Perfusion
-
Review Case Reports
Cardiopulmonary bypass and mitral valve replacement during pregnancy.
Gravid patient cardiopulmonary bypass remains a high-risk procedure with regard to fetal preservation. Maternal mortality is similar to that of the nonpregnant female at 1.5-5%. However, fetal mortality remains high at 16-33%, with an average of 19% over the past 25 years, with no correlation to gestational age. ⋯ The total cardiopulmonary bypass time was 99 min with an aortic crossclamp time of 83 min. The literature, as expected, is limited to case reports and reviews since a controlled clinical trial during pregnancy is nonexistent, using extracorporeal circulation. This greatly challenges the medical staff in managing such difficult cases, with an incidence of heart disease during pregnancy of 1.2-3.7%.
-
Comparative Study
A new practical technique to reduce allogeneic blood exposure and hospital costs while preserving clotting factors after cardiopulmonary bypass: the Hemobag.
Recent data independently linking allogeneic blood use to increased morbidity and mortality after cardiopulmonary bypass (CPB) warrants the study of new methods to employ unique and familiar technology to reduce allogeneic blood exposure. The Hemobag allows the open-heart team to concentrate residual CPB circuit contents and return a high volume of autologous clotting factors and blood cells to the patient. Fifty patients from all candidates were arbitrarily selected to receive the Hemobag (HB) therapy. ⋯ Factor VII, IX and X levels in three HB contents averaged 259% greater than baseline. Substantial reductions were achieved in both allogeneic blood product avoidance and cost to the hospital with use of the HB. Infusion of the Hemobag concentrate appears to recover safely substantial proteins, clotting factor and cell concentration for all types of cardiac procedures, maintaining the security of a primed circuit.
-
Acute respiratory failure is complicated by acidosis and altered end-organ perfusion. NOVA-LUNG iLA is an interventional lung assist (ILA) device for arteriovenous carbon dioxide removal (AVCO2R). The present study was conducted to evaluate the device for short-term CO2 removal performance and hemodynamic response. ⋯ NOVALUNG iLA can provide near total CO2 removal with Qb 1-2 L/min, Qg 5 L/min, and minimal flow resistance (3.88+/-0.82 mmHg/L/min). PaCO2 correlates with CO2 removal and is dependent on Qb and Qg.
-
In infants, technologies for obtaining rapid, quantified measurements of cardiac output (CO) following weaning from cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation are not readily available. A new technique to measure CO based on ultrasound velocity dilution is described. It utilizes reusable probes placed on the extracorporeal circuit that permits convenient measurement of CO prior to decannulation. ⋯ Linear regression analysis revealed a correlation between the CO by ultrasound dilution (CO UD) technique and the vascular probe and PA thermodilution techniques to be R2 =0.94 and 0.81. This pilot study demonstrated that the CO UD technique correlates to other benchmarks of CO measurements. This novel technology has specific application in the field of pediatric open heart surgery in that it would allow the surgeon to accurately and inexpensively measure the CO of neonatal and pediatric patients before and after surgical manipulation of the heart without the need for placement of additional catheters or probes.
-
The effects of polyvinyl chloride (PVC) tubing and membrane oxygenator (MO) on the concentrations of lorazepam and morphine in the neonatal extracorporeal membrane oxygenation (ECMO) circuit were evaluated using an in vitro model that included a closed ECMO circuit with a MO, heat exchanger, bladder and PVC tubing. The circuit was primed with blood, electrolytes, albumin and heparin and maintained at physiologic pH and temperature throughout by frequent measurement of blood gas pH and a temperature probe. Lorazepam and morphine were each studied separately in three separate, but identical circuits for 6 h on the day of circuit prime (new circuit) and then again for 6 h at 24 h (old circuit). ⋯ This single-dose study shows that up to 50% of a dose of lorazepam and 40% of a dose of morphine may be extracted by PVC and MO during bypass, depending on the age of the circuit. As the circuits become older, this amount could increase. These data may explain, in part, the higher doses of lorazepam and morphine required to sedate patients during ECMO.