Pediatric Extracorporeal Membrane Oxygenation: An Introduction for Emergency Medicine Physicians.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) therapy has supported critically ill pediatric patients in the intensive care unit setting with cardiac and respiratory failure. This therapy is beginning to transition to the emergency department setting. OBJECTIVE OF REVIEW: This article describes the fundamentals of ECMO and familiarizes the emergency medicine physician with its use in critically ill pediatric patients. DISCUSSION: ECMO can be utilized as either venoarterial (VA) or venovenous (VV), to support oxygenation and perfusion in respiratory failure, sepsis, cardiac arrest, and environmental hypothermia.

Medication adsorption into contemporary extracorporeal membrane oxygenator circuits.

OBJECTIVE: This study was conducted to evaluate the amount of medication adsorbed into extracorporeal membrane oxygenation (ECMO) circuits with a polymethylpentane membrane oxygenator and heparin-coated polyvinyl chloride tubing. METHODS: An ECMO circuit with the aforementioned components was set up ex vivo and primed with expired blood. Midazolam, lorazepam, morphine, and fentanyl were administered to the circuit. Fifteen minutes after medication administration, 60 mL of blood were removed and stored in a 60-mL syringe to serve as a control. Medication levels were drawn from the ECMO circuit (test) and control syringe (control) 15 minutes, 24 hours, and 48 hours after the medications were administered. ECMO circuit medication levels were compared to their corresponding syringe control medication levels. Descriptive statistics were used to determine the percentage of medication remaining in the blood and compare it to the control value. RESULTS: Except for morphine, there was a large decline in medication levels over the 48-hour period. Compared to control values, 17.2% of midazolam, 41.3% of lorazepam, 32.6% of fentanyl, and 102% of morphine remained in the ECMO circuit. CONCLUSION: Despite the use of newer components in ECMO circuits, a large quantity of medication is adsorbed into the ECMO circuit. Midazolam, lorazepam, and fentanyl all showed reductions in medication levels greater than 50%. Morphine may have advantages for patients on ECMO, as its concentration does not appear to be affected.

Are there benefits to a fresh whole blood vs. packed red blood cell cardiopulmonary bypass prime on outcomes in neonatal and pediatric cardiac surgery?

Techniques for pediatric cardiac surgery requiring cardiopulmonary bypass (CPB) have significantly improved over the years. The use of fresh whole blood (FWB) and pre-bypass ultrafiltration (PBUF) has been suggested as means for improving perioperative and postoperative outcomes. It is the intent of this study to show that fresh whole blood along with PBUF will result in balanced CPB prime that can offer a reduction in blood product exposures and blood loss along with improving several measured postoperative outcomes. After institutional review board approval, a retrospective review was conducted on 100 patients to analyze the benefits of FWB and PBUF on outcomes in neonatal and pediatric cardiac surgery. Data analysis included preoperative and CPB data, perioperative inotrope and blood product exposure, and postoperative blood loss and blood product exposure measured for up to a 12-hour period in the intensive care unit (ICU). The three groups compared were FWB prime vs. packed red blood cell (PRBC) prime, < 5 kg FWB prime vs. < 5 kg PRBC prime, and 5+ kg FWB prime and 5+ kg PRBC prime. Cumulative blood product exposures for the FWB prime group found 62% received one blood exposure for the operative and postoperative period (p < .0001). The majority of patients who received a PRBC prime (64%) received three or more cumulative exposures (p < .0003). The < 5 kg FWB group also received significantly less cumulative blood exposure, with 64% receiving just one exposure. Comparatively, 85% of the < 5 kg PRBC patients received three or more blood product exposures perioperatively and postoperatively (p < .0001). Perioperative inotrope and postoperative blood loss did not differ among the groups. Outcomes for intraoperative death, intraoperative extubation, delayed sternal closure, and mediastinal reexploration were also not statistically different. The results of this study found that FWB leads to significantly less blood exposure, specifically in the < 5-kg population. Finally, the use of PBUF is an effective method for achieving a balanced, physiologic prime. Future research would be helpful in determining which specific patient populations would receive the greatest benefit from FWB and PBUF.

Conversion from extracorporeal membrane oxygenation to total cardiopulmonary bypass: a simplified method.

Pediatric patients who have preoperative hemodynamic instability or postoperative cardiac decompensation may frequently require the use of extracorporeal membrane oxygenation (ECMO) for stabilization of cardiac and respiratory function. While ECMO can be a therapeutic treatment for the congenital pediatric patient, it does not allow the additional functions of a complete cardiopulmonary bypass (CPB) circuit should subsequent surgical revision in the operating room be required. This paper will discuss our approach to converting the ECMO circuit to total cardiopulmonary bypass allowing the use of cardioplegia, cardiotomy suction, and modified ultrafiltration. This technique allows the conversion to CPB without ceasing support to the critically ill patient or exposing them to additional blood products or surface area in the priming of a new extracorporeal circuit. In addition, this circuit design allows for the resumption of ECMO support utilizing the same circuit if the patient necessitates it.