Establishment of a swine experimental model of non-occlusive mesenteric ischemia: Combining induced hemorrhagic shock and vasopressor administration.

Aim: Non-occlusive mesenteric ischemia (NOMI) is associated with high mortality rates, but definitive treatments have not yet been established. Although experimental animal models are worthwhile, reproducible models that reflect the pathophysiology of NOMI have not been developed. Methods: We combined risk factors for NOMI, comprising hemorrhagic shock, systemic vasopressor infusion, and local vasopressor infusion from the superior mesenteric artery (SMA) in swine under maintained anesthesia. Experiment 1 involved full-intensity (40%) phlebotomy and systemic vasopressor (norepinephrine and epinephrine). Experiment 2 involved full-intensity (40%) phlebotomy, systemic norepinephrine, and local vasopressor infusion into the SMA. Experiment 3 involved moderate (27%) phlebotomy, systemic norepinephrine infusion, and local epinephrine infusion. We evaluated serum lactate levels, intestinal serosa color, computed tomography (CT) angiography, and pathological findings. Results: After inducing hemorrhage, systemic vasopressor alone and in combination with local vasopressin or norepinephrine infusion did not induce ischemic color changes in the intestine. The combination of systemic norepinephrine and local epinephrine (0.5 µg/kg/min) after moderate (27% blood loss) hemorrhage induced gross color change, pathological destruction, and elevation of serum lactate. Patent flow in the SMA was confirmed on CT angiography. Conclusion: We established a swine NOMI model with systemic norepinephrine infusion and local epinephrine with moderate hemorrhagic shock.

Ultrasound assessment is useful for evaluating balloon volume of resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: Endovascular balloon occlusion of the aorta (EBOA) increases proximal arterial pressure but may also induce life-threatening ischemic complications. Although partial REBOA (P-REBOA) mitigates distal ischemia, it requires invasive monitoring of femoral artery pressure for titration. In this study, we aimed to titrate P-REBOA to prevent high-degree P-REBOA using ultrasound assessment of femoral arterial flow. METHODS: Proximal (carotid) and distal (femoral) arterial pressures were recorded, and perfusion velocity of distal arterial pressures was measured by pulse wave Doppler. Systolic and diastolic peak velocities were measured among all ten pigs. Total REBOA was defined as a cessation of distal pulse pressure, and maximum balloon volume was documented. The balloon volume (BV) was titrated at 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the perfusion velocity of distal arterial pressures were recorded. RESULTS: Proximal blood pressure increased with increasing BV. Distal pressure decreased with increasing BV, and distal pressure sharply decreased by > 80% of BV. Both systolic and diastolic velocities of the distal arterial pressure decreased with increasing BV. Diastolic velocity could not be recorded when the BV of REBOA was > 80%. CONCLUSION: The diastolic peak velocity in the femoral artery disappeared when %BV was > 80%. Evaluation of the femoral artery pressure by pulse wave Doppler may predict the degree of P-REBOA without invasive arterial monitoring.

The Efficacy of Isochronal 3D Mapping-Based Ablation of Ventricular Arrhythmia.

Treatment of ventricular arrhythmias (VAs) commonly involves ablating sites showing electrograms with the earliest activity relative to the VA, but there is no threshold value for prematurity guaranteeing success. Ablation of sites with great prematurity can still result in failure.We hypothesized that isochronal map area (ISCA), derived from isochrones indicating electrogram prematurity, could help identify ablation targets in VA patients, as well as predict outcome. Specifically, we hypothesized that smaller ICSA for a given prematurity value would indicate a shallower arrhythmogenic focus leading to a higher likelihood of successful ablation.We studied ICSA in 29 patients (12 males, 57 [17-65] years old) undergoing VA ablation. The VAs originated from the right and left ventricles in 11 and 18 patients, respectively. The earliest activation site of the VAs, ECG morphology of sinus beats and premature ventricular complexes (PVCs), and ISCA of activation preceding PVCs were evaluated.RF ablation at the site showing earliest prematurity resulted in VA elimination in 21 patients (success group). The 5-ms ISCA was smaller in the success group than in the failure group (0.2 [0.1-0.6] versus 1.0 [0.8-1.5] cm2, respectively; P < 0.01). No significant difference was noted in prematurity itself (36 [30-45] versus 30 [29-33] ms, respectively; P = 0.07). The cut-off value of the 5 ms ISCA for successful RF ablation was 0.7 cm2 with 87.5% sensitivity and 85.6% specificity.Isochrones of activity preceding PVCs appear to contain information beyond prematurity values and may help dictate suitable areas for successful ablation of VAs.

Intrahospital transport of mechanically ventilated intensive care patients using new equipment attached to a transfer board.

Aim: Multiple lines and tubes often complicate bed transfer in critically ill patients. To solve this problem, the authors developed medical equipment attached to a transfer board ("transfer board tree") that integrates the patient, transfer board, and medical equipment. The objective of this study was to evaluate the efficiency and safety of the transfer board tree. Methods: Forty mechanically ventilated patients (20 transfer board tree, 20 conventional) in the intensive care unit who were transported for computed tomography were enrolled. Transfer times and adverse events were recorded. Results: Transfer board tree patients had significantly shorter transfer times. There were two adverse events only in the conventional group. Conclusions: The transfer board tree enables rapid intrahospital transport of intensive care patients with sufficient monitoring.

Gram-scale synthesis of nickel(II) norcorrole: the smallest antiaromatic porphyrinoid.

Small is beautiful: A ring-contracted sister of porphyrin, norcorrole, has been synthesized efficiently as a stable molecule by a nickel-templated strategy. The norcorrole complex is stable but exhibits a distinct antiaromatic character according to the Hückel rule. Oxidation of the norcorrole complex provides an aromatic oxacorrole complex.

Synthesis of nickel(II) azacorroles by Pd-catalyzed amination of α,α'-dichlorodipyrrin Ni(II) complex and their properties.

Synthesis of nickel(II) complexes of meso-aryl-substituted azacorroles was performed by Buchwald-Hartwig amination of a dipyrrin Ni(II) complex with benzylamine through C-N and C-C coupling. The highly planar structure of Ni(II) azacorroles was elucidated by X-ray diffraction analysis. (1)H NMR analysis and nucleus independent chemical shift (NICS) calculation on Ni(II) azacorrole revealed its distinct aromaticity with [17]triaza-annulene 18π conjugation. In addition, acylation of azacorrole selectively afforded N- and C-acylated azacorroles depending on the reaction conditions, showing the dual reactivity of azacorroles.