bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of extracorporeal membrane oxygenation in patients with Gram-negative or viral sepsis
Authors: Stewart Dan L , Cruz Teddy V Dela , Ziegler Craig , Goldsmith Linda J 
Published: January 2013

To evaluate the use of extracorporeal membrane oxygenation (ECMO) in patients with Gram-negative or viral sepsis, a survey of ECMO centres comprising the Extracorporeal Life Support Organization was conducted. Data collected from neonatal and paediatric intensive care units included patient demographics, indicators of infection, presence of cardiac instability and respiratory criteria for ECMO. One-hundred-and-seven patients with documented sepsis were divided into survivors and nonsurvivors. Prior to ECMO, the patients with a persistent metabolic acidosis ( p < 0.008) and/or hypotension requiring more than two inotropic agents ( p < 0.02) to support blood pressure were less likely to survive. Also, patients with Gram-positive infections (77%) were more likely to survive their ECMO course than those with Gram-negative (60%) or viral infections (40%). Although survival is less in septic infants than in infants with traditional respiratory failure placed on ECMO, sepsis should not be a contraindication to the use of ECMO. The parents should be informed of the chances of survival with each type of sepsis or respiratory infection (if known), so that a truly informed decision can be made by the parents. We feel that the additional information regarding Gram-negative and viral sepsis should assist the clinician in this goal.
The effect of protamine on the epicardial microflow and the graft flow in open-heart surgery
Authors: Belboul Ali , Al-Khaja Najib 
Published: January 2013

To evaluate the effect of coronary revascularization on myocardial perfusion and surgical outcome regarding graft flow, we used laser Doppler flowmetry to assess the epicardial microcirculation in patients undergoing coronary artery bypass grafting (CABG) or valve replacement (VR) and electromagnetic flowmetry to measure graft flow in the CABG group. In the CABG group, the preoperative mean laser Doppler flow rate (LDF) in the epicardium of the left ventricle significantly increased at the end of cardiopulmonary bypass (CPB) (22 ± 7 arbitrary units (AU) to 60 ± 13 AU, p < 0.001). This value further increased 10 min after protamine infusion (66 ± 14 AU, p < 0.01), but was significantly reduced 30 min later (51 ± 14 AU, p < 0.002). Compared to the post-CPB value (34 ± 10 ml/min) before protamine infusion, the mean graft flow (ml/min) to this area significantly increased 10 min after protamine infusion (41.3 ± 10 ml/min, p < 0.001) but significantly decreased 30 min later (29 ± 9 ml/min, p < 0.001). The preoperative mean LDF in the VR group was significantly higher than in the CABG group ( p < 0.01). In the CABG group, there was a positive correlation between the LDF and graft flow at the end of CPB ( r = 0.788) and 10 ( r = 0.767) and 30 ( r = 0.784) min after protamine infusion. This study shows that coronary bypass grafting increases the myocardial microcirculation which, together with graft flow. could give an early indication of the effect of surgery on myocardial microcirculation. Furthermore, protamine was found to be one of the factors contributing to graft flow reduction postoperatively and, therefore, newer methods of heparin reversal may be desirable.
A comparison of gaseous emboli release in five membrane oxygenators
Authors: Beckley Philip D , Shinko Paul D , Sites Jeffrey P 
Published: January 2013

The purpose of this study was to compare the air handling capability of five currently used membrane oxygenators: the Avecor Affinity™, the Bentley® SpiralGold™, the Medtronic Maxima Plus™, the Sarns Turbo™ and the Sorin Monolyth™ M. A circuit was constructed to include a hardshell venous reservoir and roller pump. Pressure monitoring sites and ultrasonic microbubble detection probes were located proximal and distal to the oxygenator. An air injection/infusion site was provided proximal to the roller pump inlet. Each circuit was primed with fresh anticoagulated bovine blood, adjusted to a haematocrit of 25% and maintained at 38 ± 1°C. Three different bolus amounts of air (10, 20 and 40 cm3) were injected at three blood flow rates (3, 4.5 and 6 l/min). A 1-min infusion of air delivered at 1 ml/s was also administered at three blood flow rates (3, 4.5 and 6 l/min). The hardshell reservoir was also completely emptied at each flow rate to simulate a massive air infusion. At any given blood flow, outlet microbubble counts were usually higher with greater bolus amounts of air. When indexed to the inlet bubble counts, the following average percent microbubbles were released from the outlet: Turbo™ 25%, Affinity™ 7%, Monolyth™ 5%, Maxima™ 3% and SpiralGold™ 1%. With a constant air infusion of 1 ml/s, greater outlet microbubble counts were associated with higher blood flow rates. Again, when indexed to the inlet bubble counts, the following average percent microbubbles were released from the outlet: Turbo™ 44%, Affinity™ 25%, Maxima™ 19%, Monolyth™ 16% and SpiralGold™ 0%. All oxygenators deprimed when the hardshell reservoir was emptied and all shed microbubbles into the outlet blood except the SpiralGold™. The results of this study indicate that air handling is not a simple function of blood flow pattern (i.e. top to bottom versus bottom to top), but also includes dynamics associated with oxygenator design, fibre arrangement and flow resistance.
Coagulopathic-induced membrane dysfunction during extracorporeal membrane oxygenation: a case report
Authors: Stammers Alfred H , Fristoe Lance W , Christensen Kevin , Deptula Joseph , Sydzyik R Troy , Zavadil Douglas , Willett Lynne 
Published: January 2013

This paper describes an unusual complication of membrane dysfunction during extracorporeal membrane oxygenation (ECMO) for treatment of neonatal respiratory distress. A 2.8-kg term infant presented to our facility in severe respiratory distress and was diagnosed with primary pulmonary hypertension. After routine priming of the extracorporeal circuit, the patient was placed on veno-arterial ECMO with 8 F arterial and 12 F venous cannulae. Transfusion criteria were established which included trigger values of the following: platelet count 100 000/μl, fibrinogen 150 mg/dl, haematocrit 40%. The ECMO course was uneventful until approximately the 132nd hour on support when the patient developed a consumptive coagulopathy, as evidenced by 55-60% reductions in both platelet count and fibrinogen concentrations, despite transfusion therapy. Total autogeneic blood product transfusion during the first 120 h of ECMO averaged 4.4 ± 2.2 ml/h, while the transfusion rate for the final 35 h was 7.8 ± 3.5 ml/h. Coinciding with this rise in transfusion requirements was an increase in transmembrane pressure from 0.29 to 1.52 mmHg/ml blood flow. The patient was separated from ECMO after 175 h due to a continuing coagulopathy and haemothorax. The patient was then treated with nitric oxide therapy before succumbing on the twelfth postoperative day due to refractory respiratory failure. The circuit was dissected and significant clots found in both the venous bladder and oxygenator. In addition, approximately one-third of the membrane compartment had a ‘fused’ circumferential pattern of dessicated clot which interrupted blood path continuity. In conclusion, this report describes an unusual complication of the ECMO oxygenator that occurred during long-term extracorporeal life support which most likely resulted from a coagulopathy.
Use of blood products in cardiac surgery
Authors: Renton M C , McClelland D BL , Sinclair C J 
Published: January 2013

The quantity of blood products used perioperatively during cardiac surgery is known to vary widely between institutions. This study looked at the amount of blood products used perioperatively in 74 consecutive elective cardiac operations in one institution. The results are compared with those from other European centres and a cost analysis carried out. On average 2.33 ± 0.74 (95% confidence interval 1.93-2.77) units of red cell concentrate were transfused perioperatively per patient. Six (8%) patients received no blood products. In addition a number of preoperative factors were studied in an attempt to identify predictors of transfusion requirements. Age, preoperative haemoglobin, female sex and red cell mass were all found to have some predictive value. In the face of increasing demands on a limited supply of blood products we question the need for crossmatching more than four units of red cell concentrate in elective cardiac surgery.
Monitoring aortic root effluent during retrograde cardioplegia delivery
Authors: Mannebach Patrick C , Sistino Joseph J 
Published: January 2013

Continuous monitoring of myocardial protection during aortic crossclamping is not always performed, due to limitations with current technology. The purpose of this study was to use readily available technology to evaluate the effectiveness of retrograde cardioplegia delivery by monitoring the aortic root vent effluent. The CDI 400, a commonly used blood monitoring device, was used to monitor changes in temperature, pO2, pCO2, and pH by placing a 1/4-inch CDI Quick Cell and probe in the aortic root vent line prior to each case. Twenty adult patients undergoing coronary bypass surgery were involved in the study, which resulted in 48 doses of retrograde cardioplegic solution. The study revealed a significant correlation between the temperature of the cardioplegia solution and the temperature of the aortic root effluent ( p <0.001, r = 0.88). The cardioplegia temperature did not correlate with the change in effluent pO2 ( p = NS) or the degree of effluent temperature change ( p = NS). Furthermore, the change in effluent temperature was not influenced by the amount of cardioplegia solution delivered ( p = NS), or the time between administrations ( p = NS). Both the decreasing and increasing trends of the effluent pO2 significantly correlated with the cardioplegia solution flow rate ( p = 0.034, r = 0.32 and p = 0.013, r = 0.37, respectively), but not with the time between doses (p = NS) or volume of cardioplegia solution delivered ( p = NS). The increase in effluent pO2 did correlate with the coronary sinus pressure ( p < 0.001, r = 0.48). Measuring aortic root vent effluent may be used to assure the successful delivery of retrograde cardioplegic solution and aid in the detection of various procedural problems. Once the trends from this technique are established by the surgical team, they may be used to adjust cardioplegic solution administration and provide documentation of myocardial protection.
Interleukin-8 mRNA expression in circulating leucocytes during cardiopulmonary bypass
Authors: John Alison E , Galea Joseph , Francis Sheila E , Holt Cathy M , Finn Adam 
Published: January 2013

Interleukin-8 (IL-8) is found in patients following cardiopulmonary bypass (CPB). It may contribute to microvascular injury by activating neutrophils. We examined IL-8 mRNA expression in leucocytes in bypass. IL-8 mRNA levels were measured by Northern analysis and densitometry of isolated mononuclear leucocytes and neutrophils from blood samples taken before, during, and 2 and 48 h after CPB. Plasma IL-8 was measured at each time-point by immunoassay. A strong signal for IL-8 mRNA was detected in neutrophils in five of five and, more weakly, in mononuclear leucocytes of three of five patients studied. The signal peaked consistently during, and fell following bypass, usually to undetectable levels by 48 h. There was always a detectable signal in neutrophils preoperatively. Plasma IL-8 increased from undetectable prebypass levels and peaked later (2 h postbypass) in four of five patients. In the other patient, the cytokine remained detectable throughout. These data demonstrate that IL-8 transcription occurs in leucocytes before and during CPB, but suggest that much of the IL-8 detectable in plasma following bypass may derive, not from these leucocytes, but from other cell types. The release of some IL-8 by neutrophils could lead to local positive feedback in neutrophil recruitment and associated endothelial injury.
Acute phase and opsonin response in cardiac surgery patients: influence of underlying cardiac disease
Authors: Welters I , Menges T , Ballesteros M , Sablotzki A , Görlach G , Hempelmann G 
Published: January 2013

Cardiopulmonary bypass (CPB) leads to an activation of plasma cascade systems, complement activation, and an acute phase response. To evaluate the influence of the underlying cardiac disease on the activation pattern of these systems, we compared inflammatory changes in coronary artery bypass grafting (CABG) patients with patients undergoing aortic valve replacement. We investigated changes of the acute phase proteins α1-proteinase inhibitor and fibrinogen, the unspecific opsonin fibronectin, and the complement components C3c and C4 induced by extracorporeal circulation in 12 patients undergoing aortic valve replacement and in 12 patients undergoing CABG. Concentrations of C3c and C4 decreased in both groups after the onset of CPB and C4 concentration remained below post-induction levels up to 24 h after onset of CPB ( p = 0.04). Fibronectin levels dropped immediately before the onset of CPB ( p = 0.01), reaching the lowest values after 20 min of extracorporeal circulation. Fibrinogen and α1-proteinase inhibitor levels after induction of anaesthesia were significantly higher in the CABG group and remained higher throughout the entire study period ( p < 0.001). As an indicator of a postoperative acute phase response, concentrations of both proteins rose in the postoperative period above post-induction levels ( p < 0.02). It can be concluded that, based on pre-existing differences of acute phase protein concentrations, the CPB-induced inflammatory response takes place at a higher level in CABG patients. A different level in acute phase and opsonin response in patients suffering from coronary artery sclerosis may contribute to infectious complications in the postoperative period.
In vitro evaluation of new surface coatings for extracorporeal circulation
Authors: Baksaas Svein T , Videm Vibeke , Fosse Erik , Karlsen Harald , Pedersen Thore , Mollnes Tom E , Hagve Tor A , Svennevig Jan L 
Published: January 2013

Cardiopulmonary bypass (CPB) exposes blood to large, foreign surfaces. This exposure may activate the cellular and humoral inflammatory systems, resulting in inflammatory reactions and organ dysfunction. Coating the inner surfaces of the bypass circuit may help alleviate these side-effects. The objective of this study was to determine the influence of two new surface treatments on blood cell and complement activation. Oxygenator and tubing sets coated with synthetic polymers ( n = 7) or heparin ( n = 7) were compared to uncoated sets ( n = 7) in an in vitro model of CPB. The circuits were run at 4 l/min and recirculated for 120 min. The inflammatory response was assessed at regular intervals by platelet counts, and activation of complement, leucocytes and platelets. We found that the median platelet counts decreased from 127 to 122 × 109/l (not significant, NS) in the synthetic polymer sets, from 96 to 88 × 109/l (NS) in the heparin-coated sets, and from 93 to 54 × 109/l ( p < 0.01) in the uncoated sets after 2 h of recirculation. There were significant differences in platelet counts between the coated sets and the uncoated set at end of experiments ( p < 0.05). Beta-thromboglobulin (BTG) concentrations increased in the synthetic polymer sets from 166 to 352 ng/ml ( p < 0.01), in the heparin coated sets from 336 to 1168 ng/ml ( p < 0.01), and in the uncoated sets from 301 to 3149 ng/ml ( p < 0.01) after 2 h of recirculation. The differences in BTG at termination of the experiments were significant among all three sets ( p < 0.05). Myeloperoxidase (MPO) concentrations in the synthetic polymer sets increased from 63 to 86 μg/l ( p < 0.01), in the heparin-coated sets from 90 to 208 μg/l ( p < 0.01), and in the uncoated sets from 122 to 513 μg/l ( p < 0.01) after 2 h of recirculation. The differences in MPO at termination of the experiments were significant among all three groups ( p < 0.01). There were no significant differences at termination of the experiments among the three sets regarding complement activation as measured by C3 activation products and the terminal complement complex. We conclude that in the current in vitro model of a CPB circuit, the synthetic polymer coating and the heparin coating caused significantly less platelet loss and granulocyte and platelet activation than the uncoated surface ( p < 0.05). The synthetic polymer coating caused significantly less granulocyte and platelet activation than the heparin coating ( p < 0.05). There was moderate complement activation within each group, but no significant differences among the three groups.
Lipid peroxidation during initiation of extracorporeal membrane oxygenation after hypoxia in endotoxemic rabbits
Authors: Trittenwein Gerhard , Rotta Alexandre T , Gunnarsson Björn , Steinhorn David M 
Published: January 2013

Initiation of extracorporeal membrane oxygenation (ECMO) in septic children with severe respiratory failure often improves oxygenation but not pulmonary function. The factors affecting pulmonary function following onset of ECMO are not completely understood, but are thought to involve injury mediated, in part, by reactive oxygen species. We hypothesized that induction of ECMO using 100% oxygen as the sweep gas through the oxygenator would increase lipid peroxidation in endotoxin-primed animals after severe hypoxia. We further speculated that provision of oxygenated blood to the pulmonary circulation via venovenous ECMO would promote a greater degree of oxidative damage to the lung as compared to venoarterial ECMO. Eighteen New Zealand White rabbits were assigned to a control group (control) or two intervention groups subjected to 60 min of venoarterial or venovenous ECMO. ECMO was initiated following an intravenous challenge with 0.5 mg/kg of E. coli endotoxin and a period of global hypoxia leading to an arterial pH of 6.99 ± 0.09, PaCO2 of 103 ± 31 mmHg and PaO2 of 27 ± 5 mmHg. Malondialdehyde (MDA), a marker of lipid peroxidation, was measured in lung tissue homogenates and in arterial plasma. Lung tissue MDA demonstrated a strong trend towards an increase in the venoarterial group (1884 ± 945 nmol/g protein) and in the venovenous group (1905 ± 758 nmol/g protein) in comparison to the control group (644 ± 71 nmol/g protein) ( p = 0.1; significance at 95% in Scheffe test). Lung tissue MDA in the venovenous group had a significant correlation with mean PaO2 during ECMO by regression analysis ( r2 = 0.678, p = 0.044). The change in blood MDA concentration between pre-ECMO and post-ECMO values was greater in the venovenous group (pre 1.62 ± 0.61 versus post 5.12 ± 0.2.07 μmol/l, p = 0.043) compared with that seen in the venoarterial group (pre 1.46 ± 0.38 versus post 3.9 ± 0.93 μmol/l). Our data support the hypothesis that initiation of ECMO with a circuit gas oxygen concentration of 100% after global hypoxia enhances oxidative damage to lipids in endotoxin-challenged animals. During venovenous ECMO this finding is dependent on PaO2.
Investigation of the phenomenon of electrostatic compromise of a plastic fiber heat exchanger
Authors: Elgas R J 
Published: January 2013

The use of a new generation of blood oxygenator design using plastic fibers for the heat exchange material is growing. The benefits of a plastic heat exchange material are improved biocompatibility and performance over some of the traditional metals used. During the initial period of clinical use of one of these new oxygenators, there were reports of four blood-to-water leaks. No patient complications were associated with these leaks, but the product was withdrawn from the market. After a thorough evaluation, the cause of the leaks was found to be an electrostatic discharge that occurred within the heat exchanger during priming of the extracorporeal circuit. It was found that an electrostatic potential between the blood path and the water path of the heat exchanger is generated as the prime solution is recirculated by a roller pump with polyvinyl chloride (PVC) pumphead tubing. The magnitude of the potential generated was found to vary with the make and model of the roller pump. If this voltage exceeds the dielectric strength of the fiber, a discharge through the wall of a single heat exchange fiber will occur and produce a hole. Several solutions to this problem of roller pumps generating an electrostatic charge when used with PVC pumphead tubing were identified. Centrifugal blood pumps and roller pumps using silicone rubber pumphead tubing were found to generate no significant electrostatic potential between the blood path and the water path. Another solution, a charge equalization line (CEL), was designed to provide a conductive path for the charge to equilibrate across the fiber wall. The CEL can be either external or internal to the oxygenator. Each of these solutions was validated and the product has been reintroduced for clinical use.
Albumin in the cardiopulmonary bypass prime: how little is enough?
Authors: Palanzo David A , Zarro Debra L , Montesano Ralph M , Manley Norman J 
Published: January 2013

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.