氧流量对可用于监测呼吸频率吸氧管监测效果的影响

Effects of different concentrations of oxygen flow on respiratory rate monitoring through anesthesia monitor

目的探讨吸入不同氧流量对可用于监测呼吸频率吸氧管监测效果的影响。方法选择在椎管内麻醉下行下肢手术的患者270例，年龄18～60岁，体重55～85kg，美国麻醉医师协会分级I或Ⅱ级。采用随机数字表法将患者分为对照组、研究1组、研究2组、研究3组、研究4组、研究5组共6组，每组45例。所有患者行椎管内麻醉后取平卧位，接鼻氧管吸氧，研究1组、研究2组、研究3组、研究4组和研究5组的氧气流量分别为1、2、3、4、5L／min，对照组只接鼻氧管不吸氧气。20min后，通过吸氧管的二氧化碳采集端连接麻醉监护仪，采集患者的呼吸频率和呼气末二氧化碳分压（petCO2），同时记录脉搏血氧饱和度（SpO2）。经桡动脉取动脉血进行血气分析检测动脉血氧分压（paCO2）和二氧化碳分压（paCO2），同时目测计数患者的呼吸频率。结果各研究组的SpO2和PaO2均显著高于对照组（P值均〈0．05），研究2组、研究3组、研究4组、研究5组的PetCO2均显著低于对照组（P值均〈0．05），研究3组、研究4组、研究5组监护仪测得的呼吸频率均显著低于对照组（P值均〈0．05）。研究3组、研究4组、研究5组的PetCO2显著低于同组paCO2（P值均〈0．05），研究4组、研究5组监护仪测得的呼吸频率显著低于同组目测计数的呼吸频率（P值均〈0．05）。结论应用可用于监测呼吸频率吸氧管吸氧时，给予3L／min氧气流量，麻醉监护仪可准确监测患者的呼吸频率。

Objective To observe the effects of different concentrations of oxygen flow on respiratory rate （RR） monitoring. Methods A total of 270 patients, American Society of Anesthesiologists （ASA） physical status Ⅰ or Ⅱ, aged 18-60 years, weighing 55-85 kg and undergoing lower extremity operation under spinal anesthesia, were randomly divided into 6 groups （n = 45 each）. Nasal catheter was connected in all the patients and oxygen （1, 2, 3, 4, and 5 L/min） were given in groups A, B, C, D and E, respectively, but no oxygen were given in control group. The anesthesia monitor was connected at the CO2collection port after 20 minutes, and the RR, partial pressure of carbon dioxide in end expiratory gas （petCO2）, and saturation of pulse oximetry （SpO2） were recorded. Radial artery blood was collected for blood gas analysis, and arterial partial pressure of oxygen （paO2） and partial pressure of carbon dioxide （paCOz） were measured. Meanwhile, RR was determined visually. Results SpO2 and p,O2 in groups A, B, C, D and E were significantly higher than those in the control group （all P〈0.05）. petCO2 in groups B, C, D and E were significantly lower than that in the control group （all P〈0.05）. RR measured by anesthesia monitor in groups C, D and E was significantly lower than that in the control group （all P〈0. 05）. petCO2 were significantly lower than paCO2 in groups C, D were E （all P〈0.05）. RR recorded by anesthesia monitor were significantly lower than RR determined by visual in groups D and E （both P〈0.05）. Conclusion The respiratory rate can be accurately monitored by anesthesia monitor when 3 L/min oxygen flow is given through nasal catheter in patients undergoing lower extremity operation. （Shanghai Med J, 2016, 39： 356-358）