Evaluating Health Impact at High Altitude in Antarctica and Effectiveness of Monitoring Oxygen Saturation

[Background] The Japanese Antarctic Research Expedition (JARE) has been conducting research activities in inland Antarctica, which is extremely cold dryland covered with a thick ice sheet. This environment may cause a health disorder called acute mountain sickness (AMS). To improve the safety of expedition members, we evaluated the impact of extreme environmental conditions on human health and the effectiveness of monitoring of hypoxia for the early detection of AMS. [Methods] In total, 9 members from JARE 59 were studied. Dome Fuji Station (Dome F), located 3,810 m above sea level (ASL), was the destination of the research party. We analyzed daily AMS scores (higher values correspond to more severe AMS-related symptoms), physiological findings, and percutaneous arterial blood oxygen saturation (SpO2) during the inland activity. We also determined the factors related to AMS scores. [Results] The average AMS score on arrival at Dome F was significantly higher than that at the departure point (560 m ASL). The average SpO2 level was significantly lower than that at other points. The SpO2 level correlated negatively with the AMS score in Spearman’s rank correlation. Generalized estimating equations analysis showed that the AMS score was negatively associated with SpO2 level and positively associated with age. [Conclusion] Hypoxia is a contributory factor to AMS which we can easily assess by measuring the SpO2 level with a pulse oximeter. SpO2 monitoring is a potentially useful health management tool for members in inland Antarctic expeditions. In addition, our results are helpful for understanding physiological responses and health issues in extreme environments

Therapeutic Efficacy of pH-Dependent Release Formulation of Mesalazine on Active Ulcerative Colitis Resistant to Time-Dependent Release Formulation: Analysis of Fecal Calprotectin Concentration

Purpose. Few reports have compared the clinical efficacy of a pH-dependent release formulation of mesalazine (pH-5-ASA) with a time-dependent release formulation (time-5-ASA). We examined whether pH-5-ASA is effective for active ulcerative colitis (UC) in patients resistant to time-5-ASA. Methods. We retrospectively and prospectively analyzed the efficacy of pH-5-ASA in mildly to moderately active UC patients in whom time-5-ASA did not successfully induce or maintain remission. The clinical efficacy of pH-5-ASA was assessed by clinical activity index (CAI) before and after switching from time-5-ASA. In addition, the efficacy of pH-5-ASA on mucosal healing (MH) was evaluated in a prospective manner by measuring fecal calprotectin concentration. Results. Thirty patients were analyzed in a retrospective manner. CAI was significantly reduced at both 4 and 8 weeks after switching to pH-5-ASA. In the prospective study (n=14), administration of pH-5-ASA also significantly reduced CAI scores at 4 and 8 weeks in these patients who were resistant to time-5-ASA. In addition, fecal calprotectin concentration was significantly decreased along with improvement in CAI after switching to pH-5-ASA. Conclusions. Our results suggest that pH-5-ASA has clinical efficacy for mildly to moderately active patients with UC in whom time-5-ASA did not successfully induce or maintain remission

Bleeding Risk Related to Upper Gastrointestinal Endoscopic Biopsy in Patients Receiving Antithrombotic Therapy: A Multicenter Prospective Observational Study

Background: Although antithrombotic agents are widely used for cardiac and cerebrovascular disease prevention, they increase the risk of gastrointestinal (GI) bleeding. Objective: To examine GI bleeding risk in association with an esophagogastroduodenoscopy (EGD) biopsy performed in patients without cessation of antithrombotic therapy. Methods: This study was prospectively conducted at 14 centers. EGD biopsies were performed in patients receiving antithrombotic agents without cessation, as well as age- and sex-matched controls not receiving antithrombotic therapy. Patients treated with warfarin before the biopsy had a prothrombin time-international normalized ratio level <3.0. The proportion of GI bleeding events was compared between the groups. Results: The patient group (n = 277) underwent a total of 560 biopsies while continuing antithrombotic therapy, of whom 24 were receiving multiple antiplatelet drugs, and 9 were receiving both antiplatelet and anticoagulant agents. The control patients (n = 263) underwent 557 biopsies. The upper-GI bleeding rate within 30 days after the EGD biopsy did not increase in patients without cessation of antithrombotic treatment, regardless of receiving single or multiple antithrombotic agents. Conclusions: We found no significant increase in upper-GI bleeding risk following an EGD biopsy in patients taking antithrombotic agents, suggesting its safety without the need for antithrombotic treatment interruption