Defibrillators, Undergoing Metamorphosis

Traditional defibrillators with a single, pulse-modified Lown waveform is gradually being replaced with a biphasic, modified Lown waveform having additional advanced multifunctional features.

Life is precious! It should not be allowed to go easily and one should be always prepared to take all possible necessary actions to save it. A single shock, if given at the right time can prevent someone from dying. Every year, a lot of people die of heart attack and severe arrhythmia (irregular heartbeat) resulting in sudden and uncertain cardiac death due to the lack of medical knowledge amongst the people around. Basic knowledge of cardiopulmonary cerebral resuscitation (CPCR) can save the lives of many such human beings. There are a lot of instances, where people lost their lives, in the absence of immediate medical help and needful measures. Necessary medical devices like defibrillators can convert/revert life-threatening arrhythmias of the heart and help to regain the normal rhythm of the heart.

Defibrillators are so important not only because they can save lives with defibrillation but also can be used as a transport monitor. Most defibrillators are configured with ECG, most have external pacing capability, pulse oximetry, and even CO₂ monitoring. They are one of the most important and versatile devices in the hospital. Defibrillator devices are spreading with advances in technology, defibrillation methods, and the advancement of engineering. For the last couple of years technology of defibrillators has been gradually changing. Implantable defibrillators are available, using the same technology and implantation techniques used for pacemakers. They are highly effective and reliable. External defibrillators are undergoing a metamorphosis of sorts. What has been the tradition in defibrillators (a single, pulse-modified Lown waveform) is being replaced with a biphasic, modified Lown waveform.

As a result, the standards for defibrillation are changing, with lower maximum output required to achieve defibrillation. Also, a major change has been observed with the demand for higher parameters in the biphasic defibrillator, which include SpO₂, NIBP, and EtCO₂. This also makes it a multi-parameter defibrillator. We have been seeing an increase in demand for these parameters from the government sector lately. Automatic external defibrillators (AEDs) have become important outside a nursing floor. They can be found in an office area, cafeteria, at schools, and even at an auto dealership. AEDs allow the non-clinical person to perform defibrillation with no training. They are truly life-saving devices.

Government role in saving lives
In a bid to regulate medical and diagnostic devices in India, the health ministry has notified eight medical equipment, including all implantable devices, as drugs under Section 3 of the Drugs and Cosmetics Act, with effect from April 1, 2020. The medical equipment includes all implantable medical devices, CT scan, MRI equipment, defibrillators, dialysis machine, PET equipment, X-ray machine, and bone marrow cell separator. A majority of medical devices are unregulated in India. This move is important for patient’s safety as with this notification, all implantable and diagnostic devices will come under the regulatory framework. 

The government has also taken appropriate steps and made it mandatory to install defibrillators at crowded places like airports, railway stations, bus stands, workplaces, and parks; but in a country like India, where more than 50 percent of the population is living in villages and does not understand the gravity of the disease/cardiac arrhythmias and other ailments, one may not expect such devices will be used in a proper manner. Still, one life saved using such device, helps achieve goals and expectations. Therefore, it should be made mandatory for each and every student of schools, colleges, institutions, and each and every worker of any government or private workplace to know, how to operate the defibrillator and proceed for CPCR and have basic life support (BLS) training. The government should take necessary action and give some sort of subsidy in procuring such devices at the above mentioned places. Not only the government, but each and every health professional should also take the initiative to teach and inform about the use of such an important device, to all the people around. This will definitely change the scenario and will make a new beginning in the process of saving lives.

Technological advancements
Sudden cardiac arrest (SCA) has always been a major cause of concern worldwide; the keyword here is that it comes without warning. Statistically, over 80 percent of unexplained sudden death is attributed to SCA. And if that is not enough, more than 60 percent of the coronary artery disease cases reported worldwide are from South Asia.
Defibrillators act as the front line of defense against SCA. The older mono-phasic designs had the inability to maintain a relatively constant current flow for a significant amount of time. This is where the newer topology, the bi-phasic defibrillators come in. Employing sophisticated control mechanisms, they maintain a predefined amount of current during the entire phase of defibrillation while reversing the direction in between for better coverage. ECG monitoring is a default option available in defibrillators. With the new addition of pulse oximetry and capnography, these devices are all that is needed to confirm the return of spontaneous circulation. With the addition of transcutaneous pacing, it is possible to address any post recovery symptomatic bradycardia events; all using a single device.

The latest advances include, but are not limited to, having a more consistent shock with a higher confidence level. Another advancement is the ability to deliver more current. These are important because it is a matter of life and death and these devices need to be reliable. Many of the newest defibrillators now have wireless capability. This is used for recording events during codes and can be used to create reports of the actions taken during a code event. They have the capability to transmit ECG via wi-fi or cellular connection to the healthcare facility before the patient arrives. Most of the defibrillators now do automatic internal diagnostics usually once a day to ensure the defibrillator is working properly. Some also test the battery and report the status back to a central computer. Newer systems indicate when there is an issue with a lead or if it is not capturing pacing data which are often missed in an emergency. Many can be used as a full-fledged patient monitor with some having 12 lead ECG, pulse oximetry and CO₂ monitoring. CPR feedback and/or real-time feedback are new advancements that most manufacturers are adopting and SpCO (carbon monoxide) measurement for pre-hospital models is also becoming popular.

Advanced multifunctional biphasic defibrillators are also available in the market. They enable monitoring of patient’s vital signs, such as ECG, pulse oximetry, arterial pressure measured by non-invasive (NIBP) and invasive (IBP) methods, temperature, respiration, and end-tidal carbon dioxide. The energy impulse is precisely adjusted to the patient’s physical parameters, thanks to the analysis of the impedance during the impulse delivery. The use of this technology allows minimizing an injury of the heart muscle, relating to the delivery of too high defibrillation energy comparing to the energy chosen by a user. The device can perform defibrillation in a manual, synchronous (cardioversion) or automatic (AED) modes. The large, high-brightness color screen provides legible information about defibrillation and stimulation, as well as about measured patient’s parameters. Due to a wide range of available defibrillation energies (from 1 to 300 J) and integrated accessories, the new defibrillators are safe for both pediatric and adult patients.

Outlook
Currently, there are over a dozen different manufacturers of defibrillators in the market. They offer constructionally similar devices. The differences between them result primarily from innovativeness supported by competition. The lack of uniformity of devices is, therefore, the main reason for the occurrence of difficulties during training processes, as well as the subsequent use of the equipment in everyday life. An effective and more common access to defibrillation, therefore, has to be harmonized. In addition to technical issues, the aspect worth paying attention to in the future is the definition of uniform standards related to the external appearance of the AED.

There is also a definite need to create awareness among the buyers. Rural areas still prefer to buy monophasic defibrillators as they are cheaper than the biphasic defibrillators. Comparing the trend of last 2-3 years, the market shows positive growth for mainly biphasic defibrillators and AED (public access defibrillators). Along with EtCO₂, wireless data transmission and daily self-test function to be features in the near future. Looking forward, it seems that the defibrillator market in India will see a considerable amount of growth year-on-year. With most government tenders coming up with the requirement for advanced features and biphasic defibrillators being in huge demand, the market surely looks positive.