bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Slow Rewarming on Inotropy, Tissue Metabolism, and “After Drop” of Body Temperature in Pediatric Patients
Authors: Saleh Mohamed , Barr TMF Abdel
Published: July 2023

Pediatric patients undergoing surgical correction of congenital heart diseases using cardiopulmonary bypass (CPB) are subjected to hypothermia. Core temperature is cooled down to 26–28°C during CPB. Postoperative hypothermia in these patients remains a source of long-intensive care unit (ICU) stay. Therefore, this study was performed to build a rewarming strategy aiming to improve the cardiac performance, minimize the early after-drop in both core and foot temperatures, and to achieve early achievement of homeostasis. Thirty pediatric patients of acyanotic congenital heart diseases were randomly allocated into one of three equal groups of 10. Group I was kept at 3°C between nasopharyngeal and heater-cooler unit water temperatures during rewarming whereas group II and group III were kept at 5°C and 7°C, respectively. The following parameters were measured: 1) cardiac performance (cardiac index and peak velocity); 2) cumulative amrinone consumption, blood lactate levels, and total body oxygen consumption; 3) intraoperative and postoperative peak and trough core and foot temperatures; and 4) time to extubation and ICU stay. Group I patients showed statistically significant increase in cardiac index and peak velocity compared with groups II and III, at p < 0.05 and p < 0.025, respectively. Statistically, the consumption of amrinone was significantly decreased in group I compared with groups II and III, with p < 0.005 and p < 0.0005, respectively, at 6 hours postoperatively. Group I showed an insignificant increase in blood lactate level, where groups II and III showed significant increases compared with controls (p < 0.001 at 6 hours postoperatively). Intraoperatively, both trough core and peak foot temperatures of group I patients statistically were significantly higher than in group III patients at p < 0.0005 and p < 0.05, respectively. The same applies in the ICU as regards to the time to core temperature (p < 0.005) and the rate of foot warming (p < 0.01). It was found that a difference of 3°C (group I) between nasopharyngeal and heater-cooler unit water temperatures during rewarming demonstrated the best outcome compared with 5°C and 7°C differences (groups II and III, respectively). This outcome was obvious in the following parameters: 1) the best cardiac performance (cardiac index and peak velocity); 2) the lowest values of cumulative amrinone consumption and blood lactate level; 3) the least after-drop in both core and foot temperatures; and 4) achievement of early homeostasis, shortest ICU stays, and conservation of the ICU resources.
Gaseous Microemboli and the Influence of Microporous Membrane Oxygenators
Authors: Weitkemper Heinz-H. , Oppermann Bernd , Spilker Andreas , Knobl Hermann-J. , Körfer Reiner
Published: July 2023

Gaseous microemboli (GME) are still an unsolved problem of extracorporeal circuits. They are associated with organ injury during cardiopulmonary bypass. Microbubbles of different sizes and number are generated in the blood as the result of different components of the extracorporeal circuit as well as surgical maneuvers. The aim of our study was to observe the behavior of microporous membrane oxygenators to GME in the daily use and in an in vitro model. For the detection of microbubbles, we used a two-channel ultrasonic bubble counter based on 2-MHz Doppler-System with special ultrasound probes. The amount and size of GME were monitored before and after membrane. In 28 scheduled cases with 3 different oxygenators and variability of surgical procedures, we observed the bubble activity in the extracorporeal circuit. In addition, we used an in-vitro model to study the ability of six different oxygenators by removing air in various tests. The oxygenators tested were manufactured with different membrane technologies. The results of our investigations showed varying membrane design lead to a partial removal of GME as well as a change in size and numbers of microbubbles.
Clinical Performance and Biocompatibility of Novel Hyaluronan-Based Heparin-Bonded Extracorporeal Circuits
Authors: Gunaydin Serdar , Mccusker Kevin , Vijay Venkataramana
Published: July 2023

We tested documented in vitro and ex vivo advantages of novel hyaluronan based heparin bonded extracorporeal circuits in a prospective randomized study. During the period from June until September 2005, 40 patients undergoing reoperation for coronary artery bypass grafting were allocated into two equal groups (n= 20): Group 1 was treated with hyaluronan-based heparin-bonded circuits and group 2 was treated with uncoated control circuits. Complete blood count, fibrinogen, albumin, C3a, interleukin-2 levels, and thromboelastographic data were documented after induction of anesthesia (T1) and heparin administration before cardiopulmonary bypass (CPB) (T2), 15 minutes after initiation of CPB (T3), before cessation of CPB (T4), 15 minutes after reversal with protamine (T5), and the first postoperative day at 8:00 a.m. (T6). Hollow fibers were collected for consecutive biomaterial analysis by optical and scanning electron microscopy (SEM). Desorbed protein deposition on fibers was compared by spectrophotometry. Leukocyte counts were lower in T4-T6 in group 1 (p< .05). Platelet counts demonstrated significant differences at T4 and T5 in coated group (p< .05). Albumin and fibrinogen levels were better preserved in Group 1 at T4, T5 and T4, T6, consecutively (p< .05). C3a and IL-2 levels were lower at T3-T5 and T4-T5 in intervention group (p< .05). Postoperative hemorrhage was 412 ± 50 mL in group 1 and 684 ± 50 ml in group 2 (p< .05). Respiratory support time was shorter in group 1 versus control (p< .05). Platelet adhesion was significantly lower in intervention group. Amount of desorbed protein was 1.44 ± 0.01 mg/dL in group 1 and 1.94 ± 0.01 mg/dL in control (p< .05). SEM and spectrophotometry demonstrated better surface preservation in the hyaluronan coated group. Novel hyaluronan-based heparin-bonded circuits reduce platelet adhesion-aggregation and protein adsorption and provide better perioperative clinical parameters through platelet, albumin, and fibrinogen-sparing effects.
Use of Bivalirudin as an Anticoagulant During Cardiopulmonary Bypass
Authors: Veale James J. , McCarthy Harry M. , Palmer George , Dyke Cornelius M.
Published: July 2023

Bivalirudin is a short-acting direct thrombin inhibitor that has been used in cardiac surgical patients with heparin-induced thrombocytopenia (HIT) or suspected HIT. Although no direct thrombin inhibitor is indicated for anticoagulation during cardiac surgery in patients with heparin-induced thrombocytopenia (HIT) or suspected HIT, use of heparin-alternatives are increasing as the awareness of HIT increases. Reports of anticoagulation with bivalirudin are sporadic, however, with variable dosing and management strategies. In this report, we describe our management techniques for cardiopulmonary bypass with bivalirudin based upon our personal experience. Although the reported clinical experience with bivalirudin in cardiac surgery is reviewed, operative techniques for the perfusionist/surgeon team are discussed in detail. We recognize that the use of bivalirudin during cardiopulmonary bypass is evolving and modifications of technique will undoubtedly occur as further data and experience accumulate.
Fentanyl Plasma Levels After Modified Ultrafiltration in Infant Heart Surgery
Authors: Taenzer Andreas H. , Groom Robert , Quinn Reed D.
Published: July 2023

Modified ultrafiltration (MUF) is a novel application of ultrafiltration to remove excess water after cardiopulmonary bypass in pediatric patients that was first reported in 1991. It has gained widespread use as an important adjunct to fluid management in neonates, infants, and pediatric cardiac surgery patients. Now more than two decades after its original description, the exact mechanism of action and effects of this therapy are still a matter of discussion. The aim of this study was to determine the effects of MUF on plasma fentanyl levels using a two-phase in vitro and in vivo study. We designed an in vitro experimental model to simulate MUF that allowed measurement of plasma fentanyl levels while eliminating biologic variables. Plasma fentanyl levels were measured during five consecutive operations on neonates and infants undergoing repair of congenital heart defects. Increases in plasma fentanyl levels were found in vitro as well as in vivo. Fentanyl plasma levels more than doubled after MUF (increased by a factor of 2.22, from 12.4 to 27.5 ng/ml in vivo). The increase in plasma fentanyl levels needs to be taken into account when delivering anesthetic care and when analyzing the effect of MUF on outcome variables.
Evaluation of Biocompatible Cardiopulmonary Bypass Circuit Use During Pediatric Open Heart Surgery
Authors: Deptula Joseph , Glogowski Kimberly , Merrigan Kellie , Hanson Kim , Felix Donald , Hammel James , Duncan Kim
Published: July 2023

The contact of blood with nonbiological surfaces during cardiopulmonary bypass (CPB) induces a whole body inflammatory response and increases postoperative morbidity directly related to bleeding complications and end organ dysfunction. Methods to reduce these effects have included modification of extracorporeal circuits through biocompatible coating of disposables and the application of various pharmacological agents. Biocompatible coated surfaces are designed to mimic physiologic surfaces. This study was designed to ascertain the effects of using coated circuits during pediatric CPB. After Institutional Review Board approval and parent/guardian consent, patients undergoing CPB, weighing less than 15 kg, with target CPB temperatures more than 28°C, were enrolled into the Coated Circuit Group using an entirely biocompatible CPB circuit with poly(2methoxyethylacrylate) (PMEA) and a biocompatible coated oxygenator (n= 16). Those patients were retrospectively matched to control patients having the same congenital repair with respect to patient size, surgeon, anesthesiologist, bypass time, cross-clamp time, bypass temperature, and noncoated bypass disposables; (n= 16). CPB data collected included on-bypass platelet count, hematocrit (HCT), and CPB blood product use. Postprotamine data collected in the operating room included blood product use, time from initial protamine administration to chest closure, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (INR). Postoperative intensive care unit (ICU) data included blood product use, HCT, chest tube output, platelet count, PT, aPTT, INR, blood gases, lactate, and ventilator settings at 1, 2, 4, 6, 12, and 24 hours. Other data collected included intubation time, length of time to chest tube removal, and length of ICU stay. Statistical significance (p< .05) was seen in units of platelets transfused postprotamine, ventilator peak inflation pressure (PIP) on admission to the ICU, postoperative day 0 packed red blood cells (PRBC) and fresh frozen plasma (FFP) transfused, and lactate at 1, 2, 4, 6, and 12 hours postoperative. Several parameters approached statistical significance, including PRBC transfused postprotamine, time from protamine administration to chest closure, postoperative day 0 platelets transfused, and ICU stay. The data suggest that PMEA biocompatible CPB circuits can be used safely during pediatric heart surgery, resulting in a decrease in postoperative blood product use, improved postoperative lung function, and a reduction in the time spent in the ICU.
Quantification of Fat Mobilization in Patients Undergoing Coronary Artery Revascularization Using Off-pump and On-pump Techniques
Authors: Ajzan Ahmed , Modine Thomas , Punjabi Prakash , Ganeshalingam Kandeepan , Philips Gary , Gourlay Terence
Published: July 2023

Fat mobilization during cardiopulmonary bypass (CPB) is a recognized risk of the procedure. Intravascular mobilization of fat emboli subsequent to CPB has been implicated in some of its recognized pathophysiologies, particularly with regard to cerebral embolic injury. The aim of this study was to investigate whether fat mobilization is still a real issue in modern perfusion practice and to determine whether off pump coronary artery bypass techniques minimize this risk. Thirty patients undergoing routine elective coronary artery bypass graft (CABG) surgery were divided into two groups. Group 1 patients underwent off pump coronary artery bypass (OPCAB) procedures, and group 2 underwent CABG supported with CPB. Blood samples were taken from the CPB patients at the beginning, middle, and end of the procedure, from the suction line, from the arterial line, and from the venous line for measurement of fat emboli present. Samples were taken at corresponding time-points from the OPCAB patients for similar measurements. Fat emboli were counted manually using Oil red O staining and light microscopy. The fat emboli were sized using calibrated microspheres as a visual size contrast. No fat emboli were observed in any of the blood samples taken from the OPCAB patients. There were fat emboli present in all samples taken during CPB from all sources. The count was highest in the suction system and lowest in the venous blood and tended to increase during CPB. There was an absence of large fat emboli in the venous blood, which tends to indicate that the larger fat emboli lodge in the microvasculature. OPCAB surgery eliminates the risk of fat embolization in patients undergoing coronary revascularization. The suction system is the major source of fat emboli during CPB, and despite the multiple filtration components of the CPB system, fat emboli of various and significant sizes do reach the patient. Fat embolization remains a risk in routine elective CABG surgery. Cardiotomy suction should be eliminated where possible.
Use of Autologous Platelet Gel in Bariatric Surgery
Authors: Brady Chad , Vang See , Christensen Kevin , Isler Jack , Vollstedt Keith , Holt David
Published: July 2023

Gastric bypass surgery is a common corrective procedure for obesity that is associated with many risks. Recent studies describing the use of autologous platelet gel (APG) have shown promise in preventing certain operative complications and improved healing processes. These improvements have been credited to the concentrated platelets and growth factors present in APG, as well as the native concentrations of fibrinogen. There are numerous applications for the use of APG in surgery, and the list continues to expand. However, little research exists to support the efficacy of APG in bariatric surgery. This case series describes using APG with patients undergoing laparoscopic Roux-en-Y gastric bypass surgery.
Hyperglycemia as an Effect of Cardiopulmonary Bypass: Intra-operative Glucose Management
Authors: Najmaii Samira , Redford Daniel , Larson Douglas F.
Published: July 2023

Cardiopulmonary bypass (CPB) is associated with surgical stress, hypothermia, hyperoxia, enhancement of neuroendocrine outflow, and administration of glucogenic catecholamines that are associated with glucogonolysis and glucogenesis that result in hyperglycemia. The hyperglycemic state during CPB has been associated with adverse outcomes, such as infection, neurological impairment, cardiac dysfunction, prolonged hospitalization, and higher mortality rates. This report justifies vigilant monitoring of blood glucose levels and a rational protocol for the treatment of hyperglycemia of all open heart surgical patients that may improve post-CPB surgical outcomes.
Normoxia vs. Hyperoxia: Impact of Oxygen Tension Strategies on Outcomes for Patients Receiving Cardiopulmonary Bypass for Routine Cardiac Surgical Repair
Authors: Brown D. Mark , Holt David W. , Edwards Jeff T. , Burnett Robert J.
Published: July 2023

Oxygen pressure field theory (OPFT) was originally described in the early 1900s by Danish physiologist, Dr. August Krogh. This revolutionary theory described microcirculation of blood gases at the capillary level using a theoretical cylindrical tissue model commonly referred to as the Krogh cylinder. In recent years, the principles and benefits of OPFT in long-term extracorporeal circulatory support (ECMO) have been realized. Cardiac clinicians have successfully mastered OPFT fundamentals and incorporated them into their clinical practice. These clinicians have experienced significantly improved survival rates as a result of OPFT strategies. The objective of this study was to determine if a hyperoxic strategy can lead to equally beneficial outcomes for short-term support as measured by total ventilator time and total length of stay in intensive care unit (ICU) in the cardiopulmonary bypass (CPB) patient at a private institution. Patients receiving traditional blood gas management while on CPB (group B,n= 17) were retrospectively compared with hyperoxic patients (group A,n= 19). Hyperoxic/OPFT management was defined as paO2values of 300–350 mmHg and average VSAT> 75%. Traditional blood gas management was defined as paO2values of 150–250 mmHg and average VSAT< 75%. No significant differences between treatment groups were found for patient weight, CPB/AXC times, BSA, pre/post Hgb, pre/post-platelet (PLT) counts, pre/post-creatinine levels, pre/post-BUN, UF volumes, or CPB urine output. Additionally, no significant statistical differences were found between treatment groups for total time in ICU (T-ICU) or total time on ventilator (TOV). Hyperoxic management strategies provided no conclusive evidence of outcome improvement for patients receiving CPB for routine cardiac surgical repair. Additional studies into the impact of hyperoxia in short-term extracorporeal circulatory support are needed.
Autologous Platelet Gel: An In Vitro Analysis of Platelet-Rich Plasma Using Multiple Cycles
Authors: Christensen Kevin , Vang See , Brady Chad , Isler Jack , Allen Keith , Anderson John , Holt David
Published: July 2023

Autologous platelet gel (APG) has become an expanding field for perfusionists. By mixing platelet-rich plasma (PRP) with thrombin and calcium, platelet gel is prepared and used in many surgical settings. There are many devices used to produce PRP. This study evaluates the Medtronic Magellan Autologous Platelet Separator. The purpose of this study was to show that processing two cycles of the same syringe could reduce the amount of blood required to produce a specific volume of PRP. Three 60-mL syringes of whole blood with anticoagulant were removed from 15 elective coronary artery bypass patients. Each syringe produced 9 mL of PRP and 1 mL was sent to the laboratory for analysis. The remaining whole blood in each syringe was processed a second time with a yield of 5 mL of PRP with 1 mL sent to the laboratory. With this data, the Magellan was assessed in three phases. The first phase focused on the consistency of the Magellan. Laboratory values of hematocrit, platelet count, white blood cell count, and fibrinogen were compared between each syringe processed by the device. The second phase dealt with the percentage of platelets in the PRP that the Magellan was able to capture. Finally, results of both cycles were combined and compared against baseline values. Most of the hematological factors evaluated between each syringe were consistent in both cycles. The Magellan was able to capture nearly 70% of all platelets in the PRP of the first cycle and 18.5% in the second cycle. By mathematically combining both cycles, platelet counts averaged 2.8 times baseline with a 3.3 times baseline increase when the volume of the two cycles was weighted. This weighted average was done to reflect a higher concentration of Cycle 1 platelets than Cycle 2 in each sample. This study proved that processing each syringe of whole blood twice could reduce blood requirements while maintaining an effective platelet yield and volume. It also showed that the Magellan does conform to benchmark testing done at Medtronic.
Dose Titration of Recombinant Factor VIIa Using Thromboelastograph Monitoring in a Child With Hemophilia and High Titer Inhibitors to Factor VIII: A Case Report and Brief Review
Authors: Trowbridge Cody C. , Stammers Alfred H. , Ciccarelli Nancy , Klayman Myra
Published: July 2023

The administration of recombinant factor VIIa (rFVIIa) is complicated by a wide inter-subject variation in response, a short half-life, evolving indications for use, and the absence of a test that has been shown to correlate with clinical effect. This report describes a method used to titrate rFVIIa to thromboelastography (TEG) parameters in a difficult to manage hemophilic patient with high titer inhibition to factor VIII. The current concepts of monitoring rFVIIa administration in hemophiliacs and uncontrolled hemorrhage in cardiac surgery are briefly reviewed.
Autologous Platelet Gel in Coronary Artery Bypass Grafting: Effects on Surgical Wound Healing
Authors: Vang See N. , Brady Chad P. , Christensen Kevin A. , Allen Keith R. , Anderson John E. , Isler Jack R. , Holt David W. , Smith Lynette M.
Published: July 2023

Stimulating the body’s natural healing at the cellular level can be achieved through the application of growth factors located within platelets. Once combined with a mixture of calcium and thrombin, this substance, now referred to as autologous platelet gel (APG), can be applied to surgical wound sites for patients undergoing cardiac surgery. The purpose of this study was to examine the effects of APG on surgical site infection, post-operative pain, blood loss, and bruising. After 30 mL platelet-rich plasma (PRP) was processed, 10 mL PRP was distributed on the sternum after re-approximation and 7 mL PRP before skin closure. Ten milliliters PRP was used on the endoscopic leg harvest (EVH) site. The remaining 3 mL was sent to the laboratory for hematologic testing. Both the control (CTR) and treatment (TRT) groups were well matched, with the exception of ejection fraction and pre-operative platelet count, which was significantly higher in the TRT group. Average platelet count yield was 4.2 ± 0.5 × 103/mcL, white blood count (WBC) yielded 1.9 ± 0.7 × 103/mcL, and fibrinogen yielded 1.2 ± 0.2 mg/dL above baseline. There were no deep or superficial sternal infections. However, one patient from each group did experience a leg infection at the EVH site, which occurred after hospital discharge. More patients in the TRT group experienced less pain on postoperative day (POD) 1 and at the post-operative office follow-up. Blood loss and bruising was less in the TRT group on POD 2; however, there was no statistical significance. The application of APG seems to confer beneficial effects on pain, blood loss, and bruising. However, further studies with a greater sample size are needed to power significant differences.
Extracorporeal Membrane Oxygenation in Severe Acute Respiratory Failure in Postpartum Woman With Rheumatic Mitral Valve Disease: Benefit, Factors Furthering the Success of This Procedure, and Review of the Literature
Authors: Fayad Georges , Larrue Benoît , Modine Thomas , Azzaoui Richard , Regnault Alexi , Koussa Mohammad , Gourlay Terry , Fourrier François , Decoene Christophe , Warembourg Henri
Published: July 2023

Pregnancy is a common decompensation factor for women with post-rheumatic mitral disease. However, valvular heart diseases causing severe acute respiratory distress are rare. Use of extracorporeal membrane oxygenation (ECMO) early in the event of cardiorespiratory failure after cardiac surgery may be of benefit. Indeed, ECMO cardiopulmonary bypass (CPB) support could help pulmonary recovery if the mitral pathology is involved. A 31-year-old female patient at 30 weeks of amenorrhea was admitted to the obstetrics department with 40°C hyperthermia and New York Heart Association (NYHA) class 4 dyspnea. The patient’s medical history included a post-rheumatic mitral stenosis. Blood gases showed severe hypoxemia associated with hypocapnia. The patient needed to be rapidly intubated and was placed on ventilatory support because of acute respiratory failure. Transesophageal echocardiography showed a severe mitral stenosis, mild mitral insufficiency, and diminished left ventricular function, hypokinetic, dilated right ventricle, and a severe tricuspid regurgitation. An urgent cesarean section was performed. Because of the persistent hemodynamic instability, a mitral valvular replacement and tricuspid valve annuloplasty were performed. In view of the preoperative acute respiratory distress, we decided, at the beginning of the operation, to carry on circulatory support with oxygenation through an ECMO-type CPB at the end of the operation. This decision was totally justified by the unfeasible CPB weaning off. ECMO use led to an efficient hemodynamic state without inotropic drug support. The surgical post-operative course was uneventful. Early use of cardiorespiratory support with veno-arterial ECMO allows pulmonary and right heart recovery after cardiac surgery, thus avoiding the use of inotropic drugs and complex ventilatory support.
Survey: Retrospective Survey of Monitoring/Safety Devices and Incidents of Cardiopulmonary Bypass for Cardiac Surgery in France
Authors: Charrière Jean-Mathias , Pélissié Jérôme , Verd Christophe , Léger Philippe , Pouard Philippe , de Riberolles Charles , Menestret Pascal , Hittinger Marie-Claude , Longrois Dan
Published: July 2023

Several surveys showed that cardiopulmonary bypass (CPB) is associated with incidents that negatively affect outcome and suggested that improved monitoring and safety could be associated with a decreased rate of incidents. In 2004, the French “Haute Autorité de Santé”(an independent French government advisory agency) and the French College of Perfusion issued recommendations concerning safety and monitoring devices for CPB. The aims of this study were to investigate the difference between the recommendations and the clinical practice of CPB shortly after publication of the recommendations and compare the 2005 situation with the results of a previous survey performed in France and to investigate the rate of perfusion incidents and their outcome. A 62-item questionnaire was sent in January 2006 to all 66 centers performing cardiac surgery and CPB in France. The survey investigated the use of safety and monitoring devices as well as perfusion incidents for 2005. Fifty-seven centers (response rate, 86%) returned the questionnaire, totaling 34,496 CPB procedures. There was a wide difference between the recommendations and the reported use of safety and monitoring devices with no clinically relevant change from the previous French survey concerning 2001. An incident was reported for every 198 CPB procedures with death at a frequency of 1:4864 and permanent sequelae of 1:11,349, respectively (a permanent injury or death in 1:3220 procedures). The three most frequent perfusion incidents were adverse effects to protamine (1:1702), dissection at the arterial cannulation site (1:1792), and coagulation of the circuit (1:4864). In conclusion, this survey showed that an important effort must be made in France to implement into clinical practice the recommendations concerning CPB monitoring and safety devices. The analysis of CPB-related incidents suggest that, with the exception of protamine adverse effects, the majority of deaths and severe permanent injuries in this survey could probably be avoided by improved use of the monitoring and safety devices.
Preventing Gaseous Microemboli During Blood Sampling and Drug Administration: An In Vitro Investigation
Authors: Myers Gerard J.
Published: July 2023

The detection and prevention of gaseous microemboli (GMEs) during cardiopulmonary bypass has generated considerable interest within the cardiac surgical community. There have been several landmark papers that have used transcranial Doppler devices during cardiopulmonary bypass to detect gaseous microemboli activity in the patients’ middle cerebral artery during perfusionist interventions. To determine if this source of emboli could be prevented, a shunt was developed between the oxygenator’s sampling manifold and the oxygenator’s venous line. This shunt bypassed the venous line and emptied into the oxygenator’s integral cardiotomy. An in vitro experiment was performed using three open system oxygenators (Sorin Synthesis, Sorin PrimeOx2, and Terumo Capiox SX25) to compare post-arterial filter emboli detection using the Hatteland CMD20 Microbubble Detector under tightly controlled conditions. After injection of air through the sampling manifold, the PrimeOx2 and the Synthesis oxygenators had statistically significant fewer GMEs with the shunt used than when the shunt was not used. Using a shunt in the sampling manifold during perfusionist interventions will dramatically reduce or eliminate gaseous microemboli transmission to the patient during bypass with both the PrimeOx2 and Synthesis oxygenators. However, results indicate that further study of GME handling with all oxygenator’s integral cardiotomies is warranted.
“Orpheus” Cardiopulmonary Bypass Simulation System
Authors: Morris Richard W. , Pybus David A.
Published: July 2023

In this paper we describe a high-fidelity perfusion simulation system intended for use in the training and continuing education of perfusionists. The system comprises a hydraulic simulator, an electronic interface unit and a controlling computer with associated real-time computer models. It is designed for use within an actual operating theatre, or within a specialized simulation facility. The hydraulic simulator can be positioned on an operating table and physically connected to the circuit of the institutional heart-lung machine. The institutional monitoring system is used to display the arterial and central venous pressures, the ECG and the nasopharyngeal temperature using appropriate connections. The simulator is able to reproduce the full spectrum of normal and abnormal events that may present during the course of cardiopulmonary bypass. The system incorporates a sophisticated blood gas model that accurately predicts the behavior of a modern, hollow-fiber oxygenator. Output from this model is displayed in the manner of an in-line blood gas electrode and is updated every 500 msecs. The perfusionist is able to administer a wide variety of drugs during a simulation session including: vasoconstrictors (metaraminol, epinephrine and phenylephrine), a vasodilator (sodium nitroprusside), chronotropes (epinephrine and atropine), an inotrope (epinephrine) and modifiers of coagulation (heparin and protamine). Each drug has a pharmacokinetic profile based on a three-compartment model plus an effect compartment. The simulation system has potential roles in the skill training of perfusionists, the development of crisis management protocols, the certification and accreditation of perfusionists and the evaluation of new perfusion equipment and/or techniques.
Can Vacuum Assisted Venous Drainage be Achieved using a Roller Pump in an Emergency? A Pilot Study using Neonatal Circuitry
Authors: Hill S. L. , Holt D. W.
Published: July 2023

There has been much advancement in perfusion technology over its 50 years of progression. One of these techniques is vacuum-assisted venous drainage (VAVD). Many perfusionists augment venous drainage using VAVD, typically from a wall vacuum source. This study explores alternates to providing VAVD if the wall vacuum fails. In two porcine laboratories, ∼36 in. of 3/16-in. tubing was connected to a sucker return port and placed into the roller head next to the arterial pump. The vacuum was monitored with a DLP pressure monitoring system (Medtronic). This system was connected to small-bore tubing and attached to a stopcock on top of the reservoir. The vacuum was regulated using another stopcock connected to a non-filtered luer lock port on top of the reservoir or by a segment of 3 × 0.25-in.-diameter tubing attached to the vent port with a c-clamp. Vacuum drainage was achieved, ranging from −18 mmHg to −71 mmHg by manipulating the stopcock or c-clamp. Changes in venous drainage were seen by volume fluctuations in the venous reservoir. The vacuum was adjusted to account for dramatic changes. Augmented venous drainage using a roller pump can be achieved successfully during cardiopulmonary bypass (CPB). This method of active drainage can be used in lieu of wall suction or during times of emergency if wall suction fails.
Optimization of the Perfusion Circuit and Its Possible Impact on the Inflammatory Response
Authors: De Somer Filip
Published: July 2023

Although there has been a steady improvement in cardiopulmonary bypass (CPB) techniques since its early introduction, it is still associated with some morbidity. Further attenuation of bypass-related systemic inflammatory reaction demands multidisciplinary action because the basic physiopathology is complex and cannot be controlled by one approach alone. This is an overview of the literature. Introduction of “mini” CPB circuits makes it easier to compare perfusion outcomes between different centers. Indeed, these circuits have a comparable fluid dynamic characteristic and surface area. All of them have a hemocompatible coating, and the technique avoids return of the pleuropericardial aspirations into the systemic circulation. As a consequence, results are very comparable to those obtained by beating heart surgery. However, vascular access and the resultant change in flow pattern in the aorta still have a negative correlation with neurocognitive outcome. A better understanding of the delicate balance between fluid dynamics, foreign material, coagulation, and inflammation is still a major requirement, especially because recent research combining pharmacologic, surgical, and anesthesia techniques with perfusion techniques has shown attenuation of the inflammatory response sequelae. For example, a better neurologic outcome is achieved by combining separation of suction, reducing hemodilution, administration of high-dose aprotinin, and volatile anesthetics and alternative cannulation techniques. Further improvement of CPB requires more uniform CPB circuits with known characteristics. The design should be based on evidence-based medicine philosophy. Combined efforts should be made by anesthesiologists, perfusionists, and surgeons to attenuate contact activation, ischemia-reperfusion injury, blood-material interaction, cell damage, and neurocognitive outcome.
Pharmacologic Strategies for Combating the Inflammatory Response
Authors: Landis Clive
Published: July 2023

The “systemic inflammatory response” is a multifaceted defensive reaction of the body to surgical trauma and cardiopulmonary bypass (CPB), characterized by systemic activation of fibrinolysis, coagulation, complement, immune cells, platelets, and oxidative pathways, all overlaid onto localized trauma to the grafted vessel or vascular beds susceptible to ischemia/reperfusion. There is going to be no single magic bullet to diminish such a broad host defense response to surgery. The best chance lies with combinatorial—or promiscuous—pharmacotherapy. Combinations of anti-fibrinolytics, anti-coagulants targeted higher up the coagulation cascade, anti-thrombin receptor therapy, improved coated circuits, anti-complement, anti-leukocyte, and antioxidant therapies may blunt sufficient arms of the systemic inflammatory response to be clinically effective. The alternative is a promiscuous drug like aprotinin, which targets plasmin in the fibrinolytic pathway, kallikrein in the coagulation pathway, thrombin receptors on platelets and endothelium, and leukocytes at the extravasation step. Because of the overriding safety concerns relating to the use of anti-fibrinolytics in cardiothoracic surgery, any future combinatorial or promiscuous pharmacotherapy involving anti-fibrinolytics will require solid underpinning with a known mechanism of action and clinical safety data powered to detect well-defined adverse events (stroke, myocardial injury, renal failure requiring dialysis), preferably in isolation and not as a composite endpoint.
Cardiopulmonary Bypass Recommendations in Adults: The Northern New England Experience
Authors: DioDato Christian P. , Likosky Donald S. , DeFoe Gordon R. , Groom Robert C. , Shann Kenneth G. , Krumholz Charles F. , Warren Craig S. , Pieroni John W. , Benak Arnold , McCusker Kevin , Olmstead Elaine M. , Ross Cathy S. , O’Connor Gerald T. ,   for The Northern New England Cardiovascular Disease Study Group
Published: July 2023

Using a regional cardiopulmonary bypass (CPB) registry, we compared the practice of CPB at eight northern New England institutions to recently published recommendations. We examined CPB practice among 3597 adult patients undergoing isolated coronary artery bypass grafting surgery from January 2004 to June 2005. Registry variables were used to compare regional CPB practice to recommendations on topics of neurologic protection (pH management, avoidance of hyperthermia, minimizing return of pericardial suction blood, aortic assessment, arterial line filtration), maintenance of euglycemia, reduction of hemodilution, and attenuation of the inflammatory response. We report overall regional practice (regional minimum, maximum). All centers used alpha-stat pH management and arterial line filters. Avoidance of hyperthermia (temperature <37°C) was achieved during 23.4% of procedures (regional minimum, 1.5%; maximum, 83.2%). Minimizing return of pericardial suction blood was achieved in 23.7% of cases (0.7%, 93.6%). Aortic assessment was performed during 45.7% of procedures (1.3%, 98.9%). Maintenance of euglycemia (<200 mg/dL) was accomplished in 82.7% (57.1%, 97.9%) of cases. Hemodilution (hematocrit <23% on CPB) was lower for men 32.4% (20.6%, 52.3%) than women 77.9% (64.7% 88.9%). Men were less likely to receive red blood cell transfusions in the operating room (11.0%; 1.8%, 20.9%) than women (54.6%; 30.1%, 70.6%). In an effort to attenuate the inflammatory response, surface coated circuits were used in 83.3% of procedures (8.8%, 100%). During this time, gaps existed between regional CPB practice and recently published recommendations. We continue to prospectively measure CPB practice relating to these recommendations to monitor and improve the care provided to our patients.
Use of Leukocyte-Depleting Filters During Cardiac Surgery With Cardiopulmonary Bypass: A Review
Authors: Boodram Shalini , Evans Ed
Published: July 2023

Numerous researchers and clinicians have shown that cardiopulmonary bypass (CPB) plays a large role in the initiation of the systemic inflammatory response during cardiac surgery. The activation of leukocytes during this process has been implicated as one of the major contributors to multi-organ dysfunction experienced by some patients after cardiac surgery. Thus, in an attempt to attenuate the systemic inflammatory response and to reduce the amount of activated leukocytes from the systemic circulation during CPB, leukocyte-depleting filters were developed in the early 1990s. Since the clinical introduction of these filters into the CPB circuit, several articles have been published evaluating the effectiveness of leukocyte filtration; however, the results have been conflicting. This article will review some of the most recent literature, ∼40 papers published within the past 10 years, regarding the use of leukocyte-depleting filters during CPB and its effectiveness in preserving organ function. In addition, the effect of different filtration strategies and the effectiveness of the filter to attenuate the systemic inflammatory response in combination with other mechanical and pharmaceutical strategies will be reviewed.
Influence of Intraoperative Fluid Volume on Cardiopulmonary Bypass Hematocrit and Blood Transfusions in Coronary Artery Bypass Surgery
Authors: Campbell Jeffrey A. , Holt David W. , Shostrom Valerie K. , Durham Samuel J.
Published: July 2023

A hematocrit (Hct) of less than 25% during cardiopulmonary bypass (CPB) and transfusion of homologous packed red blood cells (PRBC) are each associated with an increased probability of adverse events in cardiac surgery. Although the CPB circuit is a major contributor to hemodilution intravenous (IV) fluid volume may also significantly influence the level of hemodilution. The objective of this study was to explore the influence of asanguinous IV fluid volume on CPB Hct and intraoperative PRBC transfusion. After Institutional Review Board approval, a retrospective chart review of 90 adult patients that had undergone an elective, isolated CABG with CPB was conducted. Regression analysis was used to determine if pre-CPB fluid volume was associated with the lowest CPB Hct and the incidence of an intraoperative PRBC transfusion. In separate multivariate analyses, higher pre-CPB fluid volume was associated with lower minimum CPB Hct (p< .0001), and higher minimum CPB Hct was associated with a decreased probability of PRBC transfusion (p< .0001). Compared to patients that received <1600 mL (n= 55) of pre-CPB fluid, those that received >1600 mL (n= 35) had a decreased mean low CPB Hct (22.4% vs 25.6%,p< .0001), an increased incidence of a CPB Hct <25% (74% vs. 38%,p= .0008) and PRBC transfusion (60% vs. 16%,p< .0001), and increased median PRBC units transfused (2.0 vs 1.0,p= .1446) despite no significant difference in gender, age, patient size, baseline Hct, or CPB prime volume. Patients that received a PRBC transfusion (n= 30) received a significantly higher volume of pre-CPB fluid than nontransfused patients (1800 vs. 1350 mL,p= .0039). These findings suggest that pre-CPB fluid volume can significantly contribute to hemodilutional anemia in cardiac surgery. Optimizing pre-CPB volume may preserve baseline Hct and help limit intraoperative hemodilution.
Pharmacodynamic and Efficacy Profile of TGN 255, a Novel Direct Thrombin Inhibitor, in Canine Cardiopulmonary Bypass and Simulated Mitral Valve Repair
Authors: Nelson David A. , Nelson Katherine T. , Miller Matthew W. , Dupe Robert , Chahwala Suresh B. , Kennedy Anthony , Chander Chaman , Fossum Theresa W.
Published: July 2023

Heparin-induced thrombocytopenia can be a life-threatening sequel to conventional use of unfractionated heparin in cardiopulmonary bypass (CPB). This study evaluated the pharmacokinetic/pharmacodynamic (PK/PD) and efficacy profile of a novel direct thrombin inhibitor, TGN 255, during cardiac surgery in dogs. Point-of-care coagulation monitoring was also compared against the plasma concentrations of TRI 50c, the active metabolite of TGN 255. The study was conducted in three phases using 10 animals: phase 1 was a dose-ranging study in conscious animals (n = 6), phase 2 was a similar but terminal dose-ranging study in dogs undergoing CPB (n = 6), and phase 3 was with animals undergoing simulated mitral valve repair (terminal) using optimal TGN 255 dose regimens derived from phases I and II (n = 4). During the study, PD markers and drug plasma levels were determined. In addition, determinations of hematologic markers and blood loss were undertaken. Phase 1 studies showed that a high-dose regimen of a 5-mg/kg bolus and infusion of 20 mg/kg/h elevated PD markers in conscious animals, at which time there were no measured effects on platelet or red blood cell counts, and the mean plasma concentration of TRI 50C was 20.6 fg/mL. In the phase 2 CPB dose-ranging study, this dosing regimen significantly elevated all the PD markers and produced hemorrhagic and paradoxical thrombogenic effects. In the phase 3 surgical study, a lower TGN 255 dose regimen of a 2.5-mg/kg bolus plus 10 mg/kg/h produced anticoagulation, elevated PD markers, and produced minimal post-operative blood loss in the animals. Plasma levels of TRI 50C trended well with the conventional point-of-care coagulation monitoring. TGN 255 provided effective anticoagulation in a canine CPB procedure, enabling successful completion with minimal blood loss. These findings support further evaluation of TGN 255 as an anticoagulant for CPB.
Off-Pump Coronary Artery Bypass Grafting for Spontaneous Coronary Dissection in a 26-Year-Old Patient Two Weeks Post-Partum: A Case Report and Review
Authors: Patel Kirti P. , Sotolongo Rodolfo P. , Myrick Terry W.
Published: July 2023

Spontaneous coronary artery dissections are an infrequent cause of myocardial infarction and have been reported in late stages of pregnancy and in the puerperium phase. We report a case of a 26-year-old post-partum woman who was diagnosed with a spiral coronary dissection of the left anterior descending artery, with a compromised diagonal branch. She underwent an emergent surgical revascularization without the use of cardiopulmonary bypass. The patient’s in-hospital clinical course, prognosis, treatment, and potential etiologies are discussed.
North American Neonatal Extracorporeal Membrane Oxygenation (ECMO) Devices and Team Roles: 2008 Survey Results of Extracorporeal Life Support Organization (ELSO) Centers
Authors: Lawson D. Scott , Lawson Andrea F. , Walczak Rich , McRobb Craig , McDermott Patty , Shearer Ian R. , Lodge Andrew , Jaggers James
Published: July 2023

In early 2008, surveys of active extracorporeal membrane oxygenation (ECMO) centers in North America were conducted by electronic mail regarding neonatal ECMO equipment and professional staff. Eighty of 103 (78%) North American ECMO centers listed in the Extracorporeal Life Support Organization directory as neonatal centers responded to the survey. Of the responding centers, 82.5% routinely used roller pumps for neonatal ECMO, and the remaining 17.5% used centrifugal pumps. Silicone membrane oxygenators were used by 67% of the respondents, whereas 19% used micro-porous hollow fiber oxygenators, and 14% used polymethylpentene hollow fiber oxygenators. Of the silicone membrane oxygenator users, 86% used the Medtronic Ecmotherm heat exchanger, 10% used the Gish HE-4 heat exchanger, and 4% used the Terumo Conducer device. Sixty-four percent of the responding centers used some form of in-line blood gas monitoring. Six percent of the centers used a bubble trap in the arterial line, and 5% used an arterial line filter. A bladder was used by 85% of the centers, and 4% of these used a mechanical bladder box for servo regulation; the remaining 96% used pressure servo regulation. An air bubble detector was used by 88% of the responding centers. A surface coating was used by 44% of the centers on all their neonatal ECMO patients. Thirty-one percent of the centers use an activated clotting time of 180–220 seconds. At 54% of the responding centers, perfusionists were involved with the ECMO program, registered nurses were involved at 70% of the centers, and respiratory therapists were involved at 46% of the centers. Compared with a 2002 survey, silicone membrane use is declining, and the use of centrifugal blood pumps and coated ECMO circuits is becoming more apparent. ECMO teams are still multidisciplinary, made up of combinations of registered nurses, respiratory therapists, and perfusionists.