130,658 research outputs found
Do clinical examination gloves provide adequate electrical insulation for safe hands-on defibrillation? II: Material integrity following exposure to defibrillation waveforms
No full textIntroductionMaintaining 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
Exploring representativeness and reliability for late medieval earthquakes in Europe
No full textSeismic catalogues of past earthquakes have compiled a substantial amount of information about historical seismicity for Europe and the Mediterranean. Using two of the most recent European seismic databases (AHEAD and EMEC), this paper employs GIS spatial analysis (kernel density estimation) to explore the representativeness and reliability of data captured for late medieval earthquakes. We identify those regions where the occurrence of earthquakes is significantly higher or lower than expected values and investigate possible reasons for these discrepancies. The nature of the seismic events themselves, the methodology employed during catalogue compilation and the availability of medieval written records are all briefly explored
Pharmacological vasodilatation improves efficiency of rewarming from hypothermic cardiopulmonary bypass
No full textAn afterdrop in core temperature after hypothermic cardiopulmonary bypass (CPB) is related to inadequate peripheral rewarming. We proposed that pharmacological vasodilatation during rewarming on bypass would improve peripheral rewarming and reduce the degree of afterdrop. Fifty-nine of 120 patients were randomized to receive a sodium nitroprusside (SNP) infusion during the rewarming stage of hypothermic CPB. Mean systemic vascular resistance (SVR) during the rewarming phase of CPB was 1129 dyne s-1 cm-5 in the control group and 768 dyne s-1 m-5 in the SNP group (P < or = 0.001). Patients receiving SNP rewarmed to 37.0 degrees C faster (299 min vs 376 min; P = 0.003) and were extubated earlier (490 min vs 621 min; P = 0.001). Patients receiving SNP had a warmer mean peripheral temperature (MPT) (32.9 degrees C vs 32.4 degrees C; P = 0.05) on termination of CPB. Postoperative core temperature fell less in the SNP group (35.6 degrees C vs 35.2 degrees C; P = 0.01) as did MPT (31.8 degrees C vs 31.2 degrees C; P = 0.004). SNP-induced vasodilatation during rewarming from hypothermic CPB improves peripheral rewarming, reduces the degree of postoperative core and peripheral hypothermia and reduces time to extubation
Detecting slope deformation using two-pass differential interferometry:Implications for landslide studies on Earth and other planetary bodies
No full textLandslide features have been identified on Earth and the Moon, Mars, Venus, as well on the Jovian moons. By focusing on a terrestrial landslide complex we test the operational parameters of RADARSAT-1 and the use of two-pass differential interferometry to detect change, to map its extent, and to measure the amount of movement over a given time period. RADARSAT-1 was chosen because of its variable imaging modes and geometry. For investigations of landslide motions using remote sensing techniques, repeat-pass data are required. Synthetic aperture radar (SAR) interferometry (InSAR) can ideally monitor movements across the whole surface of a landslide to a millimeteric precision, yielding a coverage significantly better than that obtained by ground instrumentation. Obtaining optimal data for InSAR analysis requires controlled orbital characteristics and imaging geometries, an understanding of the landslide characteristics and behavior, a cooperative surface, and mitigation of the factors that can affect phase. Using two-pass differential interferometry, a slope deformation map has been generated from RADARSAT-1 data for part of the Black Ven landslide (2°52′W, 50°40′N), on the south coast of England. Four months separate the InSAR pair during which time 0.03 m of subsidence was measured. From this a movement rate of 0.09 m/yr can be calculated. This agrees well with ground observations and an in situ record of movement, thus demonstrating that the technique can be used to investigate landslides. With further refinement it can provide more direct measurements of landslide deformation on Earth and other planetary bodies than are currently available
Hands-on defibrillation: theoretical and practical aspects of patient and rescuer safety
No full textDefibrillators 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
No full textIntroductionCurrent 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
SAR Interferometry in landslide monitorino: experience from Black Ven Landslide, Dorset 2001
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Defibrillation during renal dialysis: a survey of UK practice and procedural recommendations
No full textIntroductionDefibrillation 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
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