飯塚 悠祐

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: Tracking preload dependency non-invasively to maintain adequate tissue perfusion in the perioperative period can be challenging.The effect of phenylephrine on stroke volume is dependent upon preload. Changes in stroke volume induced by phenylephrine administration can be used to predict preload dependency. The change in the peripheral perfusion index derived from photoplethysmography signals reportedly corresponds with changes in stroke volume in situations such as body position changes in the operating room. Thus, the peripheral perfusion index can be used as a non-invasive potential alternative to stroke volume to predict preload dependency. Herein, we aimed to determine whether changes in perfusion index induced by the administration of phenylephrine could be used to predict preload dependency. METHODS: We conducted a prospective single-centre observational study. The haemodynamic parameters and perfusion index were recorded before and 1 and 2 min after administering 0.1 mg of phenylephrine during post-induction hypotension in patients scheduled to undergo surgery. Preload dependency was defined as a stroke volume variation of ≥ 12% before phenylephrine administration at a mean arterial pressure of < 65 mmHg. Patients were divided into four groups according to total peripheral resistance and preload dependency. RESULTS: Forty-two patients were included in this study. The stroke volume in patients with preload dependency (n = 23) increased after phenylephrine administration. However, phenylephrine administration did not impact the stroke volume in patients without preload dependency (n = 19). The perfusion index decreased regardless of preload dependency. The changes in the perfusion index after phenylephrine administration exhibited low accuracy for predicting preload dependency. Based on subgroup analysis, patients with high total peripheral resistance tended to exhibit increased stroke volume following phenylephrine administration, which was particularly prominent in patients with high total peripheral resistance and preload dependency. CONCLUSION: The findings of the current study revealed that changes in the perfusion index induced by administering 0.1 mg of phenylephrine could not predict preload dependency. This may be attributed to the different phenylephrine-induced stroke volume patterns observed in patients according to the degree of total peripheral resistance and preload dependency. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN000049994 on 9/01/2023).

BACKGROUND: It has been 50 years since the pulmonary artery catheter was introduced, but the actual use of pulmonary artery catheters in recent years is unknown. Some randomized controlled trials have reported no causality with mortality, but some observational studies have been published showing an association with mortality for patients with cardiogenic shock, and the association with a pulmonary artery catheter and mortality is unknown. The aim of this study was to investigate the utilization of pulmonary artery catheters (PACs) in the intensive care unit (ICU) and to examine their association with mortality, taking into account differences between hospitals. METHODS: This is a retrospective analysis using the Japanese Intensive care PAtient Database, a multicenter, prospective, observational registry in Japanese ICUs. We included patients aged 16 years or older who were admitted to the ICU for reasons other than procedures. We excluded patients who were discharged within 24 h or had missing values. We compared the prognosis of patients with and without PAC. The primary outcome was hospital mortality. We performed propensity score analysis to adjust for baseline characteristics and hospital characteristics. RESULTS: Among 184,705 patients in this registry from April 2015 to December 2020, 59,922 patients were included in the analysis. Most patients (94.0%) with a PAC in place had cardiovascular disease. There was a wide variation in the frequency of PAC use between hospitals, from 0 to 60.3% (median 14.4%, interquartile range 2.2-28.6%). Hospital mortality was not significantly different between the PAC use group and the non-PAC use group in patients after adjustment for propensity score analysis (3.9% vs 4.3%; difference, - 0.4%; 95% CI - 1.1 to 0.3; p = 0.32). Among patients with cardiac disease, those with post-open-heart surgery and those in shock, hospital mortality was also not significantly different between the two groups (3.4% vs 3.7%, p = 0.45, 1.7% vs 1.7%, p = 0.93, 4.8% vs 4.9%, p = 0.87). CONCLUSIONS: The frequency of PAC use varied among hospitals. PAC use for ICU patients was not associated with lower hospital mortality after adjusting for differences between hospitals.

BACKGROUND: The incidence of delirium is high in older patients undergoing cardiovascular surgery with cardiopulmonary bypass (CPB). Intraoperative tissue hypoperfusion and re-reperfusion injury, which generate reactive oxygen species (ROS), are suggested to induce delirium. Ascorbic acid is an excellent antioxidant and may reduce organ damage by inhibiting the production of ROS. This prospective observational study aimed to measure pre- and postoperative plasma ascorbic acid levels and examine their association with delirium. METHODS: Patients older than 70 years of age scheduled for elective cardiovascular surgery using CPB were enrolled. From September 2020 to December 2021, we enrolled 100 patients, and the data of 98 patients were analyzed. RESULTS: In total, 31 patients developed delirium, while 67 did not. Preoperative plasma ascorbic acid levels did not differ between the non-delirium and delirium groups (6.0 ± 2.2 vs. 5.5 ± 2.4 µg/mL, p = 0.3). Postoperative plasma ascorbic acid levels were significantly different between the groups (2.8 [2.3-3.5] vs. 2.3 [1.6-3.3] µg/mL, p = 0.037). CONCLUSIONS: In patients who undergo cardiovascular surgery with CPB, lower postoperative plasma ascorbic acid levels may be associated with the development of delirium.