Cerebral and Peripheral Tissue Oxygenation in Children Supported on ECMO for Cardio-Respiratory Failure

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for patients with cardio-respiratory failure. Establishing, maintaining and weaning from ECMO may increase the risk for intracranial injury. We used a dual channel near infrared system to monitor cerebral and peripheral tissue oxygenation in 3 venoarterial (VA) and 1 venovenous (VV) ECMO patients undergoing manipulations in the ECMO circuit flows. Spectral analysis was performed on the oxyhaemoglobin data collected from these patients with the aim of comparing oscillations at range of frequencies appearing in the two measurement sites

Safety and efficacy of a multi-electrode renal sympathetic denervation system in resistant hypertension: The EnligHTN I trial

Aims: Catheter-based renal artery sympathetic denervation has emerged as a novel therapy for treatment of patients with drug-resistant hypertension. Initial studies were performed using a single electrode radiofrequency catheter, but recent advances in catheter design have allowed the development of multi-electrode systems that can deliver lesions with a pre-determined pattern. This study was designed to evaluate the safety and efficacy of the EnligHTN™ multi-electrode system. Methods and results: We conducted the first-in-human, prospective, multi-centre, non-randomized study in 46 patients (67% male, mean age 60 years, and mean baseline office blood pressure 176/96 mmHg) with drug-resistant hypertension. The primary efficacy objective was change in office blood pressure from baseline to 6 months. Safety measures included all adverse events with a focus on the renal artery and other vascular complications and changes in renal function. Renal artery denervation, using the EnligHTN™ system significantly reduced the office blood pressure from baseline to 1, 3, and 6 months by −28/10, −27/10 and −26/10 mmHg, respectively (P < 0.0001). No acute renal artery injury or other serious vascular complications occurred. Small, non-clinically relevant, changes in average estimated glomerular filtration rate were reported from baseline (87 ± 19 mL/min/1.73 m2) to 6 months post-procedure (82 ± 20 mL/min/1.73 m2). Conclusion: Renal sympathetic denervation, using the EnligHTN™ multi-electrode catheter results in a rapid and significant office blood pressure reduction that was sustained through 6 months. The EnligHTN™ system delivers a promising therapy for the treatment of drug-resistant hypertension.Stephen G. Worthley, Costas P. Tsioufis, Matthew I. Worthley, Ajay Sinhal, Derek P. Chew, Ian T. Meredith, Yuvi Malaiapan, and Vasilios Papademetrio

Wavelet cross-correlation to investigate regional variations in cerebral oxygenation in infants supported on extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation can potentially affect cerebral blood flow dynamics and consequently influence cerebral autoregulation. We applied wavelet cross-correlation (WCC) between multichannel cerebral oxyhemoglobin concentration (HbO(2)) and mean arterial pressure (MAP), to assess regional variations in cerebral autoregulation. Six infants on veno-arterial (VA) ECMO were studied during sequential changes in the ECMO flows. WCC between MAP and HbO(2) for each flow period and each channel was calculated within three different frequency (wavelet scale) bands centered around 0.1, 0.16, and 0.3 Hz chosen to represent low frequency oscillations, ventilation, and respiration rates, respectively. The group data showed a relationship between maximum WCC and ECMO flow. During changes in ECMO flow, statistically significant differences in maximum WCC were found between right and left hemispheres. WCC between HbO(2) and MAP provides a useful method to investigate the dynamics of cerebral autoregulation during ECMO. Manipulations of ECMO flows are associated with regional changes in cerebral autoregulation which may potentially have an important bearing on clinical outcome

Multichannel near infrared spectroscopy indicates regional variations in cerebral autoregulation in infants supported on extracorporeal membrane oxygenation

Assessing noninvasively cerebral autoregulation, the protective mechanism of the brain to maintain constant cerebral blood flow despite changes in blood pressure, is challenging. Infants on life support system (ECMO) for cardiorespiratory failure are at risk of cerebral autoregulation impairment and consequent neurological problems. We measured oxyhaemoglobin concentration (HbO(2)) by multichannel (12 channels) near-infrared spectroscopy (NIRS) in six infants during sequential changes in ECMO flow. Wavelet cross-correlation (WCC) between mean arterial pressure (MAP) and HbO(2) was used to construct a time-frequency representation of the concordance between the two signals to assess the nonstationary aspect of cerebral autoregulation and investigate regional variations. Group data showed that WCC increases with decreasing ECMO flow indicating higher concordance between MAP and HbO(2) and demonstrating loss of cerebral autoregulation at low ECMO flows. Statistically significant differences in WCC were observed between channels placed on the right and left scalp with channels on the right exhibiting higher values of WCC suggesting that the right hemisphere was more susceptible to disruption of cerebral autoregulation. Multichannel NIRS in conjunction with wavelet analysis methods can be used to assess regional variations in dynamic cerebral autoregulation with important clinical application in the management of critically ill children on life support systems

Optical topography to measure variations in regional cerebral oxygenation in an infant supported on veno-arterial extra-corporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for patients with cardio-respiratory failure which exposes the patient to the risk for in-tracranial injury. We used a 12-channel optical topography system to monitor ce-rebral oxygenation in a venoarterial (VA) ECMO patient during alterations in the ECMO flows. Changes in oxy-(HbO2), deoxy-(HHb) and total-(HbT) haemoglo-bin concentrations were measured simultaneously with systemic and ECMO cir-cuit parameters. Decreasing the flows resulted in a decrease in venous (SvO2) and arterial (SpO2) saturations. These were reflected in the haemoglobin data by a sig-nificant increase in HHb of varying magnitude across the 12 channels and mod-erate changes in HbO2 suggestive of cerebral arterial dilation to compensate for the lack of oxygen delivery. In the patient studied here ECMO flows appear to present a significant haemodynamic challenge to cerebral circulation

Canonical correlation analysis in the study of cerebral and peripheral haemodynamics interrelations with systemic variables in neonates supported on ECMO.

Neonates supported on extracorporeal membrane oxygenation (ECMO) are at high risk of brain injury due to haemodynamic instability. In order to monitor cerebral and peripheral (muscle) haemodynamic and oxygenation changes in this population we used a dual-channel near-infrared spectroscopy (NIRS) system. In addition, to assess interrelations between NIRS and systemic variables, collected simultaneously, canonical correlation analysis (CCA) was employed. CCA can quantify the relationship between a set of variables and assess levels of dependency. In four out of five patients, systemic variables were found to be less inter-related with cerebral rather than peripheral NIRS measurements. Moreover, during ECMO flow manipulations, we found that the interrelation between the systemic and the NIRS cerebral/peripheral variables changed. The CCA method presented here can be used to assess differences between NIRS cerebral and NIRS peripheral responses due to systemic variations which may be indicative of physiological differences in the mechanisms that regulate oxygenation and/or haemodynamics of the brain and the muscle

Building inclusive nations in the age of migration

This is an Accepted Manuscript of an article published by Taylor & Francis in Identities: Global Studies in Culture and Power on 06 Apr 2016, available online: http://dx.doi.org/10.1080/1070289X.2016.1148607Nation and diversity are often casted in oppositional terms. The present joint-intervention explores the limits and possibilities of what we call ‘inclusive nation’, i.e. a nation which embraces rather than expunging diversity. To reflect on this idea, the Loughborough University Nationalism Network (LUNN) organized a symposium, bringing together both academics and relevant stakeholders, to explore both theoretically and practically the feasibility of the inclusive nation. For reason of space, here we present only the theoretical views of academics. While Billig and Yuval-Davis highlight the inherent exclusive thrust of nationalism, Kaufmann and Hearn suggest two distinct ways to move away the traditional understanding of nationalism as a site of singularity, oppression and exclusion. A final rejoinder by Nyhagen pushes the debate further interrogating the boundaries of national belonging

The Rise and Fall of Hypertension: Lessons Learned from Eastern Europe

Hypertension is a progressive cardiovascular syndrome that arises from many differing, but interrelated, etiologies. Hypertension is the most prevalent cardiovascular disorder, affecting 20% to 50% of the adult population in developed countries. Arterial hypertension is a major risk factor for cardiovascular diseases and death. Epidemiologic data have shown that control of hypertension is achieved in only a small percentage of hypertensive patients. Findings from the World Health Organization project Monitoring Trends and Determinants in Cardiovascular Diseases (MONICA) showed a remarkably high prevalence (about 65%) of hypertension in Eastern Europeans. There is virtually no difference however, between the success rate in controlling hypertension when comparing Eastern and Western European populations. Diagnosing hypertension depends on both population awareness of the dangers of hypertension and medical interventions aimed at the detecting elevated blood pressure, even in asymptomatic patients. Medical compliance with guidelines for the treatment of hypertension is variable throughout Eastern Europe. Prevalence of hypertension increases with age, and the management of hypertension in elderly is a significant problem. The treatment of hypertension demands a comprehensive approach to the patient with regard to cardiovascular risk and individualization of hypertensive therapy