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This study investigates the psychological profiles of highly stressed medical technologists. One hundred and four individuals representing a cross-section of the United States who function as operators of heart-lung machines during open heart surgery (perfusionists) were studied using both internal and external models based on the works of Eric Berne and Karen Horney. Daily exposure to life and death responsibilities combined with the constant pressures of maintaining current technical skills can make the profession selected for this study representative of high technology professions that require a great deal of coping. Results of this study indicate that there is a balanced psychological profile in successful technologists functioning in long-term, high-stressed occupations. Female perfusionists appear to be more aggressive and critical than their male counterparts. This is seen as an attempt by female perfusionists to compensate for what has historically been a male dominanted, highly technical and high-stressed occupation. Generalizations for candidate selections to high stressed occupations could be made as well as projections of foundations for possible progressive disillusionment (burn out).

A 58-year-old male patient was posted for double valve replacement under hypothermic cardiopulmonary bypass (CPB). During aortic cross-clamp (AXC), the central venous pressure (CVP) was found to have increased to 22 mmHg. After 4 minutes of sustained increase in CVP, burst suppression (SR) started increasing. After 5 min of increase in SR, bispectral index (BIS) declined rapidly to 17. Propofol infusion was stopped and re-evaluation of signs of facial congestion showed changes to that effect. The perfusionist noted steadily decreasing venous return. As soon as the superior vena cava (SVC) cannula was withdrawn by 3 cm, CVP immediately declined to 6 mmHg. The venous return in the CPB reservoir normalized and BIS returned to 42 after a transient rise to a maximum of 58 and SR decreased to 0 within 2 min of repositioning of the venous cannula. The patient was successfully extubated after 7 hours without any sequelae.

Aims: CPB is an essential component of cardiac surgery, with still unknown device/patient interactions. In order to evaluate the response of CPB to hemodynamic, biochemical, inflammatory, as well as thermo- pharmacodynamic interactions, a novel miniaturized oxygenator with controlled and standardized specifications has been developed together with an improved surgical central cannulation technique. Methods: A hollow-fibre small priming volume (6.3ml) oxygenator was manufactured according to specifications resulting from engineering, heart surgery and perfusionist expertise (Dideco-Sorin Group, Italy) with the following characteristics: Gas Exchange Surface-450cm2, Heat Exchange Surface-16cm2. The oxygenator was tested in vitro and in vivo in 5 anaesthetised, ventilated, open-chest rats using a miniaturized roller pump and heat exchanger. Pressures were monitored in the animal, before and after the oxygenator. Central venous cannulation through the right atrium, and aortic cannulation, through the carotid artery, were used. Results:In vitro: blood oxygenation increased 10-fold (from room air to 100% FIO2) and PCO2 removal was 2.5-fold. In vivo: CPB was performed without blood prime for 60mins (no ventilation) maintaining stable haemodynamics. A maximal blood flow rate of 124ml/min/kg was obtained. Arterio-venous PO2 gradients were 10-fold (FIO2@100%) with only small variations when changing blood flow rates. Conclusions: The results obtained with this new, standardized and miniaturized hollow fibre oxygenator, new cannulation technique and CPB circuit, achieves optimal gas transfer with small asanguinous priming volumes. This study opens new potentials for various CPB-related study protocols in the small animal.

During cardiopulmonary bypass, the heart-lung machine and the patient's gas exchange systems (uptake and elimination) form an undissociable couple. Changes in one of the components lead to corresponding changes in the other. In the artificial lung, like in the natural lung and peripheral tissues, gas exchanges depend on several parameters: blood inlet conditions, blood flow rate, temperature, composition of the gas mixture used for ventilation, blood tissue perfusion, O2 consumption, etc. The perfusionist's primary objective is to obtain from the artificial lung adequate O2 delivery to and CO2 removal from the tissues. This paper discusses the main parameters which must be taken into account and analyses the main sensors currently available for in-line measurement of blood gases.

A perfusionist conducts cardiopulmonary bypass by managing a patient on a heart lung machine during open heart surgery. The perfusionist is responsible for taking corrective actions while the heart lung machine is working normally and under fault conditions. These responsibilities can be met only if the perfusionist has sufficient skills, dexterity and training. In this study, a simulator was developed to provide pre-clinical experience for perfusion students. The system is composed of a laptop computer (PC) controlling various solenoids, relays, and electronic components which are interfaced at a Sarns 9000 heart lung machine. Electronic components are connected to the parallel port of the PC. The software in the PC turns on or off relays and solenoids that affect the heart lung machine and the simulated patient. The system simulates the real operating room (OR) environment. The trainer can direct the system to work normally or cause the system to simulate problems that may appear during open heart surgery. Hence, the instructor can evaluate performance of the student by observing his or her reactions to the faults. The system was tested by a perfusion team and was found to be useful in training perfusion students prior to clinical rotations.

m t o o e i w i a p c ENO-VENO BYPASS (VVB) is widely used in liver transplantation to maintain hemodynamic stability during urgery by diverting blood from the inferior vena cava (IVC) nd the portal circulation back to the right heart.1 In addition, it as the additional benefits of decompressing the portal circuation, reducing the congestion in the lower extremities and planchnic circulation and allowing for more stability after pening of the cross-clamps to the graft; it also helps to aintain normothermia and can be used to regulate the blood olume and potassium in these patients. The complication rate, ase of placement, and time needed to place the cannulas are educed if used routinely on all patients. The routine use of VVB appears to vary across institutions.2 lthough some centers never use the technique at all and all urgery is performed by using a piggyback technique and no omplete clamping of the IVC, many use VVB in selected ases; others use the technique on all cases routinely, the xception being small pediatric patients. In centers in which the VB circuit is used selectively, the decision is based on surical technique (piggyback or standard) and the patient’s conition.3 Selection of these patients may be difficult to predict, lthough it is widely accepted as helpful in patients with ulminant hepatic failure, volume overload, or severe portal ypertension. Some centers decide on the use of VVB intraopratively by observing if the patient will hemodynamically olerate the clamping of the IVC.4 This approach means that the urgery would have to stop at that point to allow the placement f the VVB return cannula and allow the perfusionist to set up he pump, which adds additional time and inconvenience to the ntire team. The piggyback technique is becoming widely used for orhotopic liver transplantation and avoids the need to clamp the ntire IVC5; however, there is partial obstruction to flow in the

The heart-lung machine is perhaps the most important contribution to the advancement of surgery in the last century. This apparatus was designed to perform the functions of both the human heart and the lungs allowing surgeons to suspend normal circulation to repair defects in the heart. The development of a clinically safe and useful machine was the rate-limiting step to the development of modern cardiac surgery. Since its inception, the heart-lung machine has enabled the surgical treatment of congenital heart defects, coronary heart disease, valvular heart disease, and end-stage heart disease with heart transplantation and mechanical assist devices or artificial hearts. The heart-lung machine consists of several components that together make up a circuit that diverts blood away from the heart and lungs and returns oxygenated blood to the body. Commercial investment and production of these components has resulted in wide variability in the design of each, but the overall concept is preserved. During an operation, a medical specialist known as a perfusionist operates the heart-lung machine. The role of the perfusionist is to maintain the circuit, adjust the flow as necessary, prevent air and particulate emboli from entering the circulation, and maintain the various components of the blood within physiologic parameters. Keywords: cardiopulmonary bypass; cardiac surgery; assisted circulation; CPB circuit

Increasing perioperative haemoglobin level by reducing priming volume and maintaining a safe cardiopulmonary bypass (CPB) system is the aim of every perfusionist. In this study, we have compared the two membrane oxygenators and pump systems used for paediatric bypass at the Royal Children’s Hospital on a regular basis since 1988. We looked at all patients who had the Cobe VPCML (Cobe Laboratories, Denver, CO, USA) and Terumo RX-05 (Terumo Corporation, Tokyo, Japan) oxygenators used for flows from 800 mL/min up to the maximum rated flow for the respective oxygenator from January 2002 until March 2004. The VPCML refers to using only the 0.4-m2 section of the oxygenator. The pump systems used were the Stöckert CAPS (Stöckert Instrumente GmbH, Munich, Germany) and Jostra HL 30 (Jostra AB, Lund, Sweden). Changing from the VPCML to the RX-05 resulted in a 37% reduction in priming volume. The introduction of the Jostra HL 30 with a custom-designed mast system reduced the priming volume by another 15%. This change in priming volume allowed a significant increase, from 6 to 34%, in the percentage of patients who received bloodless primes, and for those patients who received blood primes, an increase in haemoglobin (Hb) on bypass from 8.2 to 9.6 g/dL, on average.

The fixed incidence of congenital heart defects and improved survival have resulted in increasing numbers of adults with congenital heart disease (CHD) who have undergone complex repairs and/or palliations. Eventually, there will be more adults with CHD than children. They will require cardiac surgical interventions associated with progression of their CHD or for age-related disease, such as coronary revascularization. During bypass, anatomical shunts may exist within or without the heart. Left-to-right shunts can result in dramatically lower systemic blood flow than pump flow due to ‘steal’, while pulmonary edema ensues due to excessive pulmonary flow. Right-to-left shunts carry risks of massive air embolism and double or triple venous cannulation may be necessary. Cannulation of composite reconstructed aortas may be difficult, risking dissection or aortic obstruction, and double arterial cannulation may be indicated. Aberrant coronary arterial and venous anatomy may preclude adequate myocardial preservation with common techniques and can be complicated by aortic insufficiency. Valves and conduits may exhibit failure. Conventional monitoring, such as central venous oximetry, may be misleading. Monitoring, such as serial lactate measurement, near-infrared spectroscopy and transcranial Doppler blood velocity, offer advantages for such patients. The perfusionist needs to be aware of such conditions as much congenital aberrancy may present unexpectedly during cardiac surgery.

Introduction: High intensity transient signals (HITS) have been reported to occur following perfusionist intervention during cardiac surgery. This study investigates the relationship of the syringe bore, injection rate, and HITS created. Methods: Syringes (10 mL) with a male luer-lock connection (Large Bore) and Abboject ‘jet syringes’ with a 20 GA needle and male luer-lock connector (Small Bore) were filled with 10 mL of 0.9 N saline. A perfusionist was randomly assigned a set of four similar syringes followed by the other syringe bore. Each of the four syringes was injected into an in vitro saline-primed cardiopulmonary bypass (CPB) system over 5, 10, 15, or 20 sec. Sixteen randomizations of small and large bore syringes were completed at the four injection times (128 injections). HITS in the CPB arterial line were detected with transcranial Doppler (TCD) probes, were recorded for the 2 min following the injection, and were counted independently off-line by two reviewers. Results: The use of a large bore syringe compared to a small bore syringe created significantly fewer HITS (29±6 versus 145±17 [mean±SEM], p Conclusion: Significantly fewer HITS are introduced into the CPB system by using standard syringes and slower injection time.

We have compared occupational exposure to isoflurane and desflurane during cardiopulmonary bypass, with and without a scavenging system at the membrane oxygenator outlet. Trace concentrations of volatile anaesthetics were measured by a direct reading instrument in 40 elective heart surgery procedures. Measurements were obtained in the breathing zones of the anaesthetist and perfusionist. When a scavenging system was used, median desflurane values were less than 0.3 ppm and isoflurane values less than 0.2 ppm. Without a scavenging system values were, in general, three- (isoflurane) to five- (desflurane) fold higher. We conclude that the use of a scavenging system at the membrane oxygenator outlet can reduce occupational exposure to volatile anaesthetics. We therefore recommend routine use of scavenging devices during cardiopulmonary bypass.

Objective: To determine the association between high-intensity transient signals (HITS) and perfusionist interventions, purging techniques, pump flows and venous reservoir blood volume levels during cardiopulmonary bypass. Methods: Transcranial Doppler was used to detect HITS in the middle cerebral artery during the period of aortic crossclamping in patients undergoing coronary artery bypass grafting. Perfusionist-related interventions were recorded and included blood sampling (including the number of times that the oxygenator sampling manifold was purged), drug bolus injections and infusions (vasopressors, crystalloid and mannitol). Pump flows and venous reservoir volume levels were also documented. Results: There were 534 interventions in 90 patients [median number of interventions per patient: 6 (quartiles: 4, 8)]. The median total HITS count from all interventions was 17 (5, 37). This represented 38% of the total HITS counts during aortic crossclamping. Factors contributing to differences in the HITS count included type of intervention ( p Conclusions: Cerebral emboli associated with perfusionist interventions can be minimized by not purging the sampling manifold, using continuous infusions rather than bolus injections, and maintaining high blood-volume levels (>800 mL) in the venous reservoir.

The major obstacles of organ transplantation are the shortage of available organs from donors and the limited time an organ remains viable. The scarcity of organs has increased the importance of effective preservation technology. The optimal lung preservation techniques are controversial and in a state of evolution. Recent areas of research include the ideal perfusate solution, the benefit of different pharmacological additives and the best techniques for organ preservation. Our technique for lung preservation has yielded highly successful results. The perfusionist delivers 4-5 L of modified Euro-Collins solution and 500 mg of prostaglandin E1 through a circuit. The designed circuit allows the perfusate to be delivered cold and at a pressure less than 40 mmHg via the use of a manually operated centrifugal pump. Results: In 2002, the operative mortality for all lung transplants was 2.7%. One-year and two-year survival for recipients was 79% and 68% respectively; the national average for one-year survival was around 77% with a 9% mortality. As organ transplant surgery continues to grow, effective organ preservation techniques and technology will expand as well.

A 74-year-old male patient’s circulation was supported by an intra-aortic balloon for a period of six days following multiple cardiac infarcts. On the sixth day, several ‘leak in IAB circuit’ alarms appeared. The nursing staff checked the tubing and refilled the balloon, as described in the manual, without notifying the medical staff or perfusionist. A few hours later, the balloon showed a leak, as blood was seen in the catheter tubing. This leak resulted in considerable damage to the device caused by a large amount of blood migrating back to the tubing and flooding the internal drive system, due to a failing ‘blood detection’ sensor. The balloon catheter was removed percutaneously and intra-aortic counterpulsation was discontinued. The patient died 20 days later of heart failure. This raises doubts over the adequacy of the protective sensors of such devices and, importantly, how to interpret the present user manuals and the instructions for troubleshooting.

During cardiopulmonary bypass (CPB) haemodynamic alterations, haemostasis and the inflammatory response are the main causes of homeostatic disruption. Even with CPB procedures of short duration, the homeostasis of a patient is disrupted and, in many cases, requires intensive postoperative treatment to re-establish the physiological state of the patient. Although mortality is low, disruption of homeostasis may contribute to increased morbidity, particularly in high-risk patients. Over the past decades, considerable technical improvements in CPB equipment have been made to prevent the development of the systemic inflammatory response syndrome (SIRS). Despite all these improvements, only the inflammatory response, to some extent, has been reduced. The microcirculation is still impaired, as measured by tissue degradation products of various organs, indicating that CPB may still be considered as an unphysiological procedure. The question is, therefore, whether we can detect the pathophysiological consequences of CPB in each individual patient with valid bedside markers, and whether we can relate this to determinant factors in the CPB procedure in order to assist the perfusionist in improving the adequacy of CPB. The use of these markers could play a pivotal role in decision making by providing an immediate feedback on the determinant quality of perfusion. Therefore, we suggest validating the proposed markers in a nomogram to optimize not only the CPB procedure, but also the patient’s safety.

Methods: There have been 784 coronary artery bypass grafting (CABG) procedures performed at a new center for treating cardiovascular disease in Tuzla, Bosnia and Herzegovina, and the surgical team has been fully trained in off-pump coronary artery bypass (OPCAB) surgery. All surgical patients were considered for on-pump CABG (ONCAB) and OPCAB surgical procedures. Minimally invasive direct coronary artery bypass grafting and robotic procedures were done as OPCAB. For multivessel median sternotomy cases, the selection criteria were arbitrary (approximately 50% were performed as ONCAB for perfusionist training). Patients who were scheduled for and began their operations as OPCAB but who were then placed on cardiopulmonary bypass during the surgical procedure were counted as conversions. The outcomes of converted patients were studied and are the subject of this report. Results: Of the 784 CABG procedures, 391 (49.6%) were scheduled and performed as ONCAB operations; 357 (45.5%) were performed as OPCAB; and 36 (9.2% of the originally scheduled OPCAB patients or 4.6% of the total number of CABG surgeries) were originally scheduled as OPCAB operations but were converted to ONCAB. Reasons for conversions were hemodynamic instability (21 patients), difficult revision of grafts (8), ventricular fibrillation (5), and poor native vessel (2). Outcomes of patients undergoing conversions were analyzed with respect to the conversion cause. When the cause of the conversion was mild-to-moderate hemodynamic instability or difficult graft revision (n = 27), no adverse ischemic effects were seen; however, when the cause of conversion was severe hemodynamic instability, ventricular fibrillation, or cardiac arrest (n = 9), 6 patients (66.6%) had severe ischemic complications involving the central nervous system or the myocardium. Discussion: Myocardial ischemia must be monitored and treated aggressively in OPCAB surgery. In patients with mild hemodynamic instability, conversion did not adversely affect outcome. In patients with severe hemodynamic compromise and cardiac arrest, serious complications of cerebral and myocardial ischemia were observed. The appropriate timing of conversion is essential.

Optimal flow rate with minimal pressure gradient is the goal of arterial cannulation for cardiopulmonary bypass (CPB). Misplacement of the arterial cannula or vascular pathology can lead to hemolysis or intimal damage with subsequent aortic dissection. The risk of dissection with aortic cannulation is low, 0.04-0.2% for ascending aortic cannulation and 0.2-3% for femoral cannulation. However, dissection-related mortality is significant. Common methods for assessing adequacy of arterial cannulation include minimal pressure when injecting 100-mL boluses and the presence of pulsation in the cannula. Using these techniques, misplacement of the cannula can be masked due to the small amount of volume that is transfused during the assessment. Displacement of fluid into a cannula that is in a false lumen or close to the intimal surface may not indicate a misplaced arterial cannula. Negative fluid displacement is an alternative method of evaluating the integrity of arterial cannulation. During retrograde arterial priming (RAP), fluid is drained from the arterial cannula into a collection bag. Absence of fluid return or a flow B /500 mL/minute is indicative of either arterial line occlusion or cannula misplacement. At this point, the arterial cannula can be repositioned prior to instituting CPB. Since using this technique in over 13 000 bypass procedures, we have had only one dissection. This one event occurred during partial occlusion clamping of the ascending aorta. With increased use of femoral cannulation for minimally invasive cardiac surgical procedures, this RAP technique can enhance the perfusionist’s and the surgeon’s ability to safely perform bypass in the presence of higher dissection risk.

Perfusionists have a critically important role in cardiac surgery. Their responsibilities include providing cardiovascular support, maintaining adequate blood flow and blood pressure, maintaining adequate oxygenation, operating suction pumps and other devices, regulating blood temperature, and keeping records. The relationship between perfusionist and anesthesiologist as members of the cardiac surgical team should be one of mutual support. Although many anesthesiologists do not control the pharmacology of perfusion, it is their responsibility to ensure that the perfusionist understands the pharmacopsia being used and to know what the perfusionist is administering. In-depth knowledge of the techniques and practices of cardiopulmonary perfusion is a prerequisite for cardiac anesthesiologists. The future is likely to see an increasingly supportive relationship between anesthesiologists and perfusionists.

Objective:To investigate an outbreak ofStaphylococcus aureussurgical-site infections.Design:Case–control study.Setting:Pediatric cardiothoracic surgery service of a tertiary-care university medical center.Method:Molecular typing was used to identify healthcare workers who carried the epidemic strain.Results:Three children acquired surgical-site infections caused by a single strain ofS. aureus. Fourteen (25%) of the staff members in the operating room and 17 (11%) on nursing units carried the epidemic strain (P= 01). A case–control study identified 4 healthcare workers who were associated statistically with the outbreak, 2 of whom (a cardiothoracic surgeon and a perfusionist) carried the epidemic strain in their nares. The surgeon also carried the epidemic strain on his hands. Each staff member who carried the epidemic strain was treated with mupirocin; those carrying the strain on their hands were required to wash their hands with chlorhexidine. The surgeon was not allowed to perform surgery until 2 of his hand cultures did not growS. aureus.Conclusions:Only three children were infected with the epidemic strain, but it was disseminated widely among staff who cared for children who underwent cardiothoracic surgery. No additional cases were identified after staff members who carried the epidemic strain were decolonized. Both classic epidemiologic methods and molecular typing techniques were necessary to identify the source and extent of this outbreak.

Cardiac surgery on Jehovah’s Witnesses is a great challenge for the cardiothoracic surgery team and especially for the perfusionist. To reduce the risk of surgery in these patients, a very small extracorporeal circuit was designed to decrease the amount of priming volume and thereby the degree of hemodilution. A small bypass system was built, consisting of a 3/8-in. arterial line and a 3/8-in. venous line, a venous collapsible reservoir, a centrifugal pump, a hollow fiber oxygenator and a cell saver reservoir. The circuit priming volume was 650 ml. By using antegrade and retrograde autologous priming, the total amount of priming was reduced to ± 50 ml. Bypass time was 63 min with an average blood flow of 5300± 114 ml/min and postmembrane pressures of 180± 45 mmHg. Venous line pressure was monitored and kept between -8 and -20 mmHg with a mean arterial pressure (MAP) of 55± 12.3 mmHg. The hematocrit before extracorporeal circulation (ECC) was 36%, per-ECC 35% and post-ECC 35%. On the fifth postoperative day, the hematocrit was 40%. The patient was discharged 7 days after surgery. A low-prime circuit, in combination with autologous priming, seems to be safe and effective in avoiding the use of banked blood.

Objective: Neuropsychologic impairment is a common complication of coronary bypass surgery. Cerebral microemboli during cardiopulmonary bypass are the principal cause of cognitive deficits after coronary bypass grafting. We have previously demonstrated that the majority of cerebral emboli occur during perfusionist interventions (ie, during the injection of air into the venous side of the cardiopulmonary bypass circuit). The purpose of this study was to determine whether an increase in perfusionist interventions is associated with an increased risk of postoperative cognitive impairment. Methods: Patients undergoing elective coronary artery bypass grafting (n = 83) underwent a battery of neuropsychologic tests preoperatively and 3 months postoperatively. Patients were divided into 2 groups according to the median value of perfusionist interventions during cardiopulmonary bypass. Group 1 patients (n = 42) had fewer than 10 perfusionist interventions, and group 2 patients (n = 41) had 10 or more interventions. Results: The 2 groups of patients were similar for all preoperative, intraoperative, and postoperative variables, with the exception of longer cardiopulmonary bypass times in group 2 patients (P

A 34-year-old male diagnosed with pseudomyxoma peritoneii presented for an exploratory laparotomy and hyperthermic intraoperative intraperitoneal chemotherapy. A circuit using two roller pumps and a cardioplegia administration set was assembled to deliver the chemotherapy perfusate at a consistent temperature. The authors discuss a case in which this treatment modality was used, describing the perfusionist’s role and the circuit design.

Brain injury remains a significant problem in patients undergoing cardiac surgery using cardiopulmonary bypass (CPB) despite continuous improvements in surgical technique, anesthesia management, and CBP equipment (type of oxygenator, gradients in the heat exchanger, intracardiac sucker systems). Although the cause of brain injury during cardiac surgery is certainly multifactorial, evidence suggests that microemboli play an important role because embolized particles cause transient obstructions to flow (Fig. 1). Evidence linking microemboli to neurological complications is supported by studies using carotid and transcranial Doppler ultrasound (TCD) (6, 11, 18). The number of emboli correlates well with early neuropsychological deficits and risk of stroke as well as length of hospital stay (15). Incidence rates for stroke are around 2% to 3% (5) and may be contrasted with the much higher reported incidence of cognitive defects assessed by neuropsychological testing (1). There are a variety of ways, at least potentially, in which the brain may be injured during an operation with CPB, including reduced cerebral blood flow, microembolism, and systemic inflammatory response (Table 1). Cerebral microemboli are known to occur during specific surgical interventions, but the source of a large proportion of emboli remains unexplained. Also important is, that interventions of the perfusionist could account for the appearance of cerebral microemboli (16). Many sources of microemboli during open heart surgery have been suggested, including microembolism of air, fat, platelet aggregate or silicone (5, 13).

Unintended internal suturing of central venous lines or pulmonary artery catheters in the superior caval vein or the right atrium following cardiac surgery remains a rare but troublesome complication. The line is normally entangled in safety or hemostasis sutures after the removal of the superior caval cannulation. If mild tension is unsuccessful, the patient normally undergoes resternotomy. The objective of this brief communication is to describe of a simple and safe removal method using a transvenous rotational cutting device to divide the hemostasis suture. In order to avoid complicating bleeding, a time delay between initial placement and removal is highly recommended. For extraction, a fully equipped cardiovascular operating room with central venous and arterial lines, attached defibrillator pads, transesophageal echo monitoring, fluoroscopy, and a surgical team, including a heart and lung machine and a perfusionist standby, is mandatory.

Microemboli to the cerebral circulation occur during cardiopulmonary bypass (CPB) and can contribute to postoperative neurologic dysfunction. Cerebral microemboli are known to occur during specific surgical interventions, but the source of a large proportion of emboli remains unexplained. We investigated whether interventions by the perfusionist could account for the appearance of cerebral microemboli.Transcranial Doppler ultrasonography was used to continuously monitor the middle cerebral artery of 18 patients undergoing coronary artery bypass grafting. The CPB circuit consisted of a softshell venous reservoir, a hollow-fiber membrane oxygenator, and a 32-microm arterial filter. The mean embolic rate was calculated for three time periods: (1) during surgical interventions (aortic cannulation and decannulation, cross-clamp application and removal, CPB start and end, and start of cardiac ejection); (2) during perfusionist interventions (blood sampling and drug administration into the venous reservoir); and (3) during baseline (all other time periods during CPB).Microemboli were detected in all patients (mean +/- standard deviation, 207+/-142 per patient, median, 132). The number of emboli per minute was significantly (p0.001) higher during perfusionist interventions (6.9+/-4.5) than during surgical interventions (1.5+/-1.5) or during baseline (0.4+/-0.5). Drug administration resulted in a higher embolic rate than blood sampling.Interventions by the perfusionist account for a large proportion of previously unexplained cerebral microemboli during CPB. These emboli likely represent air bubbles that are not eliminated by the arterial line filter. Although further studies of additional types of CPB circuits are required, we believe that air in the venous reservoir should be avoided whenever possible to minimize the risk of neurologic injury.

T HE CARE OF CHILDREN undergoing surgery requiring cardiopulmonary bypass (CPB) provides a remarkable challenge to the anesthesiologist, surgeon, and perfusionist. Much of the knowledge regarding appropriate care for adults undergoing cardiac surgery may not apply in this unique scenario. Because surgical outcomes have improved and mortality has decreased, more attention is being given to decreasing the important morbidities still associated with repair of congenital heart lesions. It is critical to understand the important relevant anatomic and physiologic differences between infants and neonates relative to adults and how these differences interact in the setting of perfusion of the pediatric patient.

A repeated cross-sectional study on the psychological profiles and interpersonal styles of highly stressed medical technologists (perfusionists) has found remarkable consistency in internal psychological profiles and differences in interpersonal dynamics over a 6-year period. Six years ago a longitudinal study was begun to track the psychological profiles of perfusionists. Surgeons can repair cardiac defects only after a beating heart has been stopped. In order for the brain and other organs to survive cardiac surgery, they must be perfused with well-oxygenated blood. As a result, the life of every cardiac surgery patient literally sits in the hands of the cardiac perfusionist The stress of placing patients on and off the 'pump' is one that is experienced by cardiovascular perfusionists on a daily basis. This stress has been likened to that of air traffic controllers who continually prepare planes for take off and/or landing. In the 6 years between studies, medical technologists have changed very little psycholog cally. They remain very well palanced, However, there have been significant changes in their interpersonal behaviours. Instead of the 'well-balanced' interpersonal profiles of 6 years ago, there is a higher degree of assertiveness/aggressiveness being reported. Managed Care has begun to impact interpersonal behaviours but has not yet altered the more resilient platform of internal psychological balance.

This year, the 20th qualifying examination on the extracorporeal circulation technique for a certified perfusionist was conducted. A total of 569 certified perfusionists had qualified in Japan up to November 2006.

Port-Access minimally invasive cardiac surgery systems (Heartport, Inc., Redwood City, CA, U.S.A.) enable surgeons to perform many procedures including valve surgery and complete coronary artery revascularization of all surfaces of the heart through small anterior thoracotomies. The endovascular based EndoCPB (Heartport, Inc.) cardiopulmonary bypass system uses a modified extracorporeal circuit to afford the same level of myocardial protection through cardioplegic cardiac arrest and bypass as is provided in traditional open chest surgery. We describe the changes required to convert a conventional CPB pump circuit to perform Port-Access procedures and make recommendations based on clinical experience to facilitate establishing a Port-Access surgical team and interpreting EndoCPB pressure and flow data. Specific emphasis is placed on the expanded role of the perfusionist in these cases.

BACKGROUND/OBJECTIVES: Despite adherence to evidenced-based practice recommendations, SSIs can still occur. The Cardiac Surgical Team, Infection Control & Prevention Department, and the Performance Improvement Department collaborated to implement best practices for reducing SSI morbidity and mortality in cardiac surgical patients. We proceeded to compare the Centers for Disease Control & Prevention (CDC) and the Surgical Care Improvement Project's (SCIP) best practices to our current practice. Additionally, process of care opportunities were identified from intense analyses involving cardiac surgical patients. Time was spent observing patient care in the Operating Room and Cardiac Surgical Intensive Care Unit. Opportunities to improve the correct timing, dosing, and documentation of antibiotics during the preoperative & intraoperative periods were found. METHODS: Buy-in from the Department of Anesthesia and Surgery Chiefs was obtained. A summary of hospital preoperative antibiotic timing data compared to best practices was presented to the members of the Departments of Anesthesia and Surgery. The practice of giving antibiotics “on-call” was discontinued; instead, the medication was administered in the Operating Room Holding Area. The Anesthesia Record was revised to highlight the preoperative antibiotic. Questioning if the preoperative antibiotic has been administered became part of the surgical time out process. The Cardiac Perfusionist assisted with antibiotic documentation on the Perfusion Record. Timers were placed in every operating room suite as a reminder to ensure the re-bolusing of selected antibiotics. Cefazolin 2 Grams was given preoperatively to all patients who weigh ≥200 pounds. Preoperative antibiotic timing and postoperative antibiotic discontinuation continued to be reviewed monthly for every case. Cardiac surgical infection surveillance continued for all open heart procedures. RESULTS: Pre-op antibiotic administration compliance within one hour before surgery was at 28.6% during December 2003 and has now been sustained at or near 100%. Use of appropriate antibiotics has been consistently 100% since October 2003. Surgical Site Infection Rates for Risk 1 CABG procedures, previously slightly greater than the 50th decile during 2002, is now below the 10th decile when compared to NNIS data. CONCLUSIONS: The Cardiac Surgical Team's acceptance/buy-in of the numerous recommendations came willingly. Operational issues at times were challenging. However, our multidisciplinary team was able to improve and sustain a high rate of performance to significantly reduce infection in the cardiac surgical patient.

Safe cardiopulmonary bypass has been paramount from its first use in the early 1950s until the present. The original perfusion circuits incorporated complex feedback loops and multiple safety devices. As circuits improved and became simpler to operate, advances in safety did not always keep pace. Surveys have illustrated areas that needed improvement and extra attention has been focused on those problems. As the field of perfusion evolved, so has the perfusionist. Perfusion has progressed from on-the-job training to formalized training, certification, and accreditation, and is now approaching national standardization. As the computer age proceeds, the use of safety devices and feedback mechanisms whose developments have been aided by the newly available technologies increases. As the 21st century approaches, cardiopulmonary bypass will continue to become safer, but the perfusionist must continue to stay up-to-date in education and remain vigilant while in the operating room.

The aim of the study was to validate clinically a new technique of myocardial protection developed for intra- and extra-cardiac surgery on the beating heart. The concept combines the principle of continuous pressure- and volume-controlled coronary artery perfusion (PVC-CONTHY-CAP) with the specific myocardioprotective effects of hypothermia and nitrates and, on the other hand, with the beta-blocker-mediated reduction of chronotropy and inotropy necessary for convenient surgery. Under standard ECC conditions after cross-clamping the aorta coronary perfusion with oxygenated blood enriched with nitroglycerine (10 micrograms/kg/h) and esmolol (0.05 mg/ml flow/min) is started via an additional perfusion cannula placed in the aortic root. The temperature of the perfusate is maintained at 32 degrees C, the intraaortic pressure at 40-70 mmHg and the perfusion flow in the range 0.8-1.0 ml/g heart muscle/min. In CABG procedures an additional perfusion catheter is used for perfusion of distal coronary artery segments. Using this technique 100 consecutive patients, adults and children, were operated on between 2/96 and 8/96. In 84 adult patients (age: 45-82 yrs), 78 CABG procedures (54 elective, 13 urgent, 11 acute) with a mean bypass count of 3.7 (range 1-7), 69 ITA grafts, 72 grafts to CX, and 3 MVRec/MVRpl, and 6 pure MVRec/MVRpl procedures (1 urgent, 1 emergency) were performed. The mean coronary perfusion time was 48 min (range 21-88 min). In 5 patients perioperative infarction (CABG; 1 emergency after PTCA, 4 elective) with significant increase of CK-MB values (57-98 U/L) occurred. In the 4 elective patients (3 with diabetes mellitus) re-intervention was not possible due to small-vessel disease. In one patient with preoperative infarction IABP was necessary. No patient died. There were 16 children (age: 4weeks-16 yrs): VSD, n = 6, AV-C, n = 2, TOF, n = 1, MVRec, n = 1, DORV (Rastelli), n = 2, SV (TCPC), n = 3, and PV obstruction, n = 1. The mean coronary perfusion time was 97 min (range: 27-260 min). The mean ICU stay 3.9 d (range: 1-10 d). One child died (TCPC) on the 10th postoperative day due to multi-organ failure. In conclusion, PVC-CONTHY-CAP is designed especially for emergency and urgent procedures, i.e. patients with PTCA-related complications, patients with severely depressed LV function, and patients with complex congenital cyanotic heart defects. Using PVC-CONTHY-CAP, coronary artery bypass grafting as well as intracardiac procedures for congenital and acquired heart defects can be performed safely and conveniently, the system is easy to handle for both the cardiac surgeon and perfusionist. Due to its pharmacological properties continuous intracoronary application of nitrates in combination with hypothermia seems to be essential as a preventive treatment modality for the ischemic state.

Cardiac surgery is a relatively new speciality which has burgeoned from its nascent state in the 1960s to a mammoth industry, such that over 1,000,000 cardiac procedures are conducted in the US on an annual basis.1 The development of safe cardiopulmonary bypass and the surgical techniques which it facilitated saw a huge rise in coronary and valve surgery over the subsequent 30 years. However, the “bread and butter” of cardiac surgery remained relatively unchanged despite the advent of off-pump bypass and use of arterial grafts until the last 10–15 years. Interventional cardiology, changing social views on what constitutes “too old” or “too sick”, improved intensive care and an increased use of mechanical assist devices such as intra-aortic balloon pump devices has changed the face of cardiac surgery. The increased uptake of percutaneous coronary interventions (PCI) since the advent of devices such as drug-eluting stents has all but removed the simple single vessel coronary graft for the cardiac operating list. As PCI devices improve, more and more studies comparing CABGs to PCI with stents are being reported, showing similar results in terms of death, MI and stroke, and whilst stents are associated in these studies with an increased need for re-vascularization, this gap is narrowing.2 The cardiac surgeon and cardiac anaesthetist are therefore being presented with octogenarians with poor left ventricular function and the associated organ dysfunction commonly seen in this age group. Paediatric patients, many of whom would not have previously survived birth, are now being presented for consideration of surgery in the first weeks post birth. Children and adults are supported on ventricular assist devices for many months or years, either as bridging or destination therapy. These patient groups are the sickest, frequently with the most to gain from a successful outcome, but occupy more ICU bed days, and many more health care pounds and dollars. The care pathway of the un-complicated post cardiac surgery patient is clear and generally straight, with a supervisory eye being the main function of the intensivist in the post operative period. However, as the patients become sicker and older (or younger in the paediatric population), and pre-operative organ dysfunction becomes the rule rather than the exception, the close collaboration of surgeon, intensivist, anaesthetist and perfusionist becomes key in the final discharge of these patients from hospital. A clear understanding of pre-operative risks, intraoperative procedures and post operative organ support are essential for the optimal result for the patient. This issue has chosen a number of fields associated with “high-end” cardiac surgery. It is by no means exhaustive, but reflects the major changes as they have impacted the critical care environment over the past decade. We have included a review on ventricular assist devices as recent data confirms their efficacy and improvement in survival in patients with severe heart failure, a condition whose incidence increases with each passing year. Some of the articles are reviews of a specific field, and some “tricks” or “pearls” that we wished we had learned many years ago. The articles are the combined work of intensivists, anaesthetists and cardiac surgeons, and the issue aims to be a practical guide augmented with recent data and evidence, rather than an isolated academic precis.

We have examined the use of a 6 kg strain-gauge load cell for the purpose of continuous measurement of cardiotomy reservoir volume during cardiopulmonary bypass. It performed reliably and reproducibly and was found to be simple to interface to an anaesthesia monitor. The resolution of the cell was ±15 ml and the bias and limits of agreement for a series of 221 measurements were +15 ml and 175 ml, respectively. A continuously available digital level signal can present significant advantages to the perfusionist. The signal can be presented remotely in the form of a bar graph or a digital display, or can be interfaced to an intelligent alarm system which can be triggered on the basis of 'time to expected reservoir exhaustion' rather than absolute reservoir level. The alarm state can also be conveyed in spoken form using speech synthesis. Finally, when recorded by an automatic record keeping system, the reservoir level constitutes an important addition to the perfusion record.

An integrated heart surgery system is under development. The system is the successor of two previous custom-built generations of automatic charting systems for the anesthetist and the perfusionist during heart surgery. The system can be used to collect, present and archive all important physiological parameters, the medical events and the medical, and administrative data. Janus offers multiple views on the data collected during an operation. By configuration a view for the anesthetist as well as a view for the perfusionist can be created. The system is connected to the monitoring system, our custom-built heart-lung system and the servo ventilators. It includes access to the hospital information system, and the departmental information systems of the Thoraxcenter. The first preliminary version of this system will be introduced in our operation rooms in the fall/winter of 1996.

BACKGROUND: Mediastinitis is a rare but serious complication of cardiothoracic surgery. Active surveillance of children undergoing cardiac surgery with median sternotomy revealed a cluster of five cases of deep sternal wound infection or mediastinitis (DSW-M) within a 2-month period. OBJECTIVES: To identify risk factors for DSW-M in children undergoing median sternotomy. METHODS: Cases of DSW-M were identified by active surveillance of all cardiac surgical patients at the Children's Hospital of Philadelphia. Four control patients were randomly selected from all patients undergoing median sternotomy who survived for >30 days after surgery. Controls for each case were matched by month of surgery and age group. Data was collected from review of microbiology laboratory reports and medical records. RESULTS: Bacterial cultures revealed three infections due to Staphylococcus aureus , and one due to vancomycin-resistant Enterococcus. The fifth patient's infection was polymicrobial; cultures from this patient grew Serratia marcescens and Pseudomonas aeruginosa . DSW-M was more common in children with complex cardiac physiology. Children with two ventricles with a normal aortic arch at the time of surgical procedure had a lower risk of developing DSW-M (p=0.02). Factors associated with an increased risk of deep wound infection included prolonged bypass time (p=0.004), need for re-operation within 48 hours (p=0.04), and inappropriate timing of peri-operative antibiotic prophylaxis (p=0.05). Factors not associated with DSW-M included presence of intracardiac pacemaker wires, right atrial catheters, or the use of prosthetic material. In addition, DSW-M was not associated with a specific surgeon, anesthetist, perfusionist, or nurse. CONCLUSION: DSW-M occurs more commonly following surgical intervention for severe congenital heart anomalies. Most identified risk factors for DSW-M were not modifiable. However, improved timing of peri-operative antibiotic prophylaxis might reduce the incidence of DSW-M in these susceptible patients.

S URGICAL repair of an ascending aortic aneurysm involving the aortic root presents a challenge for the surgeon, anesthesiologist, and perfusionist. Hemorrhage is an important indicator for mortality after repair of annuloaortic ectasia, l?and when a patient refuses all blood products, complications of hemorrhage would likely increase the risks. Hemorrhage during repair of aortic root aneurysm can be caused by the surgical anastomoses, systemic heparinizatlon, exposure to the cardlopulmonary bypass (CPB) circuit, or the prosthetic graft itself) The impairment in hemostasls associated with CPB remains unclear but hkely involves a combination of a reduction m platelet adhesiveness, complement achvation, kaltikrein/ klnin activation, a sUmulation of the fibrinolytic system, and dilution. 4 Aprotmin, a serine protease inhibitor, has been shown to preserve platelet adhesive receptors (Gplb), inhabit contact activation of the kallikrein system, and inhibit plasmin-lnduced fibrmolysIs. When used in conjunction with heparln, aprotinin prevents thrombln formation through inhibmon of the intrinsic clotting cascade. 5 The effectiveness of aprotmin in reducing perloperative blood loss and amount of transfused blood products during cardiac surgery has been demonstrated. T M The combinanon of heparin-bonded perfusion systems and reduced systemic heparinlzation for CPB has been reported 12-i4 Reported advantages of heparin-bonded perfusion systems include reduced actwation of the complement and coagulation systems and improved platelet function caused by the Improved blocompatibility of a heparin-bonded material, both leading to reduced penoperatlve bleeding. 13-16 A drawback in the use of a heparinbonded system is that because of the continuous air-toblood interface associated with roller pump suction, shed mediastlnal blood and vented blood must be returned to a cell-saving device for washing instead of directly into the CPB circuit. In cases involving extensive suctlonmng and venting and excessive surgical bleeding, washing and autotransfusion of suctioned blood may result in a tremendous loss of plasma and platelets, negating the benefits of reduced systemic heparinlzation. Because of this patient's religious behefs, and the nature of her disease process, a heparin-bonded perfusion system for CPB was used in conjunction with full systemic heparinlzatlon and aprotinln administration.

Cardiopulmonary bypass (CPB), initiated percutaneously or via “cutdown,” serves as an effective means of resuscitating patients suffering cardiac arrest in or out of the cardiac catheterization laboratory. 1–5 More recently, portable CPB units have been used to support patients undergoing “high-risk” angioplasty or valvuloplasty. 6–19 These portable bypass systems, available commercially as self-contained units, have been employed prophylactically during high-risk procedures for hemodynamic support, or have been employed in a standby fashion with either guide wires or femoral cannulas in place, with a perfusionist in attendance. This chapter will follow the evolution of supported percutaneous transluminal coronary angioplasty (S-PTCA) and delineate the role of this important treatment modality in the armamentarium of the cardiologist and cardiac surgeon.

During the past 12 years, percutaneous transluminal coronary angioplasty (PTCA) has undergone remarkable growth as a revascularization modality in the care of patients with coronary artery obstructive disease.1 With the increasing number of institutions offering coronary angioplasty services, an increasing number of cardiac surgical services will be involved in the surgical support of angioplasty patients. Since 4% to 7% of coronary angioplasty procedures result in acute ischemic complications necessitating emergency coronary artery revascularization, the cardiac surgery team must be familiar with the medical and surgical problems associated with this group of patients in their often difficult and urgent clinical circumstances.2 To be successful in managing these failed angioplasty patients, it is essential to establish and maintain cooperative teamwork among the caregivers: the physician who performs the angioplasty, the cardiac anesthesiologist, the cardiac surgeon, the perfusionist, and the operating room nurses.

The ability to control a patient’s body temperature within a very wide range is one of the most important therapeutic modalities available to the cardiac surgeon, anesthesiologist, and perfusionist. Hypothermia facilitates coronary arterial bypass surgery, heart valve repair or replacement, and the correction of congenital cardiac defects. Furthermore, precise anatomic correction of complex congenital heart defects, in a bloodless and motionless surgical field, is possible even in tiny premature infants during profoundly hypothermic total circulatory arrest. The technology of deep hypothermia and total circulatory arrest also is useful in operations on the thoracic aorta, the aortic arch, the brachiocephalic vessels, and the brain, during which cerebral or spinal cord blood flow is compromised or interrupted. Therapeutic clinical hypothermia, usually used for support of the patient during operation on or within the heart, requires uniform cooling of the entire body.

May 6, 1953 could very well be one of the most significant dates in medical history. On this day 50 years ago, Dr John H. Gibbon, Jr, performed surgery at Philadelphia’s Jefferson Hospital on a young woman in what was the world’s first successful open heart operation using a mechanical heart-lung device on a human being. In 1953 this patient was a 17-year-old college student in Wilkes-Barre, Pennsylvania, who had a congenital heart defect: a hole the size of a half dollar in the wall between the two upper chambers of the heart. She came in for regular follow-up for years and I had the chance to meet her during those visits as a nurse/perfusionist here at Jefferson. In 1978, about 25 years after her surgery, I lost track of her but up until that time she was living a healthy life working as a secretary in Philadelphia. At about this time I remember an article in the Philadelphia Bulletin, which was the evening paper at that time, in which she was quoted as saying she always had a youthful hunch or teenager’s intuition that her surgery would be a success. She felt it would go her way with Dr Gibbon, his machine, and prayers. In 1956–1957 I attended Hood College in Frederick, Maryland. From there I came to Jefferson Medical College School of Nursing from 1957–1960. While studying I met Sylvia Shopp, the head nurse of the cardiac operating room and I spent some time working in the dog laboratory where I met Dr Gibbon. Doctor Gibbon said to me one day, “What’s a nice young girl from Friends Central [he had attended our sister school Penn Charter] doing cleaning out cages? You should study hard instead.” In fact he often called me, “Hey, Friends Central!” So I did study hard and my fascination with the machinery continued for another 30 years. After graduation from nursing school I went straight to the cardiac operating room. While working as a nurse at Jefferson I was also training with Drs Templeton and Bacharach in operating the heart-lung machine. I also learned a great deal about cardiac surgery and nursing from Sylvia. When Sylvia left to get married I became the head nurse/pumpist. From 1960–1975 I had the honor of working with Dr Gibbon and his young associate, Dr John Young Templeton, first in the operating room as a scrub/circulating nurse, then as head nurse of that operating room, and finally from 1962 on as a nurse “pumpist” as we were then called. While the work was challenging, historical, and life changing for our patients, I also remember great times on such a close team, especially Christmas parties at Dr Gibbon’s farm in Media. The first Gibbon machine was a film oxygenator using a series of vertical screens. It was made to Dr Gibbon’s specifications working with IBM. It required a large prime of whole fresh heparinized blood, which was donated from many donors (some 25 of them), mostly sleepy medical students who would line up in the hallway to donate the morning of surgery or some local donors and perhaps even the Red Cross. Those were the days when students really did have to bleed for their profession. The pump was primed and the oxygenator recirculated using the whole fresh blood. The machine was the size of a grand piano and there were hoses and lines everywhere. The water supply for the heat exchanger was behind the autoclaves in a room between operating rooms 3 and 4 in the Pavilion Building. As you can imagine people were walking and tripping over the lines and hoses constantly. By the time I first used the Gibbon machine in the 1960s, there were many changes. The screens had been replaced by mylar coated aluminum sheets and the artificial lung was tailored to the patients surface area the night before. The larger the patient, the more sheets in the lung case and then of course it was all sterilized. Most of the reservoirs including the lung case were Lexan. The tubing connectors were highly polished stainless steel with very sharp edges. Some things remained the same however, as there were still hoses everywhere. At the conclusion of bypass the machine had to be dismantled and cleaned. This process took several hours, even over night. Before a solution called Hemosol came along, each piece had to be soaked separately in plastic trays in order to avoid any harm to the highly polished surfaces that could cause blood aggregates to be delivered to the next patient. Some parts had to be first cleaned with large pipe cleaners. The lung required two men to lift it in and out of the sterilizer. The Lexan parts could not be autoclaved and had to be ethylene oxide sterilized, which was a large improvement for those times, however we didn’t have any venting for the gas at the end of sterilization. This would hardly be acceptable to OSHA today. We were not yet in the age of disposables. Others like Dr DeWall and Dr Lillihei were demonstrating that a simple bubble diffusion oxygenator could be effective for temporary cardiopulmonary byass. The first one of these that I saw clinically was the 3-L Travenol bag. It was a heavy duty plastic heat sealed helical device Presented at the symposium, “Gibbon & His Heart-Lung Machine: 50 Years & Beyond,” Philadelphia, PA, May 2, 2003.

The purpose of this investigation was threefold: (1) could the perfusionist accurately estimate oxygen transfer ( VO2/minute) while on CPB; (2) could this estimate, and its position on the oxygen transfer slope (OTS), predict resultant PaO 2 values within a specific range; and (3) could previously derived performance 'normals' be used during this study. Fifty-four sets of samples (both arterial and venous) from 27 oxygenators were used in this study. Each oxygenator provided one normothermic and one hypothermic set of samples. In 48 of the 54 samples (88.9%) the predicted VO2/Minute was within ± 10% of the actual VO2/Minute. Thirty-nine of these 48 (81.25%) had resultant PaO2 values within our target range of 140 ± 30 mmHg. The PaO2 for these 39 samples ranged from 110 to 168 mmHg with a mean of 133 mmHg. The percentage of predicted shunt (POPS) ranged from 59.0 to 192.4% with a mean of 109.3% (SD = 23.81 %). With this degree of variability, we concluded that the perfusionist must assess VO2/minute as well as POPS in order to predict the resultant PaO2.

Left atrial to femoral arterial bypass was evaluated as a means of supporting patients who were considered to be at high risk for the performance of percutaneous transluminal coronary angioplasty. A 20 French drainage catheter was inserted percutaneously into the left atrium via a modified transseptal technique. Blood was withdrawn from the left atrium and returned through a femoral arterial cannula using a roller pump. Thirteen patients were treated in this fashion with excellent circulatory support. Pump flows varied from 1.5 to 3 liters per minute and bypass time ranged from 27 to 106 min (mean 43±17). Aortic mean pressure was well supported during balloon inflation. No significant complications were encountered. Neither an oxygenator nor a perfusionist is required. The ability to obtain direct left ventricular decompression offers a major potential advantage. Further evaluation of this technique for the support of such patients is indicated. © 1993 Wiley-Liss, Inc.

0 NE OF OUR faculty, who wishes to remain anonymous, invented an acronym, namely “SIGMA” to stand for “Society for Isolation and Glorification of Myocardia1 Anesthesiologists.” The other acronym used in this communication, namely ROA, stands for “regular old anesthesiologist.” With that as background, please consider the following scenario, which takes place at 3:00 AM. Mr Smith, who is 63 years old, has undergone a quadruple-vessel CABG during yesterday’s surgical schedule, and is bleeding. The decision has been made to re-operate. His blood pressure briefly dipped to 87/67 mmHg and a tentative diagnosis of “tamponade” is being entertained. The ROA on cal1 in the hospita1 does not have SIGMA credentials. There is a SIGMA member on cal1 at home. From an anesthesia standpoint, what is actually involved with this re-operation for bleeding? Differential diagnosis of hypotension, airway management, fluid, blood and electrolyte replacement, arrhythmia control, blood gas management, obliteration of awareness, analgesia, and muscle relaxation are some of the most likely elements involved. ROAs work quite effectively in al1 these arenas daily. The cardiac anesthesiologist who believes that he or she somehow has a priori extra expertise in these areas is naive (and wrong). A true blue SIGMA member presented with the above argument wil1 solemnly intone, “Ah, but what if this patient needs to go back on cardiopulmonary bypass?” Can an ROA provide competent and safe care for such a case, which suddenly needs CPB? During cannulation, severe bleeding andior hypotension can occur. Hemodynamic and fluid management are again required. During CPB, the argument goes that a SIGMA member is needed because he or she wil1 know the proper arterial pressures at each stage of the procedure. Actually, that knowledge does not yet exist. Can the ROA remember to give heparin‘? Usually the perfusionist (1) calculates the dose; (2) fills the syringe; and (3) measures activated coagulation time (ACT) and wil1 keep track of when the heparin was given, as wel1 as the effects of the heparin on the ACT. What about the all-important period during emergence from CPB? How many cardiac anesthesiologists actually make independent decisions to start specific inotropes without at least consulting with the surgeon during this crucial period? Not many. How many cardiac anesthesiologists actually merely follow pharmacologic orders from the surgeon during this critical period? If an anesthesiologist claims to be a “cardiac anesthesiologist” but simply awaits surgical orders for dopamine, isoproterenol, epinephrine

Since its establishment many researchers have been trying to automate the process of extracorporeal circulation (ECC). We developed a preliminary experimental model of an automatic regulatory system for ECC. The purpose of the system was to regulate basic hemody-namic parameters such as pump flow and withdrawal blood volume. It was divided into three main components: data sampling unit, central processing unit, and controlling unit. Based on this model we were able to achieve autoreg-ulation of ECC using minimum configuration; however, the system lacked smoothness. This was partly because it was based on a “static” regulation system which used conditional statements having multiple parameters. In this study, we applied fuzzy logic to the former model to achieve more accurate and reliable regulation. We report experimental results for the new system and compare the data between clinical circulation in 13 infants (mean body weight, 13.32 ‡ 5.99 kg) and experimental regulation in 7 mongrel dogs (mean body weight, 11.9 ‡ 2.53 kg). The comparative study revealed no statistical difference between the two groups. This result suggests that the automatic regulation of ECC may be an alternative to manual operation by a professional perfusionist in the near future.

Left ventricular venting has many physiologic and practical benefits. A venting technique is described that employs a simple, closed system which allows the perfusionist to monitor left ventricular distention. By monitoring the left ventricular volume the perfusionist can regulate the degree of negative pressure on the vent and thus reduce the chance of air entering the heart.