Patients with univentricular heart disease may undergo a superior cavopulmonary anastomosis, an operative intervention that raises cerebral venous pressure and impedance to cerebral venous return. ...The ability of infantile cerebral autoregulation to compensate for this is not well understood.
We identified all patients undergoing a superior cavopulmonary anastomosis (cases) and compared metrics of cerebral oxygenation upon admission to the ICU with patients following repair of tetralogy of Fallot or arterial switch operation (controls). The primary endpoint was cerebral venous oxyhaemoglobin saturation measured from an internal jugular venous catheter. Other predictor variables included case-control assignment, age, weight, sex, ischemic times, arterial oxyhaemoglobin saturation, mean arterial blood pressure, and superior caval pressure.
A total of 151 cases and 350 controls were identified. The first post-operative cerebral venous oxyhaemoglobin saturation was significantly lower following superior cavopulmonary anastomosis than in controls (44 ± 12 versus 59 ± 15%, p < 0.001), as was arterial oxyhaemoglobin saturation (81 ± 9 versus 98 ± 5%, p < 0.001). Cerebral venous oxyhaemoglobin saturation correlated poorly with superior caval pressure in both groups. When estimated by linear mixed effects model, arterial oxyhaemoglobin saturation was the primary determinant of central venous oxyhaemoglobin saturation in both groups (β = 0.79, p = 3 × 10-14); for every 1% point increase in arterial oxyhaemoglobin saturation, there was a 0.79% point increase in venous oxyhaemoglobin saturation. In this model, no other predictors were significant, including superior caval pressure and case-control assignment.
Cerebral autoregulation appears to remain intact despite acute imposition of cerebral venous hypertension following superior cavopulmonary anastomosis. Following superior cavopulmonary anastomosis, cerebral venous oxyhaemoglobin saturation is primarily determined by arterial oxyhaemoglobin saturation.
Intravascular oxygen delivery holds great potential for the treatment of numerous hypoxic conditions and emergencies, including pulmonary disorders, hypoxic tumors, hemorrhagic shock, stroke, cardiac ...arrest and so on. Different biomaterials strategies are available to incorporate oxygen gas as potential injectable therapeutics. For more information, see the Concept article by B. D. Polizzotti et al. on page 18820 ff.
Regional cerebral oxygenation index (rSO2) based on near-infrared spectroscopy (NIRS) is frequently used to detect low venous oxyhemoglobin saturation (ScvO2). We compared the performance of 2 ...generations of NIRS devices. Clinically obtained, time-matched cerebral rSO2 and ScvO2 values were compared in infants monitored with the FORE-SIGHT (n = 73) or FORE-SIGHT ELITE (n = 47) by linear regression and Bland-Altman analyses. In both devices, cerebral rSO2 correlated poorly with measured ScvO2 (FORE-SIGHT partial correlation 0.50 95% confidence interval {CI}, 0.40-0.58; FORE-SIGHT ELITE partial correlation 0.47 0.39-0.55) and mean bias was +8 (standard deviation SD 13.2) for FORE-SIGHT and +14 (SD 12.5) for FORE-SIGHT ELITE. When ScvO2 was <30%, rSO2 was <40 in 8% of FORE-SIGHT ELITE readings. Future NIRS should be validated in more hypoxic cohorts.
Microbubbles (MBs) have tremendous application in a number of fields and strategies to impart them with tunable properties are of great interest to the scientific community. We recently reported a ...robust platform to produce polymeric MBs (more appropriately termed polymeric microcapsules, PMCs) with highly tunable materials properties by controlling the self‐emulsification of oil‐in‐water emulsions. In this study, we used design of experiments to develop a model to predict PMC internal architectures and mean particle diameter as a function of three key processing parameters: concentration of self‐emulsifier (0.1% < F68 < 0.25% wt/wt), homogenization speed (1500–3000 rpm), and dilution factor (15 < DF < 30). We show that the homogenization speed and F68 concentration strongly influence both PMC morphology and size, with porous shell hollow cored PMCs being favored at low speeds and high F68 concentrations and nonporous‐shelled gas‐in‐oil cored PMCs (g/o‐PMCs) being favored at faster speeds and lower F68 concentrations. Models were subsequently validated by successfully predicting the relative percent yield and mean particle diameter of g‐PMCs and g/o‐PMCs for four sets of randomly selected factor settings. We anticipate that the results shown here will serve as a roadmap for other investigators interested in evaluating the utility of g‐PMCs, g/o‐PMCs or, combinations of the two, as novel gas carriers, diagnostic imaging agents, acoustic insulators, shock absorbers, and lightweight building materials, among many others.
We aimed to characterize extracorporeal CPR (ECPR) outcomes in our center and to model prediction of severe functional impairment or death at discharge.
All ECPR events between 2011 and 2019 were ...reviewed. The primary outcome measure was severe functional impairment or death at discharge (Functional Status Score FSS ≥ 16). Organ dysfunction was graded using the Pediatric Logistic Organ Dysfunction Score-2, neuroimaging using the modified Alberta Stroke Program Early Computed Tomography Score. Multivariable logistic regression was used to model FSS ≥ 16 at discharge.
Of the 214 patients who underwent ECPR, 182 (median age 148 days, IQR 14–827) had an in-hospital cardiac arrest and congenital heart disease and were included in the analysis. Of the 110 patients who underwent neuroimaging, 52 (47%) had hypoxic-ischemic injury and 45 (41%) had hemorrhage. In-hospital mortality was 52% at discharge. Of these, 87% died from the withdrawal of life-sustaining therapies; severe neurologic injury was a contributing factor in the decision to withdraw life-sustaining therapies in 50%. The median FSS among survivors was 8 (IQR 6–8), and only one survivor had severe functional impairment. At 6 months, mortality was 57%, and the median FSS among survivors was 6 (IQR 6–8, n = 79). Predictive models identified FSS at admission, single ventricle physiology, extracorporeal membrane oxygenation (ECMO) duration, mean PELOD-2, and worst mASPECTS (or DWI-ASPECTS) as independent predictors of FSS ≥ 16 (AUC = 0.931) and at 6 months (AUC = 0.924).
Mortality and functional impairment following ECPR in children remain high. It is possible to model severe functional impairment or death at discharge with high accuracy using daily post-ECPR data up to 28 days. This represents a prognostically valuable tool and may identify endpoints for future interventional trials.
Coarctation of the aorta (CoA) is a ductus arteriosus (DA)-dependent form of congenital heart disease (CHD) characterized by narrowing in the region of the aortic isthmus. CoA is a challenging ...diagnosis to make prenatally and is the critical cardiac lesion most likely to go undetected on the pulse oximetry-based newborn critical CHD screen. When undetected CoA causes obstruction to blood flow, life-threatening cardiovascular collapse may result, with a high burden of morbidity and mortality. Hemodynamic monitoring practices during DA closure (known as an "arch watch") vary across institutions and existing tools are often insensitive to developing arch obstruction. Novel measures of tissue oxygenation and oxygen deprivation may improve sensitivity and specificity for identifying evolving hemodynamic compromise in the newborn with CoA. We explore the benefits and limitations of existing and new tools to monitor the physiological changes of the aorta as the DA closes in infants at risk of CoA.
Colloids, known as volume expanders, have been used as resuscitation fluids for hypovolemic shock for decades, as they increase plasma oncotic pressure and expand intravascular volume. However, ...recent studies show that commonly used synthetic colloids have adverse interactions with human biological systems. In this work, a low‐fouling amine(N)‐oxide‐based zwitterionic polymer as an alternative volume expander with improved biocompatibility and efficacy is designed. It is demonstrated that the polymer possesses antifouling ability, resisting cell interaction and deposition in major organs, and is rapidly cleared via renal filtration and hepatic circulation, reducing the risk of long‐term side effects. Furthermore, in vitro and in vivo studies show an absence of adverse effects on hemostasis or any acute safety risks. Finally, it is shown that, in a head‐to‐head comparison with existing colloids and plasma, the zwitterionic polymer serves as a more potent oncotic agent for restoring intravascular volume in a hemorrhagic shock model. The design of N‐oxide‐based zwitterionic polymers may lead to the development of alternative fluid therapies to treat hypovolemic shock and to improve fluid management in general.
A low‐fouling N‐oxide‐based zwitterionic polymer is developed as a colloid for fluid resuscitation, which simultaneously improves oncotic potency and biocompatibility to resist interference with coagulation or deposition in major organs. When used as fluid therapy in a severe hemorrhagic shock model, it significantly improves resuscitation outcomes when compared with existing colloids or plasma (the gold standard).
The ability to tailor acoustic cavitation of contrast agents is pivotal for ultrasound applications in enhanced imaging, drug delivery, and cancer therapy, etc. A biopolymer-based system of ...microbubbles and nanobubbles was developed as acoustic reporters that consist of extremely porous hard shells. Despite the existence of an incompressible shell, these porous contrast agents exhibited strong nonlinear acoustic response under very low acoustic pressure, e.g, harmonics, characteristic of free gas bubbles. The large air/water surface area within the transmural capillaries are believed to facilitate oscillation of the inner gas core. Furthermore, the acoustic cavitation can be tailored by variation in polymer structures. This synthetically based platform offers insight for the rational design of advanced acoustic biomaterials.
Encapsulation and delivery of oxygen, carbon dioxide, and other therapeutic gases, using polymeric microcapsules (PMCs) is an emerging strategy to deliver gas as an injectable therapeutic. The gas ...cargo is stored within the PMC core and its release is mediated by the physiochemical properties of the capsule shell. Although use of PMCs for the rapid delivery of gases has been well described, methods which tune the material properties of PMCs for sustained release of gas are lacking. In this work, we describe a simple method for the high-yield production of gas-in-oil-filled PMCs with tunable sizes and core gas content from preformed polymers using the sequential phase separation and self-emulsification of emulsion-based templates. We demonstrate that prolonged gas release occurs from gas-in-oil PMCs loaded with oxygen and carbon dioxide gas, each of which could have significant clinical applications.
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