吉永 晃一

BACKGROUND: Ascorbic acid is a strong antioxidant that prevents postoperative delirium by inhibiting reactive oxygen species production. This pilot study was designed to investigate the prevalence of postoperative delirium among older patients undergoing cardiovascular surgery, who received perioperative ascorbic acid administration, to estimate an appropriate sample size for further randomized controlled trials. METHODS: This single-arm prospective interventional study enrolled patients aged > 70 years scheduled to undergo elective cardiovascular surgery using cardiopulmonary bypass. Ascorbic acid (500 mg) was administered intravenously every 6 h for a total of eight times following the induction of general anesthesia. The incidence of postoperative delirium was evaluated until discharge using the Confusion Assessment Method for the Intensive Care Unit. RESULTS: Data from 48 patients were analyzed. Of the 48 patients, 16 developed postoperative delirium (33.3%). Patients in the delirium group had more severe heart failure (New York Heart Association Classification), higher European System for Cardiac Operative Risk Evaluation scores, lower intraoperative Bispectral Index, longer duration of cardiopulmonary bypass and surgery, incidence of postoperative cerebral infarction, longer intubation time, and length of intensive care unit stay. CONCLUSIONS: The incidence of postoperative delirium among older patients undergoing cardiovascular surgery who received ascorbic acid perioperatively (2 g/day for 2 days) was 33%. This incidence was comparable to that observed in a previous observational study, suggesting that ascorbic acid administration may not be effective in preventing the incidence of postoperative delirium.

PURPOSE: The purpose of this study is to describe the implementation of life-supporting interventions and the short-term outcomes of older patients in ICUs in Japan. METHODS: All adult patients admitted to ICUs participating in the Japanese Intensive Care Patient Database (JIPAD) from April 1, 2015, to March 31, 2022, were eligible for inclusion. Information, including life-supporting interventions, was retrieved from the database. Patients were divided into six age groups. The primary outcome of interest was the proportion of receiving a composite of the following interventions: mechanical ventilation, continuous renal replacement therapy, and veno-venous or veno-arterial extracorporeal membrane oxygenation. RESULTS: Data of a total of 233,093 patients were analyzed. The median age was 71 years, with 18.2% of the patients in their 80s, 5303 patients in their 90s (2.3%), and 67 patients in their 100s. Many life-supporting interventions were provided to older patients. The proportion of patients older than 90 years who received the composite interventions decreased from 40.4% in 18-59 to 27.6% in 90-99. Non-invasive ventilation (NIV) use increased with age, resulting in a consistent proportion of patients receiving either NIV or mechanical ventilation until their 90s. ICU mortality for patients aged 80 years or older was 5.6%, and hospital mortality for this age group was 12.9%. Approximately half of the patients in their 80s and 60% of those older than 90 years did not return home. CONCLUSION: Although life-supporting interventions tended to decrease with age, a considerable number of patients of advanced age still received these interventions.

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.