A counterbalanced cross-over study of the effects of visual, auditory and no feedback on performance measures in a simulated cardiopulmonary resuscitation

<p>Abstract</p> <p>Background</p> <p>Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR). Feedback on rate and depth mitigate decline in performance quality but not completely with the residual performance decline attributed to rescuer fatigue. The purpose of this study was to examine the effects of feedback (none, auditory only and visual only) on the quality of CPR and rescuer fatigue.</p> <p>Methods</p> <p>Fifteen female volunteers performed 10 minutes of 30:2 CPR in each of three feedback conditions: none, auditory only, and visual only. Visual feedback was displayed continuously in graphic form. Auditory feedback was error correcting and provided by a voice assisted CPR manikin. CPR quality measures were collected using SkillReporter^®software. Blood lactate (mmol/dl) and perceived exertion served as indices of fatigue. One-way and two way repeated measures analyses of variance were used with alpha set <it>a priori </it>at 0.05.</p> <p>Results</p> <p>Visual feedback yielded a greater percentage of correct compressions (78.1 ± 8.2%) than did auditory (65.4 ± 7.6%) or no feedback (44.5 ± 8.1%). Compression rate with auditory feedback (87.9 ± 0.5 compressions per minute) was less than it was with both visual and no feedback (p < 0.05). CPR performed with no feedback (39.2 ± 0.5 mm) yielded a shallower average depth of compression and a lower percentage (55 ± 8.9%) of compressions within the accepted 38-50 mm range than did auditory or visual feedback (p < 0.05). The duty cycle for auditory feedback (39.4 ± 1.6%) was less than it was with no feedback (p < 0.05). Auditory feedback produced lower lactate concentrations than did visual feedback (p < 0.05) but there were no differences in perceived exertion.</p> <p>Conclusions</p> <p>In this study feedback mitigated the negative effects of fatigue on CPR performance and visual feedback yielded better CPR performance than did no feedback or auditory feedback. The perfect confounding of sensory modality and periodicity of feedback (visual feedback provided continuously and auditory feedback provided to correct error) leaves unanswered the question of optimal form and timing of feedback.</p

[EXERCISE &quot;REFAJA&quot;: An exercise in the admission and treatment of groups of patients following a chemical accident, held on june 30, 1992 in Dordrecht.]

Abstract niet beschikbaarThe Drechtsteden Hospital, location Refaja is the first to participate in a national network set up for the admission and treatment of groups of patients exposed to physical, biological or chemical agents. The training offered the hospital the opportunity to admit patients from a mass-casualty chemical incident. For this purpose the hospital had available written protocols and was supported by the National Poison Control Center (NVIC) and the Emergency Hospital Utrecht. Major goals for the training were: - to activate the hospital as a participant in the national network of hospitals for chemical accidents coordinated by the medical assistance team of the NVIC/-Emergency Hospital Utrecht - to evaluate the written protocols for mass-casualty accidents and observe procedures - to evaluate medical en nursing aspects in patient treatment. The planning and the execution of the training are described. Conclusions are formulated as to the procedural and medical aspects in the training. Some of these show possibilities for the improvement in efficiency by a recognizable coordinator, the need to adapt to the quantity of patients and the registration of relevant (medical) data. Some suggestions are made to strengthen the disaster management plan.GH

[The admission and treatment of 14 victims from the aircraft disaster in Faro, Portugal, in the Emergency Hospital Utrecht in the period December 23rd through 29th 1992.]

On December 21st, 1992 the Martinair DC-10 charterflight MP-495, with on board 327 passengers and 13 crewmembers, crashed on landing in Faro, Portugal. Shortly after the crash the plane started to burn and exploded. Uninjured passengers and those with minor injuries were repatriated the following day. The majority of the patients who had been admitted to Portuguese hospitals followed on the 23rd. Of the patients repatriated on the 23rd, 13 were admitted to the Emergency Hospital at the University Hospital Utrecht. Two other patients were repatriated at later dates, of which one was appended to the group. The other patient (the 15th) was admitted directly to the surgical Intensive Care Unit. Within the Emergency Hospital they were placed in quarantaine, as foreseen by the Disaster Management Plan and the Methicillin resistant Staphylococcus aureus (MRSA) protocol. This report describes the admission and treatment of the patients. Of these patients, 13 were in stable condition. They had second and third degree burns of the extremities and of the face. Three patients required plastic surgical intervention. Two patients were shown to be contaminated with MRSA. The 14th patient required several days of ICU-treatment. The report also shows that disaster plans should be modular in structure, so that they can be used for admitting different sizes of groups of patients and that the quality of care supplied by different departments during the period of isolation in the special units is geared to the needs of patients.GH

Measuring Arterial Stiffness in Animal Experimental Studies

The arterial wall is a composite material of elastin, collagen, and extracellular matrix with acutely modifiable material properties through the action of smooth muscle cells. Therefore, arterial stiffness is a complex parameter that changes not only with long-term remodeling of the wall constituents but also with acute contraction or relaxation of smooth muscle or with changes in the acute distending pressure to which the artery is exposed. It is not possible to test all these aspects using noninvasive or even invasive techniques in humans. Full characterization of the mechanical properties of the artery and the specific arterial factors causing changes to stiffness with disease or modified lifestyle currently require animal studies. This article summarizes the major in vivo and ex vivo techniques to measure the different aspects of arterial stiffness in animal studies

The donders model of the circulation in normo- and pathophysiology.

Item does not contain fulltextThe solution of some recent as well as of long standing problems, unanswerable due to experimental inaccessibility or moral objections are addressed. In this report, a model of the closed human cardiovascular loop is developed. This model, using one set of 88 equations, allows variations from normal resting conditions to exercise, as well as to the ultimate condition of a circulation following cardiac arrest. The principal purpose of the model is to evaluate the continuum of physiological conditions to cardiopulmonary resuscitation (CPR) effects within the circulation.Within the model, Harvey's view of the circulation has been broadened to include impedance-defined flow as a unifying concept, and as a mechanism in CPR. The model shows that depth of respiration, sympathetic stimulation of cardiac contractile properties and baroreceptor activity can exert powerful influences on the increase in cardiac output, while heart and respiratory rate increases tend to exert an inhibiting influence, with the pressure and flow curves compatible with accepted references. Impedance-defined flow encompasses both positive and negative effects.The model also demonstrates the limitations to cardiopulmonary resuscitation caused by external force applied to intrathoracic structures, with effective cardiac output being limited by collapse and sloshing. Stroke volumes from 6 to 51 ml are demonstrated. It shows that the clinical inclination to apply high pressures to intrathoracic structures may not be rewarded with improved net flow