飯塚 悠祐

BACKGROUND: Interatrial right-to-left shunt flow through a patent foramen ovale (PFO) can be caused by changes in heart position for anastomosis during off-pump coronary artery bypass (OPCAB). We herein present a case in which the direction of PFO shunt flow changed with heart position during OPCAB and the ventilation settings after sternal closure. CASE PRESENTATION: A 66-year-old man with interstitial pneumonia underwent OPCAB. Preoperative transesophageal echocardiography revealed right-to-left shunt flow through a PFO induced by the Valsalva maneuver. During OPCAB, heart displacement resulted in right-to-left shunting and acute hypoxemia, which quickly improved with increase of inspired oxygen fraction. After chest closure, bidirectional shunt flow developed under increased airway pressure. CONCLUSIONS: Vigilant intraoperative monitoring with TEE and postoperative airway pressure management are important to address shunt flow and hypoxemia due to PFO.

Introduction Remifentanil is an opioid with rapid onset and elimination. Theoretically, reducing sedation using high-dose remifentanil may contribute to early emergence and prevention of postanesthetic complications related to residual anesthesia. However, there have been few reports of high-dose remifentanil anesthesia in neonatal surgery. This study aims to describe the techniques of high-dose remifentanil anesthesia in neonates and their safety outcomes. Methods This is a single-center, retrospective observational study from January 2016 to February 2022. Medical records from neonatal surgical procedures performed using high-dose remifentanil anesthesia were reviewed. "High dose" was defined as 0.5 mcg/kg/min or more. Patient profiles, anesthetic drugs used, and intra- and post-operative adverse events, including cardiopulmonary complications, were abstracted. Results There were 15 neonatal abdominal operations performed under high-dose (>0.5 mcg/kg/min) remifentanil anesthesia during the study period. The average remifentanil infusion rate was 1.9 (0.68-3.1) mcg/kg/min. Hypotension occurred in two patients (13%). Bradycardia was not observed in any patients. The mean time for tracheal extubation was 16 minutes. Five patients (33%) received naloxone administration before extubation, and two patients (13%) experienced hypoxemia immediately after extubation. No patient had cardiorespiratory complications after leaving the operating room. Conclusions High-dose remifentanil can be used without impairing hemodynamic stability in neonatal surgery, although there is concern about respiratory depression. Further research is needed on its potential impact on long-term outcomes.

OBJECTIVE: Systemic heparinization during cardiopulmonary bypass (CPB) can significantly affect thromboelastography (TEG). This study investigated the feasibility of adding protamine in vitro to allow assessment of coagulation status using the TEG 6s system during CPB. METHODS: In this prospective observational study, 21 patients undergoing elective cardiac valve surgery were evaluated. During CPB, protamine was added in vitro to the heparinized blood of these patients at a concentration of 0.05 mg/mL and analyzed with the TEG 6s (Pre). The TEG parameters were compared to those analyzed after CPB withdrawal and systemic protamine administration (Post). RESULTS: The citrated kaolin maximal amplitude (CK-MA) and the citrated functional fibrinogen maximal amplitude (CFF-MA) exhibited strong correlations between Pre and Post measurements (r = 0.790 and 0.974, respectively, P < 0.001 for both), despite significant mean differences (-2.23 mm for CK-MA and -0.68 mm for CFF-MA). Bland-Altman analysis showed a clinically acceptable agreement between Pre and Post measurement of CK-MA and CFF-MA (the percentage error was 10.6% and 12.2%, respectively). In contrast, the citrated kaolin reaction time (CK-R) showed no significant correlation between Pre and Post measurements (r = 0.328, P = 0.146), with a mean difference of 1.42 min (95% CI: -0.45 to 3.29). CONCLUSIONS: In vitro protamine addition allows assessment of coagulation status during CPB using the TEG 6s system. CK-MA and CFF-MA measured during CPB using this method revealed a strong correlation and agreement with post-CPB measurements, suggesting that our method potentially facilitates early prediction of post-CPB coagulation status and decision-making on transfusion strategies. CLINICAL TRIAL REGISTRATION: The study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR, registration number: UMIN000041097, date of registration: July 13, 2020, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046925 ) before the recruitment of participants.

BACKGROUND: Masks are well accepted in Japan, where they were already part of daily life even before the COVID-19 pandemic. Unlike many other countries where mask mandates were lifted as soon as the pandemic was under control, Japan was one of the last countries to ease mask-wearing guidelines. Even after the formal announcement to allow masks-off in mid-March 2023, many Japanese still voluntarily wear masks. In this work, possible reasons for this extreme "mask-affinity" of Japanese people were studied by exploring various information sources including tweets (now known as X posts) and subsequent text-analysis, online news, and medical literature. METHODS: An observational study was conducted based on tweets prospectively collected during 5 months from June 26th, 2022 to November 26th, 2022. Tweets with the hashtag "mask (in Japanese)" were collected weekly via the Twitter application programming interface by using R version 4.0.3 to gauge public opinions. The word clouds to allow intuitive understanding of the key words were drawn from the tokenized text. RESULTS: The data collection period included the 7th flareups of the newly infected cases i.e. "the 7th surge". In total, 161,592 tweets were collected. Word clouds for 1) before the 7th surge based on 18,000 tweets on June 26th and 2) during/after the 7th surge based on 143,592 tweets between July-November were created with the R package "wordcloud2". The results indicated that the people wanted to take off masks due to the heat in summer, then shifted again toward mask-wearing along with the 7th surge but with a certainly growing "no-mask" sentiment. CONCLUSIONS: Subsequent review of domestic information sources suggested that various factors, not only well-known peer pressure, may have contributed the public's mask affinity in Japan. This work revealed an aspect of Japanese struggle toward adaptation to life in an unexpected pandemic by focusing on masks as our closest daily adjunct over the past 3 years of isolation.Trial registration: not applicable.

Andexanet alfa neutralizes factor Xa inhibitors in critical bleeding situations. However, in cardiac surgery with cardiopulmonary bypass (CPB), heparin resistance induced by andexanet alfa should be a concern, and the lack of point-of-care monitoring of plasma concentration of factor Xa inhibitors makes it difficult to decide when to administer andexanet alfa. A 69-year-old man underwent emergency surgery for acute pulmonary thromboembolism. The patient had been on edoxaban until the day before the surgery. Withdrawal from CPB required venoarterial extracorporeal membrane oxygenation due to right heart failure, followed by severe bleeding that required massive transfusion. Despite adequate coagulation factor replacement, bleeding persisted and citrated kaolin-reaction time (CK-R) on thromboelastography (TEG) was prolonged. Administering andexanet alfa achieved excellent hemostasis without any thrombosis and normalized the prolonged CK-R of TEG. This is the first report of a change in TEG findings before and after administration of andexanet alfa in a cardiac surgery patient taking factor Xa inhibitor. Monitoring CK-R in TEG may help evaluate the anticoagulant effect of factor Xa inhibitors and the reversal effect of andexanet alfa.