Abstract：
Arterial blood pressure is one of the vital signs monitored mandatory in anaesthetised patients. Even short episodes of intraoperative hypotension are associated with increased risk for postoperative organ dysfunction such as acute kidney injury and myocardial injury. Since there is little evidence whether higher alarm thresholds in patient monitors can help prevent intraoperative hypotension, we analysed the blood pressure data before (group 1) and after (group 2) the implementation of altered hypotension alarm settings. The study was conducted as a retrospective observational cohort study in a large surgical centre with 32 operating theatres. Alarm thresholds for hypotension alarm for mean arterial pressure (MAP) were altered from 60 (before) to 65 mmHg for invasive measurement and 70 mmHg for noninvasive measurement. Blood pressure data from electronic anaesthesia records of 4222 patients (1982 and 2240 in group 1 and 2, respectively) with 406,623 blood pressure values undergoing noncardiac surgery were included. We analysed (A) the proportion of blood pressure measurements below the threshold among all measurements by quasi-binomial regression and (B) whether at least one blood pressure measurement below the threshold occurred by logistic regression. Hypotension was defined as MAP < 65 mmHg. There was no significant difference in overall proportions of hypotensive episodes for mean arterial pressure before and after the adjustment of alarm settings (mean proportion of values below 65 mmHg were 6.05% in group 1 and 5.99% in group 2). The risk of ever experiencing a hypotensive episode during anaesthesia was significantly lower in group 2 with an odds ratio of 0.84 (p = 0.029). In conclusion, higher alarm thresholds do not generally lead to less hypotensive episodes perioperatively. There was a slight but significant reduction of the occurrence of intraoperative hypotension in the presence of higher thresholds for blood pressure alarms. However, this reduction only seems to be present in patients with very few hypotensive episodes.
摘要：
动脉血压是麻醉患者必须监测的生命体征之一。即使是短时间的术中低血压也会增加术后器官功能障碍的风险，例如急性肾损伤和心肌损伤。由于几乎没有证据表明患者监护仪中更高的警报阈值是否有助于预防术中低血压，我们分析了低血压警报设置改变之前(第1组)和之后(第2组)的血压数据.该研究是在一个拥有32个手术室的大型外科中心进行的回顾性观察性队列研究。平均动脉压（MAP）低血压警报的警报阈值从60（之前）更改为65mmHg，用于有创测量，用于无创测量。包括4222例患者（第1组和第2组分别为1982年和2240年）的电子麻醉记录中的血压数据，其中有406,623例血压值接受非心脏手术。我们通过准二项回归分析了（A）在所有测量中低于阈值的血压测量值的比例，以及（B）通过逻辑回归分析了是否发生了至少一个低于阈值的血压测量值。低血压定义为MAP<65mmHg。在调整警报设置之前和之后，平均动脉压的低血压发作的总体比例没有显着差异（低于65mmHg的值的平均比例在第1组中为6.05％，在第2组中为5.99％）。在第2组中，在麻醉期间经历低血压发作的风险显着降低，比值比为0.84（p=0.029）。总之,较高的警报阈值通常不会导致围手术期低血压发作较少。在存在较高血压警报阈值的情况下，术中低血压的发生率略有但显着降低。然而,这种减少似乎只存在于很少有低血压发作的患者中.
