Till date, the most common mode of death in death certificates is cardiorespiratory failure. Even, if rest of the system and the body is intact, cardio/respiratory arrest is synonymous with cessation of life. Over the years, it was quite frustrating, to watch helplessly, our patients succumbing untimely, to cardiac and / or respiratory in sufficiency, after all machines and medicines fail to assist the heart and / or the lung to minimum efficiency.
ECMO: principles of treatment
Upto recent past, all modalities of critical cardiorespiratory management were assist therapy whether it may be IABP or ventilator or inotropes. They were to support the existing organ and improve its performance. If the organs are damaged beyond a particular limit, they require absolute rest for recovery. Further step up in assist mechanism will create more harm than good. Also, if rest to the organ is not given timely, it will lead to cumulative and collateral damages. At this particular stage of advanced organ damage or malfunction, the mainstay of recovery is rest and substitution. Since, respiration and circulation can not take rest throughout life, ECMO appears as the only makeshift arrangement in this juncture. It is always wise to take a timely decision to switch over to temporary replacement treatment after assist therapy has failed and before secondary multiorgan failure has set in.
ECMO stands for Extracorporeal Membrane Oxygenation. ECMO comes under the auspices of ELSO (Extracorporeal life support organization) is a useful modality of mechanical circulatory/ventilatory support (MCS) for refractory cardiorespiratory failure. ECMO is a form of replacement therapy from extracorporeal route for a defined period of time.that can support the patient’s body when his own heart and/or lung function is inadequate. The technology of ECMO is similar to the heart-lung bypass techniques used in cardiovascular surgery.
ECMO is a set of machines used for temporary replacement treatment of heart and/or lung function by mechanical means via extracorporeal route. Blood drains from the patient through a tube (catheter) placed in a large vein. This blood passes through a plastic pouch, or bladder, and then in pumped by a mechanical pump which serves as a artificial heart . This heart pump provides the necessary force (blood pressure) for the blood to circulate without and within the body. The blood is then diverted inside the tubings to a artificial lung (respiratory filter) for oxygenation and removal of carbon dioxide. The blood then passes through a heat exchanger that maintains the blood at normal body temperature. Finally, the blood re enters the body through a large catheter placed in an artery in the neck or leg with pressure and oxygen to perfuse and ventilate the cells of the body.
Types of ECMO
There are two different ways for ECMO to support a patient. The first method is called venoarterial or VA bypass. VA ECMO will support the heart and lungs. One cannula is placed in the right atrium of the heart (filling chamber) and a second cannula in the aorta (main artery of the body). The second method is called veno-venous or V V bypass. This is used for lung support only. This type of ECMO requires only one / two catheters to be place through large vein in leg and /or neck.
Other applications of ECMO
We feel, there is a great future of ECMO due to its wide applications, like rescue circuit, first line short term replacement therapy in all refractory acute heart or lung failure, e-CPR, organ preservation in brain dead donors and switch over therapies.
ECMO: advantages and challenges
It is a simple percutaneous procedure which can be initiated in short time. It can be done at bed side in any ICU without the need of any specialised machines. It is portable system and allows patients to be shifted across great distances by any transport and can be combined with other support systems. It has great flexibility and various combinations can be designed to support only heart / only lungs or both heart and lungs.
Management of the ECMO circuit is done by a team of ECMO specialists that includes intensive care unit (ICU) physicians, pulmonologist, cardiologist and intensivist, perfusionists, respiratory therapists, Medical Laboratory Technologists and registered nurses that have received training in this speciality. ECMO has shown great utility in all age groups from pediatrics to geriatrics. With increasing usage and indications, the results are promising and life rewarding.
There is lot of physiology involved about hematology and haemorheology, physics of cannulae and pump, chemistry of respiratory membrane and hemofiltration, biology of the living, dying and dead cells, pathology of the disease process and overall medical management of the entire corpus. Thus, entire science is at work and the operator has to master of all and not jack of one. The challenge is worth taking and success is gratifying to the extent of playing GOD.
ECMO SOCIETY OF INDIA
ECMO is widely applied in specific indications all over the western hemisphere for more than silver jubilee years. We have been quite late in adopting this power of science i.e. ECMO due to its complexity and logistics. It is a multidisciplinary project requiring a team approach. It is a novel technology and should be adopted with utmost meticulousness and sincerity because your results grows with experience.
Since the patient population reaching ECMO criteria are limited. We should learn from other mistakes. This has led us to start the “ ECMO society of India ”. The root motive of this national registry is to maintains uniformity of data entry. Every one should contribute to streamlining the methodology of working protocols and record upkeeping, and thus, reach valuable statistical inferences at the end of the day.
Every country has their own ECMO society which follows advise and instructions at international level. Thus, every member have an access to large and valuable international registry data of more than 50,000 patients which is not possible for an individual in his lifetime.
We seek your suggestions on the same and invite you to join the group if you are interested in starting a ECMO programme at your centre.