David A Palanzo

Hetastarch as a Prime for Cardiopulmonary Bypass

Hetastarch, a synthetic colloid osmotic plasma volume expander, was employed in a prime for cardiopulmonary bypass in 37 patients undergoing myocardial revascularization. Comparison of laboratory values to those of 42 patients undergoing myocardial revascularization using an albumin-containing prime showed lower postoperative platelet counts (p less than 0.02) with hetastarch. There were no differences in chest tube drainage, blood use, plasma hemoglobin, fibrinogen levels, of coagulation times. The hetastarch prime cost

Effect of surface coating on platelet count drop during cardiopulmonary bypass

119.50 per patient, whereas the albumin-containing prime cost

Current ultrafiltration techniques before, during and after pediatric cardiopulmonary bypass procedures

321.35 per patient.

Evaluation of membrane oxygenators and reservoirs in terms of capturing gaseous microemboli and pressure drops.

This study was designed to investigate the effect of surface coating on platelet count drop during cardiopulmonary bypass (CPB). Sixty patients undergoing open-heart surgery were randomly divided into three groups each receiving a different type of coated hollow-fiber membrane oxygenator. The patients were given either an uncoated oxygenator (noncoated group), an oxygenator coated with Carmeda® (Carmeda group) or an uncoated oxygenator with albumin in the priming solution (albumin group). Comparisons were made in platelet count pre-CPB, on bypass (15-25 min) and during the warming period. Calculations were used to account for the effect of hemodilution. The albumin group had significantly lower platelet count drops (-4.8 ± 7.1%) than the Carmeda group (11.0 ± 8.3%) and the noncoated group (20.3 ± 14.5%). Carmeda surface coating demonstrated some beneficial effects, but to a lesser degree than the albumin.

Albumin in the cardiopulmonary bypass prime: how little is enough?:

Ultrafiltration, which is currently considered as a standard method to remove excess water administered during pediatric cardiopulmonary bypass (CPB), aims to minimize the adverse effects of hemodilution, such as tissue edema and blood transfusion. Three ultrafiltration techniques can be used before, during and after CPB procedures, including conventional ultrafiltration (CUF), modified ultrafiltration (MUF) and zero-balance ultrafiltration (Z-BUF). These methods are widely different, but they have common benefits on hemoconcentration, less requirement for blood products, and reduction of the systemic inflammatory responses (SIRS). The present review attempts to restate these ultrafiltration circuitries, application methods, end-points, and clinical impacts.

CORONARY ARTERY BYPASS GRAFTING IN A PATIENT WITH HAEMOPHILIA B

An increasing amount of evidence points to cerebral embolization during cardiopulmonary bypass (CPB) as the principal etiologic factor of neurologic complications. In this study, the capability of capturing and classification of gaseous emboli and pressure drop of three different membrane oxygenators (Sorin Apex, Terumo Capiox SX25, Maquet QUADROX) were measured in a simulated adult model of CPB using a novel ultrasound detection and classification quantifier system. The circuit was primed with 1000 mL heparinized human packed red blood cells and 1000 mL lactated Ringers solution (total volume 2000 mL, corrected hematocrit 26-28%). After the injection of 5 mL air into the venous line, an Emboli Detection and Classification Quantifier was used to simultaneously record microemboli counts at post-pump, post-oxygenator, and post-arterial filter sites. Trials were conducted at normothermic (35 degrees C) and hypothermic (25 degrees C) conditions. Pre-oxygenator and post-oxygenator pressure were recorded in real time and pressure drop was calculated. Maquet QUADROX membrane oxygenator has the lowest pressure drops compared to the other two oxygenators (P < 0.001). The comparison among the three oxygenators indicated better capability of capturing gaseous emboli with the Maquet QUADROX and Terumo Capiox SX25 membrane oxygenator and more emboli may pass through the Sorin Apex membrane oxygenator. Microemboli counts uniformly increased with hypothermic perfusion (25 degrees C). Different types of oxygenators and reservoirs have different capability of capturing gaseous emboli and transmembrane pressure drop. Based on this investigation, Maquet QUADROX membrane oxygenator has the lowest pressure drop and better capability for capturing gaseous microemboli.

Hemodynamic Evaluation of the Avalon Elite Bi-Caval Dual Lumen Cannulae

Previous studies have demonstrated high transoxygenator pressures with noncoated hollow-fiber membrane oxygenators. These reports have been associated with dramatic platelet count drops during cardiopulmonary bypass (CPB). It has also been shown that adding human albumin to the prime of the bypass circuit reduces, if not eliminates, these problems. This study was conducted to determine what is the smallest amount of albumin added to the prime that will still display its protective effects. Eighty patients undergoing nonemergency open-heart surgery were randomly divided into four groups. Groups I and II received the Sarns Turbo 440 oxygenator with 0.0375 g of albumin/100 ml of prime and 0.125 g of albumin/100 ml of prime, respectively, added to the pump prime. Groups III and IV received the Medtronic Maxima-PRF oxygenator with 0.0375 g of albumin/100 ml of prime and 0.125 g of albumin/100 ml of prime, respectively, added to the pump prime. Pre-CPB, on CPB (15-20 min after the initiation of bypass) and warming hemoglobin, hematocrit and platelet counts were drawn on all patients. Net platelet count drop, which accounted for hemodilutional effects, was calculated for all specimens and compared to previous results obtained from the test oxygenators without albumin in the prime. The net platelet count drops for the study groups were as follows: • Sarns oxygenator with no albumin in the prime = 11.8 ± 12.5%; • Sarns oxygenator with 0.0375 g of albumin/100 ml prime = -3.7 ± 10.8%; • Sarns oxygenator with 0.125 g of albumin/100 ml prime = -2.0 ± 12.6%; • Medtronic oxygenator with no albumin in the prime = 20.1 ± 14.5%; • Medtronic oxygenator with 0.0375 g albumin/100 ml prime = -6.9 ± 8.7%; and • Medtronic oxygenator with 0.125 g albumin/100 ml prime = -14.0 ± 12.4%. Our results illustrate that adding as little as 0.0375 g albumin/100 ml prime (3 ml of 25% solution/2000 ml of prime) to the pump prime illicits the beneficial effects of surface coating on platelet loss during CPB.

Current Techniques and Outcomes in Extracorporeal Life Support

Patients with coagulation disorders present the entire open-heart surgical team with an increased challenge. A patient with a known history of moderately severe Factor IX deficiency (2.4% activity) was evaluated for coronary artery disease. Cardiac catheterization revealed a 99% right coronary artery lesion, a long 99% circumflex lesion and normal left ventricular function. Sextuple coronary artery bypass grafting was performed with the aid of aprotinin and Factor IX transfusions. The patients platelet count after cardiopulmonary bypass was 65 000/mm3, down from a preoperative level of 172 000/mm3, requiring the transfusion of six units of pooled platelets immediately postoperation. The patient was extubated five and a half hours after arriving in the Intensive Care Unit, and his chest-tube drainage after the first 24 hours was 373 ml. Other than a transient episode of atrial fibrillation on the third postoperative day, the patient had an uneventful postoperative course and was discharged on the sixth postoperative day. With the use of aproptinin and the newer monoclonal antibody-purified Factor IX concentrates that have been developed, many of the added risks of performing open-heart surgery on patients with haemophilia B are greatly reduced if not eliminated.

Successful treatment of peripartum cardiomyopathy with extracorporeal membrane oxygenation

In previous studies, we have evaluated the hemodynamic properties of selected oxygenators, pumps (centrifugal and roller), and single lumen cannulae. Because the dual lumen cannulae are widely used in veno-venous extracorporeal life support (ECLS) and are receiving popularity due to their advantages over the single lumen cannulae, we evaluated the flow ranges and pressure drops of three different sizes of Avalon Elite dual lumen cannulae (13Fr, 16Fr, and 19Fr) in a simulated neonatal ECLS circuit primed with human blood. The experimental ECLS circuit was composed of a RotaFlow centrifugal pump, a Capiox BabyRX05 oxygenator, 3 ft of 1/4-in venous and arterial line tubing, an Avalon Elite dual lumen cannula, and a soft reservoir as a pseudo-right atrium. All experiments were conducted at 37°C using an HCU 30 heater-cooling unit and with human blood at a hematocrit of 36%. The blood pressure in the pseudo-right atrium was continuously monitored and maintained at 4-5 mm Hg. For each cannula, pump flow rates and pressures at both the arterial and venous sides were recorded at revolutions per minute (RPMs) from 1750 to 3750 in 250 intervals. For each RPM, six data sets were recorded for a total of 162 data sets. The total volume of the system was 300 mL. The flow range for the 13Fr, 16Fr, and 19Fr cannulae were from 228 to 762 mL/min, 478 to 1254 mL/min, and 635 to 1754 mL/min, respectively. The pressure drops at the arterial side were higher than the venous side at all tested conditions except at 1750 rpm for the 19Fr cannula. The results of this study showed the flow ranges and the pressure drops of three different sized dual lumen cannulae using human blood, which is more applicable in clinical settings compared with evaluations using water.

Effect of Trillium™ Biopassive Surface coating of the oxygenator on platelet count drop during cardiopulmonary bypass

For patients with catastrophic cardiac or pulmonary failure, extracorporeal life support (ECLS) often represents the last line of defense against impending and near-certain demise. Recent increases in the application of this technology for adult support have contributed to the continued growth of ECLS utilization in the USA and around the world. With widened application, there is increased clinical demand for this expensive yet potentially life-saving technology. For scientists and clinicians working in the field, there is an obligation to pursue the continued refinement of ECLS technology, all with the goal of improving patient survival and subsequent quality of life. As ECLS becomes more common, providers will be challenged to be judicious in the selection of both the most appropriate patients for ECLS as well as the most appropriate equipment. In this report, we aim to review current ECLS use and outcomes, both nationally and at our center, and to describe our recent and future translational research projects intended to elevate ECLS circuitry.