術後血圧管理の取り組み

Strategies for Postoperative Blood Pressure Management

はじめに

　周術期管理において，術中低血圧（intraoperative hypotension：IOH）は非心臓手術後心筋傷害（myocardial injury after noncardiac surgery：MINS）や急性腎障害（acute kidney injury：AKI）などの主要臓器合併症と関連することが知られている^1）。一方で，術後低血圧（postoperative hypotension：POH）の体系的検討は遅れていた。近年，POHがMINS，AKI，脳梗塞と関連が示唆されることが報告され，IOHに加えてPOHを周術期管理の対象として位置づける必要がある^2）～5）。POHは病因が多様で見過ごされやすく，予防と管理は新たな課題である。

　本論文では，POHの定義，頻度，複数の関連病因，主要臓器転帰との関連を概説する。加えて，当院で運用しているPOH管理プロトコル（術前のMINSハイリスク抽出，統一循環管理目標，術後高度治療室（high care unit：HCU）でのノルアドレナリン・スケール運用）を紹介し，エビデンスの臨床応用と課題を考察する。

　In perioperative patient management, intraoperative hypotension（IOH）is well known to be associated with major organ complications such as myocardial injury after non-cardiac surgery（MINS）and acute kidney injury（AKI）. There have been few systematic investigations of postoperative hypotension（POH）. Recent evidence suggests that POH is also associated with MINS, AKI, and stroke, indicating the need to address both IOH and POH in perioperative care. POH arises from diverse etiologies ranging from residual anesthesia effects and bleeding to autonomic dysfunction, and it is often overlooked, making its prevention and management a clinical challenge. This review summarizes the current definitions, incidence, etiologic factors, and organ outcomes related to POH. We also introduce our institutional protocol for POH management, which includes the preoperative identification of the risk of MINS development, standardized hemodynamic targets, and postoperative norepinephrine scale management in the high-care unit. We then discuss the clinical applications of emerging evidence and the remaining challenges in optimizing postoperative blood pressure control.