Hemorrhagic Complications in Pediatric Cardiac Patients on Extracorporeal Membrane Oxygenation

Abstract

Objectives To determine the prevalence of and risk factors for hemorrhagic complications in children with cardiac disease requiring extracorporeal membrane oxygenation. Design Retrospective review of the Extracorporeal Life Support Organization Registry (2002–2013). Setting Participating Extracorporeal Life Support Organization centers. Patients Patients less than 18 years old on extracorporeal membrane oxygenation. Interventions None. Measurements and Main Results Of 21,845 patients requiring extracorporeal membrane oxygenation during the study period, 8,905 (41%) had cardiac disease, and 79% of whom (6,995) had cardiac surgery. Hemorrhagic complications occurred in 8,480 patients (39% of overall cohort), with higher rates in cardiac versus noncardiac patients (49% vs 32%; p < 0.0001) related to cannulation and surgical site bleeding. Cardiac surgical patients had higher rates of hemorrhage compared with cardiac medical patients (57% vs 38%; p < 0.0001), and cardiac patients with hemorrhage had higher extracorporeal membrane oxygenation mortality compared with those without (42% vs 22% in medical patients and 34% vs 20% in surgical patients; both p < 0.0001). In multivariable analysis in both the cardiac medical and surgical groups, hemorrhage risk was higher in children greater than 1 year old and in patients with longer extracorporeal membrane oxygenation duration. Additional independent risk factors for hemorrhage in cardiac surgical patients included pre-extracorporeal membrane oxygenation mediastinal exploration (odds ratio, 3.6; 95% CI, 2.1–6.3), Society of Thoracic Surgeons morbidity category 4–5 (odds ratio, 1.2; 95% CI, 1.03–1.5), cannulation less than 24 hours after surgery (odds ratio, 1.6; 95% CI, 1.3–1.9), and longer cardiopulmonary bypass time (≥ 282 min [upper quartile]; odds ratio, 1.5; 95% CI, 1.3–1.9). Conclusions In this large, multicenter analysis, hemorrhagic complications occurred in nearly half of children with heart disease on extracorporeal membrane oxygenation and were associated with a significant mortality risk. Several factors were associated with hemorrhagic complications in cardiac surgical patients including pre-extracorporeal membrane oxygenation mediastinal exploration, greater surgical complexity, early postoperative cannulation, and longer bypass times. Whether these risks can be mitigated by modifying or delaying systemic anticoagulation requires further investigation.

Epidemiology of Stroke in Pediatric Cardiac Surgical Patients Supported With Extracorporeal Membrane Oxygenation

“…Neck cannulation has been shown in other cohorts to be highly associated with neurologic injury in ECMO patients (6), though we found no association in our cohort. The link between neck cannulation and stroke has been hypothesized to be due to carotid artery ligation and increased jugular venous pressures (26-27).…”

“…Pro-coagulant factors related to cardiopulmonary bypass and ECMO circuits, decreased cardiac output preceding cannulation, and other factors likely increase the risk of stroke and may exacerbate neurologic injury in this population (10). We previously reported higher frequencies of hemorrhagic stroke in cardiac surgical patients compared to other cardiac ECMO patients (6). …”

“…While ECMO remains a final option to salvage patients in need of temporary cardiopulmonary support after surgery, treatment can be limited by complications (3-6). ECMO exposure incites both bleeding, clotting cascades, and necessitates systemic anticoagulation during therapy, which places patients at high-risk for both hemorrhagic and ischemic strokes (7).…”

Mechanical circulatory support: balancing bleeding and clotting in high-risk patients

“…Mortality of cardiac patients with hemorrhage is significantly higher than patients without hemorrhage (38% vs 21%; p Ͻ 0.0001). 28 Hemorrhagic stroke rates were 8.7% and 4.1% in cardiac ECMO versus 7.4% and 6.2% in respiratory ECMO in neonates and children, respectively. 28…”

“…30 The variability between treatment centers lead to the development of the ELSO anticoagulation management guidelines which are based on expert consensus and review of multiple anticoagulation practices. 28,32 UFH is recommended with a 50-100 unit/kg bolus at cannulation followed by an infusion starting at 7.5-20 units/kg/hr and adjusted based on an ACT of 180 to 220 seconds. Typically 20-50 units/kg/hr is required to achieve the target ACT range.…”