No abstract

Dexmedetomidine (DEX), a highly selective alpha2 adrenergic receptor agonist, directly protects hearts against ischemia/reperfusion (I/R) injury. However, the detailed mechanism has not been fully elucidated. We studied differentially expressed mRNAs and miRNAs after DEX administration in rat hearts by comprehensive analysis. Additionally, bioinformatics analysis was applied to explore candidate genes and pathways that might play important roles in DEX-induced cardioprotection. The results of microarray analysis showed that 165 mRNAs and 6 miRNAs were differentially expressed after DEX administration. Through bioinformatics analysis using differentially expressed mRNAs, gene ontology (GO) terms including MAP kinase tyrosine/serine/threonine phosphatase activity and pathways including the p53 pathway were significantly enriched in the down-regulated mRNAs. Dusp1 and Atm were associated with the GO term of MAP kinase tyrosine/serine/threonine phosphatase activity and the p53 pathway, respectively. On the other hand, no significant pathway was found in the target mRNAs of deregulated miRNAs. The results indicated some possible key genes and pathways that seem to be of significance in DEX-induced cardioprotection, although miRNAs seem to be unlikely to contribute to cardioprotection induced by DEX.

Visitation restrictions for family members are problematic in intensive care management due to the COVID-19 pandemic. We analyzed the usefulness of an intensive care unit (ICU) diary about the experiences of family members of critical COVID-19 patients. Four family members of 2 COVID-19 patients participated in this report. Both patients were transferred to our ICU after 2 weeks of treatment at another ICU. An ICU diary was given to their family members post-transfer. The family members were interviewed before and after the patients’ discharge; the recorded interviews were analyzed and categorized into several clusters using a text mining method. Five categories regarding their anxious feelings were classified before the use of the ICU diary, and 3 categories were based on their positive feelings after the use of the ICU diary. Intensive care unit diaries may be beneficial for disclosing patients’ information when visitation restrictions are exercised due to the COVID-19 pandemic.

The anesthetic management of myasthenia gravis patients undergoing cardiac or aortic surgery under cardiopulmonary bypass, especially with deep hypothermic circulatory arrest, is challenging. We describe a case of successful anesthetic management of a myasthenia gravis patient undergoing total arch replacement with deep hypothermic circulatory arrest under neuromuscular monitoring and complete reversal of the action of neuromuscular blocking drugs by sugammadex. The present case suggests that patients with well-controlled myasthenia gravis might be safely managed in cardiac or aortic surgery under cardiopulmonary bypass with deep hypothermic circulatory arrest.

Background. Chronic and/or intermittent exposure to hypobaric hypoxia reportedly exerts cardioprotective effects against ischemia-reperfusion injury. However, few studies have focused on the cardioprotective effects of acute and/or short-term hypobaric and hypoxic exposures. This study investigated the effects of acute hypobaric hypoxia on myocardial ischemia-reperfusion injury. Materials and Methods. Rats were assigned to groups receiving normobaric normoxia (NN group), hypobaric hypoxia (HH group), or normobaric hypoxia (NH group). HH group rats were exposed to 60.8 kPa and 12.6% fraction of inspired oxygen in a hypobaric chamber for 6 h. NH group rats were exposed to hypoxic conditions under normal pressure. After each exposure, 30 min of myocardial ischemia was followed by 60 min of reperfusion. Cardiac function and infarct size were determined after reperfusion. Expression of hypoxia-inducible factor 1 alpha (HIF1α) was also measured. Results. Cardiac function was better preserved in the HH and NH groups than in the NN group ( p  < 0.01 each). Median infarct size/area at risk was significantly lower in the HH group (50%, interquartile range [IQR] 48–54%; p  < 0.01 vs. NN group) and NH group (45%, IQR 36–50%; p  < 0.01 vs. NN group) than in the NN group (72%, IQR 69–75%). HIF1α expression was significantly higher in the HH group ( p  < 0.05 vs. NN group) and NH group ( p  < 0.01 vs. NN group) than in the NN group. Conclusions. Exposure to acute and/or short-term hypobaric and hypoxic conditions might exert cardioprotective effects against myocardial ischemia-reperfusion injury via HIF1α modulation.