A Dynamic Objective Evaluation of Peripheral Arterial Disease by Near-Infrared Spectroscopy

AbstractObjectivesNear-Infrared Spectroscopy (NIRS), suitable for dynamic measurements, is not routinely used for peripheral arterial disease (PAD). We propose a dynamic NIRS-based measurement to quantify variations in muscle metabolism in PAD.MethodSixty-seven consecutive PAD patients (males=56, age 71.6±8.7 years) and 28 healthy subjects (males=12, age 30.4±11.9 years) were studied. An echo-colour Doppler (ECD) was performed and the ankle–brachial index (ABI) was calculated. Participants performed an incremental treadmill test with NIRS probes on the gastrocnemius. Variations in oxygenated (HbO2), deoxygenated (HHb), total (tHb=HbO2+HHb), and differential (dHb=HbO2−HHb) haemoglobin were recorded and quantified as area-under-curve (AUC) within the range 1.7–3.0kmh−1. Heart rate was recorded, and the number of beats in the same interval was calculated (dHr).ResultsO2HbAUC, HHbAUC and dHbAUC differed between diseased and non-diseased legs (P<0.0001) and exhibited different patterns related to PAD severity according to the ABI value. A compensatory heart rate increase was observed in PAD patients. Compared with the ECD positivity for occlusions/stenoses or multiple plaques, only the receiver-operating characteristic (ROC) analysis of dHbAUC (area=0.932, P<0.0001) showed a sensitivity/specificity of 87.6/93.4 for values ≤−197 (LR+LR−: 13.36/0.13).ConclusionThe dynamic NIRS-based test, quantifying muscle metabolic response according to presence and degree of PAD, allows the evaluation of patients with walking disabilities

Mobile Phone Data for Mapping Urban Dynamics

During the last few years, new tools for estimating people’s density in cities have emerged through mobile network data. As opposed to the more traditional methods of urban surveys, the use of aggregated and anonymous mobile phone network log files has shown promise for large-scale surveys with notably smaller efforts and costs. Moreover, a frequent data feed from the mobile network has been argued to demonstrate fine grain over-time variation in urban movements, lacking from the traditional prediction methods. Despite the positivist approach to the new methodology, additional evidence is needed to show how mobile network data correlate with the actual presence of people, and how they can be used to map different urban domains. We try to address this shortcoming presenting the results of a research carried out in Lombardy Region, using mobile phone data provided by Telecom Italia, as a promising approach to assist the traditional database and analysis of urban dynamics as new challenges for urban plannin

Seasonal pattern in elderly hospitalized with acute kidney injury: a retrospective nationwide study in Italy

Purpose: Acute kidney injury (AKI) frequently complicates hospitalization and is associated with in-hospital mortality (IHM). It has been reported a seasonal trend in different clinical conditions. The aim of this study was to evaluate the possible relationship between seasons of the year and IHM in elderly hospitalized patients with AKI. Methods: We selected all admissions complicated by AKI between 2000 and 2015 recorded in the Italian National Hospital Database. ICD-9-CM code 584.xx identified subjects with age ≥ 65 years and age, sex, comorbidity burden, need of dialysis treatment and IHM were compared in hospitalizations recorded during the four seasons. Moreover, we plotted the AKI observed/expected ratio and percentage of mortality during the study period. Results: We evaluated 759,720 AKI hospitalizations (mean age 80.5 ± 7.8 years, 52.2% males). Patients hospitalized with AKI during winter months had higher age, prevalence of dialysis-dependent AKI, and number of deceased patients. In whole population IHM was higher in winter and lower in summer, while the AKI observed/expected ratio demonstrated two peaks, one in summer and one in winter. Logistic regression analysis demonstrated that parameters such as age, autumn, winter, comorbidity burden were positively associated with IHM. Conclusion: We conclude that a seasonality exists in AKI, however, relationship between seasons and AKI could vary depending on the aspects considered. Both autumn and winter months are independent risk factors for IHM in patients with AKI regardless of age, sex and comorbidity burden. On the contrary, summer time reduces the risk of death during hospitalizations with AKI