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Mark Kurusz

Publications and source records attributed to Mark Kurusz.

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Invited commentary.

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Cardiopulmonary Bypass↗

Standards update on perfusion equipment and practice.

Standards applying to the manufacture, testing and labeling of perfusion components and equipment, as well as those dealing with clinical use of extracorporeal circulation, have been promulgated by both standards-setting organizations and professional organizations. The rationale and purpose for device standards are discussed, and many organizations and the processes involved in developing standards are described. Perfusion checklists used during equipment set-up, use and at termination have a long track record of acceptance by clinicians. Evolving techniques have prompted revisions to the basic perfusion checklist, which should be considered a guide for development of institution-specific checklists. Current and future work by international standards-setting organizations is described.

Cardiopulmonary Bypass↗

Bubbles and bypass: an update.

Bubbles in the bloodstream are not a normal condition--yet they remain a fact of cardiopulmonary bypass (CPB), having been extensively studied and documented since its inception some 50 years ago. While detectable levels of gaseous microemboli (GME) have decreased significantly in recent years and gross air embolism has been nearly eliminated due to increased awareness of etiologies and technological advances, methods of use of current perfusion systems continue to elicit concerns over how best to totally eliminate GME during open-heart procedures. A few studies have correlated adverse neurocognitive manifestations associated with excessive quantities of GME. Newer techniques currently in vogue, such as vacuum-assisted venous drainage, low-prime perfusion circuits, and carbon dioxide flooding of the operative field, have, in some instances, exacerbated the problem of gas embolism or engendered secondary complications in the safe conduct of CPB. Doppler monitoring (circuit or transcranial) primarily remains a research tool to detect GME emanating from the circuit or passing into the patients' cerebral vasculature. Newer developments not yet widely available, such as multiple-frequency harmonics, may finally provide a tool to distinguish particulate microemboli from GME and further delineate the clinical significance of GME.

Carbon Dioxide↗

Early techniques of extracorporeal circulation.

While the techniques and equipment used 50 years ago may seem primitive by today's standards, they did permit cardiac surgery to rapidly develop. As early as 1951, Karlson would write: 'Recent advances in surgery have made operations upon the heart much more than surgical stunts, and have opened a hitherto relatively untouched field of surgical endeavor. A few years later, Mustard would defend his abysmal series of repairs of congenital cardiac defects by saying, 'Our techniques of perfusion and operation have proved feasible in three human cases, but the results are not adequate to operate freely on good-risk patients at the present time. It is hoped that improvements in techniques will soon make this possible'. By the end of the decade of the 1950s. Gross would express the following: In the support of human patients on pump oxygenators, the intricacies of technic are many, and the extent of problems is broad, but much clarity of thought is now evident. We can set forth certain statements considered to represent truths or valuable viewpoints, since in most cases they have derived from scores of laboratory experiences during which some 800 dogs have been used by us, or else they have been crystallized from bitter experience at the operating table, or shattering disappointments in postoperative failures. Fortunately, many of the conclusions have sprung from happy and rewarding results exhibited by patients who have weathered corrective surgery in a very satisfactory manner. In closing, after reviewing the early perfusion literature, it is evident that many techniques used in the 1930s, 1940s, and 1950s persist to the present. Some techniques fell out of favor, such as elective hyperkalemic arrest, only to be re-established decades later. Simplicity is the hallmark of the most enduring techniques, a thought expressed by Lillehei in 1955. Somewhat amazingly, full automation of the extracorporeal circuit existed on some of the very early machines, but perhaps because of the explosive growth of cardiac surgery and the need for disposable circuits that could be rapidly assembled, the safety aspects of heart-lung machines were neglected for many decades. Some would argue it still has not realized its potential for elimination of error in the conduct of cardiopulmonary bypass. However, cardiac surgery would not wait, and in 1956, Osborn would boldly state: 'Extracorporeal circulation for surgery of the heart has now come of age.

Animals↗

The evolution of perfusion education in America.

Clinical cardiopulmonary perfusion has evolved significantly during its 50 years. The science, technology and educational processes related to cardiopulmonary bypass have undergone continual change and metamorphosis. Perfusionists were initially trained on the job or in the laboratory, but with the advent of myocardial revascularization and the explosion in cardiac surgery, the need for formal educational training programs became apparent. The American Society of Extracorporeal Technology began the arduous processes of credentialing and developing certification guidelines that have continued under the American Board of Cardiovascular Perfusion. Licensure has also been adopted in many states during the past 10 years where nearly 50% of all perfusionists are covered by some legislative act. One additonal challenge has been developing minimal standards in which perfusionists practice. The initial standards included the use of a checklist and have evolved to monitoring and recording the significant events and parameters of each clinical procedure. The education of perfusionists will continue to be a challenge related primarily to reduced fiscal resources, the applicant pool and the ever-changing demands for extracorporeal circulation services. According to demographic and census information, it is expected the overall number of cardiovascular interventions will increase dramatically towards the latter end of the current decade in the US. The question arises as to what role perfusionists will play, as treatment strategies continue to change. If the number of education programs and new graduates continue to decline, the total number of perfusionists will decline, especially as many senior perfusionists leave the field or retire. It may be difficult to predict the total number of cardiovascular interventions that will be required in the next several years. However, if the total number of cardiovascular interventions that require perfusion services increase as a function of the aging population and if the overall incidence of cardiovascular treatment does not change, it will be imperative that perfusion education ramp up and train more perfusionists to meet the supply and demand or a shortage of skilled personnel may develop.

Accreditation↗

Coronary sinus rupture with retrograde cardioplegia.

Coronary sinus (CS) rupture occurring during retrograde cardioplegia (RCP) is a rare complication. Patients with left ventricular hypertrophy are at higher risk for injury to the CS. The patient was a 66-year-old female with hypertension, ischemic cardiomyopathy and dysrhythmias, who had evidence of an anterior wall myocardial infarction, congestive heart failure and angina. During coronary artery bypass surgery, antegrade cardioplegia was initially administered, but aortic insufficiency prevented adequate myocardial cooling. RCP was then administered and the heart cooled appropriately. After approximately 300 ml of blood cardioplegic solution had been given, the CS pressure suddenly dropped from 30 mmHg to zero. RCP administration was stopped, and the surgeon palpated a hematoma over the area of the CS, which later ruptured upon rotation of the heart. A primary repair could not be performed, so a pericardial patch was placed over the area of disruption, which appeared to provide adequate hemostasis. The patient was weaned from cardiopulmonary bypass (CPB), but began to bleed freely from the CS distal to the pericardial patch. The patient was placed back on CPB to allow further repair of the CS, but the tissues were thin and friable and the ventricle disassociated from the ventricular septum. The situation was deemed not salvageable and further attempts at repair were stopped. The perfusionist should monitor infusion pressures and the CS waveform during RCP delivery. Changes in the waveform may indicate cannula malposition, loss of balloon seal, or, more rarely, CS rupture; such changes should prompt immediate cessation of RCP delivery.

Aged↗

Leukocyte filtration in lung transplantation.

Controlled reperfusion of the transplanted lung has been used in nine consecutive patients to decrease manifestations of lung reperfusion injury. An extracorporeal circuit containing a roller pump, heat exchanger and leukodepleting filter is primed with substrate-enhanced reperfusion solution mixed with approximately 2000 ml of the patient's blood. This solution is slowly recirculated to remove leukocytes prior to reperfusion. When the pulmonary anastomoses are completed, the pulmonary artery is cannulated through the untied anastomosis using a catheter containing a pressure lumen for measurement of infusion pressure. An atrial clamp is left in place on the patient's native atrial cuff to decrease the risk of systemic air embolism during the brief period of reperfusion from the extracorporeal reservoir. During reperfusion, the water bath to the heat exchanger is kept at 35 degrees C and the flow rate for reperfusion solution is between 150 and 200 m/min, keeping the pulmonary artery pressure <14 mmHg. Eight of nine patients were ventilated on 40% inspired oxygen within a few hours of operation and 7/9 were extubated on or before postoperative day 1. Six of nine patients are long-term survivors.

Animals↗

Percutaneous cardiopulmonary bypass for cardiac emergencies.

Percutaneous cardiopulmonary support systems (PCPS) are compact, battery-powered, portable heart-lung machines that can be implemented rapidly in any area of the hospital using thin-walled cannulae inserted via the femoral vessels. PCPS provides temporary circulatory support by actively aspirating blood from the patient's venous system using a centrifugal pump and hollow fiber membrane oxygenator for gas exchange. A review of clinical reports has delineated several indications for emergent applications, with the most frequent being cardiac arrest (CA) or cardiogenic shock (CS). Survival is more likely in patients with CS (40%) compared to CA (21%). Implementation of PCPS after unwitnessed CA or cardiopulmonary resuscitation > 30 min yields a patient survival rate of < 10%. The likelihood of patient survival after emergent PCPS is most often related to the patient undergoing a definitive anatomic surgical repair such as coronary artery bypass or pulmonary embolectomy. If the need for circulatory support extends beyond 6 h, conversion to conventional long-term extracorporeal membrane oxygenation or a ventricular assist device is recommended.

Cardiopulmonary Bypass↗