Journal of pediatric surgery
-
A rare state of acquired hypercoagulability known as heparin-associated or heparin-induced thrombocytopenia and thrombosis (HATT, HITT) exists. It appears to be caused by an antibody reaction with heparin-platelet factor 4 complexes. ⋯ The authors describe a fatal neonatal case of hypercoagulability on extracorporeal membrane oxygenation, and their evaluation that determined the etiology as type II HATT. They discuss the pathophysiology of HATT as well as possible alternative anticoagulation approaches.
-
The retention of extracorporeal membrane oxygenation (ECMO) cannulae of ECMO is discontinued was originally developed to avoid reexploration of the neck in patients who may require a second course of ECMO. Because of the incidence, at the authors' institution, of thrombi noted on the ends of retained cannulae and their potential to cause significant morbidity, a critical review of this procedure was initiated. A telephone survey of 72 Extracorporeal Life Support Organization (ELSO) centers was conducted, and ELSO registry forms were requested for patients who had their cannulae retained. ⋯ Five of the 25 patients who required two courses of ECMO had serious complications from their retained cannulae and all were nonsurvivors. The authors conclude that patients with retained ECMO cannulae are at high risk for developing thrombi, which can lead to severe embolic events. Therefore, the procedure of retaining cannulae should only be used in patients at high risk for requiring a second course of ECMO and not for the convenience of surgical availability to remove the cannulae.
-
A new heparin binding method was applied to a miniature extracorporeal membrane oxygenation (ECMO) system with a nonporous membrane oxygenator (the priming volume, 45 mL; the membrane surface area, 0.4 m2; maximal flow rate, 2 L/min) that is resistant to plasma leakage. The authors evaluated the stability of the immobilized heparin in vitro and the feasibility of this system in animals. Samples of hollow fibers and tubing were rinsed at 40 degrees C for 4 days in normal saline, Ringer's lactate, and 1 mol/L NaCl solution. ⋯ O2 transfer of the oxygenators at a flow rate of 300 mL/min were 12.3 +/- 0.4 mL/min at 30 minutes, 14.3 +/- 1.2 mL/min at 5 hours, and 14.7 +/- 1.7 mL/min at 10 hours (no statistical difference). Histological examination of the brains and the kidneys showed no evidence of thromboembolic sequela in any of the animals. These results suggest that this new system is a promising device for long-term ECMO in which the amount of systemic heparinization can be reduced with the minimal possibility of plasma leakage.