Point-of-care platelet function assays demonstrate reduced responsiveness to clopidogrel, but not aspirin, in patients with Drug-Eluting Stent Thrombosis whilst on dual antiplatelet therapy

BackgroundTo test the hypothesis that point-of-care assays of platelet reactivity would demonstrate reduced response to antiplatelet therapy in patients who experienced Drug Eluting Stent (DES) ST whilst on dual antiplatelet therapy compared to matched DES controls. Whilst the aetiology of stent thrombosis (ST) is multifactorial there is increasing evidence from laboratory-based assays that hyporesponsiveness to antiplatelet therapy is a factor in some cases.MethodsFrom 3004 PCI patients, seven survivors of DES ST whilst on dual antiplatelet therapy were identified and each matched with two patients without ST. Analysis was performed using (a) short Thrombelastogram PlateletMapping™ (TEG) and (b) VerifyNow Aspirin and P2Y12 assays. TEG analysis was performed using the Area Under the Curve at 15 minutes (AUC15) as previously described.ResultsThere were no differences in responses to aspirin. There was significantly greater platelet reactivity on clopidogrel in the ST group using the Accumetrics P2Y12 assay (183 ± 51 vs. 108 ± 31, p = 0.02) and a trend towards greater reactivity using TEG AUC15 (910 ± 328 vs. 618 ± 129, p = 0.07). 57% of the ST group by TEG and 43% of the ST cases by Accumetrics PRU had results > two standard deviations above the expected mean in the control group.ConclusionThis study demonstrates reduced platelet response to clopidogrel in some patients with DES ST compared to matched controls. The availability of point-of-care assays that can detect these responses raises the possibility of prospectively identifying DES patients at risk of ST and manipulating their subsequent risk

The re-regulation of broadcasting: Or the mill owners’ triumph

Discusses the driving forces behind the Communications Bill 2001 of Great Britain. Terms of the bill; Arguments concerning the re-regulation

Abstracts from the NIHR INVOLVE Conference 2017

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Il meticciato nell'Italia contemporanea. Storia, memorie e cultura di massa.

L'idea diffusa degli "italiani brava gente" e della diversit\ue0 della nostra storia rispetto alla storia USA, segnata da razzismo istituzionale, si fonda sul silenziamento del passato coloniale e razzista italiano. Il ripudio della categoria di razza da parte dell'Italia repubblicana e la smentita scientifica dell'esistenza biologica della categoria non hanno cancellato la presenza della razza, formazione storico-culturale che paradossalmente esiste e non esiste. Priva di referenti oggettivi nella realt\ue0, la razza produce in essa effetti significativi, opera sia come categoria sociale e strumento di esclusione, sia come costruzione simbolica e istanza identitaria. A fronte del silenziamento del meticciato storico nell'uso pubblico della storia e nella memoria nazionali del secondo dopoguerra, il saggio sottolinea la presenza diffusa del meticciato nei prodotti della cultura di massa italiani contemporanei e ne indaga i significati con gli strumenti degli studi critici sulla razza e in prospettiva comparata tra Italia e Stati Uniti

Do clinical examination gloves provide adequate electrical insulation for safe hands-on defibrillation? II: Material integrity following exposure to defibrillation waveforms

IntroductionMaintaining contact with the patient during defibrillator discharge has been proposed as a method for reducing no flow time but carries an associated risk of electrocution of the rescuer. This study describes an investigation to determine if typical clinical examination gloves possess the dielectric strength needed to prevent breakdown at defibrillation voltages; a factor essential to protect the rescuer.MethodsFour types of examination glove typically used in a clinical environment were tested with two types of defibrillation waveform commonly used. For each type of glove, 10 samples were tested initially using a monophasic defibrillation waveform and then, using a fresh sample of gloves, with a Biphasic waveform. For each glove the number of shocks required before electrical breakdown occurred was recorded.ResultsKimberly Clark KC300 (nitrile), Kimberly Clark KC500 purple (nitrile), PH Medisavers GN90 (nitrile) and Bodyguards GL6622 (Vinyl) were tested using a monophasic defibrillation waveform and broke down after a median of 1, 4.5, 1 and 1 shocks respectively. The equivalent values for Biphasic defibrillator were 2, >10, 2.5 and 1 shocks.DiscussionTypical clinical examination gloves do not possess the dielectric strength required to protect a rescuer from defibrillation voltages during hands-on chest compressions

Hands-on defibrillation: theoretical and practical aspects of patient and rescuer safety

Defibrillators are used to treat many thousands of people each year using very high voltages, but, despite this, reported injuries to rescuers are rare. Although even a small number of reported injuries is not ideal, the safety record of the defibrillator using the current protocol is widely regarded as being acceptable.There is increasing evidence that clinical outcome is significantly improved with continuous chest compressions, but defibrillation is a common cause of interruptions; even short interruptions, such as those associated with defibrillation, may detrimentally affect the outcome. This has led to discussions regarding the possibility of continuing chest compressions during defibrillation; a process involving a rescuer working in close proximity to voltages of up to 5000 V.Not only do voltages of this magnitude have significant implications for the rescuer performing chest compressions, but there are also risks to other rescuers in the proximity, the patient and other bystanders. Clearly any deviation from accepted practice should only be undertaken following careful consideration of the risks and benefits to the patient, rescuers and others.This review summarises the physical principles of electrical risk and identifies ways in which these could be managed. In doing so, it is hoped that in future it may be possible to deliver continuous and safe manual chest compressions during defibrillator discharge in order to improve patient outcome

Assessment of the quality of cardiopulmonary resuscitation following modification of a standard telephone-directed protocol

IntroductionCurrent Advanced Medical Priority Dispatch System (AMPDS) V.11.1 telephone instructions are limited in their ability to produce correctly performed basic life support. The current telephone instructions were modified in an attempt to improve areas of poor CPR performance.MethodsFifty subjects performed CPR on an instrumented adult manikin by following instructions modified from AMPDS V.11.1 instructions. Instructions were given by telephone from a different room.ResultsNo improvements were seen with opening the airway or delivering rescue breaths. The rate of chest compression improved from 52 to 81 min?1 (P = 0.004), although the depth of chest compression fell to 2.0 cm compared with 3.2 cm documented with the original AMPDS instructions (P = 0.004). Instructions to put the telephone down while performing CPR improved all aspects of CPR.DiscussionThe effective delivery of telephone-directed CPR to untrained bystanders is a complex process. Changing verbal instructions to improve the quality of CPR is not easy. Further work is urgently needed to strengthen this important link in the chain of survival

Defibrillation during renal dialysis: a survey of UK practice and procedural recommendations

IntroductionDefibrillation of patients connected to medical equipment that is not defibrillation proof risks ineffective defibrillation and harm to the operator as a result of aberrant electrical pathways taken by the defibrillation current. Many renal dialysis systems are not currently defibrillation proof. Although national and international safety standards caution against defibrillating under this circumstance, it appears to be an area of confusion that we have investigated in more detail.MethodsThirty renal dialysis units across the UK were invited to participate in a telephone survey of current practice from 1 October 2004 to 1 October 2005. The Medical Healthcare Regulatory Agency and renal dialysis machine manufacturers were contacted for advice, and current safety standards were reviewed.ResultsTwenty-eight renal dialysis units completed the survey. Seven (25%) units would not disconnect patients from dialysis equipment during defibrillation, collectively reporting 14 patients who had required defibrillation during dialysis. Eighteen (64.3%) units would disconnect patients from dialysis equipment during defibrillation, collectively reporting 29 patients who had required defibrillation during dialysis. No complications were identified by this survey, through the MHRA or through a literature search.ConclusionDefibrillation of patients while undergoing renal dialysis is common practice in the UK. Although no adverse events have been reported, this practice risks injury to the patient and clinical staff, and equipment damage if the dialysis equipment is not defibrillation proof. It is in breach of national and international safety standards and should not be practiced

What is the optimal paddle force during paediatric external defibrillation?

Introduction: Transthoracic impedance (TTI) is a major determinant of transmyocardial current flow, and therefore, the success of defibrillation. European Resuscitation Council (ERC) paediatric guidelines recommend that ‘firm’ paddle force should be applied to the paddles during defibrillation. No study has yet established the optimal paddle force required to minimise TTI in children of different ages. Methods: Eighty patients aged 10 weeks to 17 yrs undergoing general anaesthesia for routine surgery were studied. Using defibrillation paddles placed in an anterior-apical position, TTI (?) was measured for increasing values of force from 0.5 kgf (baseline) to 6.5 kgf. The optimal force, the force to achieve 95% of the overall reduction in TTI, was then determined. According to current guidelines, paediatric paddles (surface area 16 cm2) were used for infants (?10 kg) and adult paddles (82 cm2) for older children. Optimal force was then calculated for infants ?10 kg, children >10 kg and ?8 yrs and children 9–17 yrs age. Results: Increasing paddle force from 0.5 kgf progressively decreased TTI. Optimal force using paediatric paddles was 2.9 kgf in infants. Optimal force using adult paddles was 5.1 kgf in children >10 kg but ?8 yrs and 5.3 kgf in children aged 9–17 yrs. Conclusions: Force is an important determinant of TTI and therefore, outcome of defibrillation. It is recommended that a minimum of 3 kgf be applied to paddles when defibrillating infants with paediatric paddles, and a minimum of 5 kgf be applied to all older children when adult paddles are used