Anand Gurpreet W, Heuss Ludwig T
Gurpreet W Anand, Ludwig T Heuss, Division of Internal Medicine, Zollikerberg Hospital, 8125 Zollikerberg/Zurich, Switzerland.
World J Gastrointest Endosc. 2014 Mar 16;6(3):82-7. doi: 10.4253/wjge.v6.i3.82.
To determine whether a newly developed respiratory rate monitor can practically and accurately monitor ventilation under propofol sedation in combination with standard monitoring.
Patients [American Society of Anesthesiologists (ASA) Classification I-III] scheduled for elective colonoscopy under propofol sedation were monitored with a new device that measures the respiratory rate based on humidity in expired air. Patients with clinically significant cardiac disorders or pulmonary disease and patients requiring emergency procedures were excluded from study participation. All of the patients also received standard monitoring with pulse oximetry. This was a single-center study conducted in a community hospital in Switzerland. After obtaining written informed consent from all subjects, 76 patients (51 females and 25 males) were monitored during colonoscopy under propofol sedation. The primary endpoint was the occurrence of any respiratory event (apnea or hypopnea). Apnea was defined as the cessation of breathing for a minimum of 10 s. Significant apnea was defined as the cessation of breathing for more than 30 s. Hypopnea was defined as a reduction in the respiratory rate below 6/min for a minimum of 10 s. Any cases of significant apnea triggered interventions by the endoscopy team. The interventions included withholding propofol, verbal stimulation of the patients, and increased oxygen supplementation or the chin lift maneuver. A secondary endpoint was the correlation of apnea or hypopnea with hypoxemia (measured as a decrease in SaO2 of at least 5% from baseline or less than 90%).
At least one respiratory event was detected in thirty-seven patients (48.7%). In total, there were 73 respiratory events, ranging from one to six events in a single patient. Significant apnea (> 30 s) occurred in five patients (6%). Only one episode of apnea led to a relative SaO2 reduction (from 98% to 93%) after a 50 s lag time. No event requiring assisted ventilation was recorded. Our analysis revealed that the total propofol dose was an independent risk factor for respiratory events (P = 0.01). Artifacts developed with the same frequency with the new device as with conventional pulse oximetry. Compared with pulse oximetry alone, this new monitoring device detected more respiratory events and may provide earlier warning of impending respiratory abnormalities.
Apnea commonly occurs during endoscopy under sedation and may precede hypoxemia. We recommend this respiration rate monitor as an alternative to capnography to aid in detecting ventilatory problems.
确定一种新开发的呼吸频率监测仪能否在丙泊酚镇静联合标准监测下切实准确地监测通气情况。
计划在丙泊酚镇静下进行择期结肠镜检查的患者[美国麻醉医师协会（ASA）分级I - III级]，使用一种基于呼出气体湿度测量呼吸频率的新设备进行监测。患有具有临床意义的心脏疾病或肺部疾病的患者以及需要急诊手术的患者被排除在研究之外。所有患者还接受脉搏血氧饱和度标准监测。这是一项在瑞士一家社区医院进行的单中心研究。在获得所有受试者的书面知情同意后，76例患者（51例女性和25例男性）在丙泊酚镇静下进行结肠镜检查期间接受监测。主要终点是任何呼吸事件（呼吸暂停或呼吸不足）的发生。呼吸暂停定义为呼吸停止至少10秒。严重呼吸暂停定义为呼吸停止超过30秒。呼吸不足定义为呼吸频率降至6次/分钟以下至少10秒。任何严重呼吸暂停病例均会引发内镜检查团队的干预。干预措施包括停用丙泊酚、对患者进行言语刺激以及增加氧气补充或抬下颌动作。次要终点是呼吸暂停或呼吸不足与低氧血症的相关性（定义为血氧饱和度（SaO₂）较基线下降至少5%或低于90%）。
37例患者（48.7%）检测到至少一次呼吸事件。总共发生了73次呼吸事件，单个患者的事件数从1次到6次不等。5例患者（6%）出现严重呼吸暂停（>30秒）。仅1次呼吸暂停事件在延迟50秒后导致血氧饱和度相对下降（从98%降至93%）。未记录到需要辅助通气的事件。我们的分析显示，丙泊酚总剂量是呼吸事件的独立危险因素（P = 0.01）。新设备出现伪差的频率与传统脉搏血氧饱和度监测仪相同。与单独使用脉搏血氧饱和度监测相比，这种新的监测设备检测到更多呼吸事件，可能为即将发生的呼吸异常提供更早的预警。
镇静下内镜检查期间常出现呼吸暂停，且可能先于低氧血症出现。我们推荐这种呼吸频率监测仪作为二氧化碳监测的替代方法，以帮助检测通气问题。
