Published papers

Oxidative stress plays a key role in the pathophysiology of post-cardiac arrest syndrome. Molecular hydrogen reduces oxidative stress and exerts anti-inflammatory effects in an animal model of cardiac arrest. However, its effect on human post-cardiac arrest syndrome is unclear. We consecutively enrolled five comatose post-cardiac arrest patients (three males; mean age, 65 ± 15 years; four cardiogenic, one septic cardiac arrest) and evaluated temporal changes in oxidative stress markers and cytokines with inhaled hydrogen. All patients were treated with target temperature management. Hydrogen gas inhalation (2% hydrogen with titrated oxygen) was initiated upon admission for 18 h. Blood hydrogen concentrations, plasma and urine oxidative stress markers (derivatives of reactive oxygen metabolites, biological antioxidant potential, 8-hydroxy-2'-deoxyguanosine, N ɛ-hexanoyl-lysine, lipid hydroperoxide), and cytokines (interleukin-6 and tumor necrosis factor-α) were measured before and 3, 9, 18, and 24 h after hydrogen gas inhalation. Arterial hydrogen concentration was measurable and it was equilibrated with inhaled hydrogen. Oxidative stress was reduced and cytokine levels were unchanged in cardiogenic patients, whereas oxidative stress was unchanged and cytokine levels were diminished in the septic patient. The effect of inhaled hydrogen on oxidative stress and cytokines in comatose post-cardiac arrest patients remains indefinite because of methodological weaknesses.

BACKGROUND: Hydrogen gas (H2) inhalation during hemorrhage stabilizes post-resuscitation hemodynamics, improving short-term survival in a rat hemorrhagic shock and resuscitation (HS/R) model. However, the underlying molecular mechanism of H2 in HS/R is unclear. Endothelial glycocalyx (EG) damage causes hemodynamic failure associated with HS/R. In this study, we tested the hypothesis that H2 alleviates oxidative stress by suppressing xanthine oxidoreductase (XOR) and/or preventing tumor necrosis factor-alfa (TNF-α)-mediated syndecan-1 shedding during EG damage. METHODS: HS/R was induced in rats by reducing mean arterial pressure (MAP) to 35 mm Hg for 60 min followed by resuscitation. Rats inhaled oxygen or H2 + oxygen after achieving shock either in the presence or absence of an XOR inhibitor (XOR-I) for both the groups. In a second test, rats received oxygen alone or antitumor necrosis factor (TNF)-α monoclonal antibody with oxygen or H2. Two hours after resuscitation, XOR activity, purine metabolites, cytokines, syndecan-1 were measured and survival rates were assessed 6 h after resuscitation. RESULTS: H2 and XOR-I both suppressed MAP reduction and improved survival rates. H2 did not affect XOR activity and the therapeutic effects of XOR-I and H2 were additive. H2 suppressed plasma TNF-α and syndecan-1 expression; however, no additional H2 therapeutic effect was observed in the presence of anti-TNF-α monoclonal antibody. CONCLUSIONS: H2 inhalation after shock stabilized hemodynamics and improved survival rates in an HS/R model independent of XOR. The therapeutic action of H2 was partially mediated by inhibition of TNF-α-dependent syndecan-1 shedding.

Refeeding syndrome potentially causes death from refeeding-induced central nervous system disorders, such as hypoglycemic encephalopathy, Wernicke encephalopathy, and hypophosphatemic encephalopathy. However, there is no established management for malnourished patients with this refeeding-induced central nervous system syndrome. We report a case of successful neurological critical care for refeeding-induced central nervous system syndrome. A 15-year-old female with anorexia nervosa presented to our hospital after fainting. Her body mass index (BMI) was 8.8 kg/m². Upon arrival, her Glasgow Coma Scale was E4V4M6, plasma glucose was 25 mg/dL, aspartate aminotransferase was 1393 U/L, and alanine transaminase was 1368 U/L. We started a continuous 5% dextrose. However, her Glasgow Coma Scale dropped to E4V1M1 1 hour later, and her plasma glucose was 28 mg/dL. We delivered her to the neurological critical care unit and started critical nutritional management. Her laboratory data had gradually improved. On day five from admission, her Glasgow Coma Scale had improved to G4V4M6. On day 15. She was transferred to the psychiatric department. In conclusion, clinicians should recognize that refeeding-induced central nervous system syndrome is neurologically critical and life-threatening. However, our management successfully improved this patient's condition. Additionally, she gained enough weight on day 15 after admission. Our moderate-calorie nutritional management might be adequate for refeeding-induced central nervous system syndrome. However, it is a little too exaggerated to conclude that our management is safe and the best nutritional management, based only on this case. We recommend a future observational study as the next step.

PURPOSE: To modify a surgical catheterization method using the bent needle introducer in small animals. METHODS: Eight-week-old male Lewis rats were used in the study. A needle introducer was created by bending a 21G injection needle at 45°. The bent needle introducer was used for catheter insertion into the left femoral artery of the rats under anesthesia. As a control, a catheter was directly inserted into the blood vessel without the introducer. The insertion time of each method was measured. Blood pressure and heart rate were measured 24 h after catheter insertion using the telemetry system. RESULTS: Using the introducer, the catheter was successfully inserted within a short time in all rats. Without the introducer, a longer duration was required for catheter insertion. The frequency of the insertion with no catheter-based errors with the introducer tended to be higher than that without the introducer. The mean arterial pressure and heart rate 24 h after catheter insertion in each group were almost the same. CONCLUSIONS: We developed a surgical catheterization method using the introducer in small animals. This could potentially reduce the frequency of the insertion with catheter-based errors and insertion time.