The Clinical Application of Hydrogen as a Medical Treatment.

In recent years, it has become evident that molecular hydrogen is a particularyl effective treatment for various disease models such as ischemia-reperfusion injury; as a result, research on hydrogen has progressed rapidly. Hydrogen has been shown to be effective not only through intake as a gas, but also as a liquid medication taken orally, intravenously, or locally. Hydrogen's effectiveness is thus multifaceted. Herein we review the recent research on hydrogen-rich water, and we examine the possibilities for its clinical application. Now that hydrogen is in the limelight as a gaseous signaling molecule due to its potential ability to inhibit oxidative stress signaling, new research developments are highly anticipated.

Soft tissue hematoma of the neck due to thyroid rupture with unusual mechanism.

INTRODUCTION: Massive bleeding from the thyroid gland causing airway compromise secondary to indirect neck trauma is rare. PRESENTATION OF CASE: An 89-year-old woman was transferred to our emergency department due to anterior neck pain after a traffic accident. She had been propelled forward and struck her head on the front mirror during emergency braking. Airway patency was confirmed at the first contact. Although her vital signs were stable at presentation, she gradually suffered from respiratory distress and severe dyspnea, implying airway compression, therefore requiring endotracheal intubation. Computed tomography (CT) revealed a large, encapsulated hematoma in the left thyroid gland lobe extending to the upper mediastinum. Contrast-enhanced CT demonstrated an extravasation of the contrast agent around the left superior thyroid artery. The left thyroid artery was ligated and the hematoma was removed immediately. She had a favorable course without further complications and was discharged 36days after admission. DISCUSSION: Airway management is the most important consideration in patients with thyroid injury. Treatment should be customized depending on the degree of respiratory distress resulting from of either involvement of the direct airway or secondary compression. CONCLUSION: Although hemorrhage from the thyroid gland without blunt trauma is rare, emergency physicians should regard possible thyroid gland rupture in patients with swelling of the neck or acute respiratory failure after direct/indirect trauma to the neck. Observation or operative management for limited or expanding hematoma are appropriately based on fundamental neck trauma principles.

Mean lung pressure during adult high-frequency oscillatory ventilation: an experimental study using a lung model.

In adult high-frequency oscillatory ventilation (HFOV), stroke volume (SV) and mean lung pressure (PLung) are important for lung protection. We measured the airway pressure at the Y-piece and the lung pressure during HFOV using a lung model and HFOV ventilators for adults (R100 and 3100B). The lung model was made of a 20-liter, airtight rigid plastic container (adiabatic compliance: 19.3 ml/cmH2O) with or without a resistor (20 cmH2O/l/sec). The ventilator settings were as follows: mean airway pressure (MAP), 30 cmH2O; frequency, 5-15 Hz (every 1 Hz); airway pressure amplitude (AMP), maximum;and % of inspiratory time (IT), 50% for R100, 33% or 50% for 3100B. The measurements were also performed with an AMP of 2/3 or 1/3 maximum at 5, 10 and 15 Hz. The PLung and the measured MAP were not consistently identical to the setting MAP in either ventilator, and decreasing IT decreased the PLung in 3100B. In conclusion, we must pay attention to the possible discrepancy between the PLung and the setting MAP during adult HFOV.

Successful extracorporeal life support for life-threatening hypercapnia with bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation.

Bronchiolitis obliterans (BO) is a disease with a poor prognosis, and a key factor that limits long-term survival after allogeneic hematopoietic stem cell transplantation (HSCT). We here report a case of a 31-year woman with acute lymphatic leukemia, which was treated by chemotherapy and HSCT, and consequently developed BO 2 years after HSCT. A non-tuberculous mycobacterial infection occurred and showed gradual exacerbation. She started taking anti-mycobacterial drugs, but lost appetite, felt tired and finally lost consciousness one month after beginning medication. Arterial blood gas revealed marked hypercapnia. Using extracorporeal life support (ECLS), the carbon dioxide concentration was reduced and her consciousness recovered. To our knowledge, this is the first case in which ECLS was successfully used for hypercapnia in a patient with BO.

Evaluation of pressure support ventilation with seven different ventilators using Active Servo Lung 5000.

In modern emergency and critical care, physicians tend to choose the mode of mechanical ventilation based on spontaneous breathing for the purpose of promoting discharge of pulmonary secretion and preventing atelectasis in patients with acute respiratory insufficiency. However, we often observe "differences in recovery" among patients treated using the same PSV settings beyond "differences in individual characteristics." We evaluated the Pressure Support Ventilation (PSV) mode aiming to certify the difference among 7 representative mechanical ventilators using the Active Servo Lung 5000 (ASL5000) respiratory simulation system. The following parameters were measured: The time delay that resulted in the lowest inspiratory pressure from the point at which the ventilator recognized spontaneous breathing (TD), the lowest inspiratory airway pressure (cmH2O) generated prior to the initiation of PSV (DeltaPaw), the work of breathing while triggering required to achieve the lowest inspiratory negative pressure from the beginning of inspiratory support (WOBtrig), and the inspiratory work of breathing (WOBi). The mean TD of the Puritan-Bennett type 840 (PB840) was signifi cantly shorter than those of other ventilators (p0.01). The WOBtrig of the PB840 was significantly lower than those of others (p0.01). However, the WOBi values of the Servo-I and T-Bird were greater than the others, with the Evita series showing the smallest WOBi of the 7 ventilators tested. According to this simulation study using ASL 5000, we concluded that PB840 was the most rapid response ventilator, but the Evita series was the gentlest mechanical ventilator among 7 ventilators from the standpoint of the total work of breathing during the inspiration phase in the setting of PSV.