No abstract

The veno-venoarterial (VVA) mode of extracorporeal membrane oxygenation (ECMO) is defined by having both venous and arterial reinfusion cannulas. It is purposed to improve upper body oxygenation as the venous reinfusion cannula is typically placed in the upper body. We performed a single-center retrospective review to better characterize the patients placed on this mode. Adults (n = 23) were 40.4 ± 14.7 years old and were supported with ECMO for a median of 141 (97, 253) hours, with VVA support 110 (63, 179) hours. Ten (43%) were initially cannulated VVA; reasons for conversion included cardiac failure (46%), North-South syndrome (38%), and worsening hypoxia (15%). Survival was 39% and neurological complications 13%. Pediatrics (n = 8) were 13.0 ± 2.4 years old and were supported with ECMO for a median of 258 (168, 419) hours, with VVA support 131 (98, 161) hours. One (12.5%) was initially cannulated VVA; reasons for conversion were North-South syndrome (42%), cardiac failure (29%), and worsening hypoxia (29%). Survival was 71% and neurological complications 29%. We concluded that there was neither survival advantage nor complication reduction with the VVA mode in this cohort; however, VVA does have value for unique clinical situations when conventional ECMO modes do not meet support needs.

A novel electrochemically controlled release method for nitric oxide (NO) (based on electrochemical reduction of nitrite ions) is combined with an amperometric oxygen sensor within a dual lumen catheter configuration for the continuous in vivo sensing of the partial pressure of oxygen (PO2) in blood. The on-demand electrochemical NO generation/release method is shown to be fully compatible with amperometric PO2 sensing. The performance of the sensors is evaluated in rabbit veins and pig arteries for 7 and 21 h, respectively. Overall, the NO releasing sensors measure both venous and arterial PO2 values more accurately with an average deviation of −2 ± 11% and good correlation (R2 = 0.97) with in vitro blood measurements, whereas the corresponding control sensors without NO release show an average deviation of −31 ± 28% and poor correlation (R2 = 0.43) at time points >4 h after implantation in veins and >6 h in arteries. The NO releasing sensors induce less thrombus formation on the catheter surface in both veins and arteries (p < 0.05). This electrochemical NO generation/release method could offer a new and attractive means to improve the biocompatibility and performance of implantable chemical sensors.

n/a (basic/translational science).

Since its introduction to bedside clinical practice over 40 years ago, extracorporeal life support (ECLS) has been continually changing and improving as a life-saving technology. Extracorporeal life support disrupts the normal finely maintained balance of coagulation and fibrinolysis by exposing large amounts of blood to nonendothelial surfaces. This leads to an inflammatory response with activation of the coagulation cascade and the need for systemic anticoagulation. Unfractionated heparin (UNFH) is currently the standard anticoagulant in ECLS. Alternative anticoagulants have been recently developed with improved safety profiles and reliable monitoring. Within this group of agents are the direct thrombin inhibitors (DTIs) bivalirudin and argatroban. The purpose of this article is to compare these DTIs to the current standard of UNFH anticoagulation during ECLS, to evaluate the current literature surrounding the use of these drugs in ECLS, and finally to propose therapeutic guidelines for their use in ECLS.

Background. Lung injury prediction score (LIPS) is valuable for early recognition of ventilated patients at high risk for developing acute respiratory distress syndrome (ARDS). This study analyzes the value of LIPS in predicting ARDS and mortality among ventilated surgical patients. Methods. IRB approved, prospective observational study including all ventilated patients admitted to the surgical intensive care unit at a single tertiary center over 6 months. ARDS was defined using the Berlin criteria. LIPS were calculated for all patients and analyzed. Logistic regression models evaluated the ability of LIPS to predict development of ARDS and mortality. A receiver operator characteristic (ROC) curve demonstrated the optimal LIPS value to statistically predict development of ARDS. Results. 268 ventilated patients were observed; 141 developed ARDS and 127 did not. The average LIPS for patients who developed ARDS was 8.8 ± 2.8 versus 5.4 ± 2.8 for those who did not (p < 0.001). An ROC area under the curve of 0.79 demonstrates LIPS is statistically powerful for predicting ARDS development. Furthermore, for every 1-unit increase in LIPS, the odds of developing ARDS increase by 1.50 (p < 0.001) and odds of ICU mortality increase by 1.22 (p < 0.001). Conclusion. LIPS is reliable for predicting development of ARDS and predicting mortality in critically ill surgical patients.

No abstract

An artificial placenta (AP) utilizing extracorporeal life support (ECLS) could protect premature lungs from injury and promote continued development. Preterm lambs at estimated gestational age (EGA) 114–128 days (term = 145) were delivered by Caesarian section and managed in one of three groups: AP, mechanical ventilation (MV), or tissue control (TC). Artificial placenta lambs (114 days EGA, n = 3; 121 days, n = 5) underwent venovenous (VV)-ECLS with jugular drainage and umbilical vein reinfusion for 7 days, with a fluid-filled, occluded airway. Mechanical ventilation lambs (121 days, n = 5; 128 days, n = 5) underwent conventional MV until failure or maximum 48 hours. Tissue control lambs (114 days, n = 3; 121 days, n = 5; 128 days, n = 5) were sacrificed at delivery. At the conclusion of each experiment, lungs were procured and sectioned. Hematoxylin and eosin (H&E) slides were scored 0–4 in seven injury categories, which were summed for a total injury score. Slides were also immunostained for platelet-derived growth factor receptor (PDGFR)-α and α-actin; lung development was quantified by the area fraction of double-positive tips of secondary alveolar septa. Support duration of AP lambs was 163 ± 9 (mean ± SD) hours, 4 ± 3 for early MV lambs, and 40 ± 6 for late MV lambs. Total injury scores at 121 days were 1.7 ± 2.1 for AP vs. 5.5 ± 1.6 for MV (p = 0.02). Using immunofluorescence, double-positive tip area fraction at 121 days was 0.017 ± 0.011 in AP lungs compared with 0.003 ± 0.003 in MV lungs (p < 0.001) and 0.009 ± 0.005 in TC lungs. At 128 days, double-positive tip area fraction was 0.012 ± 0.007 in AP lungs compared with 0.004 ± 0.004 in MV lungs (p < 0.001) and 0.016 ± 0.009 in TC lungs. The AP is protective against lung injury and promotes lung development compared with mechanical ventilation in premature lambs.