Are difficult mask ventilation and difficult intubation the same? Learn key differences, risks, and ASA 2022 airway guidelines.

マスク換気困難と挿管困難は同じではありません．リスク因子や評価の重要性をわかりやすく解説．

How long does an oxygen cylinder last? Learn easy formulas with examples, cylinder factors, and safety margins explained clearly.

救急や手術で必須の酸素ボンベ．残量の計算方法を写真付きで解説．MPaと気圧の関係や，実際にどれくらいもつのかをシンプルに学べます．

Oxygen therapy after anesthesia is routine, but why? This article explains the mechanisms of postoperative hypoxemia, why oxygen is supportive not curative, and the risks of excessive oxygen flow.

術後に酸素を投与する理由を解説．低酸素血症のメカニズム，高流量酸素のリスク，原因検索の重要性をわかりやすく整理．麻酔科専門医試験対策や周術期管理チーム試験対策．

Functional Residual Capacity (FRC = RV + ERV) is the lung volume at end-tidal expiration, where lung and chest wall forces balance. It acts as an intrathoracic oxygen tank, crucial for safe apnea. General anesthesia, obesity, pregnancy, and supine positioning all reduce FRC, predisposing patients to atelectasis and hypoxemia. Preoxygenation and PEEP help preserve FRC and extend safe apnea time.

機能的残気量（FRC）とは何か？残気量との違い，測定法，標準値，低下させる因子，そして臨床での意味をわかりやすく解説しました．周術期管理チーム試験対策・麻酔科専門医試験対策に役立ちます．

Why epinephrine for anaphylaxis? This article explains the mechanisms—α1 vasoconstriction, β1 cardiac support, β2 bronchodilation, and mediator suppression. We also review administration routes, pharmacokinetics, and safety considerations, with reference to major guidelines.