Simulating Haemorrhage in Medical Students

Abstract

This article is a descriptive report of a novel way of teaching the cardiovascular response to progressive haemorrhage in a first year medical undergraduate setting using simulation. Simulation may provide the means to allow students to see in practice the theoretical knowledge they have gained from lectures, thus giving clinical relevance to that knowledge, which may improve retention. A progressive haemorrhage is simulated in a volunteer medical student by applying sub-atmospheric pressure to the air surrounding the lower body using a lower body negative pressure (LBNP) chamber. This sub-atmospheric pressure will result in 'pooling' of blood in the vessels (particularly veins) of the legs and pelvis. This 'pooling' will reduce the amount of blood returning to the heart (venous return) and thus mimic the effects of loosing blood from the cardiovascular system. The body responds by engaging the various physiological responses to blood loss. To demonstrate these responses a range of cardiovascular parameters are monitored throughout the demonstration to allow students to observe the response to progressive haemorrhage. One of these parameters is cardiac stroke volume, which is monitored by using a portable ultrasound device. In addition to demonstrating an important point of physiology that the students have just encountered in their lectures, using the ultrasound device also fulfils an aspiration by the General Medical Council (GMC) to familiarise medical students to clinically relevant 2-dimensional imaging equipment early in their studies. Conclusion: Durham University Medical Programme uses simulation to reinforce didactic teaching of the cardiovascular response to haemorrhage utilising a LBNP chamber. The use of simulation in medical education is becoming increasingly more commonplace as its potential benefits are recognised. The simulated haemorrhage may provide the means to allow students to see in a 'clinical' context the theoretical knowledge they have gained from lectures, which may improve knowledge retention.