慢性疼痛を有する高齢者の術前評価と周術期管理

The Preoperative Assessment and Perioperative Risk Management of Chronic Pain in the Elderly

はじめに

　高齢者において慢性疼痛の有病率は40％前後と報告されており^1）2），術前評価時に鎮痛薬を常用している患者も少なくない。特に腰痛，肩関節痛，頸部痛，膝関節痛などの筋骨格系疼痛は加齢に伴って増加する^1）～3）が，“年のせい” とみなされ，十分な評価が行われないことも多い^4）。麻酔科医が術前評価を行う際にも，慢性疼痛の有無を詳細に確認する機会は限られているのが現状である。

　しかし慢性疼痛は術後回復や合併症発生に多大な影響を及ぼしうる潜在的な危険因子である。わが国では急速に高齢化が進行しており，2030年には65歳以上の人口が全人口の約1/3を占めると推計されている。高齢者に対する外科手術も増加すると予想され，術前評価における慢性疼痛の意義は一層重要となっている。本論文では慢性疼痛を有する高齢者の術前評価と周術期管理に焦点を当て，慢性疼痛が周術期転帰に及ぼす影響を整理し，実際の対応を考察する。

　Chronic pain is highly prevalent among the elderly, and many patients who are at an advanced age are already regularly taking analgesics when they are about to undergo surgery. Although musculoskeletal pain is common among elderly patients it is often under-evaluated, dismissed as a normal part of aging. This paper reviews chronic pain’s multifaceted impact on perioperative outcomes, highlighting its significance as a major factor for several types of risk. For example, links between chronic pain and multiple perioperative risks have been observed. Multisite chronic pain（MCP）not only increases the risk of severe postoperative pain；it also accelerates the frailty cycle through reduced physical activity and social isolation. Frailty is a key predictor of adverse outcomes, including increased mortality, complications, and prolonged hospital stays. Chronic pain is also an independent cardiovascular risk factor, potentially surpassing diabetes in its impact. The polypharmacy that is often observed in elderly patients（i.e., multiple medications for pain and other conditions）increases the risk of adverse drug events and postoperative delirium. Polypharmacy is also a reported risk factor for postoperative cognitive dysfunction（POCD）.

　Given these implications, it is crucial to screen for chronic pain during elderly patients’ preoperative assessments, with regular analgesic use being a useful indicator of chronic pain. The perioperative management in this population should focus on a multimodal approach for achieving effective pain control, minimizing opioid use, and maintaining the patient’s physical and cognitive function. This involves comprehensive pain management, early mobilization, and careful polypharmacy management. A collaborative, multidisciplinary approach is essential to improve the safety and quality of life for older patients undergoing surgery.