Structured exercise improves calf muscle pump function in chronic venous insufficiency: a randomized trial

OBJECTIVE: Deterioration of calf muscle pump function is associated with progression of chronic venous insufficiency (CVI). We postulated that a supervised exercise program would improve calf muscle strength and venous hemodynamics in patients with CVI. METHODS: We recruited 31 patients for this randomized, prospective trial. Inclusion criteria required the presence of skin changes or ulceration (CEAP 4, 5, 6), and duplex ultrasound scanning (reflux or scarring) and air plethysmographic (APG) evidence of CVI. Subjects were randomized into control (n = 13) and therapy (n = 18) groups. Class II (30-40 mm Hg) compression hosiery was given to all. The experimental group received physical therapy designed specifically to strengthen calf musculature. Dynamic strength and power were measured with a Biodex II dynamometer (Biodex Medical Systems, Shirley, NY) at slow and fast speeds. Reflux (venous filling index) and calf pump function (ejection fraction, residual volume fraction) were measured with APG. Quality-of-life questionnaires and venous severity scores were also administered. Outcomes were compared 6 months after initiation of exercise. Probability of treatment effect was tested with univariate analysis of variance, with control for baseline values. RESULTS: Demographic variables and medical comorbidities were not different between groups. After 6 months of intervention, indicators of calf pump function returned to a normal range in the therapy (experimental) group. Mean residual volume fraction was improved in the exercise group (-8.75 +/- 4.6 vs 3.4 +/- 2.9 in the control group; P <.029). Mean ejection fraction was increased in the exercise group (3.48 +/- 2.7 vs -1.4 +/- 2.1 in the control group; P <.026). Reflux, while substantially greater than the normal value of 2.0 mL/s in both groups, was unchanged. The exercise regimen improved isokinetic peak torque/body weight at both slow speed (3.1 +/- 1.4 in the therapy group vs -1.0 +/- 1.1 in the control group; P <.05) and fast speed (2.8 +/- 0.9 in the therapy group vs - 0.3 +/- 0.6 in the control group; P <.03). No changes were observed in quality-of-life or severity scores. CONCLUSIONS: Calf muscle pump function and dynamic calf muscle strength were improved after a 6-month program of structured exercise. Directed physical conditioning of the calf musculature may prove beneficial for patients with or without alternative management options for severe CVI. Further research on exercise for patients with CVI is warranted.     

Changes in calf muscle function in chronic venous disease.

The aim of this study was to assess calf muscle function in patients with chronic venous disease and recently healed venous ulcers. Forty-nine consecutive patients with recently healed proven venous leg ulcers and 20 age- and sex-matched control subjects were entered into this study. Both patients and control subjects underwent duplex scan evaluation of their leg veins and isokinetic measurement for calf muscle strength and endurance. Calf muscle function was significantly impaired in patients with chronic venous disease compared with control subjects. Both peak torque/body weight (strength), P = 0.049 (CI 0.3-18.4%) and total work (endurance), P = 0.05 (Cl 6.01-97.6 Nm) were reduced. This study has shown that patients with chronic venous disease have a significant impairment of calf muscle function compared with healthy control subjects. This study suggests that there is a need to evaluate whether a programme to improve muscle strength may be of benefit in both healing and preventing the recurrence of chronic venous ulcers.     

Pathogenesis of venous ulceration in relation to the calf muscle pump function

Air plethysmography has been used to quantitate venous reflux by measuring the average filling rate of the veins (venous filling index; in milliliters per second) on standing from the supine position, the ejection fraction of the calf muscle pump as a result of one tip-toe movement, and the residual volume fraction after 10 tip-toe movements. Thirty normal limbs, 110 limbs with primary varicose veins, 34 limbs with reflux in the deep veins but without occlusion, and 31 limbs with deep venous occlusion, with or without reflux, have been studied. An increase in the incidence of ulceration occurred with increasing values of reflux and decreasing values of the calf muscle pump ejection fraction. A poor ejection fraction was the primary cause of venous ulceration in limbs with minimal reflux. A good ejection fraction, however, significantly reduced the incidence of ulceration in limbs with marked reflux (p less than 0.05). The residual volume fraction, which expresses the combined effect of venous reflux and ejection fraction with rhythmic exercise, showed a good correlation with the incidence of ulceration and the measurements of ambulatory venous pressure (r = 0.81). The air-plethysmographic measurements completely assess the calf muscle pump function and provide an accurate method to identify the predominant hemodynamic factor (ejection fraction, reflux, or both) responsible for the clinical picture of the patient.     

Hemodynamic effects of supervised calf muscle exercise in patients with venous leg ulceration: a prospective controlled study

HYPOTHESIS: Because more than two thirds of patients with venous ulcer have an impaired calf muscle pump, enhancement of its ejecting ability with physical training may generate an improved hemodynamic milieu sufficient to promoting ulcer healing. This study evaluated the effects of short-term supervised calf exercise on calf muscle pump function and venous hemodynamics in limbs with venous ulceration. DESIGN: Prospective controlled study. SETTINGS: University-associated tertiary care hospital. PATIENTS: The study consisted of 2 groups. An exercise group comprised 10 patients (median age, 72 years) receiving supervised isotonic calf muscle exercise for 7 consecutive days. A control group comprised 11 patients matched with those in the exercise group for age, sex, ulcer size, and ulcer duration (all, P>.09). Patients in both groups had perimalleolar venous leg ulcers, impaired calf muscle function (ejection fraction, <60%), and full ankle joint movement. INTERVENTIONS: After providing a complete clinical history, both groups underwent a physical examination, venous duplex scanning, and air plethysmography. The venous filling index, venous volume, residual venous volume, and residual volume fraction of the calf on standing were measured plethysmographically at baseline and on day 8, in addition to calf muscle endurance as determined by the maximal number of plantar flexions performed against a fixed 4-kg resistance during 6 minutes (1 flexion/s). Operators were blinded to the subject's group. Exercise in the first group entailed consecutive active plantar flexions using a standardized 4-kg resistance pedal ergometer. Subjects daily completed 3 sets of flexions of 6 minutes each. All patients had short-stretched compression bandaging. MAIN OUTCOME MEASURES: The ejected venous volume and ejection fraction were evaluated in both groups at baseline and on day 8. RESULTS: Both groups had a similar hemodynamic performance at baseline for all the variables evaluated (P>.10). After 7 days of exercise, patients in the exercise group improved their ejected venous volume by 67.5%, ejection fraction by 62.5%, residual venous volume by 25% (all 3, P =.006), and their residual volume fraction by 28.6% (P =.008). Changes in the control group within the same period were small (all, P>.10). By day 8, the exercise group had a significantly better ejected venous volume (P<.001) and ejection fraction (P<.001) than the control group. The venous filling index and the venous volume did not change (P>.50) in either study group. Calf muscular endurance in the exercise group increased 135%, from a median 153 plantar flexions at baseline to 360 on day 7 (P<.001). CONCLUSIONS: By increasing the muscular endurance, efficacy, and power of the calf muscle, isotonic exercise improves its ejecting ability and the global hemodynamic status in limbs with venous ulceration. Prospective evaluations of the clinical effects of calf muscle pump strengthening for the treatment of venous leg ulceration are indicated by the results of this study.     

Effect of graduated compression stockings on limb oxygenation and venous function during exercise in patients with venous insufficiency

Despite the established role of compression as the basis for nonoperative treatment of chronic venous insufficiency (CVI), its mechanism of action remains unclear. Near-infrared spectroscopy (NIRS) provides continuous noninvasive monitoring of changes in tissue oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb). We applied NIRS to evaluate the effect of graded stockings on venous function and calf muscle oxygenation during exercise in patients with CVI. Ten patients (age 56 +/- 5 years) with CVI were rested in supine posture for 20 minutes. NIRS optodes were attached to the calf. Venous function was assessed in each patient with and without graded compression stockings (classes I to III) at rest in the supine position, standing, with 10 tiptoe exercises, and on standard walking at 1.6 km/h for 5 minutes. Venous function was assessed by measuring changes in Hb and total hemoglobin (HbT) during the test, and muscle oxygenation was assessed by the oxygenation index (HbD), which is the difference between HbO2 and Hb. Standing without stockings caused a significant increase in Hb concentration by 10.75 +/- 2.24 micromol/L compared with the supine position (p < .001). This value was reduced when stockings were applied to 6.38 +/- 2.75 micromol/L with class III stockings (p = .005). During tiptoe exercise, the residual Hb concentration value without stockings was 7.62 +/- 2.12 micromol/L compared with 5.88 +/- 2.87, 3.77 +/- 3.37, and 3.46 +/- 2.73 micromol/L for class I, II, and III stockings, respectively. The reduction in Hb concentration reached significance with class II and III stockings compared to without stockings (p = .04). The HbT concentration was also reduced during tiptoe exercise, with increasing compression from 15.46 +/- 5.31 micromol/L without compression to 11.52 +/- 4.26 pmol/L with class III stockings (p = .048). During walking, the Hb concentration was 11.40 +/- 3.10 pmol/L without stockings, decreasing significantly (p < .001) and progressively to 8.49 +/- 3.24, 7.71 +/- 3.51, and 6.89 +/- 3.16 micromol/L with class I, II, and III stockings, respectively. Limb oxygenation (as measured by HbO2 concentration) during walking exercise, however, increased with higher-compression stockings and reached significance with class III stockings only (p = .03). In patients with venous insufficiency, graduated compression stockings may achieve their beneficial effects by reducing venous pooling and improving deeper tissue oxygenation.     

Physical activity, walking exercise, and calf skeletal muscle characteristics in patients with peripheral arterial disease

OBJECTIVE: This cross-sectional study was set in an academic medical center and conducted to identify associations of physical activity level and walking exercise frequency with calf skeletal muscle characteristics in individuals with lower extremity peripheral arterial disease (PAD). METHODS: Calf muscle characteristics in 439 men and women with PAD were measured with computed tomography at 66.67% of the distance between the distal and proximal tibia. Physical activity was measured continuously during 7 days with a vertical accelerometer. Patient report was used to determine the number of blocks walked during the past week and walking exercise frequency. Results were adjusted for age, sex, race, comorbidities, ankle-brachial index, body mass index, smoking, and other confounders. RESULTS: For both objective and subjective measures, more physically active PAD participants had higher calf muscle area and muscle density. Calf muscle area across tertiles of accelerometer-measured physical activity were first activity tertile, 5071 mm(2); second activity tertile: 5612 mm(2); and third activity tertile, 5869 mm(2) (P < .001). Calf muscle density across tertiles of patient-reported blocks walked during the past week were first activity tertile, 31.4 mg/cm(3); second activity tertile, 33.0 mg/cm(3); and third activity tertile, 33.8 mg/cm(3) (P < .001). No significant associations were found between walking exercise frequency and calf muscle characteristics. CONCLUSION: Among participants with PAD, higher physical activity levels, measured by accelerometer and by patient-reported blocks walked per week, were associated with more favorable calf muscle characteristics. In contrast, more frequent patient-reported walking exercise was not associated with more or less favorable calf muscle characteristics. Results suggest that clinicians should encourage their patients to increase their walking activity during daily life.     

Photoplethysmography and calf muscle pump function after subfascial endoscopic perforator ligation

OBJECTIVE: Subfascial endoscopic perforator surgery (SEPS) results in acceptable healing and recurrence rates. The role of hemodynamic venous testing in this situation, however, is poorly understood and inconsistently used. Our ongoing experience was reviewed to explore how SEPS affects the photoplethysmographic assessment of the leg. METHODS: Preoperative and postoperative venous refill times (VRTs) were measured with photoplethysmography in 30 limbs in 28 patients who underwent SEPS and superficial ablation, when indicated, with complete clearing of the anterolateral surface of the tibia, thus opening the deep posterior compartment from mid calf to close to the malleolus. Postoperative healing and duplex scanning were used to assess clinical and anatomic success, respectively. The VRTs were classified as "interpretable" if the leg emptied or "uninterpretable" if the calf could not empty. The "interpretable" study results were further classified as "normal" if the refill took 20 seconds or more or "abnormal" if less. RESULTS: Before the patients underwent SEPS, six study results (20%) showed inability of the calf to empty and thus were judged uninterpretable. After the patients underwent SEPS, 12 study results (40%) were uninterpretable (NS; P =.09 with the chi(2) test). Of the 24 preoperative interpretable study results, two (8%) were normal, and of the 18 postoperative interpretable study results, seven (39%) were normal (P <.03). With the consideration of only interpretable study results, the mean VRT increased slightly from 12.0 +/- 5.1 seconds (mean +/- standard deviation) to 14.3 +/- 8.1 seconds (NS). Seventeen of 19 ulcers (89%) had healed at a mean follow-up period of 8.6 +/- 4.8 months. CONCLUSION: Although VRT is unpredictably affected by SEPS, the most consistent finding is the inability of the calf to empty, which invalidates the remainder of the test. In addition, most ulcers heal, even with uninterpretable or abnormal postoperative VRTs. This suggests that photoplethysmography is a poor method of assessment of venous reflux after SEPS.     

Effect of N-acetylcysteine on renal function in patients with chronic kidney disease

BACKGROUND: N-acetylcysteine (NAC) is commonly administered to high-risk individuals to attenuate the risk of contrast-induced nephropathy in spite of the debate regarding its efficacy. In several studies serum creatinine decreased after exposure to NAC and contrast dye. The mechanism by which NAC attenuates the decline in renal function is not known. Studies in subjects with normal renal function suggest NAC may have an effect on tubular secretion. AIM: The aim of this study was to determine the effect of NAC on renal function, measured by serum creatinine and Cystatin C, in patients with stage 3 chronic kidney disease. METHOD: Serum creatinine and Cystatin C were measured prior to, 4, 24 and 48 h after the administration of 600 mg oral NAC in 30 patients. The protocol was repeated with the addition of 1200 mg oral cimetidine administered 3 h before NAC. RESULTs: Serum creatinine was not significantly different from baseline (186 +/- 65 micromol/L) to 4 h (185 +/- 62 micromol/L), 24 h (187 +/- 64 micromol/L) or 48 h (184 +/- 61 micromol/L) post NAC, nor were Cystatin C levels. Co-administration of cimetidine resulted in a significant rise in serum creatinine with no change in Cystatin C levels. CONCLUSION: This study failed to detect a change in serum creatinine or Cystatin C after a single dose of NAC in participants with stage 3 chronic kidney disease. Further randomized trials of multiple doses and longer follow up are needed to confirm these results.     

静脉高压对慢性静脉功能不全患者血小板活性的影响

目的 观察体位变化和压力对下肢慢性静脉功能不全(CVI)患者血小板活性的影响.方法 根据纳入和排除标准,选择24例CVI患者作为实验组和20例正常人作为对照组,采用酶联免疫吸附法(ELISA)测定两组人群在不同体位时下肢静脉血液、肘部静脉血液及在外在压力持续作用60 min后血小板P-选择素表达水平.结果 晨起平卧位及站立30 min后两组下肢静脉血液血小板P-选择素表达水平差异无统计学意义(P>0.05);在90～100mm Hg(1 mmHg=0.133 kPa)压力作用60 min后,CVI患者的下肢静脉血液和肘部静脉血液血小板P-选择素均明显高于对照组(P<0.01).结论 CVI患者血小板对压力具有高反应性,可能是CVI发病的重要机制之一.     

Effect of light exercise on renal hemodynamics in patients with hypertension and chronic renal disease

OBJECTIVE: Increased physical activity is followed by a stimulation of the sympathetic nervous system and this effect is probably more pronounced in patients with chronic renal failure and hypertension than in healthy controls. The role of sustained exercise in hypertensive patients with chronic renal failure, with and without antihypertensive therapy, is unclear, as is hormonal regulation of the renal hemodynamics. We hypothesized that prolonged low-intensity bicycle exercise would have a greater effect in patients with chronic renal failure than in controls, and that antihypertensive treatment would ameliorate these effects. MATERIAL AND METHODS: Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), mean arterial blood pressure (MAP), norepinephrine (NE) and atrial natriuretic peptide (ANP) were measured in the upright position before and during low-intensity exercise for 2 h in healthy controls (n = 8) and in hypertensive patients with moderately reduced renal function who were not taking antihypertensives (n = 7) or who were receiving treatment with captopril (n = 10), enalapril (n = 6) or verapamil (n = 9). RESULTS: GFR tended to decrease and ERPF decreased significantly in healthy individuals when exercise duration was prolonged from 1 to 2 h. An earlier decline in GFR and ERPF was seen in the renal failure patients compared with the controls. Filtration fraction (FF) increased during exercise in all groups except the group taking enalapril. MAP increased in the captopril group during exercise but was unchanged in the other groups. Treatment with captopril produced a more pronounced and earlier fall in exercise-induced GFR than in untreated controls, while verapamil treatment completely blunted the decline in GFR, with a concomitant increase in plasma ANP. No significant changes were seen in plasma NE levels, but urinary NE excretion increased in controls and captopril-treated patients during exercise. CONCLUSIONS: The results suggest that prolonged low-intensity exercise has a substantially greater effect on renal hemodynamics in hypertensive renal failure patients than in healthy controls, with negligible changes in plasma NE levels. Verapamil treatment seems to ameliorate the renal effects of exercise on GFR in these patients, and this may in part be mediated via a stimulatory effect on ANP.     

Effect of theophylline on exercise performance in patients with severe chronic obstructive pulmonary disease.

BACKGROUND--Theophylline is a well known bronchodilator which has been used for more than 50 years in the treatment of obstructive pulmonary diseases. In patients with severe chronic obstructive pulmonary disease whose cardiopulmonary performance is limited by their ventilatory capacity the administration of theophylline may improve exercise performance. METHODS--A randomised, placebo controlled, double blind, crossover trial was conducted in 22 patients with severe but stable disease. The patients (mean age 68 years) were studied before and after one month of placebo and one month of treatment with a sustained release preparation of theophylline administered orally. The theophylline dose was adjusted until a blood level above 55.5 mumol/l was achieved. The two treatments were administered in random order and separated by a two week washout period. After theophylline was administered for one month a mean level of 68.2 mumol/l was achieved. Pulmonary function tests, arterial blood gas measurements, maximal voluntary ventilation (MVV), and an incremental exercise test were performed before (baseline) and at the end of the first and second month of treatment. RESULTS--Pulmonary function tests showed no improvement in the flow parameters but showed an improvement in MVV after treatment with theophylline. Pulmonary gas exchange was improved after theophylline (resting arterial PO2 8.91 v 8.59 kPa, PCO2 5.38 v 5.56 kPa). The incremental exercise study showed improvement in maximal work rate (86.5 v 75.0 watts) and maximal ventilation (VEmax) (46.7 v 43.01/min). The dyspnoea index on maximal effort (VEmax/MVV), anaerobic threshold, and oxygen pulse remained unchanged. Resting and exercise heart rate were higher after theophylline. CONCLUSIONS--Theophylline improved cardiorespiratory performance in these patients with severe chronic obstructive pulmonary disease mainly by increasing the ventilatory capacity.     

Effect of oxygen on recovery from maximal exercise in patients with chronic obstructive pulmonary disease

BACKGROUND: The effects of oxygen on recovery from exercise in patients with chronic obstructive pulmonary disease (COPD) are not clearly known. A study was undertaken to determine whether oxygen given after maximal exercise reduced the degree of dynamic hyperinflation and so reduced the perception of breathlessness. METHODS: Eighteen patients with moderate to severe COPD performed maximal symptom limited exercise on a cycle ergometer. During recovery they received either air or oxygen at identical flow rates in a randomised, single blind, crossover design. Inspiratory capacity, breathing pattern data, dyspnoea intensity, and leg fatigue scores were collected at regular intervals during recovery. At a subsequent visit patients underwent a similar protocol but with a face mask in situ to eliminate the effects of instrumentation. RESULTS: When oxygen was given the time taken for resolution of dynamic hyperinflation was significantly shorter (mean difference between air and oxygen 6.61(1.65) minutes (95% CI 3.13 to 10.09), p = 0.001). Oxygen did not, however, reduce the perception of breathlessness during recovery nor did it affect the time taken to return to baseline dyspnoea scores in either the instrumented or non-instrumented state (mean difference 2.11 (1.41) minutes (95% CI -0.88 to 5.10), p = 0.15). CONCLUSIONS: Oxygen reduces the degree of dynamic hyperinflation during recovery from exercise but does not make patients feel less breathless than breathing air. This suggests that factors other than lung mechanics may be important during recovery from exercise, or it may reflect the cooling effect of both air and oxygen.     

Assessment of venous muscle pump function by ambulatory calf volume strain gauge plethysmography after surgical treatment of varicose veins: a prospective study of 21 patients

A prospective study of the improvement in leg muscle pump function after radical surgery was performed for treatment of varicose veins. Venous muscle pump function was assessed in 21 patients with primary varicose veins by means of ambulatory strain gauge plethysmography immediately before surgery and 3 months and 60 months after surgical treatment of varicose veins. The physiologic documentation of the operative efficacy was provided by the mean venous reflux, which was reduced by 54% (p less than 0.001), and the mean expelled volume, which was increased by 58% (p less than 0.001). Initially, all patients had improved venous muscle pump function. This improvement was still present 60 months after surgery. At clinical assessment 3 months after surgery, it was noted that 90% of the patients were without residual varicose veins (p less than 0.01). Sixty months after surgery, 71% of the patients were without apparent varicose veins (p less than 0.05). Subjective symptoms had virtually disappeared 3 months after surgery (p less than 0.001) but were found to a variable extent in 80% of the patients at the 60-month control follow-up. It is concluded that ambulatory strain gauge plethysmography may quantitate the effect of surgery in patients with venous valvular incompetence; in addition to measurements of refilling time, it is able to measure the muscle-pump-generated expelled volume because of in-place electrical calibration.     

Nocturnal saturation and respiratory muscle function in patients with chronic obstructive pulmonary disease.

BACKGROUND--Nocturnal desaturations, mainly caused by hypoventilation, occur frequently in patients with chronic obstructive pulmonary disease (COPD). Daytime arterial oxygen and carbon dioxide tensions (PaO2 and PaCO2) appear to predict which patients will desaturate at night. It is unknown if respiratory muscle strength, which may be decreased in these patients, plays an additional part. METHODS--Polysomnography, maximal respiratory pressures, lung function, and arterial blood gas tensions were measured in 34 patients with COPD (mean (SD) forced expiratory volume in one second (FEV1) 41.7 (19.9)% pred). RESULTS--Significant correlations were found between the mean nocturnal arterial oxygen saturation and maximal inspiratory mouth pressure (r = 0.65), maximal inspiratory transdiaphragmatic pressure (r = 0.53), FEV1 (r = 0.61), transfer coefficient (KCO) (r = 0.38), arterial oxygen saturation (SaO2) (r = 0.75), and PaCO2 (r = -0.44). Multiple regression analysis showed that 75% of the variance in nocturnal SaO2 (70%) and FEV1 (5%). CONCLUSION--Inspiratory muscle strength and nocturnal saturation data are correlated, but daytime SaO2 and FEV1 remain the most important predictors of nocturnal saturation.     

Effect of low dose nebulised morphine on exercise endurance in patients with chronic lung disease.

Low dose nebulised morphine may relieve dyspnoea through a direct effect on lung afferent nerves. To study this further 11 adult patients with advanced chronic lung disease (FEV1 range 0.4-1.41), whose exercise endurance was limited by dyspnoea, were entered into a double blind, randomised, crossover study in which low dose morphine or a placebo was inhaled. The effects were assessed by an endurance exercise test at 80% of maximum work load. One hour after a control endurance test patients inhaled 5 ml of morphine 1 mg/ml or isotonic saline for 12 minutes from a jet nebuliser. An endurance exercise test was repeated 15 minutes later and change in endurance time recorded. The two endurance tests were repeated on a separate day, before and after inhalation of the alternative solution. In all tests 100% oxygen was inhaled from a demand valve. The mean (SD) increase in endurance time was significantly greater after the subjects had inhaled morphine (64.6 (115) s, 35%) than after placebo (8.9 (55) s, 0.8%; p less than 0.01). The mean dose of morphine nebulised was 1.7 (0.66) mg, giving a mean inhaled dose of about 0.6 mg, on the assumption of 30% retention of the nebulised dose by each patient. No side effects were reported. Possibly small amounts of morphine delivered to the lungs act directly on lung afferent nerves to reduce dyspnoea.     

Successful iliac vein and inferior vena cava stenting ameliorates venous claudication and improves venous outflow, calf muscle pump function, and clinical status in post-thrombotic syndrome

OBJECTIVES: Stent therapy has been proposed as an effective treatment of chronic iliofemoral (I-F) and inferior vena cava (IVC) thrombosis. The purpose of this study was to determine the effects of technically successful stenting in consecutive patients with advanced CVD (CEAP3-6 +/- venous claudication) for chronic obliteration of the I-F (+/-IVC) trunks, on the venous hemodynamics of the limb, the walking capacity, and the clinical status of CVD. These patients had previously failed to improve with conservative treatment entailing compression and/or wound care for at least 12 months. METHODS: The presence of venous claudication was assessed by > or =3 independent examiners. The CEAP clinical classification was used to determine the severity of CVD. Outflow obstruction [Outflow Fraction at 1- and 4-second (OF1 and OF4) in %], venous reflux [Venous Filling Index (VFI) in mL/100 mL/s], calf muscle pump function [Ejection Fraction (EF) in %] and hypertension [Residual Venous Fraction (RVF) in %], were examined before and after successful venous stenting in 16 patients (23 limbs), 6 females, 10 males, median age 42 years; range, 31-77 yearas, left/right limbs 14/9, using strain gauge plethysmography; 7/16 of these had thrombosis extending to the IVC. Contralateral limbs to those stented without prior I-F +/- IVC thrombosis, nor infrainguinal clots on duplex, were used as control limbs (n = 9). Excluded were patients with stent occlusion or stenoses, peripheral arterial disease (ABI <1.0), symptomatic cardiac disease, unrelated causes of walking impairment, and malignancy. Preinterventional data (< or =30 days) were compared with those after endovascular therapy (8.4 months; interquartile range [IQR], 3-11.8 months). Nonparametric analysis was applied. RESULTS: Compared with the control group, limbs with I-F +/- IVC thrombosis before stenting had reduced venous outflow (OF4) and calf muscle pump function (EF), worse CEAP clinical class, and increased RVF (all, P < 0.05). At 8.4 months (IQR, 3-11.8 months) after successful I-F (+/-IVC) stenting, venous outflow (OF1, OF4) and calf muscle pump function (EF) had both improved (P < 0.001) and the RVF had decreased (P < 0.001), at the expense of venous reflux, which had increased further (increase of median VFI by 24%; P = 0.002); the CEAP status had also improved (P < 0.05) from a median class C3 (range, C3-C6; IQR, C3-C5) [distribution, C6: 6; C4: 4; C3: 13] before intervention to C2 (range, C2-C6; IQR, C2-C4.5) [distribution, C6: 1; C5: 5; C4: 4; C2: 13] after intervention. At this follow up (8.4 months median), venous outflow (OF1, OF4), calf muscle pump function (EF), and RVF of the stented limbs did not differ significantly from those of the control; significantly worse (P < 0.025) were the amount of venous reflux (VFI), and the CEAP clinical class, despite the improvement with stenting. Incapacitating venous claudication noted in 62.5% (10 of 16, 95% CI, 35.8%-89.1%) of patients (15 of 23 limbs; 65.2%, 95% CI, 44.2%-86.3%) before stenting was eliminated in all after stenting (P < 0.001). CONCLUSIONS: Successful I-F (+/-IVC) stenting in limbs with venous outflow obstruction and complicated CVD (C3-C6) ameliorates venous claudication, normalizes outflow, and enhances calf muscle pump function, compounded by a significant clinical improvement of CVD. The significant increase in the amount of venous reflux of the stented limbs indicates that elastic or inelastic compression support of the successfully stented limbs would be pivotal in preventing disease progression.     

Effects of regular salmeterol on lung function and exercise capacity in patients with chronic obstructive airways disease.

BACKGROUND: The aim of this study was to evaluate the effects of single and chronic dosing with salmeterol on exercise capacity and lung function in patients with chronic obstructive pulmonary disease. METHODS: Twenty nine patients of mean (SE) age 64 (1.5) years, forced expiratory volume in one second (FEV1) 42(3)% of predicted, and 5-15% reversibility to salbutamol 200 micrograms were randomised to receive four weeks treatment with salmeterol 50 micrograms twice daily or placebo in a double blind crossover fashion with a one week washout period in between. Measurements of spirometric parameters, static lung volumes, and exercise capacity were made one and six hours after a single dose, and six hours after the final dose of salmeterol or placebo. RESULTS: Salmeterol produced a small increase in FEV1 at one and six hours after a single dose, and this was maintained after chronic dosing (mean difference and 95% CI versus placebo): single dosing at one hour 0.07 (95% CI 0.02 to 0.11) 1, single dosing at six hours 0.16 (95% CI 0.09 to 0.22) 1, chronic dosing at six hours 0.11 (95% CI 0.03 to 0.19) 1. The increase in forced vital capacity (FVC) was greater with salmeterol than with placebo six hours after single but not chronic dosing: single dosing at six hours 0.17 (95% CI 0.04 to 0.29) 1, chronic dosing at six hours 0.02 (95% CI -0.18 to 0.22) 1. Slow vital capacity was increased after treatment with salmeterol compared with placebo one and six hours after single but not after chronic dosing. There were no significant differences in static lung volumes or exercise capacity after single or chronic dosing with salmeterol compared with placebo. Patients reported a significantly lower Borg score for perceived exertion following the six minute walk after chronic treatment with salmeterol compared with placebo. CONCLUSIONS: Salmeterol produced a small improvement in spirometric values compared with placebo consistent with the degree of reversibility originally shown by the subjects to salbutamol 200 micrograms. This was not associated with improvements in static lung volumes or exercise capacity, but there was some symptomatic benefit in that patients were able to walk the same distance in six minutes with less perceived exertion.