients with and without PE who were returned to therapy before 48 hours and after 48 hours (p = .018), and before and after 72 hours (p = .059), supports the hypothesis that patients who return to physical therapy earlier are more likely to develop a PE than patients who return later.

CONCLUSIONS

It is imperative to prophylactically treat all patients at risk of a DVT with anticoagulation if possible. Once a DVT is diagnosed it is prudent to keep the affected limb immobilized for at least 48 to 72 hours while the patient is being anticoagulated. A large prospective cohort study is needed to answer the question of when to mobilize a patient after diagnosis of a DVT.

The efficacy of pneumatic compression stockings in the prevention of pulmonary embolism after cardiac surgery

INTRODUCTION

Pneumatic compression stocking (PCS) devices have been introduced to decrease the incidence of postoperative deep venous thrombosis (DVT). However, their role in the prophylaxis against pulmonary embolism (PE) remains unclear. This study was undertaken to compare the prophylactic effectiveness of subcutaneous heparin (SCH) alone vs the combined use of PCS and SCH in the prevention of PE following cardiac surgery.

METHODS

We studied 2,551 consecutive patients who underwent cardiac surgery over a 10-year period. They were randomly allocated to two groups. Group A included 1,196 patients who were treated with 5,000 U of SCH every 12 h and group B included 1,355 patients treated with a combined prophylactic regimen of PCS and SCH.

RESULTS

The diagnosis of PE was established in 69 patients by either high-probability ventilation perfusion scan, pulmonary angiogram, or autopsy. The incidence of PE in group A patients was 4% (48/1,196) and in group B was 1.5% (21/1,355). The concomitant use of bilateral PCS and SCH reduced the frequency of postoperative PE in 62% in comparison to the prophylaxis with SCH alone (p < 0.001).

CONCLUSIONS

These data suggest that the combined prophylactic method of bilateral PCS and SCH is superior to SCH alone in the prevention of PE after cardiac surgery.

Varicose vein surgery and deep vein thrombosis

A questionnaire was sent to 363 members of the Vascular Surgical Society of Great Britain and Ireland about their use of deep vein thrombosis (DVT) prophylaxis at the time of varicose vein surgery. Replies were received from 289 surgeons (80 percent), of whom only 29 percent regarded varicose veins as an important risk factor for DVT. Only 12 percent used subcutaneous heparin prophylaxis routinely, while 71 percent did so selectively, being influenced by a history of thromboembolism (95 percent), obesity (47 percent), age (35 percent), recurrent varicose veins (22 percent) and inpatient status (16 percent). At the end of the operation 52 percent applied crepe bandages, 25 percent other bandages, 13 percent stockings and 10 percent Tubigrip. Subsequently, antiembolism stockings were prescribed by 55 percent. There is a wide variation in opinion regarding DVT prophylaxis for patients having varicose vein surgery, which has both clinical and medicolegal implications.

Intramuscular pressures beneath elastic and inelastic leggings

Leg compression devices have been used extensively by patients to combat chronic venous insufficiency and by astronauts to counteract orthostatic intolerance following spaceflight. However, the effects of elastic and inelastic leggings on the calf muscle pump have not been compared. The purpose of this study was to compare in normal subjects the effects of elastic and inelastic compression on leg intramuscular pressure (IMP), an objective index of calf muscle pump function. IMP in soleus and tibialis anterior muscles was measured with transducer-tipped catheters. Surface compression between each legging and the skin was recorded with an air bladder. Subjects were studied under three conditions: (1) control (no legging), (2) elastic legging, and (3) inelastic legging. Pressure data were recorded for each condition during recumbency, sitting, standing, walking, and running. Elastic leggings applied significantly greater surface compression during recumbency (20 +/- 1 mm Hg, mean +/- SE) than inelastic leggings (13 +/- 2 mm Hg). During recumbency, elastic leggings produced significantly higher soleus IMP of 25 +/- 1 mm Hg and tibialis anterior IMP of 28 +/- 1 mm Hg compared to 17 +/- 1 mm Hg and 20 +/- 2 mm Hg, respectively, generated by inelastic leggings and 8 +/- 1 mm Hg and 11 +/- 1 mm Hg, respectively, without leggings. During sitting, walking, and running, however, peak IMPs generated in the muscular compartments by elastic and inelastic leggings were similar. Our results suggest that elastic leg compression applied over a long period in the recumbent posture may impede microcirculation and jeopardize tissue viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of compression stockings on lower-limb venous haemodynamics during laparoscopic cholecystectomy

Lower-limb venous haemodynamics were studied prospectively in 40 patients (24 women, 16 men of median age 52 years) undergoing laparoscopic cholecystectomy. Patients were randomized to wear compression stockings during surgery or no stockings. All received subcutaneous heparin prophylaxis. Venous capacitance and outflow were measured non-invasively before, during and after pneumoperitoneum. In the group without compression stockings (20 patients) venous capacitance and outflow decreased during pneumoperitoneum in most patients. In the group wearing stockings (20 patients) the changes were less pronounced or abolished. There was a significant difference between the groups in venous capacitance and outflow ratios at mid-operation: median (interquartile range) 0.89 (0.56-1.16) and 0.89 (0.56-1.15) respectively in the group without stockings versus 1.48 (1.09-2.19) and 1.71 (1.20-2.19) respectively in that with stockings (P < 0.001). Pneumoperitoneum creates a significant resistance to venous return. Compression stockings counteract the changes observed.

Leg elevation and wrapping in the prevention of hypotension following spinal anaesthesia for elective caesarean section

Ninety-seven parturients undergoing elective Caesarean section were allocated randomly to have their legs elevated to approximately 30 degrees on pillows or elevated and wrapped with elasticated Esmarch bandages or neither (controls) following spinal anaesthesia. All patients received intravenous crystalloid (20 ml.kg-1 over 20 min) prior to spinal injection and were placed in the left lateral tilt position. Significant hypotension was treated with intravenous ephedrine in 5 mg bolus doses. Leg wrapping resulted in a significant reduction in the incidence of postspinal hypotension in comparison to the control group (18% compared to 53%, p = 0.004). This represents a five-fold reduction in the likelihood of postspinal hypotension (odds ratio 5.3, 95% CI 1.7-16.3). Leg elevation alone did not significantly reduce the incidence of hypotension (39%). There was no significant difference in the time of onset of hypotension between the groups. For those patients requiring ephedrine, there was no significant difference in mean dose requirements between the groups. The use of leg compression immediately postspinal provides a simple means of reducing the accompanying hypotension and should be used more widely.

Mechanism of action of external compression on venous function

Compression stockings and bandages have been shown to improve venous haemodynamics and may act by reducing venous reflux. The aim of this study was to assess the mechanism of action of compression therapy on venous function and to determine whether such treatment may correct valvular incompetence. Both lower limbs of 36 patients (median age 59 (interquartile range 45-65) years) were assessed by duplex ultrasonographic scanning. There were 17 limbs with popliteal vein reflux, 19 with long saphenous vein (LSV) reflux and 21 with short saphenous vein (SSV) reflux. A water-filled adjustable pressure cuff was applied around the knee and inflated gradually, while continuously assessing the veins for reflux using ultrasonographic imaging. The external pressure applied by the cuff was noted when reflux was abolished or when the vein was completely occluded. In four (24 per cent) of 17 popliteal veins, eight (42 per cent) of 19 LSVs and three (14 per cent) of 21 SSVs reflux was abolished before occlusion of the vein. The cuff pressures required to achieve restoration of valvular function were significantly lower than those required to occlude the veins. It is possible, in some refluxing veins, to correct valvular dysfunction by external compression therapy. Coaptation of valvular cuffs to restore valvular competence may be the mechanism of action of compression therapy in venous disease.

Effect of elastic compression stockings on venous hemodynamics in hemiplegic patients

Unilateral lower extremity edema and an increased risk of thromboembolism have been associated with hemiplegia following stroke. This study was undertaken to determine the effect of knee-high, graded elastic stockings on venous hemodynamics in hemiplegic patients. Thirty-six patients with recent cerebral infarcts were studied. The presence of underlying venous or arterial occlusive disease was excluded in all patients. Duplex scanning techniques were used to measure femoral and popliteal venous circumference, cross-sectional area, and peak flow velocity in the normal and paralyzed extremities both with and without stockings. All patients were examined and assessed for the degree of motor weakness and Brunnstrom stage of recovery. Associated medical illnesses were also reviewed. These patients were found to have a decreased flow in the femoral (p = 0.0002) and popliteal (p = 0.006) veins and an increase in the femoral vein size. The application of compression stockings resulted in a significant increase in venous size and flow velocity in both areas. The femoral and popliteal velocity correlated inversely with the degree of motor impairment and Brunnstrom stage, suggesting that factors other than the muscle pump may be responsible for the augmentation of femoral flow velocity in the paralyzed leg. There was no correlation demonstrated with other variables such as age, gender, cardiovascular disease, or diabetes. These results would indicate a potential benefit of graded knee-high elastic compression stockings in reducing venous flow stasis in hemi-paretic patients.

Deep vein thrombosis: effect of graduated compression stockings on distension of the deep veins of the calf

The mechanisms by which graduated compression stockings prevent deep vein thrombosis are not completely understood. Recent work has suggested that venous distension plays a role in initiating the process. Our previous work has shown that the deep veins of the lower limb distend in patients undergoing surgical procedures. We have investigated 40 patients receiving surgical treatment on the abdomen or neck. A medial gastrocnemius vein was studied using ultrasound imaging during the operations. In half the patients a graduated compression anti-embolism stocking was applied to the limb under study at the start of the operation, immediately after initial measurements of vein diameter. The median vein diameter in both groups was the same at the start of the operative procedures (control, 2.6 mm, interquartile range 2.1-3.3 mm; stocking, 2.6 mm, interquartile range 2.1-3.7 mm). After application of a stocking the median diameter in this group fell to 1.6 mm (interquartile range 1.3-2.8 mm) and then decreased slightly at the end of the operation. In the control group the vein diameter increased to 2.9 mm (interquartile range 2.3-4.0 mm) during the operative procedure.

Venous stasis and vein lumen changes during surgery

The mechanisms underlying the development of postoperative deep vein thrombosis remain to be fully elucidated. Previous studies have suggested that peroperative venous distension may be a factor associated with venous thromboembolism. In this study we have obtained high resolution ultrasound images of gastrocnemius and posterior tibial veins in 62 patients undergoing a range of general surgical procedures. From these we determined the changes in vein diameter occurring during the operative procedures, in response to induction of anaesthesia, and after completion of surgery. Veins showed no evidence of dilatation in response to the induction of anaesthesia, but by the end of the operative procedure showed distension of 22-28 per cent. Distension was most prominent in the gastrocnemius veins, and lesser distension was observed in the posterior tibial veins. In a series of patients who received an infusion of 1 litre of saline in addition to basal requirements, distension was 57 per cent compared with 22 per cent in the corresponding control group. Intraoperative venous distension is associated with factors that lead to deep vein thrombosis and may be involved in the mechanisms which result in the commencement of deep vein thrombosis.

Graduated compression stockings in the prevention of postoperative deep vein thrombosis

This review examines the role of graduated elastic compression stockings in the prevention of postoperative deep vein thrombosis. Used alone compression stockings reduce the incidence of postoperative deep vein thrombosis by approximately 60 per cent and when used in combination with other preventive methods, such as low dose heparin or intermittent calf compression, they further reduce the incidence by up to 85 per cent.

Mechanical prophylaxis of venous thrombosis in patients undergoing craniotomy: a randomized trial

A randomized, prospective clinical trial of 70 patients undergoing craniotomy was performed to compare and evaluate two forms of mechanical prophylaxis of deep vein thrombosis. Thirty-eight patients received antiembolism stockings, whereas 32 patients received external pneumatic compression. Prophylaxis was begun preoperatively and continued intraoperatively and post-operatively until the patients were ambulatory. Impedance plethysmography was used to detect deep vein thrombosis both preoperatively and postoperatively. Two patients, one from each group, developed thromboembolic complications postoperatively. Impedance plethysmography showed false-positive findings in two additional patients. There were no deaths. The data suggest that either form of mechanical prophylaxis is effective against the development of deep vein thrombosis in this high-risk patient population.