Practice meta-environment of the cardiovascular perfusionist.

Though historically the development of cardiovascular perfusion grew out of the need for cardiopulmonary bypass, the application of technologies of extracorporeal support has more recently expanded beyond the traditional domain of the cardiac surgical operative and peri-operative environment. As a result, perfusionists are sometimes required to work in novel clinical settings. As part of our recent national survey to evaluate the effects of changes in entry-to-practice criteria introduced in Canada in 2006, we asked perfusionists if their current position as a perfusionist involves work outside the OR. We found that, in addition to regularly working in the Intensive Care Unit and Cardiac Catheterization Lab, 55.3% of respondents reported working "occasionally" in the Emergency Room and 74.7% reported working "occasionally" or "often" in other clinical areas. However, while 96% of respondents believed their training adequately prepared them for their job as a perfusionist, only 68% felt their training adequately prepared them for their duties outside the operating room. We also noted a trend that admission under experience-based entry-to-practice criteria was associated with a higher likelihood of perceived adequacy of training in preparation for duties outside the OR than education-based admission criteria (72% vs 59.4%, p=0.065). These findings raise important questions pertaining to the sufficiency of perfusion education in Canada and the influence of soft skills in preparing perfusionists for their duties, and indicate that a systematic study of the practice environment of cardiovascular perfusionists is timely.

Effects of a change in entry-to-practice criteria for cardiovascular perfusion in Canada: results of a national survey.

INTRODUCTION: Years of experience and level of education are two important determinants of a clinician's expertise. While entry-to-practice criteria for admission to perfusion training in Canada changed from clinical experience-based criteria to education-based criteria in 2006, the effects of these changes have not been studied. OBJECTIVE: To determine the academic and clinical backgrounds of perfusionists in Canada, ascertain perceptions about the adequacy of training and evaluate the effects of the changes on the composition of the perfusion community of Canada. METHODS: An electronic questionnaire was distributed to all practicing perfusionists in Canada, addressing details regarding clinical experience, academic education and perceptions about the adequacy of training. RESULTS: Two hundred and twenty-eight questionnaires were completed, representing a 72% response rate. Perfusionists admitted under academic-based criteria have significantly higher levels of education (100% degree holders vs 69.1%, p<0.001), but less antecedent clinical training and experience (median, IQR: 0, 0 - 4.5 years vs 2, 2 - 8 years, p<0.0001), are younger (median age range 31-35 years vs 51-55 years, p<0.0001), more likely to be female (58.7% vs 41.3%, p=0.006) and are significantly more likely to enter perfusion because of attraction to the type of work (p=0.045). Many perfusionists (70, 32%) in Canada believe themselves inadequately trained for their clinical assignments outside the OR. In addition, 19% of perfusionists plan to retire over the next 10 years. CONCLUSIONS: The introduction of education-based entry criteria has changed the academic and clinical experience levels of perfusionists in Canada. Strategies designed to better prepare perfusionists for their clinical assignments outside the OR are merited.

Erroneous Pressure Reading from an Unpowered Intra-aortic Balloon Pump: Case Report.

Intra-aortic balloon pump (IABP) technology is an established treatment modality for patients with acute cardiac failure. Advances in IABP technology have simplified use and reliability such that electromechanical malfunctions are relatively rare. We present a case of an unanticipated pressure output signal from a powered off Cardiosave IABP console resulting in an erroneous mean arterial blood pressure waveform being displayed during cardiopulmonary bypass. The patient suffered no ill effects and made a full recovery. As a result of this incident, our policies have been revised to ensure that all patients with an IABP brought to the operating room for surgery have at least two arterial lines, one of which is not off the IABP, to prevent future occurrences.

Do specialist transport personnel improve hospital outcome in critically ill patients transferred to higher centers? A systematic review.

PURPOSE: The aim of the study was to determine whether the use of specialist transport personnel improves patient outcome at the receiving hospital for critically ill patients transferred to higher centers. MATERIALS AND METHODS: A search of 6 electronic databases, 15 relevant journals, and the reference lists of all retrieved articles was conducted for studies comparing outcome at the receiving hospital for critically ill adult or pediatric patients transported by dedicated transport crews or tertiary-based specialists with other forms of transport personnel including referring house staff. All potentially relevant articles were retrieved in full and reviewed independently by 2 reviewers to determine eligibility for inclusion. Data were tabulated and results were summarized. RESULTS: Six cohort studies (n = 4534) were included. When patients of equal severity were assessed, only 1 study demonstrated an improvement in outcome at the receiving hospital (survival to 6 hours) when specialist personnel transported the patients. Methodological limitations and interstudy differences in participants and transport personnel precluded pooling of results. CONCLUSIONS: Current data are insufficient. The study designs used create opportunity for significant bias, preventing any useful inferences to be drawn. Further study is warranted.

Residual air in the venous cannula increases cerebral embolization at the onset of cardiopulmonary bypass.

OBJECTIVE: When the right atrium (RA) cannula is connected to the venous return line of the cardiopulmonary bypass (CPB) circuit, air is often introduced. Air in the venous cannula may increase cerebral air embolization at initiation of CPB despite the arterial line filter. We measured the volume of air present in the venous cannula after cannulation of the RA. Transcranial Doppler quantified emboli as high-intensity transient-signals (HITS) in both middle-cerebral arteries (MCA) at the beginning of CPB. METHODS: After RA cannulation, the air column in the venous line was measured and the total volume calculated using the known lumen diameter. CPB onset was defined as the instant when the CPB machine started moving the patient's blood from the RA into the venous reservoir. Starting from CPB onset, HITS were counted: (a) until completion of the first minute on CPB (1-min count) and (b) until aortic cross clamping (pre-clamping count). RESULTS: We studied 135 patients during coronary artery bypass surgery operated on by 10 cardiac surgeons. HITS during onset of CPB were detected in 95% of patients. Median counts were 10 HITS (25th, 75th percentiles: 3, 26) at 1-min and 21 HITS (8, 51) during pre-clamping. A significant correlation was found between the volume of air in the venous cannula and the HITS counts (r=0.524, p<0.0001). Absence of retained air was associated with lower HITS counts [3 HITS (1, 11)] compared with any amount of air [13 HITS (4, 29), p=0.002)]. The volume of air in the venous cannula, the MCA mean blood flow velocity and the pre-clamping time were the only independent predictors of the pre-clamping HITS counts (p<0.001). CONCLUSION: Air in the venous cannula can result in HITS in the MCA. Minimizing the volume of air introduced into the venous cannula after cannulation of the RA can decrease cerebral air embolization at the beginning of CPB.

Currently available biomaterials for use in cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) represents one of the most important technical innovations in healthcare history, yet the systemic responses to CPB remain a fundamentally unresolved problem. Study of the blood-biomaterial interaction and development of biocompatible materials is intimately related to efforts to optimize patient outcome following CPB. This article reviews the design innovations in biomaterial surfaces that have been introduced into clinical practice in an attempt to ameliorate the detrimental consequences of CPB, contrasting the actual clinical improvements and patient benefits achieved against those predicted on the basis of theory and in vitro testing. Some discussion of the underlying mechanisms of action as presently understood is provided and the current limitations of biomaterial-dependent strategies to improve outcome following CPB are addressed.

Sudden power loss in a HeartMate II left ventricular assist device due to intermittent pin contact with the battery: case report.

Left ventricular assist device technology has improved such that mechanical malfunction, particularly with newer generation continuous flow devices, is a relatively rare event. We present a case of sudden power loss in a HeartMate II caused by intermittent contact of the battery terminals after a clip was dropped with the battery inserted in it. The clip was replaced and the patient made a complete recovery. A new inspection and testing methodology, and amended approach to patient and caregiver training, designed to prevent future occurrences is described.

The role of transport intervals in outcomes for critically ill patients who are transferred to referral centers.

PURPOSE: The aim of this study was to determine the association between transport intervals (including time from call to arrival of transport team at the sending hospital, time spent by the transport team in the sending hospital, and transport time between the sending and receiving hospital) and intensive care unit (ICU) and hospital length of stay and hospital mortality at the receiving hospital. MATERIALS AND METHODS: This was a retrospective, stratified cohort study involving all patients 15 years and older who were transferred from one hospital to another of equal or larger size in British Columbia, Canada, and who spent at least 1 day in an ICU or coronary care unit (CCU) at the receiving hospital during 1999 (n = 1930). Data were obtained from 6 administrative databases and linked using generalized software. RESULTS: After adjustment for age, sex, comorbidity, and diagnostic group, longer time from call to arrival of paramedics at the sending hospital was associated with a shorter length of ICU/CCU stay (rate ratio [RR], 0.91; 95% confidence interval [CI], 0.86-0.97) for survivors and a longer length of hospital (RR, 1.12; 95% CI, 1.05-1.21) and ICU/CCU (RR, 1.14; 95% CI, 1.04-1.25) stay for nonsurvivors in the higher-priority air transport group, and with a slightly shorter length of hospital stay (RR, 0.97; 95% CI, 0.95-0.99) for all patients in the lower-priority air transport group. Longer time spent by paramedics at the sending hospital was associated with a shorter length of hospital stay (RR, 0.79; 95% CI, 0.65-0.96) for survivors in the higher-priority air transport group. Longer time for transport between the sending and receiving hospitals was associated with a longer length of ICU/CCU stay (RR, 1.69; 95% CI, 1.26-2.27) for survivors in the higher-priority air transport group but a slightly shorter length of ICU/CCU stay (RR, 0.97; 95% CI, 0.95-0.99) for all patients in the ground transport group. There were no associations between transport times and hospital mortality. CONCLUSIONS: Transport intervals are independently associated with ICU/CCU and hospital lengths of stay at the receiving hospital for critically ill adults transferred to referral centers.

Comparison of two different extracorporeal circuits on cerebral embolization during cardiopulmonary bypass in children.

OBJECTIVE: To compare the effect of two different extracorporeal circuits on the counts of high-intensity transient signals (HITS) during pediatric cardiopulmonary bypass (CPB). METHODS: Transcranial Doppler was used to detect HITS associated with extracorporeal sources during the period of aortic crossclamping in the middle cerebral artery of children undergoing CPB. Based on body size, children were assigned one of two extracorporeal circuits (A or B). Circuit A included a D-705 oxygenator and associated reservoir, and circuit B included a Lilliput oxygenator and reservoir. Patients were further classified into two groups according to the complexity of surgical repair: single simple lesions or multiple complex lesions. RESULTS: We studied 109 pediatric patients. Surgery for multiple complex lesions was associated with longer periods of aortic crossclamping and CPB (p < 0.0001). The median count of extracorporeal HITS was 12 (25th, 75th percentiles: 3, 51). The type of extracorporeal circuit (p = 0.012) and the complexity of surgical repair (p < 0.0001) had an effect on the HITS counts. The use of circuit A was associated with higher HITS counts during surgery for multiple complex lesions compared to single simple lesions (p < 0.0001). Conversely, no differences were found with the use of circuit B between these two surgical groups (p > 0.25). During surgery for multiple complex lesions, patients treated with circuit A showed higher HITS counts than those with circuit B (p < 0.01), but there were no circuit-related differences in HITS counts (p = 0.30) during single simple lesions. CONCLUSION: Variations in the design characteristics of extracorporeal circuits can increase cerebral emboli during CPB in children. This may be related to the reduced ability of some circuits to remove emboli during long periods of CPB for complex congenital heart-surgery.