Biphasic defibrillator monitor delivers electric current in two directions – first positive, then negative – after the electric energy is discharged. In other words, it transmits electric current in both directions. During the first phase, current flows from one electrode to the other as in a monophasic defibrillator. During the second phase, in turn, the current starts to flow in the opposite direction. Various research has shown that biphasic waves provide successful defibrillation with less energy than monophasic waves, and are less harmful. Moreover, undesired side effects such as skin burns are reduced since the same result can be achieved by using less energy.
Various research has shown that biphasic waves provide successful defibrillation with less energy than monophasic waves, and are less harmful. Moreover, undesired side effects, such as skin burns, are reduced since the same result can be achieved by using less energy.
Even though the Life-Point biphasic defibrillator monitor, which also has a monitor feature, has a biphasic waveform, it is a defibrillator model designed for use in hospitals and ambulances. The Life-Point PLUS biphasic defibrillator, which has a handle for portability, monitors the patient’s 12-channel ECG, and prints out ECG waveforms with its high-resolution printer, if required. In addition to these, by adding optional features, such as the SpO2 (pulse oximeter) / EtCO2 (End-Tidal Carbon-dioxide) / NIBP (non-invasive blood pressure) / Pace Maker / AED, it can be used as a bed-side monitor.
What is the difference between Life-Point PLUS biphasic defibrillator monitor and monophasic defibrillators?
Biphasic defibrillator monitors generate an electric current flowing in a positive direction for a certain period of time after electrical discharge, and then in a negative direction for the remaining milliseconds. Moreover, they can electronically resist transthoracic impedance variations by adjusting the magnitude and continuity of the waveform. Defibrillators generating discrete exponential and rectilinear waveforms are available, but the optimal durations of their first and second phases, or which waveform to use in which type of ventricular defibrillation is not yet clear. However, the advantage of biphasic waveforms over monophasic waveforms in sustained ventricular fibrillations has been shown, and this recommendation was included in the latest resuscitation guides.
What Is a Defibrillator Device?
Defibrillators are categorized according to waveforms and usage.
In terms of waveforms; * Biphasic Defibrillator Monitors * Monophasic Defibrillator Monitors
In terms of usage; * Automated External Defibrillators * Manual Defibrillators
A defibrillator is a device, which delivers a high intensity electric current to the heart in fibrillation for a short period of time, in order to regain the heart’s normal rhythm. In short, they can be described as electroshock devices.
If fibrillation affects the ventricle, the heart quivers instead of pumping blood to the body by contracting effectively. As circulation stops, in this clinical picture survival is not possible. In such a situation, delivering an electroshock to the heart with a defibrillator should stop ventricular fibrillation.
What is Defibrillation?
The procedure applied to restore the normal functioning of the heart by delivering a direct current to the heart in order to eliminate irregular fibrillations is called “defibrillation.”
In brief, it is the procedure used to deliver a large electric current to the myocardium for a very short period of time.
It aims to revert the states of VF/VT without pulse back into normal sinus rhythm.
The defibrillation procedure is performed using a defibrillator.
What is electrocardiography (ECG)?
ECG is the waveform that records the electrical activity of the heart (cardiac rhythm, frequency, the rhythm and propagation of heart beats, and the dampening of the reaction) using electrodes placed on the skin.
Electrocardiography is an examination method based on printing on cross-sectional paper the electrical activity that occurs during the contraction and relaxation phases of the heart’s atria and ventricles, the stimulation of the heart and the transmission of the impulse.
It is an image of the heart’s electrical map. Information on the shape of the heart can also be obtained using ECG. The record of an ECG device is called an electrocardiogram.
In ECG, a complex waveform is seen, consisting of P, Q, R, S, T and U waves, which correspond to each heart beat. Changes in these waves, seeing waves other than these regular waves, and changes in the duration between waves, provides certain clues to physicians on heart disease.
What is cardioversion (synchronized defibrillation)?
Cardioversion is the procedure used to deliver a low dose of electric current to the patient in rhythm disturbances such as VT with pulse, atrial fibrillation (Af) and atrial flutter (AF). If ventricular rate is over 150 bpm, urgent cardioversion is required. The shock to be delivered in order to revert VT with pulse, Af and AF back to normal sinus rhythm is applied simultaneously with the R-wave of the QRS complex in ECG. This is called synchronized cardioversion.
Cardioversion is applied using a manual defibrillator. Using the “sync” (synchronization) button on the defibrillator,
R-wave of the patient’s ECG is captured; in other words, synchronization with the R-wave
is ensured. This procedure is called “sync-defib” or cardioverter. The R-wave is seen as
marked on the monitor. The energy level in cardioversion is lower than the energy level in defibrillation. If, instead of being synchronized, this low dose of energy is delivered as in defibrillation and during the re-polarization of the cardiac cycle, it may lead to VF. If cardioversion leads to VF, defibrillation should be applied immediately.
What is the difference between unsynchronized and synchronized defibrillation?
While unsynchronized defibrillation delivers an electric current at any point in the cardiac cycle, cardioversion delivers an electric current at the large R waves or synchronously with the QRS complex.
What is a biphasic defibrillator monitor?
Life-Point PLUS biphasic defibrillators are types of defibrillators that can be used by professional medical personnel, based on the interpretation of the ECG rhythm.
Life-Point PLUS biphasic defibrillators are medical devices that are employed in the treatment of cardiac problems. They are applied by physicians, using the device’s paddles to deliver an electric current through the patient’s chest, depending on the clinical picture of the patient and the medical diagnosis. Biphasic defibrillators are used in various cardiac situations, such as ventricular fibrillation and ventricular tachycardia. Basically, manual defibrillators are devices that are used to successfully restore heart functions in critical or emergency situations.
What does arrhythmia mean?
Arrhythmia means rhythm disorder. Arrhythmias are caused by problems in the origination or the transmission of the electrical impulse which ensures the contraction of the heart. Contrary to what was often though, arrhythmias do not always mean an irregular heartbeat.
What is atrial fibrillation?
Atrial fibrillation (AF) is one of the most frequently observed arrhythmias. In AF, rather than propagating in a regular fashion, electrical impulses create numerous impulse waves simultaneously, moving in different directions in the atrium, and competing with each other to pass through the AV node. These impulses are caused by tissues, which are not normally part of the heart’s electrical system. When these impulses are generated, they lead to a very rapid and disorganized cardiac rhythm. The number of impulses in the atrium is between 300 and 600. However, AV node limits the number of impulses that are transmitted to the ventricle. In the end, the pulse rate usually remains below 150 beats, but it may also be fast enough to cause complaints. (Dr.Ahmet Alpman)
Why is atrial fibrillation dangerous?
Many people with atrial fibrillation (AF) lead a problem-free life for years. However, as the atria contracts rapidly an irregularly, blood flow cannot be as fast as it used to be, which in turn facilitates blood clotting in the atria. If these clots break loose and are pumped from the heart, they may occlude veins in the brain, which in turn leads to stroke. Compared with the general population, the risk of stroke in people with atrial fibrillation is five times higher. While around half of the clots in patients with atrial fibrillation move to the brain, causing stroke, the other half moves to other organs (kidneys, intestines, heart), also causing problems. In the presence of an additional cardiac disease, atrial fibrillation may lead to a 20-30% decline in the heart’s systolic strength. This is important, especially in AF, which develops as a result of valvular heart disease such as mitral stenosis, for the patient’s complaints drastically increase with the development of atrial fibrillation. In the long-run, atrial fibrillation accompanied by rapid a heart rate may result in coronary failure. (Dr.Ahmet Alpman)
Warnings Regarding Defibrillation Use
The defibrillation procedure is applied with an accessory called an electrode / paddle / pedal. Gel should be applied to the pedals being used. It is necessary to ensure that there is no gel connection between the paddles. Electrodes should be compressed by approximately 10 kg in adults, and 5 kg in children. As the electrode should be firmly attached to the chest wall, if the chest is excessively hairy, it should be shaved, unless doing so would lose too much time. Before pressing the discharge button, you should make sure that nobody is touching the patient. If there is a transdermal patch on the patient’s thorax, you should pay attention to ensure that it does not come into contact with the electrodes.
The Strength of the Paddles
If you are using defibrillator paddles, hold them firmly against the chest wall. With such tight contact between the electrode and the skin, the resistivity and the volume of the chest will decrease. The person who performs defibrillation should not apply a force greater than 8 kg in adults and 5 kg is children. In the event of only the strongest member of the resuscitation team being able to apply a force of 8 kg, then it would be more appropriate to have that member perform the defibrillation procedure, since paddles have conductive metal surfaces which, on its own, cause resistivity to increase and as the possibility of sparking is high, they may cause severe burns on the patient’s skin.
CARDIAC ARREST RHYTHMS
A- Ventricular Fibrillation
Characteristic ventricular fibrillation is usually easily recognized; hence, this is the only rhythm that does not require a systematic rhythm analysis to be made. It is a situation in which electrical impulses that drive heartbeat are completely irregular. As a result, rather than contracting, ventricular muscles quiver and ventricles fail to pump blood to the body. When ventricular fibrillation is suspected, the patient should be assessed in terms of ventricular fibrillation, which requires urgent defibrillation and an artifact related appearance. If there is a pulse, the rhythm in question cannot be ventricular fibrillation.
B- Ventricular Tachycardia
Ventricular tachycardia may cause a marked decline in cardiac flow rate and cardiac arrest, especially at high heart rates or in the presence of structural cardiac disease (e.g. left ventricular dysfunction, severe left ventricular hypertrophy, aortic stenosis). Ventricular tachycardia may suddenly turn into ventricular fibrillation. Ventricular tachycardia with no pulse should be treated with early defibrillation as in ventricular fibrillation.
A high-frequency depolarization of a point on the ventricular myocardium causes this rhythm. Such excitation passes through the ventricles
following an abnormal pattern, hence QRS complexes take a wide and abnormal form. The lack of a P wave and abnormally wide QRS waves are typical of ventricular tachycardia. QRS morphology may be monomorphic or polymorphic. In monomorphic ventricular tachycardia, the rhythm is either regular or close to regular, whereas in polymorphic tachycardia, the rhythm is irregular.
This is the failure of the heart to perform the rhythmic contractions called systole. Since circulation will stop when these contractions do not occur, death is inevitable. Asystole may either occur as a result of a heart disease or as the end stage disease. The lack of pulse and the inability to hear cardiac sounds with a stethoscope are the signs of asystole. Since the heart is already depolarized, defibrillation is not performed. Sometimes asystole and fine ventricular fibrillation can be confused. Early treatment in this case is to perform a high-quality cardiopulmonary resuscitation and to continue monitoring the patient. If fine ventricular fibrillation is present, performing effective cardiopulmonary resuscitation may increase the amplitude and frequency of ventricular fibrillation, and this may increase the chance of successful defibrillation, as it confirms the diagnosis.
Pulseless Electrical Activity – This term does not imply a specific cardiac rhythm. It is characterized by a lack of the cardiac flow rate that electrical activity is normally expected to generate. It usually has a bad prognosis (especially when it develops as a result of myocardial infraction which affects a large surface). Massive pulmonary thromboembolism, tension pneumothorax, cardiac tamponade and acute massive hemorrhage are potentially treatable causes. Defibrillation should not be performed; effective treatment is cardiopulmonary resuscitation.