Until the recent development of the biphasic defibrillators, all defibrillators on the market were monophasic, with the technology remaining largely unchanged since the 1960s. Today, however, new technologies have made it possible to better control and deliver treatment. The sections below discuss some of the differences between these two different defibrillators and what those differences mean for you.
Biphasic defibrillators deliver currents in two directions. In one direction, the current moves from one defibrillator paddle to the other. Then, the current reverses. Although the exact reason is unknown, this multiple direction current lowers the threshold for successful defibrillation, saving more lives.
Speed of Defibrillation
Research shows that the speed of the first shock matters greatly. Even very small time differences in the first shock can change the overall outcome. Studies suggest that biphasic defibrillators perform better in terms of speed and efficiency on the first shock than older monophasic defibrillators. Most biphasic units have a first shock success rate of over 90 percent.
Along with the speed of the shock, a defibrillator needs to deliver an appropriate treatment level for a correct period of time. The defibrillator has to be able to shock the heart at the right current through a patient's chest. In older, monophasic models, this required a great deal of energy.
With the newer defibrillators, less energy is required to achieve the proper treatment level and units have been designed to be effective at lower current levels. The lower energy levels reduce the rates of burns and myocardial damage that were found in older models.
Personalization of Defibrillator Wave
Another critical aspect in defibrillator performance is the design of the waveform. A waveform should deliver a changing pattern of current to the patient throughout the shock, adjusting for any obstacles. Biphasic defibrillators adjust the waveform as needed to deliver the best possible waveform at any given time. This helps the current flow through to the heart.
Medical professionals believe biphasic waveforms are more effective at lower energy than monophasic waveforms. The American Heart Association considers biphasic defibrillators as safe and effective as traditional methods and includes this treatment in its cardiac life support guidelines.
Due to its speed, dosing and personalization of waveforms, biphasic defibrillators are commonly used to help save lives. Their lower energy levels translate into fewer risks and the success rate of the first shock is high.