Pulse oximetry: a new tool to assess patients with leg ulcers

The objective of the study was to investigate pulse oximetry as a guide to assessing patients with leg ulcers before treatment. Graduated elastic compression is the treatment of choice for uncomplicated venous leg ulcers, but is contra-indicated in patients with significant arterial disease. The standard assessment of arterial insufficiency by Doppler ultrasound ankle branchial pressure index (ABPI) has shortcomings which prompted this investigation of pulse oximetry as a possible additional, or alternative, method of assessment of patients with leg ulcers, prior to treatment with compression. The study, carried out on a population of patients attending hospital leg ulcer clinics, was designed to evaluate pulse oximetry assessment in the selection and monitoring of patients with venous leg ulceration leading to a prospective controlled study of ulcer healing in groups of patients with reduced and normal ABPI, selected for compression therapy by pulse oximetry criteria. Outcome measurement required follow-up of patients selected for compression therapy by pulse oximetry to record time to healing and rate of healing of leg ulcers. Results from the study show a fair correlation between the toe-finger oximetry index (TFOI) and Doppler ABPI. There is no difference between ulcer healing in patients with reduced and normal ABPI selected for treatment on the basis of pulse oximetry maximum compression pressure (MCP). In conclusion, pulse oximetry is an aid to the selection of patients who will benefit from compression therapy, but would be excluded on the basis of Doppler ABPI.     

Management of mixed arterial and venous leg ulcers

BACKGROUND: The aim was to assess healing in patients with mixed arterial and venous leg ulcers after protocol-driven treatment in a specialist leg ulcer clinic. METHODS: The study included consecutive patients referred with leg ulceration and venous reflux over 6 years. Legs without arterial disease (ankle : brachial pressure index (ABPI) above 0.85) were treated with multilayer compression bandaging and patients with severe disease (ABPI 0.5 or less) were considered for immediate revascularization. Those with moderate arterial compromise (ABPI above 0.5 up to 0.85) were initially managed with supervised modified compression and considered for revascularization if their ulcer did not heal. Healing rates were determined using life-table analysis. RESULTS: Of 2011 ulcerated legs, 1416 (70.4 per cent) had venous reflux. Of these 1416, 193 (13.6 per cent) had moderate and 31 (2.2 per cent) had severe arterial disease. Healing rates by 36 weeks were 87, 68 and 53 per cent for legs with insignificant, moderate and severe arterial disease respectively (P < 0.001). Seventeen legs with moderate and 15 with severe arterial disease were revascularized. Of these, ulcers healed in four legs with moderate and seven with severe disease within 36 weeks of revascularization (P = 0.270). Combined 30-day mortality for revascularization was 6.5 per cent. CONCLUSION: A protocol including supervised modified compression and selective revascularization achieved good healing rates for mixed arterial and venous leg ulceration.     

The validity, reliability, reproducibility and extended utility of ankle to brachial pressure index in current vascular surgical practice.

BACKGROUND: Despite the increasing sophistication of vascular surgical practice, more than three decades after its introduction to clinical practice, the ankle to brachial pressure index (ABPI) remains the cornerstone of non-invasive assessment of the patient with symptomatic peripheral arterial disease (PAD). AIM: To summarise what is known about ABPI and critically appraise its validity, reliability, reproducibility and extended utility. METHODS: A MEDLINE (1966-2004) and Cochrane library search for articles relating to measurement of ABPI was undertaken; see text for further details. RESULTS: There is considerable disagreement as to how ABPI should be measured. Furthermore, various factors, including the type of equipment used, and the experience of the operator, can result in significant inter- and intra-observer error. As such, care must be taken when interpreting data in the literature. ABPI is valuable in the assessment of patients with atypical symptoms, venous leg ulcers and after vascular and endovascular interventions. However, absolute pressures are probably more valuable in patients with critical limb ischaemia. ABPI is also useful in subjects with asymptomatic PAD where it correlates well with, and may be used in screening studies to quantify, cardiovascular risk. CONCLUSIONS: While its apparent simplicity can beguile the unwary, ABPI will continue to have a key role in the assessment of symptomatic PAD. ABPI is also likely to have extended utility in health screening and institution of best medical therapy in asymptomatic subjects.     

Deep venous thrombosis in peripheral vascular disease.

BACKGROUND: This prospective study aimed to determine the prevalence of lower limb deep venous thrombosis in patients with peripheral vascular disease (PVD). METHODS: Some 136 patients admitted for arteriography, angioplasty or arterial reconstruction with limiting claudication (n = 72), ischaemic rest pain (n = 26) or gangrene (n = 38) and 40 control subjects admitted for general surgical procedures but without evidence of PVD were screened with colour duplex ultrasonography for the presence of venous thrombosis in the lower limb deep veins before any surgical or radiological procedures were undertaken. Patient age, the ankle : brachial pressure index (ABPI) and the presence of other risk factors for venous thromboembolism were also recorded. RESULTS: Venous thrombosis was found in 27 of 136 patients with PVD and two of 40 control patients (P = 0.03). Logistic regression analysis demonstrated that decreasing ABPI independently contributed to an increased risk of deep venous thrombosis. CONCLUSION: There was a high prevalence of venous thrombosis among patients with PVD which was related to the severity of the ischaemia. Presented to the South West Vascular Surgeons Meeting in Newport, UK, March 1998     

When is reduced-compression bandaging safe and effective?

During a one-year period 44 patients were treated with reduced-compression bandaging in the vascular unit at a district general hospital. Twenty patients with venous ulcers were referred from community leg ulcer clinics because they could not tolerate standard compression bandaging (group 1). A further 24 patients had mixed aetiology leg ulcers (group 2), and high-compression bandaging was not attempted because of significant peripheral vascular disease (ankle brachial pressure index < 0.8). Forty-two patients tolerated reduced-compression bandaging without discomfort or skin pressure changes. Healing was achieved in 32 patients (13 in group 1 and 19 in group 2). All non-healed ulcers were considered smaller at the time of final follow-up, and had less exudate. Reduced-compression bandaging has been shown to be effective and well tolerated by patients with venous ulcers who cannot comply with high-compression bandaging. With close supervision, it is safe to use in patients with significant peripheral vascular disease.     

Effect of total knee arthroplasty on blood flow to the lower limb: a prospective clinical study and review of literature

Ischemic complications after total knee arthroplasty (TKA) are rare. There is a reported association with chronic lower extremity ischemia (CLEI), however. This prospective study examined changes in blood pressure in the lower limb during the early postoperative period. Arterial blood pressure was assessed before and after TKA by the ankle brachial pressure index (ABPI) using Doppler ultrasonography. Seven patients with CLEI (ABPI <0.9) and 33 patients with normal vascular status (ABPI >0.9) were studied. An ABPI of 0.65, correction of minor knee deformity, and a tourniquet time of 2 hours did not alter arterial blood pressure. TKA does not affect the distal arterial blood pressure in the lower limb in normal and CLEI-affected limbs in the immediate postoperative period.     

Coiling of the Right External Iliac Artery with Atherosclerotic Plaque as a Cause of Ischemic Ulcer on the Toe: Report of a Case

Coiling of the artery is a rare morphologic entity, most frequently found in the internal carotid arteries. Coiling of other arteries is rarely reported because it is usually asymptomatic. We report a case of 360° coiling of the right external iliac artery found by color duplex scan and arteriography. The patient was a 72-year-old man who presented with a 2-month history of an ischemic ulcer on his right toe and a right ankle-brachial-pressure index (ABPI) of 0.0 and 0.4 on admission. We resected 7 cm of the affected artery and performed end-to-end reconstruction. After 2 months of follow-up, his ischemic ulcer had healed and the ABPI of the right foot was 0.0 and 0.8.     

Modified compression therapy in mixed arterial–venous leg ulcers: An integrative review

Leg ulcers remain an increased burden to healthcare cost and morbidity in modern society. While most leg ulcers are venous in origin, recognition and prompt identification of concomitant arterial occlusive disease is critical to determine underlying aetiology and subsequent management. This integrative review presents the current evidence to establish the role of modified compression therapy (MCT) in treatment of mixed arterial venous leg ulcers (MAVLU). A literature search was conducted using the electronic databases CINAHL, MEDLINE, PUBMED, and Embase. Ten studies met the eligibility criteria and were subsequently analysed. Our review concludes that MCT, with compression pressures between 20 and 30 mmHg, can promote healing in MAVLU with moderate arterial insufficiency (0.5 ≤ ABPI ≤0.8). If ABPI is <0.5, MCT can be considered once restoration of acceptable ABPI is achieved. Intolerance, lack of response or further deterioration of disease within 3 months should prompt further arterial imaging and intervention. MCT is generally well tolerated with no adverse outcomes reported. A holistic yet individualised approach is vital in order to account for all factors influencing this patient‐led decision‐making process, ultimately ensuring effective treatment, which improves patient''s quality of life and reduces socioeconomic burden of the disease.     

Ankle-brachial index and mortality in a cohort of questionnaire recorded leg pain on walking.

OBJECTIVE: To study the association between the ankle-brachial pressure index (ABPI), premature death and the need for surgical treatment for lower limb ischaemia. DESIGN: Population based cohort study. SUBJECTS: Three hundred and fifty-three men and women, 50-89 years old, underwent a leg pain questionnaire and measurement of ABPI and was then followed for 10 years. OUTCOME MEASURES: All cause mortality, vascular procedures and major amputations. RESULTS: A low ABPI was independently associated with premature all cause mortality in the multiple regression analysis, carrying a relative risk of 3.4 (95% confidence interval 2.0-5.9) and 2.1 (1.3-3.3) for ABPIs or=1.0. Individuals with an ABPI in the interval 0.81-0.99 suffered only a slight, not statistically significant risk increase compared to normals. A low ABPI at baseline implied a continuous constant increased risk of death throughout the study period. The same risk was observed among elderly (70-89, median 77 years), and in the middle aged (50-69, median 63 years) individuals. The vast majority of those subjected to vascular intervention or major amputation during follow-up had an ABPI相似文献   

The influence of experience on the reproducibility of the ankle-brachial systolic pressure ratio in peripheral arterial occlusive disease.

OBJECTIVES: to estimate the intra-observer variability of the measurement of the ankle-brachial systolic pressure index (ABPI) and to compare the reproducibility of the measurements by experienced vascular laboratory assistants and by less-experienced general practice personnel. DESIGN: repeated measurement of ABPI by general practitioners (GPs), GP-assistants and vascular laboratory assistants using a pocket Doppler device and a random-zero sphygmomanometer. METHODS AND MATERIALS: ABPI was measured in six patients with various degrees of PAOD by two experienced observers (vascular laboratory assistants) and by 24 less-experienced observers (18 practice assistants, six GPs). RESULTS: the total number of measurements was 354. The overall intra-observer variability estimate was 11.8% ABPI. The intra-observer variability was 7.3% in the experienced observers and 12.0% in the less-experienced observers. The difference of variability between experienced and less-experienced observers was significant. CONCLUSIONS: the ABPI is suitable in follow-up studies where repeated measurements are needed. Differences between measurements can be minimised by performing repeated measurements or by using more experienced observers.     

Variation of method for measurement of brachial artery pressure significantly affects ankle-brachial pressure index values.

BACKGROUND: Mmeasurement of ankle brachial pressure indices (ABPI) is important in the assessment of patients with peripheral vascular disease. METHODS: Thirty-one hospitals with a vascular surgeon were selected at random. A telephone questionnaire was completed to assess the method used for the measurement of ABPI. Following the survey, 14 patients with peripheral vascular disease had their ABPI measurement done by two observers, a pre-registration house officer and a clinical nurse practitioner. Observers were blinded to their own and each other's results. Brachial systolic pressures were obtained using a DINAMAP(TM)(Critikon, Tampa, U.S.A.) automated blood pressure monitor, the Korotkoff method (12 cm cuff, parallel wrap) and an 8 MHz Doppler probe (Huntleigh) and sphygmomanometer. Ankle systolic pressures were obtained using the Doppler probe. The results were analysed using the Wilcoxon signed rank test. RESULTS: The survey demonstrated that at the majority of centres with vascular laboratories the brachial artery systolic pressures were measured using a Doppler probe. In contrast, at centres where the house officers performed the routine measurements, over 60% used the Korotkoff method to obtain this reading. One in four nurse practitioners used the Korotkoff method. When the ABPI values were calculated, the DINAMAP produced significantly higher median values than the Korotkoff (0.79 vs 0.72, p=0.003) and Doppler methods (0.79 vs 0.70, p<0.0001). The nurse had a higher median ABPI value of 0.76 compared with the doctor (0.71, p=0.01). CONCLUSION: This study shows that measurement of ABPI varies in different vascular units. The technique for ABPI measurement should be standardised.     

Chronic ulceration of the leg

The management of patients with chronic leg ulcers represents an enormous burden to healthcare services in the United Kingdom. Most leg ulcers are due to chronic venous hypertension, although arterial compromise, malignancy, vasculitis and other medical disorders are also recognized causes. The assessment of patients with chronic leg ulceration should include a detailed history and clinical examination, supported by relevant investigations. Ankle-brachial pressure index measurement and non-invasive venous (± arterial) imaging using colour duplex are the principal investigations. The mainstay of treatment for patients with chronic venous ulceration is compression therapy, applied by trained clinical teams bridging primary and secondary care settings. Prompt endovenous ablation of superficial venous reflux accelerates ulcer venous healing and may have an important role in reducing ulcer recurrence. Patients with arterial compromise may require endovascular or surgical revascularization to promote healing. The causes, assessment and management of patients with chronic leg ulceration are discussed in this article.     

Digital photoplethysmography in the diagnosis of suspected lower limb DVT: is it useful?

OBJECTIVE: to determine the role of digital photoplethysmography (D-PPG) in the diagnosis of deep-vein thrombosis (DVT), in comparison to the "gold standard" of either contrast ascending venography (ACV) or colour-flow duplex imaging (CFDI). METHOD: prospective study of 100 hospital inpatients (103 legs) referred to the X-ray department for ACV or CFDI with clinically suspected lower limb DVT in a district general hospital. Each patient was assessed by either ACV or CFDI, and D-PPG. RESULTS: thirty-seven limbs were found to have DVT as demonstrated by ACV or CFDI. All patients with a venous refilling time (RT) of greater than 20 s and venous pump (VP) of greater than 35 had a normal ACV or CFDI. Using RT of less than 21 s as the optimal cut-off point, D-PPG achieved a sensitivity of 100%, negative-predictive value of 100%, specificity of 47% and positive-predictive value of 51%. By using VP of less than 36 as the optimal cut-off point, a sensitivity of 100%, a negative-predictive value of 100%, a specificity of 35% and positive-predictive value of 46% were achieved. CONCLUSIONS: these results validate the use of portable D-PPG as a useful screening tool for the diagnosis of clinically suspected lower limb DVT. A positive test requires further confirmation by one of the "gold standard" methods, whereas a negative test effectively excludes DVT.     

Vascular pressure monitorization for necessity of vascular augmentation in a rat extended abdominal perforator flap model

In case blood perfusion compromises, vascular enhancement with arterial supercharge or venous superdrainage can increase viability of the flap. In this study, vascular pressure monitorization was used in a rat extended abdominal perforator flap model to reveal intraoperative vascular compromise and the need for vascular augmentation. A rat abdominal perforator flap was designed, which was based on the right second cranial perforator of epigastric artery. Vascular pressures of the flap were monitored continuously for 60 min, by catheters placed in the right superficial inferior epigastric artery and vein. Forty rats were divided into four experimental groups, as follows: group 1 (n = 10, no vascular augmentation), group II (n = 10, arterial supercharge), group III (n = 10, venous superdrainage), and group IV (n = 10, arterial and venous augmentation). Arterial supercharge and/or venous superdrainage were performed by using the left superficial inferior epigastric artery and vein. After the rats were sacrificed on the 7th day, total flap area and necrotic regions were evaluated. Mean arterial blood pressure was found significantly lower (P < 0.05) and mean venous blood pressure was measured significantly higher (P < 0.05) in group I than the groups II, III, and IV. Flap survival area was also larger in the groups II, III, and IV than the group I (P < 0.05). The results of this experimental study demonstrate that arterial insufficiency and venous congestion are almost always present in the rat extended abdominal perforator flap model, similar to deep inferior epigastric perforator flap. When such an extended perforator flap is used, arterial and venous pressure monitorization may be considered as a tool to support intraoperative clinical findings to reveal the need of vascular augmentation and ascertain flap viability.     

Chronic ulceration of the leg

The assessment and treatment of patients with chronic leg ulcers represents an enormous clinical and financial burden to community and secondary care services in the United Kingdom. Most leg ulcers are due to chronic venous hypertension, although arterial compromise, malignancy and vasculitis are also recognized causes. The assessment of patients with chronic leg ulceration should include a detailed history and clinical examination, supported by relevant investigations. Ankle brachial pressure index measurement and non-invasive venous (±arterial) imaging using colour duplex are the principal investigations. The mainstay of treatment for patients with chronic venous ulceration is multilayer compression bandaging, applied by trained staff working within a specialist service bridging primary and secondary care settings. Endovenous treatment of superficial venous reflux may also play an important role in improving outcomes. Patients with arterial compromise may require endovascular or surgical revascularization to promote healing. In this article, the causes, assessment and management of patients with chronic leg ulceration are discussed.     

Variation in measurement of ankle-brachial pressure index in routine clinical practice

Purpose: The purpose of this study was to determine the variation in ankle-brachial pressure index (ABPI) measurements in routine clinical practice.Methods: Analysis was done of preoperative and postoperative ABPIs in 130 limbs contralateral to those undergoing femoral bypass grafting in 123 patients over a 15-month period.Results: The mean initial ABPI was 0.72 (range 0.22 to 1.10). The range of observed differences between the preoperative and postoperative ABPIs was from -0.33 to +0.25. The mean (±SD) difference between the first and second ABPIs was 0.00 (±0.11). The 95% confidence limits of the difference were -0.21 to 0.21. There was no trend for the size or direction of the difference in ABPI to vary according to the mean ABPI, brachial blood pressure, or time between tests.Conclusions: ABPI is routinely used as an objective measure of peripheral vascular disease. The variation observed in this study is comparable with values obtained in reproducibility studies and is greater than that accepted in clinical practice. The difference between an ABPI measurement and the actual ABPI and the difference between repeat single measurements are not the same and should be distinguished. Vascular laboratories should determine the accuracy of ABPI measurement on a local basis to guarantee and maintain quality assurance. (J Vasc Surg 1996;24:871-5.)     

Vascular occlusion techniques during liver resection

Control of bleeding from the transected liver basically consists of vascular inflow occlusion and control of hepatic venous backflow from the caval vein. Central venous pressure determines the pressure in the hepatic veins and is an extremely important factor in controlling blood loss through venous backflow. Vascular inflow occlusion (Pringle maneuver) involves clamping of the portal vein and the hepatic artery in the hepatic pedicle and gives rise to postischemic, reperfusion injury. Several strategies have been devised to reduce reperfusion injury (pharmacological interventions) or to increase ischemic tolerance of the liver (ischemic preconditioning). Intermittent clamping is recommended in complex liver resections or in patients with diseased livers. The combination of occlusion of vascular inflow and outflow of the liver results in total hepatic vascular exclusion (THVE) and is mainly used in tumors invading the caval vein. During THVE the liver can be cooled by hypothermic perfusion allowing for extended ischemia times. Selective THVE entails clamping of the main hepatic veins in their extrahepatic course, thus preserving caval flow. Safe liver surgery requires knowledge of the regular techniques of vascular occlusion for 'on demand' use when necessitated to reduce blood loss.     

Salvage of a severely ischemic limb by arteriovenous revascularization: a case report

Severe ischemia in a limb that cannot be revascularized almost inevitably leads to gangrene and eventual amputation. For decades, surgeons have considered utilizing the venous system to revascularize ischemic tissue in numerous areas, including the lower limb, but with very limited success. This report documents the successful revascularization of a severely ischemic pregangrenous limb with a bypass graft from the femoral artery to a tibial vein. The authors believe this is the first clinical report of salvage of an ischemic limb by this approach.     

Interobserver and intraobserver reproducibility of peripheral blood and oxygen pressure measurements in the assessment of lower extremity arterial disease

INTRODUCTION: Peripheral blood pressure measurements play a prominent role in the diagnosis and follow-up of patients with peripheral vascular diseases. Toe pressure of the hallux (TP1) and second toe (TP2) and transcutaneous oxygen pressure (TCPO2) measurements are becoming more important. The ankle/brachial pressure index (ABPI) is known to be a reliable parameter, but the toe pressure and TCPO2 are evaluated less thoroughly. Therefore, we evaluated the reproducibility of TP1, TP2, TCPO2, ABPI, ankle pressure (AP), and brachial pressure (BP). PATIENTS AND METHODS: In 54 patients with various stages of peripheral vascular disease, the intraobserver and interobserver reproducibility of BP, AP, ABPI, TP1, TP2, and TCPO2 was investigated by calculating the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC) and by using Bland-Altman plots. RESULTS: The intraobserver and interobserver reproducibility at 1 day and after 1 week of BP, AP, ABPI, and TP1 was substantial and comparable (ICC range, 0.80-0.99), except for the BP after 1 week. The TP2 and TCPO2 were less reproducible (ICC range, 0.62-0.98). The interobserver RC of BP was 31 mm Hg; of AP, 44 mm Hg; of ABPI, 27%; of TP1, 41 mm Hg; of TP2, 67 mm Hg; and of TCPO2; 30 mm Hg. The difference plot showed that the observer variability was equally distributed across the range of pressure in all measurements. CONCLUSION: The BP, AP, ABPI, and TP1 have a substantial intraobserver and interobserver reproducibility, whereas TP2 and TCPO2 show worse reproducibility. Especially when low values (or values around a cutoff value) are measured, the RC should be taken into account, and repetition of the measurement is advocated.     

Pathophysiology, diagnosis, and laboratoy examination in critical limb ischemia

The term critical limb ischemia (CLI) is defined as chronic ischemic pain at rest, ulcers, or gangrene lasting more than 2 weeks attributable to objectively confirmed occlusive arterial disease. Patients with ischemic pain at rest generally have ankle pressure (AP) of less than 50 mmHg or toe pressure (TP) of less than 30 mmHg, while patients with ulcers or gangrene usually have AP of less than 70 mmHg or TP of less than 50 mmHg. Healing requires an inflammatory response and additional perfusion above that required for supporting intact skin and underlying tissues. The AP and TP levels needed for healing are, therefore, higher than the pressures found in ischemic pain at rest. A combination of blood-flow reduction due to multisegmental lesions of the proximal artery and blood-flow imbalance in the local tissue lead to CLI. It is important to evaluate not only the macroscopic blood flow but also the microcirculation to understand the pathophysiology of CLI. Transcutaneous oxygen tension measurement (critical level <30 mmHg) and skin perfusion pressure measurement (critical level < 30 mmHg) are useful methods to evaluate the microcirculation.