Lower Limb Blood Flow Research Articles

The acute effects of lower limb blood flow restriction on physiology and performance of competitive cyclists

Background: Training in conjunction with limb Blood flow restriction (BFR) is an increasingly popular method of producing increased physiological stress without the strain of high exercise loads. However little is known about the physiological responses to BFR with trained cyclists or how best to prescribe appropriate BFR training intensities. Purpose: In this study, we investigate the acute responses to different levels of BFR with trained cyclists to enable identification of specific training intensity criteria. Methods: Nine trained male cyclist (age 39.2 ± 8.1 years, height 179.1 ± 6.7 cm, weight 75.4 ± 6.7 kg, Max VO 2 4.4 ± 0.5 L.min -1 ) completed a series of tests under conditions of no BFR (N-BFR; 0mmHg), moderate BFR (M-BFR; ~40mmHg) or high BFR (H-BFR; ~80mmHg). During BFR trials restriction was applied to the proximal thighs using 11cm wide pneumatic cuffs. Testing consisted of an incremental maximal cycle test and a self-paced 3-km time-trial. Measurement of Oxygen uptake (VO 2 ), Muscle Oxygen saturation (MO 2 ) blood lactate concentration (Bla) and perceived exertion (RPE) were taken during the incremental test along with performance data from the time trial.  Physiological responses from the three trials were examined across a range of comparable power outputs and at pre-determined blood lactate concentrations of 2 and 4 Mmol. Results: At comparable power outputs, heart rate and RPE was significantly higher (p>0.05) in the H-BFR condition compared to all other conditions. However, there were no significant differences between conditions in VO 2 and MO 2 at equivalent powers. Compared to the N-BFR condition power output was lower by ~9% and ~21 % in the M-BFR and H-BFR condition respectively (fig 1) for fixed blood lactate concentration of 2 and 4mMol. Discussion: Using moderate and high levels of BFR during cycling exercise leads to substantial reductions (left shift) in power output at fixed blood lactate values. The reduced power was associated with increases in heart rate and RPE, at equivalent power outputs. However, measures of O 2 and MO 2 were not significantly different at comparable exercise intensities between the conditions. Conclusions: the decrease in attainable power output in BFR conditions appears predominately due to an increased reliance on anaerobic metabolism and an elevation in blood lactate concentration. Cardiovascular O2 delivery and extraction does not appear to be significantly affected by BFR. Â

Effects of Iliac Stenosis on Abdominal Aortic Aneurysm Formation in Mice and Humans

Reduced lower-limb blood flow has been shown to lead to asymmetrical abdominal aortic aneurysms (AAAs) but the mechanism of action is not fully understood. Therefore, small animal ultrasound (Vevo2100, FUJIFILM VisualSonics) was used to longitudinally study mice that underwent standard porcine pancreatic elastase (PPE) infusion (n = 5), and PPE infusion with modified 20% iliac artery stenosis in the left (n = 4) and right (n = 5) iliac arteries. Human AAA computed tomography images were obtained from patients with normal (n = 9) or stenosed left (n = 2), right (n = 1), and bilateral (n = 1) iliac arteries. We observed rapid early growth and rightward expansion (8/9 mice) in the modified PPE groups (p < 0.05), leading to slightly larger and asymmetric AAAs compared to the standard PPE group. Further examination showed a significant increase in TGFβ1 (p < 0.05) and cellular infiltration (p < 0.05) in the modified PPE group versus standard PPE mice. Congruent, yet variable, observations were made in human AAA patients with reduced iliac outflow compared to those with normal iliac outflow. Our results suggest that arterial stenosis at the time of aneurysm induction leads to faster AAA growth with aneurysm asymmetry and increased vascular inflammation after 8 weeks, indicating that moderate iliac stenosis may have upstream effects on AAA progression.

Use of a Muscle Pump Activator Leads to Improved Lower Limb Edema, Lower Limb Blood Flow, and Urine Output Compared With Standard TED Stockings and Compression Devices Following Kidney Transplant: A Randomized Controlled Trial

ObjectiveThe aim of this study was to evaluate the effects of using thromboembolic deterrent (TED) stockings and intermittent pneumatic compression (IPC) vs a muscle pump activator (MPA) device on limb edema and patient satisfaction after transplant. MethodsIn this single-center randomized controlled trial, 118 patients were randomly assigned to wear TED + IPC (n = 64) or the MPA device (n = 54) from postoperative days 1 to 6. We measured patients’ weight and lower leg and thigh circumferences daily. Ultrasonography of the allograft and lower limbs was carried out on postoperative days 1 and 5 to assess resistive index in the transplanted kidney and flow in the femoral vein. We monitored urine output and serum creatinine level. ResultsWe observed a significant increase in calf and thigh circumference from baseline in the TED + IPC group but not in the MPA group (2.3 [SD, 1] cm vs 0.25 [SD, 0.8] cm, respectively, P < .002). Ultrasonography showed higher femoral vein velocities in the MPA group than the TED + IPC group (0.5 [SD, 0.2] cm, P < .001). The mean total urine output in 6 days was higher in the MPA group than the TED + IPC group (P = .05), which corresponded to large change in TED + IPC weight of 6.2 kg vs 2.1 kg in the MPA group (P = .04). Patients were more satisfied with the use of the MPA device than TED + IPC. No major complications were encountered in either group. ConclusionsThis is the first study to show that the use of an MPA device in the immediate postoperative period following kidney transplant leads to decreased lower limb edema and increased total urine output. Patients were more satisfied with the use of the MPA device than TED + IPC.

Morphological and pharmacological characterization of the porcine popliteal artery: A novel model for study of lower limb arterial disease.

This study was undertaken to characterize structural and pharmacological properties of the pig popliteal artery in order to develop a novel system for the examination of lower limb blood flow regulation in a variety of cardiovascular pathologies, such as diabetes-induced peripheral artery disease. Popliteal arteries were isolated from streptozocin-induced diabetic pigs or age-matched saline-injected control pigs for morphological study using transmission electron microscopy and for examination of vasoreactivity to pharmacological agents using wire myography. Transmission electron microscopy of the porcine popliteal artery wall revealed the presence of endothelial cell-smooth muscle cell interactions (myoendothelial junctions) and smooth muscle cell-smooth muscle cell interactions, for which we have coined the term "myo-myo junctions." These myo-myo junctions were shown to feature plaques indicative of connexin expression. Further, the pig popliteal artery was highly responsive to a variety of vasoconstrictors including norepinephrine, phenylephrine, and U46619, and vasodilators including acetylcholine, adenosine 5'-[β-thio] diphosphate, and bradykinin. Finally, 2weeks after streptozocin-induced diabetes, the normalized vasoconstriction of the pig popliteal artery to norepinephrine was unaltered compared to control. The pig popliteal artery displays structural and pharmacological properties that might prove useful in future studies of diabetes-associated peripheral artery disease and other lower limb cardiovascular diseases.

VEGFR endocytosis regulates the angiogenesis in a mouse model of hindlimb ischemia.

The regulation of angiogenesis in the treatment of cardiovascular diseases has been widely studied and the vascular endothelial growth factor (VEGF) families and VEGF receptor (VEGFR) have been proven to be one of the key regulators. The VEGFR endocytosis has been recently proved to be involved in the regulation of angiogenesis. Our previous study showed that the upregulation of VEGFR endocytosis enhanced angiogenesis in vitro. In this research, we utilized mice with induced hindlimb ischemia, as a model to investigate the role of VEGFR endocytosis in the regulation of angiogenesis in vivo. Our goal was to observe the effect of revascularization with different degrees of VEGFR endocytosis after injecting atypical protein kinase C inhibitor (αPKCi) and dynasore, which could respectively promote and inhibit the VEGFR endocytosis. We induced the hindlimb ischemia in adult male mice by ligating the hindlimb artery. By directly injecting the ischemic muscles with endothelial progenitor cells (EPCs) alone or EPCs + αPKCi/EPCs + dynasore or control medium (sham group), we divided the mice into four groups and detected lower limb blood flow using a laser Doppler blood perfusion imager. We also measured the immunohistochemistry (IHC) of markers for angiogenesis, such as CD31 and alpha smooth muscle actin (α-SMA) in the ischemic hindlimb tissues. We demonstrated VEGFR endocytosis played an important role in the angiogenesis of the ischemic hindlimb model in vivo. By using atypical PKC inhibitor that increase the VEGFR endocytosis, the angiogenesis in the mice model was promoted. Treatment with EPCs + αPKCi showed greater effects on blood perfusion recovery and increased the α-SMA-positive vessels. The regulation of VEGFR endocytosis represents a valuable method of improving angiogenesis and thus revascularization in ischemic disease model.

Acute Limb Ischemia.

Acute limb ischemia (ALI) is a rapid decrease in lower limb blood flow due to acute occlusion of peripheral artery or bypass graft, and in ALI not only limbs but also life prognosis will be poor unless quick and appropriate treatment is given. The etiology is broadly divided into embolism and thrombosis with various comorbidities. The symptoms of ALI are abrupt with pain, numbness, and coldness of lower limb, and paresthesia, contracture, and irreversible purpura will appear with the exacerbation of ischemia. Severity and treatment strategy should be determined based on physical findings and image findings. Considering life prognosis, limb amputation should be done without hesitation when the limb was diagnosed as irreversible. ALI can be treated by means of open surgical revascularization, endovascular, or hybrid approach with rapid systemic administration of heparin. In any cases, evaluating the lesions by intraoperative angiography and appropriate additional treatment are important. ALI is a serious disease requiring urgent treatment, and it is essential to promptly perform the best initial treatment that can be performed at each facility. (This is a translation of Jpn J Vasc Surg 2018; 27: 109–114.)

Effect of progressive early bed exercise on blood flow in lower limb of patients on mechanical ventilation in intensive care unit

To investigate the effect of progressive early bed physical activity on blood flow in lower limb of patients on mechanical ventilation in intensive care unit (ICU). Adult patients with mechanical ventilation ≥ 72 hours admitted to ICU of the Affiliated Hospital of Zunyi Medical University from February 22nd to November 30th, 2016 were enrolled. The patients were randomly divided into experimental group and control group by random number table method. Patients in the two groups were given the same basic treatment, including antibiotics, analgesia and sedation, mechanical ventilation, nutritional support, and routine ICU activities such as maintaining functional position of limbs and raising of bed head. On the basis of those, the experimental group was given early bed physical activity with gradual enhancement of grades I-III according to the nerve, circulation and respiration situations, such as passive/active exercise of the bicycle, straight leg lifting exercise, etc. The exercise intensity was evaluated with target heart rate, and the exercise was performed for 15-30 minutes at a time, twice a day. The control group was given intermittent pneumatic compression (IPC), 30 minutes in each time, twice a day. Mean blood flow and blood volume were measured before and immediately, 5, 10 and 15 minutes after intervention on the 3rd day. Heart rate and blood pressure were measured at 5 minutes before intervention, during 5 minutes, and 5, 10, 15, 30 minutes after intervention on the 3rd day. 214 adult patients were selected, after excluding the patients who died during the intervention or gave up treatment, 160 patients were included in the data analysis, with 81 in the experimental group and 79 in the control group. The mean blood flow velocity and blood volume were increased in both groups, and the mean blood flow velocity and blood flow volume in the experimental group were significantly increased and lasted longer than those in the control group [mean blood flow velocity (mm/s) of the experimental group were 11.92±1.06, 18.19±0.17, 17.24±0.14, 15.48±0.12, 12.68±0.16, and that of the control group were 12.01±1.41, 15.65±0.18, 12.91±0.14, 12.13±0.12, 11.59±0.16, respectively, the time effect was F = 1 043.101, P = 0.000, the intervention effect was F = 151.001, P = 0.000, and the interaction effect between intervention and time was F = 224.830, P = 0.001; the blood volume (mL/min) of the experimental group were 3.39±0.96, 5.59±0.11, 5.16±0.12, 4.19±0.10. 3.35±0.09, and that of the control group were 3.28±0.82, 4.04±0.11, 3.40±0.12, 3.02±0.10, 3.00±0.10, respectively, the time effect was F = 680.405, P = 0.000, the intervention effect was F = 125.359, P = 0.000, and the interaction effect between intervention and time was F = 79.631, P = 0.012]. The heart rate and blood pressure of the two groups of patients in the course of intervention were increased first, then decreased and then slowly recovered to the change trend before intervention, but the index of the experimental group fluctuated greatly [heart rate (bpm) of the experimental group were 97.64±1.50, 113.91±1.36, 105.96±1.34, 98.52±1.48, 97.84±1.46, 97.54±1.48, and that of the control group were 97.03±1.57, 105.39±1.38, 96.76±1.35, 96.54±1.50, 97.22±1.48, 96.53±1.49, respectively, the time effect was F = 235.030, P = 0.000, the intervention effect was F = 39.473, P = 0.000, and the interaction effect between intervention and time was F = 3.494, P = 0.063; the systolic blood pressure (mmHg, 1 mmHg = 0.133 kPa) of the experimental group were 118.57±1.06, 133.05±1.01, 120.44±1.10, 117.78±1.07, 117.65±1.01, 118.14±1.00, and that of the control group were 118.10±1.08, 126.68±1.02, 118.23±1.11, 117.48±1.08, 118.04±1.03, 118.90±1.10, respectively, the time effect was F = 336.604, P = 0.000, the intervention effect was F = 26.350, P = 0.000, and the interaction effect between intervention and time was F = 0.948, P = 0.332; the diastolic blood pressure (mmHg) of the experimental group were 68.07±0.72, 72.79±0.73, 70.68±0.74, 69.30±0.72, 68.73±0.74, 67.80±0.73, and that of the control group were 68.51±0.73, 72.03±0.74, 70.05±0.75, 69.10±0.73, 68.41±0.75, 67.85±0.74, respectively, the time effect was F = 286.390, P = 0.000, the intervention effect was F = 4.812, P = 0.000, and the interactive effect between intervention and time was F = 0.055, P = 0.815]. The effects of progressive early bed physical activity on the mean blood flow velocity and blood volume of lower limbs in ICU patients with mechanical ventilation are better than those of IPC. Although the fluctuation of heart rate and blood pressure is large, it does not cause any harm to the patients.

Application of sequencing nursing based on Caprini Assessment Scale for DVT risk assessment in perioperative period of stroke patients

Objective To explore the risk grading of deep venous thrombosis (DVT) based on Caprini Assessment Scale and the application value of sequencing nursing according to the risk level in perioperative period of stroke patients. Methods A total of 136 stroke inpatients treated in Nanshi Hospital of Nanyang from January to December 2016 were selected as the control group, and given routine nursing of stroke and general prevention measures for DVT. Another 152 stroke inpatients admitted during January to December 2017 were selected as the observation group. The Caprini Assessment Scale was used for DVT risk classification, and the programmed countermeasure was taken. The nursing effects were compared between the two groups. Results The peak venous blood flow velocity, the mean blood flow velocity and the mean blood flow of affected lower limbs of the observation group were significantly higher than those of the control group after the intervention (P<0.05) . The incidence rates of lower limb swelling, skin color change of lower limbs and DVT in the observation group in perioperative period was 11.18%, 8.55% and 4.61% respectively, which were significantly lower than those in the control group (39.71%, 30.14% and 26.47%) , and the differences were statistically significant (P<0.001) . The hospitalization time of the observation group was significantly shorter than that of the control group, and the nursing satisfaction was obviously higher than that of the control group (P<0.01) . Conclusions The DVT risk classification based on Caprini Assessment Scale and programmed countermeasure can reduce the incidence of DVT, shorten the hospitalization time and improve the nursing satisfaction of stroke patients. Key words: Stroke; Venous thrombosis; Caprini assessment scale; Sequencing nursing

S2-3. Accessory effect of neuromodulation for movement disorder

The aim of Neuromodulation is the elimination of dysfunction or chronic discomfort related to neurological disorders by modulating the neural activity in specific parts of the central nervous system (Holsheimer, Neuromodulation 1(2) (1998) 57–61). Therefore, it is the treatable method for many symptom of various disease. Neuromodulation for movement disorder are DBS (Deep Brain Stimulation), ITB (Intrathecal Baclofen) and SCS (Spinal Cord Stimulation) commonly. Each of them improves not only motor dysfunction but also complicated symptoms. This accessory effects leads to further improvement of motor function. I will talk about following three cases in this symposium Improvement effect of DBS on sleep disorder of Parkinson’s disease SCS for intractable pain improves deep sensation, lower limb blood flow and mood disorder. Pain relief effect of ITB for CRPS. Recently, many pain physician have been discussing about central dysfunctional pain like CRPS. Chronic migraine is another well-known intractable disease attributable to the same mechanism with prevalence of 1.4–2.2% in Japan. Neuromodulation can possibly improve the activity of daily life of such patients. I will refer to Neuromodulation for headaches, mainly ONS (Occipital Nerve Stimulation).

Lower limb blood flow and mean arterial pressure during standing and seated work: Implications for workplace posture recommendations.

Sit-stand workstations are a popular workplace intervention. Organizations often require a medical professional's guidance for implementation. Therefore, it is important to understand potential negative outcomes associated with standing work, such as lower limb discomfort and peripheral vascular issues. The objective of this study was to compare changes in lower limb discomfort, blood pressure and blood flow accumulation during a light-load repetitive upper limb work task accomplished from seated and standing postures. At the Jewish Rehabilitation Hospital (Laval, Quebec, Canada), 16 participants were outfitted with Laser Doppler Flow (LDF) electrodes to measure blood flow in the lower limb, and a sphygmomanometer to measure lower limb mean arterial blood pressure (MAP). Participants completed simulated work over 34 min in standing and seated conditions. Repeated measures ANOVAs (Posture x Time) were used to assess the differences. There were significant effects for both Posture (p = 0.003) and Time (p = 0.007) for LDF-measured of blood flow accumulation in the soleus and the foot, with a mean increase of 77% blood flow over time in the standing posture, when compared to seated work. There was a significant ‘Posture × Time’ (p = 0.0034) interaction effect and a significant Posture (p = 0.0001) effect for MAP, with higher values in the standing posture by a mean of 37.2 mmHg. Posture had a significant effect (p < 0.001) on lower limb discomfort, with standing posture reporting higher levels. These results suggest that recommendations for using static standing work postures should be tempered, and physicians' guidance on workstation changes should consider the impacts on the lower limb.

Clinical and haemodynamic risk factors associated with discrepancies in lower limb length with capillary malformations: data from the national paediatric French cohort CONAPE.

Genetics discoveries have allowed for a better understanding of capillary malformations (CMs) associated with overgrowth syndrome. However, molecular analyses are still not easy to perform or interpret. Other analytical methods are needed. To identify clinical and haemodynamic factors associated with leg length discrepancy (LLD) in children with CMs of the lower limbs. Data were obtained from the multicentre French national cohort CONAPE (COhorte Nationale d'enfants atteints d'Angiome Plan de membrE inférieur), from children aged 2-12years old with CMs of the lower limbs. Clinical characteristics were prospectively collected. Haemodynamic factors were measured by an sonographer who calculated the arterial blood flow (ABF) in both lower limbs. An ABF difference ≥ 50% between the two lower limbs was considered relevant. LLD ≥ 2% was determined by the same radiologist on centralized radiographs. We analysed data at baseline for 96 children. The mean±SD age was 5·6±3·1years; 49 (51%) were male; and 14 (15%) showed LLD. In total, 32 patients (33%) had venous anomalies, 13 (14%) lymphatic anomalies and in one child a diagnosis of Parkes Weber syndrome was made. Only an increased circumference above the knee was more frequent with than without LLD (43% vs. 13%, P=0·02). In all, 10/79 patients (13%) showed a difference in ABF ≥ 50%: four had LLD. The frequency of differences in ABF ≥ 50% was greater with than without LLD [33% (n=4/12) vs. 9% (n=6/67), P=0·04]. ABF measured by Duplex ultrasonography is a simple, low-cost and noninvasive complementary examination for help in detecting LLD, with a difference of ≥ 50% possibly associated.

Combined Dietary Nitrate and Exercise Intervention in Peripheral Artery Disease: Protocol Rationale and Design.

BackgroundPeripheral artery disease (PAD) is caused by atherosclerotic occlusions in the legs. It affects approximately 8-12 million people in the United States alone, one-third of whom suffer from intermittent claudication (IC), defined as ischemic leg pain that occurs with walking and improves with rest. Patients with IC suffer a markedly impaired quality of life and a high perception of disability. Improving pain-free walking time is a primary goal of rehabilitation in this population.ObjectiveThe nitric oxide (NO)-PAD trial is designed to compare the effects that 12 weeks of supervised exercise training, in combination with a high inorganic nitrate-content (beetroot [BR] juice) beverage or placebo (PL) beverage, has on clinical outcomes of exercise and functional capacity in two groups of PAD+IC patients: exercise training plus beetroot (EX+BR) and exercise training plus placebo (EX+PL). The primary aims of this randomized controlled, double-blind pilot study are to determine group differences following 12 weeks of EX+BR versus EX+PL in the changes for (1) exercise capacity: pain-free walking time (claudication onset time, COT), peak walk time (PWT), and maximal exercise capacity (peak oxygen uptake, VO2peak) during a maximal-graded cardiopulmonary exercise test (max CPX) and (2) functional capacity: 6-minute walk (6MW) distance. The secondary aims will provide mechanistic insights into the exercise outcome measures and will include (1) gastrocnemius muscle oxygenation during exercise via near-infrared spectroscopy (NIRS); (2) gastrocnemius muscle angiogenesis: capillaries per unit area and per muscle fiber, and relative fraction of type I, IIa, IIb, and IId/x fibers; and (3) vascular health/function via brachial artery flow-mediated dilation, lower-limb blood flow via plethysmography, and pulse wave velocity and reflection.MethodsA total of 30 subjects between 40 and 80 years of age with PAD who are limited by IC will undergo exercise training 3 days per week for 12 weeks (ie, 36 sessions). They will be randomized to either the EX+BR or EX+PL group where participants will consume a beverage high in inorganic nitrate (4.2 mmol) or a low-nitrate placebo, respectively, 3 hours prior to each training session.ResultsData collection from this study has been completed and is in the process of analysis and write-up. While the study is too underpowered—EX+BR, n=11; EX+PL, n=13—to determine between-group differences in the primary outcomes of COT, PWT, and 6MW, preliminary observations are promising with Cohen d effect sizes of medium to large.ConclusionsExercise training is currently the most effective therapy to increase functional capacity in PAD+IC. If the addition of inorganic nitrate to an exercise regimen elicits greater benefits, it may redefine the current standard of care for PAD+IC.Trial RegistrationClinicalTrials.gov NCT01684930; https://clinicaltrials.gov/ct2/show/NCT01684930 (Archived by WebCite at http://www.webcitation.org/6raXFyEcP)

Effects of predictive phased intervention on preventing lower extremity deep venous thrombosis in ICU patients

Objective To evaluate the preventive effects of predictive phased intervention on lower extremity deep vein thrombosis in ICU patients. Methods A total of 82 cases of critically ill patients admitted to our hospital from June 2013 to June 2016 were divided into observation group and control group according to the random number table method, with 41 cases respectively. Patients in the observation group received predictive phased intervention, while patients in the control group received routine nursing intervention. After 4 weeks of intervention, the lower extremity deep venous thrombosis rate, lower limb perimeter and blood flow velocity of lower extremity venous were compared between two groups. Results The incidence of lower extremity deep venous thrombosis was 2.44% in the observation group and 19.51% in the control group. The difference between two groups was statistically significant (χ2=6.604, P<0.05) . After the intervention, the lower limb perimeter of patients in the observation group was (30.01±2.34) cm, which was significantly lower than that of the control group; the venous blood flow velocity of the lower extremity of patients in the observation group was (25.43±3.01) cm/s, which was significantly higher than that of the control group (t=2.285, 2.357; P<0.05) . Conclusions Predictive phased intervention has obvious advantages in the prevention of lower extremity deep venous thrombosis in ICU patients and it is worth clinical promotion. Key words: Venous thrombosis; Intensive care units; Predictive phased intervention; Lower limb perimeter

Способ восстановления магистрального артериального кровотока нижних конечностей

Способ восстановления магистрального артериального кровотока нижних конечностей

Influence of cold-water immersion on limb blood flow after resistance exercise

This study determined the influence of cold (8°C) and cool (22°C) water immersion on lower limb and cutaneous blood flow following resistance exercise. Twelve males completed 4 sets of 10-repetition maximum squat exercise and were then immersed, semi-reclined, into 8°C or 22°C water for 10-min, or rested in a seated position (control) in a randomized order on different days. Rectal and thigh skin temperature, muscle temperature, thigh and calf skin blood flow and superficial femoral artery blood flow were measured before and after immersion. Indices of vascular conductance were calculated (flux and blood flow/mean arterial pressure). The colder water reduced thigh skin temperature and deep muscle temperature to the greatest extent (P < .001). Reductions in rectal temperature were similar (0.2–0.4°C) in all three trials (P = .69). Femoral artery conductance was similar after immersion in both cooling conditions, with both conditions significantly lower (55%) than the control post-immersion (P < .01). Similarly, there was greater thigh and calf cutaneous vasoconstriction (40–50%) after immersion in both cooling conditions, relative to the control (P < .01), with no difference between cooling conditions. These findings suggest that cold and cool water similarly reduce femoral artery and cutaneous blood flow responses but not muscle temperature following resistance exercise.

Peripheral blood autologous CD34+ cell transplantation promotes angiogenesis in elderly patients with atherosclerotic ischemia: study protocol for a prospective, single-center, open-label, randomized, controlled, clinical trial

Background: The main clinical manifestation of senile arteriosclerosis obliterans is lower limb ischemia, which is currently difficult to treat. One method is autologous stem cell transplantation into the muscles of ischemic limbs to improve the formation of new capillaries and restore lower limb blood flow. Endothelial progenitor cell marker CD34+ cell transplantation has been shown to promote angiogenesis in ischemic limbs. Therefore, we propose that peripheral blood autologous CD34+ cell transplantation in older adult patients with atherosclerotic ischemia could effectively promote angiogenesis. Methods/Design: We propose to conduct a prospective, single-center, open-label, randomized, and controlled clinical trial at the Qingdao No. 9 People's Hospital, China. Twenty older adult patients with atherosclerotic lower limb ischemia will be randomized into two groups. In the cell transplantation group (n = 10), peripheral blood CD34+ cells transfected with vascular endothelial growth factor 165 (VEGF165) gene will be transplanted into the muscles of ischemic limbs in older adult patients with atherosclerotic lower limb ischemia. In the control group (n = 10), physiological saline will be injected into the muscles of ischemic limbs. Patients will be followed up for 6 months. The primary outcome will be ankle-brachial indices before and 6 months after transplantation to assess lower limb ischemia in both groups. The secondary outcomes will be the number of microvessels in the lower limb muscles before and 6 months after transplantation, the morphology of new blood vessels revealed by CT angiography, the number of VEGF-immunoreactive cells 6 months after transplantation and the incidence of adverse reactions. Discussion: This trial will begin in January 2018 and finish in December 2019. We aim to quantify the effects of VEGF165 gene-modified CD34+ cell transplantation in the treatment of older adult patients with atherosclerotic ischemia to develop a new effective treatment of lower limb ischemia. Trial registration: ClinicalTrials.gov identifier: NCT03098771. Ethics: The study protocol has been approved by the Ethics Committee of Qingdao No. 9 People's Hospital of China. All protocols will be in accordance with the Declaration of Helsinki, formulated by the World Medical Association. Informed consent: Written informed consent will be provided by participants.

Lower-limb hot-water immersion acutely induces beneficial hemodynamic and cardiovascular responses in peripheral arterial disease and healthy, elderly controls.

Passive heat induces beneficial perfusion profiles, provides substantive cardiovascular strain, and reduces blood pressure, thereby holding potential for healthy and cardiovascular disease populations. The aim of this study was to assess acute responses to passive heat via lower-limb, hot-water immersion in patients with peripheral arterial disease (PAD) and healthy, elderly controls. Eleven patients with PAD (age 71 ± 6 yr, 7 male, 4 female) and 10 controls (age 72 ± 7 yr, 8 male, 2 female) underwent hot-water immersion (30-min waist-level immersion in 42.1 ± 0.6°C water). Before, during, and following immersion, brachial and popliteal artery diameter, blood flow, and shear stress were assessed using duplex ultrasound. Lower-limb perfusion was measured also using venous occlusion plethysmography and near-infrared spectroscopy. During immersion, shear rate increased (P < 0.0001) comparably between groups in the popliteal artery (controls: +183 ± 26%; PAD: +258 ± 54%) and brachial artery (controls: +117 ± 24%; PAD: +107 ± 32%). Lower-limb blood flow increased significantly in both groups, as measured from duplex ultrasound (>200%), plethysmography (>100%), and spectroscopy, while central and peripheral pulse-wave velocity decreased in both groups. Mean arterial blood pressure was reduced by 22 ± 9 mmHg (main effect P < 0.0001, interaction P = 0.60) during immersion, and remained 7 ± 7 mmHg lower 3 h afterward. In PAD, popliteal shear profiles and claudication both compared favorably with those measured immediately following symptom-limited walking. A 30-min hot-water immersion is a practical means of delivering heat therapy to PAD patients and healthy, elderly individuals to induce appreciable systemic (chronotropic and blood pressure lowering) and hemodynamic (upper and lower-limb perfusion and shear rate increases) responses.

Ankle brachial index for the diagnosis of lower limb peripheral arterial disease.

Ankle brachial index for the diagnosis of lower limb peripheral arterial disease.

Effect of lower limb compression on blood flow and performance in elite wheelchair rugby athletes

Objective: To investigate the effects of compression socks worn during exercise on performance and physiological responses in elite wheelchair rugby athletes.Design: In a non-blinded randomized crossover design, participants completed two exercise trials (4 × 8 min bouts of submaximal exercise, each finishing with a timed maximal sprint) separated by 24 hr, with or without compression socks.Setting: National Sports Training Centre, Queensland, Australia.Participants: Ten national representative male wheelchair rugby athletes with cervical spinal cord injuries volunteered to participate.Interventions: Participants wore medical grade compression socks on both legs during the exercise task (COMP), and during the control trial no compression was worn (CON).Outcome Measures: The efficacy of the compression socks was determined by assessments of limb blood flow, core body temperature, heart rate, and ratings of perceived exertion, perceived thermal strain, and physical performance.Results: While no significant differences between conditions were observed for maximal sprint time, average lap time was better maintained in COMP compared to CON (P<0.05). Lower limb blood flow increased from pre- to post-exercise by the same magnitude in both conditions (COMP: 2.51 ± 2.34; CON: 2.20 ± 1.85 ml.100 ml.−1min−1), whereas there was a greater increase in upper limb blood flow pre- to post-exercise in COMP (10.77 ± 8.24 ml.100 ml.−1min−1) compared to CON (6.21 ± 5.73 ml.100 ml.−1min−1; P < 0.05).Conclusion: These findings indicate that compression socks worn during exercise is an effective intervention for maintaining submaximal performance during wheelchair exercise, and this performance benefit may be associated with an augmentation of upper limb blood flow.

间歇式压力充气泵预防下肢静脉血栓形成的研究现状

目的：了解抗血栓泵对预防下肢静脉血栓形成的作用，为临床护理实践和护理科研提供信息。方法：对比其他药物和物理方法预防下肢静脉血栓形成，抗血栓泵在预防下肢静脉血栓形成的安全性和医护心理接受程度更佳。结果：抗血栓泵模拟人体行走运动时腿部肌肉收缩，加快下肢血液流动，防止血液淤滞，从而减少了血栓的形成。从而达到预防深静脉血栓的目的。结论：间歇式压力充气泵是一种物理性非介入型的治疗仪器。它使用方法简单，减少了护士的工作量，病人也易于接受。 Objective: To investigate the effect of antithrombus pump on prevention of venous thrombosis of lower limbs, and to provide information for clinical nursing practice and nursing research. Methods: Compared with other drugs and physical methods to prevent venous thrombosis of lower limb, the antithrombus pump in the safety of the prevention of lower limb venous thrombosis and the psychological acceptance of health care is better. Result: Antithrombotic pump mimics human leg muscles’ contracting when walking, to speed up the lower limb blood flow, prevent blood silt up, thus reducing the formation of blood clots, so as to achieve the goal of prevention of deep vein thrombosis. Conclusion: The intermittent pressure air pump is a kind of physical nonintervention therapy apparatus. It is simple to use, reducing the workload of nurses, and is more acceptable to patients.