ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
-
Multicenter Study
Cerebral tissue oxygenation during the initiation of venovenous ECMO.
In an acute respiratory distress syndrome, venovenous extracorporeal membrane oxygenation (vvECMO) can rapidly normalize arterial hypoxemia and carbon dioxide tension (PaCO2). Considering the positive relationship between PaCO2 and cerebral blood flow, the aim of the current study was to evaluate cerebral regional tissue oxygen saturation (rSO2) during the implementation of vvECMO. Fifteen acute respiratory distress syndrome patients with recordings of cerebral rSO2 by near-infrared spectroscopy before vvECMO implementation until the optimization of the ECMO/ventilator settings were retrospectively studied. ⋯ median (interquartile range). The cerebral rSO2 increased significantly (p < 0.05) from 69(61-74) to 75(60-80)% after ECMO was started, concomitant to the arterial oxygenation. Until the end of the observation period after 83(44-132) minutes, cerebral rSO2 decreased significantly to 61(52-71)%. PaCO2 decreased from 70(61-87) to 43(38-54) mm Hg and the pH increased from 7.23(7.14-7.29) to 7.39(7.34-7.43). The baseline arterial oxygen saturation and tension as well as the actual bicarbonate concentration were negatively correlated with the absolute change in cerebral rSO2 (ΔrSO2). In the 11 nonhypoxemic patients (arterial oxygen saturation ≥90%) ΔPaCO2 was significantly correlated with ΔrSO2. Patients receiving vvECMO treatment are at risk for a decrease in cerebral rSO2. This decrease is more distinct in patients with normal baseline arterial oxygenation and high actual bicarbonate.
-
Case Reports
Extracorporeal membrane oxygenation with subclavian artery cannulation in awake patients with pulmonary hypertension.
Pulmonary hypertension (PH) is a challenging disease process to manage. Respiratory and hemodynamic changes that accompany general anesthesia lead to a significant risk of cardiovascular collapse. ⋯ Performing ECMO cannulation without intubation or general anesthesia in these patients may be safer given the severity of their underlying disease process. We present three cases of upper body ECMO cannulation performed on patients with pulmonary hypertension while awake and without mechanical ventilation.
-
Mechanical circulatory support--either ventricular assist device (VAD, left-sided systemic support) or cavopulmonary assist device (CPAD, right-sided support)--has been suggested as treatment for Fontan failure. The selection of left- versus right-sided support for failing Fontan has not been previously defined. Computer simulation and mock circulation models of pediatric Fontan patients (15-25 kg) with diastolic, systolic, and combined systolic and diastolic dysfunction were developed. ⋯ Systemic VAD support may be preferable to maintain systemic output during systolic dysfunction. Both systemic and cavopulmonary support may provide best outcome during combined systolic and diastolic dysfunction. These findings may be useful to guide clinical cavopulmonary assist strategies in failing Fontan circulations.
-
Chronic hemodialysis is associated with significant thrombophilia. Of interest, hemodialysis patients have increased carboxyhemoglobin (COHb) and exhaled carbon monoxide (CO), signs of upregulated heme oxygenase (Hmox) activity. Given that CO enhances plasmatic coagulation, we determined whether patients requiring chronic hemodialysis had an increase in endogenous CO, plasmatic hypercoagulability and decreased fibrinolytic vulnerability. ⋯ Furthermore, over half of COHF positive patients had a hypofibrinolytic state, evidenced by an abnormally prolonged time to maximum rate of lysis (53.3%, [37.9%-68.6%]) and clot lysis time (64.4%, [48.8%-78.1%]). Carbon monoxide enhanced coagulation and diminished fibrinolytic vulnerability in hemodialysis patients. Future investigation of hemodialysis, CO-related thrombophilia is warranted.
-
Use of extracorporeal membrane oxygenation (ECMO) in adults has surged in recent years. Typical configurations are venovenous (VV), which provides respiratory support, or venoarterial (VA), which provides both respiratory and circulatory support. In patients supported with VV ECMO who develop hemodynamic compromise, an arterial limb can be added (venovenous-arterial ECMO) to provide additional circulatory support. ⋯ Eight patients (38.1%) died during ECMO support, four patients (19.0%) died after decannulation but before hospital discharge, and nine patients (42.9%) survived to hospital discharge. Our modest survival rate is likely related to the complexity and severity of illness of these patients, and this relative success suggests that hybrid configurations can be effective. It serves patients well to maintain a flexible and adaptable approach to ECMO configurations for their variable cardiopulmonary needs.