Peripheral artery disease in patients with schizophrenia as compared to controls.

BACKGROUND: Patients with schizophrenia have an increased prevalence of risk factors for peripheral artery disease (PAD) and is expected to have an increased prevalence of PAD. PAD can be detected utilizing toe-brachial index (TBI) which screens for vascular pathology proximal to the toes. METHODS: Using a cross-sectional design, we defined the subpopulations: (1) Patients diagnosed with schizophrenia less than 2 years before inclusion (SCZ < 2), (2) Psychiatric healthy controls matched to subpopulation 1 on sex, age, and smoking status, and (3) Patients diagnosed with schizophrenia 10 or more years before inclusion (SCZ ≥ 10). TBI was calculated by dividing toe pressures by systolic brachial blood pressure, and PAD was defined by TBI < 0.70. Logistic regression analysis with PAD as outcome and sex, age, smoking status, BMI, skin temperature, diagnosis of schizophrenia, and comorbidities as explanatory variables was conducted. RESULTS: PAD was present in 26.2% of patients diagnosed with SCZ < 2 (17 of 65) and in 18.5% of psychiatric healthy controls (12 of 65) with no statistically significant difference in prevalence rates (p = 0.29). PAD was present in 22.0% of patients diagnosed with SCZ ≥ 10 (31 of 141). In logistic regression, patients diagnosed with SCZ < 2 had an increased odds of PAD with psychiatric healthy controls as reference (Odds ratio = 2.80, 95% confidence interval 1.09-7.23, p = 0.03). The analysis was adjusted for age, sex, smoking status, BMI and comorbidities such as hypertension, diabetes and heart disease. CONCLUSIONS: This study did not find statistically significant increased prevalence rates of PAD in patients with schizophrenia even though patients with SCZ were compared to psychiatric healthy controls using TBI. Utilizing logistic regression PAD was associated with schizophrenia diagnosis within the last 2 years, age and skin temperature. As PAD is initially asymptomatic, screening could be relevant in patients with schizophrenia if other risk factors are prevalent. Further large-scale multicenter studies are warranted to investigate schizophrenia as a potential risk factor for PAD. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02885792.

Normal Splanchnic Blood Flow in a Patient with Severe Stenosis of the Celiac Artery and Superior Mesenteric Artery.

The diagnosis of chronic mesenteric ischaemia is typically based on angiographic findings along with a classic symptomatology. Only a few methods are available for functional testing to establish the diagnosis, such as indirect measurement of the splanchnic blood flow and hepatic vein oxygenation. The present case is a 76-year-old woman with weight loss and intermittent abdominal pain who was clinically suspected of chronic mesenteric ischaemia based on severe stenosis of the celiac artery and superior mesenteric artery. Measurement of the total splanchnic blood flow and hepatic vein oxygenation, however, showed a normal perfusion after meal stimulation, as well as an increased hepatic vein oxygenation, indicating normal flow reserves. This was likely due to a richly developed Riolan's anastomosis arising from the inferior mesenteric artery. The present case advocates the need for functional testing when diagnosing chronic mesenteric ischaemia.

The Laparoscopic Implantation of Neuroprosthesis Procedure Increases Leg Lean Mass in Individuals With Paraplegia Due To Traumatic Spinal Cord Injury.

OBJECTIVES: We hypothesized that the laparoscopic implantation of neuroprosthesis (LION) procedure would significantly alter the body composition of patients with chronic traumatic spinal cord injury (SCI). The objectives were to determine the effect of the LION procedure on lean mass (LM), fatty mass (FM), and bone mineral content (BMC) in patients with SCI. MATERIALS AND METHODS: Five consecutive patients underwent dual-energy x-ray absorptiometry scans before the LION procedure and at the one-year postoperative follow-up to determine changes in LM, FM, and BMC. Student paired t-test was used to determine significance. RESULTS: The patients gained 2506 ± 565 g of LM in the legs (p < 0.001), which was an 18% total increase in leg LM. Total body LM was significantly increased by 3523 ± 1048 g (p < 0.003). FM was unaffected, whereas total BMC showed a small but significant increase of 99 ± 42 g (p = 0.009). CONCLUSIONS: The LION procedure and subsequent neurostimulation procedures resulted in substantial increases in leg LM in patients with chronic traumatic SCI and paraplegia. A possible incremental effect on total BMC also was observed. Further studies are needed to confirm and expand these promising results.

Improvement of the splanchnic blood flow and hepatic vein oxygenation following revascularization in patients with chronic mesenteric ischaemia.

OBJECTIVES: Chronic mesenteric ischaemia (CMI) is an underdiagnosed but severe condition. Access to functional testing is often limited and the diagnosis is usually based primarily on symptoms and imaging. One of the functional tests available is measurement of the splanchnic blood flow (SBF). The purpose of the present investigation was to evaluate if changes in the splanchnic perfusion after revascularization can be detected by measuring the SBF and hepatic vein oxygenation. MATERIALS AND METHODS: The SBF was measured in 10 patients before and after revascularization of the mesenteric arteries by either percutaneous transluminal angioplasty (n = 9) or open revascularization (n = 1). The SBF was measured indirectly using Fick's principle and using the tracer Tc-99m Mebrofenin along with assessment of hepatic blood oxygenation, before and after a standard meal, following catheterization of a hepatic vein and the femoral artery. RESULTS: Nine of 10 patients (90%) achieved a profound increase in SBF after revascularization (mean increase in postprandial response to meal stimulation from 71 ± 95 to 531 ± 295 ml/min, p = 0.001), and an increase in postprandial hepatic vein oxygen saturation (from 52 ± 14% to 59 ± 13%, p = 0.006). The symptoms of the patients diminished accordingly. One patient had no symptom relief, and no increase in postprandial SBF, but an angiographic result with no significant stenosis postrevascularization. CONCLUSIONS: Revascularization increased the SBF and hepatic vein oxygen saturation significantly concurrent with symptom relief and according with the angiographic successful result in the vast majority of patients. A satisfying angiographic result post vascular intervention does not rule out CMI.

Evaluation of a novel probe based on laser Doppler flowmetry and comparison with photo plethysmography for assessment of the skin perfusion pressure.

This study aims to compare skin perfusion pressure measurements (SPP) at midfoot and below knee level performed with a novel laser Doppler flowmetry (LD) probe with a reference method based on photo plethysmography (PP). It includes 40 patients referred with known or suspected peripheral arterial disease. The SPP was performed with both devices. Blinded re-interpretation of the SPP measurements was carried out by three observers and a consensus quality score was provided for each measurement. SPP >40 mmHg was considered a clinically relevant cut-off. This study evaluates a total of 48 paired measurements of the midfoot and 54 below knee. The two methods agreed in overall diagnostic classification in 80 of 102 measurements (78%) with both methods showing SPP ≥40 mmHg in 21 cases, and both methods showing SPP <40 mmHg in 59 cases. Of the 22 participants with disagreement (22%) in overall classification, 15 had measurements within the range of 30-50 mmHg, and 7 with a clinically relevant disagreement with one device showing SPP <30 mmHg and the other ≥40 mmHg. Analysis of inter observer variation for the LD readings showed an intraclass correlation coefficient of 0.880 (95% CI: 0.807 to 0.929, p- value <0.05) at midfoot, and 0.933 (95% CI: 0.894 to 0.959, p-value <0.05) at below knee level. The novel probe based on LD showed good correlation with PP in absolute pressures, sufficient agreement in overall disease classification as well as good to excellent reliability in terms of inter observer variation.

Chronic mesenteric ischaemia: the importance of the individual mesenteric artery.

BACKGROUND: Chronic mesenteric ischaemia (CMI) is a vastly underdiagnosed condition that typically leads to postprandial abdominal pain and weight loss. The aim of the study was to explore the involvement of various mesenteric vessels in total splanchnic blood flow (SBF) and hepatic vein oxygenation. METHODS: Single-blinded comparative trial of 476 patients clinically suspected of CMI. Routine investigation included measurement of hepatic vein oxygen saturation, indirect measurement of the total splanchnic blood flow (SBF), using Fick's principle and the tracer [99m Tc]Mebrofenin, before and after a meal, and digital subtraction angiography. RESULTS: A total of 176 of the 476 patients (36%) had at least one angiographically significant stenosis (lumen reduction ≥70%). In patients with a significant one-vessel disease, the percentage having CMI according to SBF was 10% for a celiac trunk stenosis (n = 60), 50% for a superior mesenteric stenosis (n = 24) and 6% for an inferior mesenteric artery stenosis (n = 34). In patients with a significant two-vessel disease, the percentage with CMI according to SBF response was 92%, 18% and 79%, for no significant stenosis of the celiac trunk (n = 13), superior mesenteric artery (n = 17) and inferior mesenteric artery (n = 19), respectively. CONCLUSION: Patients with significant one- or two-vessel stenosis involving the superior mesenteric artery have a higher likelihood of CMI according to flow criteria and a greater postprandial decrease in hepatic vein saturation on average than patients with no involvement of the superior mesenteric artery.

Bedside Toe Pressures Measurements in a Department of Vascular Surgery: A Study of Diagnostic Accuracy.

OBJECTIVE: In patients with peripheral arterial disease (PAD), measurements of distal blood pressure form the basis of assessing the severity of the disease along with symptoms and objective findings. The reliability and accuracy of a fully automated bedside device (SysToe) vs. strain gauge plethysmography (SGP) in patients with low toe pressures in a bedside setting in an outpatient clinic of vascular surgery were investigated. METHODS: This was a prospective, single blinded study carried out in compliance with the Standards of Reporting of Diagnostic Accuracy Studies. A total of 94 outpatients with symptomatic PAD in an outpatient vascular surgery clinic were included and had index measurements performed with the automated bedside device in a bedside setting by observers with no training in routine distal pressure measurements. SGP reference measurements were performed in a vascular laboratory. RESULTS: There was agreement between modalities regarding the diagnostic classification of chronic limb threatening ischaemia (CLTI) in 79/94 (84%) patients. For detection of CLTI, Cohen's kappa was 0.57 with a sensitivity of 94%, specificity of 82%, positive predictive value (PPV) 52%, and negative predictive value (NPV) 98%. On average, the automated bedside device underestimated the pressures, compared with the SGP. The mean difference between SGP and SysToe was 9 ± 16 mmHg for right limbs and 10 ± 16 mmHg for left limbs (p < .001). CONCLUSION: The automated bedside device showed a high sensitivity and a high NPV for excluding CLTI. However, the low PPV may result in overdiagnosis. The automated bedside device may function as a screening tool identifying patients in need of further diagnostics with more accurate equipment, for example SGP.

The Ability of the Toe-Brachial Index to Predict the Outcome of Treadmill Exercise Testing in Patients with a Normal Resting Ankle-Brachial Index.

BACKGROUND: Peripheral arterial disease (PAD) in the presence of a normal ankle-brachial index (ABI) can be diagnosed noninvasively by measuring a postexercise ABI or by measuring the toe-brachial index (TBI). METHODS: This was a prospective comparative study. Over a period of 30 months, a total of 415 patients who were referred with the suspicion of vascular claudication and resting values of 0.91 ≤ ABI<1.40 were further evaluated for the resting TBI and postexercise ABI by treadmill testing. RESULTS: A total of 325 (39%) of the 830 investigated limbs had a low TBI (≤0.70), and 505 (61%) had a normal TBI. Of the limbs with a low TBI, 160 (49%) had PAD according to a postexercise ABI versus 165 (33%) of the limbs with normal TBI. The overall agreement in PAD classification between the two methods was 500/830 (60%) with a Cohen's kappa = 0.166 (95% CI: 0.096-0.232). The data showed an inverse correlation between the magnitude of the TBI decrease, as well as the resting ABI, and the probability of an abnormal postexercise ABI. On average, limbs with a low TBI had a lower resting ABI than patients with a normal TBI (1.07 ± 0.09 vs. 1.13 ± 0.10, P < 0.001). The groups with a low TBI had a significantly higher ratio of abnormal test results than patients with a normal TBI, in limbs with ABI (0.96-1.00) and ABI >1.10 (P ≤ 0.022 for both), but there were no statistically significant differences found in other ABI intervals (P > 0.200 for all). CONCLUSIONS: The magnitude of the TBI reduction correlates with an increased probability of an abnormal postexercise ABI. However, this is due in part to limbs with a low TBI having a lower resting ABI on average than limbs with a normal TBI, which also correlates with the probability of an abnormal exercise test result. This study shows that the TBI and the postexercise ABI are not interchangeable for establishing a PAD diagnosis.

Risk factors and haemodynamic variables in patients with low toe-brachial index but normal ankle-brachial index.

BACKGROUND AND AIMS: Classically, peripheral arterial disease (PAD) is diagnosed by a low ankle-brachial index (ABI), but the diagnosis can also be made based on toe-brachial index (TBI) measurements. The objective of this study was to characterize patients with low TBI but normal ABI, and chart potential underestimation of PAD prevalence by solitary use of ABI. METHODS: A total of 3739 consecutive patients with known or suspected PAD referred for ABI and TBI measurements in a four-year period were compared to an age- and gender matched control group (n = 17,340). RESULTS: In the patient cohort, 65.0% had low ABI, 20.5% had low TBI but normal ABI, and 14.5% had normal indices. When comparing the frequencies of comorbidities related to atherosclerotic disease (myocardial infarction, congestive heart failure, cerebrovascular disease, diabetes mellitus, chronic kidney failure), there were no significant differences among patients with low ABI or low TBI with normal ABI in any of the variables (all p > 0.06). Of the patients with low TBI and normal ABI, 18.7% were diagnosed with diabetes mellitus type I or II, and 8.2% with chronic kidney disease. CONCLUSIONS: Patients with low TBI but normal ABI represented 20.5% of patients referred with the suspicion of PAD. Furthermore, patients with low TBI but normal ABI presented similar comorbid characteristics to patients with low ABI, who have a well-described increased risk of cardiovascular morbidity and mortality. The solitary use of ABI underestimated the prevalence of PAD in the population, and PAD screening could potentially be improved by routine application of TBI.

Improvement in image quality of Tc-99m-based ventilation/perfusion single-photon emission computed tomography in patients with chronic obstructive pulmonary disease through pretest continuous positive airway pressure treatment.

Ventilation/perfusion single-photon emission computed tomography performed using an aerosol of carbon-coated technetium is frequently used for diagnosing pulmonary embolism. Certain patients may suffer from chronic obstructive pulmonary disease (COPD); for such patients, the formation of mucus clots in airways can cause accumulation of the aerosol in the larger airways. This centralized deposition of the aerosol leads to insufficient activity in peripheral lung segments and subsequently results in ventilation images of substandard or even nondiagnostic quality. Continuous positive airway pressure (CPAP) therapy improves airway dynamics and quality of life for COPD patients. We report for the first time the results for two patients for whom initial ventilation scans were of insufficient quality, but diagnostic-quality images were obtained after CPAP therapy.

Practical application of spatial ecosystem service models to aid decision support.

Ecosystem service (ES) spatial modelling is a key component of the integrated assessments designed to support policies and management practices aiming at environmental sustainability. ESTIMAP ("Ecosystem Service Mapping Tool") is a collection of spatially explicit models, originally developed to support policies at a European scale. We based our analysis on 10 case studies, and 3 ES models. Each case study applied at least one model at a local scale. We analyzed the applications with respect to: the adaptation process; the "precision differential" which we define as the variation generated in the model between the degree of spatial variation within the spatial distribution of ES and what the model captures; the stakeholders' opinions on the usefulness of models. We propose a protocol for adapting ESTIMAP to the local conditions. We present the precision differential as a means of assessing how the type of model and level of model adaptation generate variation among model outputs. We then present the opinion of stakeholders; that in general considered the approach useful for stimulating discussion and supporting communication. Major constraints identified were the lack of spatial data with sufficient level of detail, and the level of expertise needed to set up and compute the models.

The performance of tranchet blows at the Late Middle Paleolithic site of Grotte de la Verpillière I (Saône-et-Loire, France).

This paper focuses on the technological characteristics of Keilmesser with a lateral tranchet blow modification on the cutting edge. It examines the underlying technological production of these bifacial objects: this implies the evaluation of their working stage succession, as well as produced forms necessary for the execution of tranchet blow performance. Furthermore, it offers a techno-morphological description of these enigmatic tools. The Keilmesser with tranchet blow and corresponding blanks of tranchet blows from Grotte de la Verpillière I in Germolles (Saône-et-Loire, France) are used as case study. The collection of Keilmesser with tranchet blow and corresponding blanks of tranchet blow has been massively expanded with new fieldwork and the review of ancient assemblages. The majority of the pieces were made on blanks from local raw material. The evaluation of the underlying production concept shows that a Keilmesser with tranchet blow, regardless of the wide range of morphologies and matrix size, always consists of specific parts that are necessary for the production sequence and the assumed function. The production of these pieces follows highly specific working stages, some of which can be interchanged in sequence. However, it is always the goal to obtain a low-angled cutting edge. The performance of a tranchet blow is not only an integral part of production, but it is rather the aim of the entire production.

Comparison of two methods based on photoplethysmography for the diagnosis of peripheral arterial disease.

AIM: To examine the interchangeability of two methods for distal pressure measurement based on photoplethysmography using a truncated or full display of the arterial inflow curve, respectively. METHODS: Toe and ankle pressures were obtained from 69 patients suspected of peripheral arterial disease (PAD). Observer reproducibility of the curve readings was examined by blinded reassessment of the pressure curves in a randomly selected subgroup (60 limbs). RESULTS: There were no significant differences in mean pressures between the two methods (p for all > .455). The limits of agreement for the differences were -15.0-15.4 mmHg for right toe pressures, -16.3-16.2 mmHg for left toe pressures, -14.2-15.7 mmHg for right ankle pressures, and -18.3-17.7 mmHg for left ankle pressures. Correlation analysis revealed intraclass correlation coefficients ≥0.960 for all measuring sites. Cohen's Kappa showed excellent agreement in diagnostic classification, with κ = 0.930 for the diagnosis of PAD and perfect agreement in the diagnosis of critical limb ischemia (κ = 1.000). The analysis of intra-observer variation for curve reading showed limits of agreement of -3.9-4.0 for toe pressures and -7.6-7.7 for ankle pressures for the method involving truncated display and -3.1-3.2 for toe pressures and -6.3-8.6 for ankle pressures for the method involving full display of the signal. CONCLUSION: The present study shows minimal differences in diagnostic classification, as well as in ankle and toe pressures, between the full display and the truncated display of the photoplethysmographic pulse signal. Furthermore, the inter-observer variation was low for both of the photoplethysmographic methods investigated.

Homicide in Greenland 1985-2010.

PURPOSE: Homicide in Greenland has not often been investigated. The latest published study documented a dramatic rise in the homicide rate from around 1/100,000 inhabitants to more than 23/100,000 inhabitants from 1946 to 1984. The aim of our study was to characterize homicides in Greenland from 1985 to 2010 and to compare trends during this period with those in previous studies and with homicide characteristics in Denmark, northern Europe, and other Arctic regions. METHODS: We identified a total of 281 homicides by legal definition and 194 by medical definition, the latter from the years 1990 to 2010. We procured case files for a total of 129 victims (71 male, 58 female) and 117 perpetrators (85 male, 32 female). RESULTS: We identified an overall decrease in the homicide rate during our study period. The decrease in the medical homicide rate was significant (p = 0.007). The homicide rate ranged from 25/100,000 inhabitants to 13/100,000 inhabitants when results were grouped within 5-year periods. There were significantly more male perpetrators (p < 0.001) and among female perpetrators there were significantly more male victims (p < 0.001). Sharp force and gunshot-related killings dominated homicide methods (41 and 29% respectively), with sharp force deaths increasing throughout the investigation period. Altercations were the main motive (49%). Alcohol-related homicides decreased in our study period. CONCLUSIONS: While the Greenlandic homicide rate has decreased, it is markedly higher compared to that seen in Denmark and northern Europe. However, it resembles the rate seen in the rest of the Arctic. Liberal gun laws do not affect the proportion of gun-related killings. Despite the high homicide rate, women account for almost half the victims.

Time matters--realism in resuscitation training.

BACKGROUND: The advanced life support guidelines recommend 2min of cardiopulmonary resuscitation (CPR) and minimal hands-off time to ensure sufficient cardiac and cerebral perfusion. We have observed doctors who shorten the CPR intervals during resuscitation attempts. During simulation-based resuscitation training, the recommended 2-min CPR cycles are often deliberately decreased in order to increase the number of scenarios. The aim of this study was to test if keeping 2-min CPR cycles during resuscitation training ensures better adherence to time during resuscitation in a simulated setting. METHODS: This study was designed as a randomised control trial. Fifty-four 4th-year medical students with no prior advanced resuscitation training participated in an extra-curricular one-day advanced life support course. Participants were either randomised to simulation-based training using real-time (120s) or shortened CPR cycles (30-45s instead of 120s) in the scenarios. Adherence to time was measured using the European Resuscitation Council's Cardiac Arrest Simulation Test (CASTest) in retention tests conducted one and 12 weeks after the course. RESULTS: The real-time group adhered significantly better to the recommended 2-min CPR cycles (time-120s) (mean 13; standard derivation (SD) 8) than the shortened CPR cycle group (mean 45; SD 19) when tested (p<0.001.) CONCLUSION: This study indicates that time is an important part of fidelity. Variables critical for performance, like adherence to time in resuscitation, should therefore be kept realistic during training to optimise outcome.

The unexpected finding of a benign mature teratoma in a forensic pathology autopsy: a rare cause for sudden, unexpected death.

Intracranial teratomas are rare tumors that are usually discovered in infancy due to progressive symptoms. We describe a case of a 38-year-old man who was found dead 9 hours after the last sign of life. The deceased's medical history could not explain the sudden, unexpected death. A forensic autopsy revealed an asymptomatic, mature teratoma in the left frontal and temporal lobes. We concluded that the cause of death must have been a generalized epileptiform seizure originating in the tumor site(s) leading to aspiration of the stomach contents and unfavorable positioning, resulting in asphyxia.

Diagnostic accuracy of laser Doppler flowmetry versus strain gauge plethysmography for segmental pressure measurement.

OBJECTIVE: To assess the diagnostic accuracy of laser Doppler flowmetry (LDF) with mercury-in-silastic strain gauge plethysmography (SGP) as a reference test for measuring the toe and ankle pressures in patients with known or suspected peripheral arterial disease (PAD). METHODS: This was a prospective, randomized, blinded diagnostic accuracy study. Toe and ankle pressures were measured using both methods in 200 consecutive patients, who were recruited at our vascular laboratory over a period of 30 working days. Classification of PAD and critical limb ischemia (CLI) was made in accordance with TASC-II criteria. RESULTS: The LDF method demonstrated 5.8 mm Hg higher mean toe pressures than the SGP method for the right limb and 7.0 mm Hg for the left limb (both P < .001). There were no significant differences in the mean ankle pressures (both P > .129). The limits of agreement for the differences (SGP - LDF) were -31.7 to 20.2 mm Hg for right toe pressures, -28.0 to 14.0 mm Hg for left toe pressures, -25.5 to 22.8 mm Hg for right ankle pressures, and -26.9 to 24.6 mm Hg for left ankle pressures. A correlation analysis of the absolute pressures using the two methods showed an intraclass correlation coefficient of 0.902 (95% confidence interval [CI], 0.835-0.938) for right toe pressures, 0.919 (95% CI, 0.782-0.960) for the left toe pressures, 0.953 (95% CI, 0.937-0.965) for right ankle pressures, and 0.952 (95% CI, 0.936-0.964) for left ankle pressures. Cohen's Kappa showed an agreement in the diagnostic classification of κ = 0.775 (95% CI, 0.631-0.919) for PAD and κ = 0.780 (95% CI, 0.624-0.936) for CLI. CONCLUSIONS: LDF showed a good correlation with SGP over a wide range of toe and ankle pressures, as well as substantial agreement for the diagnostic classification of PAD including CLI.

The toe-brachial index in the diagnosis of peripheral arterial disease.

BACKGROUND: Peripheral arterial disease (PAD) can be diagnosed noninvasively by segmental blood pressure measurement and calculating an ankle-brachial index (ABI) or toe-brachial index (TBI). The ABI is known to be unreliable in patients with vascular stiffness and fails to detect the early phase of arteriosclerotic development. The toe vessels are less susceptible to vessel stiffness, which makes the TBI useful. However, the diagnostic limits used in guidelines, clinical settings, and experimental studies vary substantially. This review provides an overview of the evidence supporting the clinical use of the TBI. METHODS: A review of the literature identified studies reporting the use of the TBI regarding guideline recommendations, normal populations, correlations to angiographic findings, and prognostic implications. RESULTS: Eight studies conducted in a normal population were identified, of which only one study used imaging techniques to rule out arterial stenosis. A reference value of 0.71 was estimated as the lowest limit of normal based on the weighted average in studies with preheating of the limbs. A further seven studies showed correlations of the TBI with angiographic findings. The TBI had a sensitivity of 90% to 100% and a specificity of 65% to 100% for the detection of vessel stenosis. Few studies investigated the value of the TBI as a prognostic marker for cardiovascular mortality and morbidity, and no firm conclusions could be made. Studies have, however, shown correlation between the TBI and comorbidities such as kidney disease, diabetes, and microvasculature disease. CONCLUSIONS: In contrast to the well-defined and evidence-based limits of the ABI, the diagnostic criteria for a pathologic TBI remain ambiguous. Although several guidelines and reviews of PAD diagnostics recommend a TBI <0.70 as cutoff, it is not strictly evidence-based. The current literature is not sufficient to conclude a specific cutoff as diagnostic for PAD. The current studies in normal populations and the correlation with angiography are sparse, and additional trials are needed to further validate the limits. Large-scale trials are needed to establish the risk of morbidity and mortality for the various diagnostic limits of the TBI.

Reliability of mercury-in-silastic strain gauge plethysmography curve reading: influence of clinical clues and observer variation.

AIM: Mercury-in-silastic strain gauge pletysmography (SGP) is a well-established technique for blood flow and blood pressure measurements. The aim of this study was to examine (i) the possible influence of clinical clues, e.g. the presence of wounds and color changes during blood pressure measurements, and (ii) intra- and inter-observer variation of curve interpretation for segmental blood pressure measurements. METHODS: A total of 204 patients with known or suspected peripheral arterial disease (PAD) were included in a diagnostic accuracy trial. Toe and ankle pressures were measured in both limbs, and primary observers analyzed a total of 804 pressure curve sets. The SGP curves were later reanalyzed separately by two observers blinded to clinical clues. Intra- and inter-observer agreement was quantified using Cohen's kappa and reliability was quantified using intra-class correlation coefficients, coefficients of variance, and Bland-Altman analysis. RESULTS: There was an overall agreement regarding patient diagnostic classification (PAD/not PAD) in 202/204 (99.0%) for intra-observer (κ = 0.969, p < 0.001), and 201/204 (98.5%) for inter-observer readings (κ = 0.953, p < 0.001). Reliability analysis showed excellent correlation between blinded versus non-blinded and inter-observer readings for determination of absolute segmental pressures (all intraclass correlation coefficients ≥ 0.984). The coefficient of variance for determination of absolute segmental blood pressure ranged from 2.9-3.4% for blinded/non-blinded data and from 3.8-5.0% for inter-observer data. CONCLUSION: This study shows a low inter-observer variation among experienced laboratory technicians for reading strain gauge curves. The low variation between blinded/non-blinded readings indicates that SGP measurements are minimally biased by clinical clues.