Perfusion
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Comparative Study Clinical Trial Controlled Clinical Trial
Stöckert roller pump generated pulsatile flow: cerebral metabolic changes in adult cardiopulmonary bypass.
There is evidence that during cardiopulmonary bypass (CPB), pulsatile pump flow improves cerebral metabolism. This was a study to explore the effect of pulsatile versus nonpulsatile perfusion on cerebral lactate, pyruvate, glucose and beta-hydroxybutyrate using a Stöckert roller pump. We found no significant differences between the arterial-venous (A-V) differences of lactate, glucose and beta-hydroxybutyrate (p > 0.05). ⋯ Therefore, the metabolic changes were not significant. There was no significant difference in systemic vascular resistance (SVR) during pulsatile and nonpulsatile flow (p = 0.4). Pulsatile flow delivered by the Stöckert roller pump appears to have no metabolic or SVR advantages in adults undergoing CPB.
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Clinical Trial Controlled Clinical Trial
Fingertip temperature during cardiopulmonary bypass.
Temperature changes in the nasopharynx, fingertip, forearm and extracorporeal circuit were continuously monitored, starting 10 min before and up to 16 min into the rewarming period of hypothermic (32 degrees C) cardiopulmonary bypass in 14 patients operated on for coronary artery revascularization. Arterial blood temperature was the first to increase after starting rewarming, followed by the nasopharynx and the fingertip temperatures. Fingertip temperature started to increase abruptly 6.2 (2.02 SD) min after rewarming started. ⋯ Assuming that increasing fingertip temperature indicates a central thermoregulatory response to warming, we suggest that nasopharyngeal temperature is a poor monitor of brain temperature. We also suggest that fingertip temperature may be used to monitor the point at which cerebral temperature reaches 'normothermia'. Further body warming, using arterial temperatures > or = 39 degrees C, should be avoided because of the danger of brain hyperthermia.
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Case Reports
Coagulopathic-induced membrane dysfunction during extracorporeal membrane oxygenation: a case report.
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. ⋯ 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.
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Comparative Study
A comparison of gaseous emboli release in five membrane oxygenators.
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. ⋯ 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.
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Surgeons have often been reluctant to use cardiopulmonary bypass (CPB) during single (SLTx) and double lung (DLTx) transplantation surgery because of the potential adverse sequelae of CPB including haemorrhage and activation of complement leading to sequestration of neutrophils and platelets in the pulmonary capillary bed, endothelial damage, increased capillary permeability and pulmonary oedema. To clarify the effect of CPB on lung transplant recipients, we reviewed our last four years' experience in 74 patients of whom 30 required CPB support. Indications for CPB were mean pulmonary artery pressure of greater than 50 mmHg, haemodynamic instability, hypoxia or hypercarbia. ⋯ Intraoperatively and postoperatively, haemorrhage was not a major problem. The 30-day mortality in the CPB group and the non-CPB group were 20% and 4.6%, respectively which was not statistically significant (p = 0.06). We conclude that CPB during lung transplantation is a safe, effective method to support these severely ill patients and should not be avoided because of concerns over adverse sequelae of CPB on postoperative graft function.