About SSECT
The Perfusionist
PERFUSION – A SMALL ALLIED-HEALTH COMMUNITY
Patients undergoing heart surgery require cardiopulmonary bypass support (CPB) when their hearts and lungs are temporarily incapacitated. Their vital functions are taken over by artificial extracorporeal devices. This allows the cardiac surgeons to perform crucial procedures to mend the ailing heart. Though a serious insult to the human body, it is, nevertheless, a necessary evil.
During cardiopulmonary bypass (CPB), deoxygenated blood from the patient is drained to an external gas-exchange device called the ‘oxygenator’ where it become oxygen-enriched blood and is pumped back to the patient. While on CPB, the perfusionists manage the patients’ haemodynamic and physiologic parameters, keeping everything under tight control. Even in patients with perilous conditions, it provides a window for parameters that have drastically deviated from normal to be corrected or optimized.
Cardiovascular Perfusionists are allied-healthcare professionals working intimately with the Cardiac Surgeons and Cardiac Anesthetists in providing crucial life-support during open heart surgery. The Perfusionists are knowledgeable about a variety of specialized equipment available; he or she is also responsible, in consultation with the surgeon, for selecting the appropriate strategy or technique to achieve optimal outcomes for the patients.
Perfusionists are required to concentrate for long periods of time while keeping track of the patient's vital signs throughout surgery. They must notify the surgeon immediately of any changes, and be able to respond promptly to the surgeon's requests. They must be detail-oriented, follow instructions thoroughly, and able to respond quickly and appropriately to emergency situations. Perfusionists are required to work well independently, under pressure and through crisis.
At times, Perfusionists are also involved is providing long-termed cardiovascular support in the Cardiothoracic Intensive Care Unit (CTICU). They set up the support systems and also provide all the accessories required for instituting Extracorporeal Life Support (ECLS). During such critical events, the Cardiac Surgeon, Intensivist, Perfusionists and ICU Nurses work together to manage and optimise the patients’ outcome. This involves paying attention to pertinent details, making vital adjustments and troubleshooting when difficulties arise. The Perfusionists also participate in the process of weaning the patient from ECLS.
The management of cardiovascular perfusion of cardiac surgical patients demands teamwork, agility and flexibility in attending to critical issues that emerge. The objective is to provide safe and professional services, incorporating cutting edge technology and expertise.
History of Heart Surgery and Perfusion
In 1813, Le Gallois first promulgated the concept of “Artificial Circulation”. He argued that "life may be preserved by external perfusion in any portion of an organism even though separated from the rest of the body".
As in most sciences, ideas led to tinkering in the laboratories. Based on the experiments of many pioneers from that time, after apparent death, the vital functions of organs and other anatomical parts could be temporary restored and maintained by permitting blood to pass through them.
Various apparatus and machines were created to move blood and to give them life-sustaining properties. With many breakthroughs in medicine and engineering, of creating extracorporeal circulation was slowly, but surely becoming a reality. The discovery of heparin in 1916 opened up greater possibilities and rapidly advanced the quest for a life-sustaining machine.
In 1937, Dr John H. Gibbon, Jr. designed an apparatus with a vertical rotating cylinder that filmed blood to oxygenate it. Blood was moved with a modified pump to maintain circulation. This permitted the bypass of the heart and lungs in experimental animals. His heart-lung machine was further perfected, intended for eventual use in humans.
On May 6 1953, Dr Gibbon used the heart-lung machine to provide cardiopulmonary bypass support for an 18 years old girl during the closure of an atrial septal defect.
Dr Gibbon’s machine has helped ushered in the age of open-heart surgery as we know it today. This new era of cardiac surgery has benefited countless of people around the world.
Heart Surgery in Singapore
Singapore has made tremendous strides in many fields since gaining independence from the waning British Empire in 1965. Many facets of our country were developed rapidly, propelling us to the forefront in many fields in a short few decades. As we progress, diseases that were once common were gradually eradicated. New ones loomed into prominence. Cancer and heart diseases has become the major health concerns and account for a large proportion of the health care costs. Economically, we have done well to be able to provide affordable world-class healthcare services to its people.
The brave new field of heart surgery reached our shore in the early 60’s. In 1963, experiments were conducted with dogs using a crude heart-lung machine that consisted of metal plates to oxygenate and propel blood. This pioneer team comprise Dr Yong Neng Kiong, Dr Foong Weng Cheong, Dr Ong Siew Chay, Mr Gomez and Mr Allan Cheang, The latter two gentlemen, who were laboratory technicians, had the roles as “pumpers”. The experiment involved creating defects and repairing them and also practices conducting cardiopulmonary bypass. Unfortunately, the results were discouraging, as hemolysis led to the death of many of the dogs.
Subsequently, an improved heart-lung machine became available. This uses roller pumps and the oxygenator was a huge cylindrical object with numerous (approximately 140) discs inside. Each disc has to be thoroughly cleaned, dried, siliconized and bake at 100oC, resulting in their surfaces being non-wettable. When these discs are rotated, a film of blood is taken up and become oxygenated in oxygen-enriched air. However, this machine was less traumatic but required about 5 units of blood to prime.
On 10 January 1965, Dr Yong Neng Kiong performed the first open heart operation in Singapore, repair of an ASD in a 25 years old Chinese female.
Dr N C Tan subsequently led the government’s effort to establish cardiothoracic surgery in Singapore. The first case at Tan Tock Seng Hospital was performed in January 1967. The first few perfusionists were sent for short overseas training in Australia and New Zealand. Heart surgery eventually moved to the expanded Singapore General Hospital.
Changes Over the Year
Heart lung machines and the associated oxygenating devices created at the infancy of cardiopulmonary bypass were very big, dwarfing the patients they were meant to support. They required large quantities of banked blood to prime. They were difficult to operate and caused considerable damage to blood components. The oxygenating devices were reusable and had to be laboriously cleaned after each use and prepared before the next use.
These devices saw gradual improvement in terms of size and efficiency over the years. In 1953, Dr Gibbon successfully use a machine to support a patient while he "closed a hole in the heart".
The first generation of compact oxygenators, circa 1970s, were the bubble oxygenators. In these oxygenators, numerous oxygen-enriched air bubbles were sent through venous blood draining from patient. Gas exchanges took place directly across blood/air interface. However, these are far from being ideal oxygenating devices, with many deleterious impacts on patients.
They were supplanted, in the mid 1980s by the mircoporous hollow-fibre membrane oxygenator. These were great improvement, effectively prevented the direct air-blood interface yet allowing efficient gas exchanges. A further improvement was made when the blood and gas flow paths were interchanged.
In the 1990s, biopassive coatings were also invented to make the extracorporeal circulation gentler to the blood and the human body. The extracorporeal circulatory circuit was also miniaturised, bringing about greater benefits to the patients.
A brave new frontier was breach when surgeons were able to operate on a small selected group of patients without stopping their heart.
As time passes, new advances will be continuously incorporated that would bring about greater benefits to our patients.
Perfusion Training
As the number of hospitals offering heart surgery in Singapore increased, the demand for perfusionists grew in tandem. Technicians from related fields or those with knowledge of mechanical processes were deemed suitable for training to ‘run the pump’. Several were sent overseas to Australia and New Zealand. Upon returning, they took new ones under their wings. The training of perfusionists during the infancy of cardiac surgery was simply an ‘on-the-job’ process, under the supervision of the senior perfusionists. Several generations of perfusionists here were trained in such manner.
In 1991, the first locally-constituted perfusion course was conducted. It was a joint effort by the National University Hospital, and the Faculty of Medicine, National University of Singapore. It was supported by the perfusion community in Singapore.
The Certificate Course in Perfusion Technology was modelled upon the syllabus of the American Board of Cardiovascular Perfusion. It was initially a six-month course, composing of both didactic and practical components. The course, subsequently reduced to five months, catered to both local needs and that of regional countries where there were also no formal perfusion courses. In the one and half decades, when the course was conducted on average once every two years, a total of six courses were conducted, with the participation of 60 trainees from 8 countries.
In this internet age, resources are readily available ‘online’. Many centres openly share their knowledge, experience, suggestions and exchange of ideas and offer training courses. Many research papers and journals are also in the public domain. All these materials are at our fingertips, allowing a perfusionist to be cognisant with current practices and are in a better position to do what is best for the patient.
History of Singapore Society of Extracorporeal Circulation Technology
A group of perfusionists in Singapore applied to the Registry of Societies (Singapore) to establish the Singapore Society of Extracorporeal Technology (SSECT). The pioneer group of ten perfusionists submitted the application on 21 October 1983. The draft constitution was submitted on 6 December 1983.
The SSECT was successfully registered on 2 June 1984.
The first Annual General Meeting was held on 22 June 1984. The Protem President was Mr Goh Beng Seng. At that time, there were 2 hospitals offering open-heart surgery; namely Singapore General Hospital and Mount Elizabeth Hospital. The latter is a private hospital.
It took quite a while to obtain a logo for the SSECT. That materialised in January 1988, when a draft design was submitted to the Registry of Society. The registry approved the logo on 18 March 1988.
This was just in time for the 2nd Asian Perfusionists Meeting held in Singapore on 29 April 1988. The first meeting of its kind was held in Bangkok, Thailand on 21 May 1986. Three members from SSECT attended this meeting.
Objectives of the Singapore Society of Extracorporeal Circulation Technology
The SSECT is a not-for-profit organization that is dedicated to promoting excellence in the field of Perfusion Technology. It was established for the furtherance of the following aims and goals:
- To foster, promote and maintain the art of the members’ paramedical (Perfusion) skills;
- To maintain the highest standard of knowledge and practice of members in the profession
- To facilitate the growth and development of the profession with the provision and exchange of information and advances in the field of extra-corporeal technology.
- To establish affiliations with like-minded organisations with the aim of furtherance of the goals of the SSECT.
- To foster having the best interests of the patients in mind while providing our professional services.
It aims to be more active for the benefit of the entire perfusion community and provide quality care to patients.
Membership
There are currently about 30 practicing perfusionists distributed amongst 4 major hospital offering heart surgery. Some of these also offer locum services in a couple of smaller private hospitals that perform a smaller number of heart surgeries.
