Ball to occlude the aorta during cardiopulmonary resuscitation
Jesus Manuel Labandeira in his doctoral thesis, read in the University of Navarre, tested this technique in pigs due to the similarity to the human cardiovascular system.
According to the results obtained by doctor Labandeira, the use of a occlusion ball in the aorta duplicates the blood pressure that goes to heart and brain during cardiopulmonary resuscitation.
Improving the results of CPR
Cardiopulmonary resuscitation (CPR) constitutes one of the most emblematic activities of emergency services since its introduction in the 60s. This technique involves ventilating the patient and applying him simultaneously a series of thoracic compressions. However, it has been observed that although the CPR is done correctly, blood quantity that circulates is limited, the blood flow does not even reach 50 % of normal values. Now the application of new techniques to increase blood quantity that goes to heart and brain is being tested.
In order to improve the results of CPR, Jesus Manuel Labandeira has made a kind of short circuit. It involves introducing a catheter with a ball through the groin via femoral artery and installing it in the aorta, under the diaphragm. When the ball is pumped up, blood is redistributed so that when blood comes out from heart it does not reach less vital extremities, but it goes to heart and brain, the most important organs.
According to doctor Labandeira, introducing a ball in the aorta, blood pressure that comes to heart and brain is practically twice as much as during normal CPR. At aortic arterial pressure it can be observed a similar phenomenon. The arterial pressure of a living person is 120 mm Hg systolic and 80 mm Hg diastolic (120/80). At the beginning of a standard CPR, the values are about 41 mm Hg systolic and 20 mm Hg diastolic (41/20). By using the ball the pressure is 74 mm Hg systolic and 39 mm Hg diastolic (74/39). They are low values, but it is twice as much as during normal CPR.
So the conclusion of the thesis of Labandeira shows that the use of a intra-aortic occlusion ball increases the systolic, diastolic and average arterial pressures, as well as the coronary and cerebral perfusion pressures. In order to obtain better results, it is important to apply this technique in time. On the other side, the necropsy carried out to pigs by Labandeira after the experiment shown that there were no internal damages produced in viscera or vascular structures.
Experiment with 14 pigs
The study of Labandeira has been done with fourteen pigs, because it is one of the most similar animals to human from the cardiovascular point of view.
A situation of cardiorespiratory arrest was introduced to the pig via ventricular fibrillation, once it was given an anaesthetic to avoid suffering. Then, CPR was started, subjecting the pig to four periods of five minutes each, alternating the CPR with and without intra-aortic occlusion ball. The results with the ball were better than without it.
Bearing in mind the future application of that system in humans, the introduction of a ball into the aorta does not suppose a significant difficulty from the technical point of view, because the femoral artery is relatively a simple way of vascular access, allowing the introduction of the catheter in less that five minutes.
The thesis of Labandeira has been published in the scientific magazine American Journal of Emergency Medicine. Actually, two more groups of scientist are investigating this subject; one in Sweden and the other one in the United States.
Garazi Andonegi | alfa