Image: Dr. Digna María González-Otero (R) and colleagues testing the algorithm on a mannequin model (Photo courtesy of UPV/EHU).
A new study describes how an algorithm that accurately computes the frequency and depth of chest compressions can improve the quality of cardiopulmonary resuscitation (CPR).
Developed at the University of the Basque Country (UPV/EHU; Vizcaya, Spain), the algorithm uses a CPR feedback device in order to compute both acceleration and compression signals during CPR in patients with cardiorespiratory arrest. In a validation study of the algorithm, the depth and rate values during actual CPR were estimated every two seconds from the acceleration data in order to guide compressions at the appropriate frequency of 100-120 compressions per minute (CPM) and at a depth between 5 and 6 cm.
The researchers also conducted a further study to assess the performance of the algorithm in terms of sensitivity and positive predictive value (PPV) for detecting compressions, and in terms of its accuracy through the analysis of measurement error. The results showed that the algorithm reported a global sensitivity of 99.98% and a PPV of and 99.79%. The median unsigned error in depth was just 0.9 mm, and the median unsigned error in compression rate was 1 CPM. The study was published on February 14, 2018, in PLOS One.
“The device functions when it is connected to the defibrillator, which tells the rescuer whether he/she has to press harder, work faster, etc.,” said app developer and lead author Digna María González-Otero, PhD. “We could say that it is a straightforward, intuitive accessory of the defibrillator and which is geared, above all, towards the emergency services. In fact, some emergency services are already using it to validate its use in actual patients, to see whether it works as expected, whether it is convenient for the rescuer, whether it meets expectations, etc.”
People suffering from a nonshockable out-of-hospital cardiac arrest (OHCA) are likelier to survive if given CPR. The 2010 American Heart Association (AHA) guidelines for hands-only CPR call for at least 100 chest compressions per minute for at least two minutes, at a depth of at least five centimeters in the center of the victim's chest.
University of the Basque Country