Barnes A M, Frantz R A
College of Nursing, University of Iowa, Iowa City, USA.
AANA J. 2000 Apr;68(2):153-61.
The purposes of this study were to (1) describe the microenvironment in terms of oxygen concentration beneath the drapes of healthy subjects who were simulating patients undergoing minor surgical procedures with supplemental oxygen and to (2) evaluate the efficacy of using a scavenger system beneath the drapes. A convenience sample of 12 healthy volunteer subjects was studied in an ambulatory surgery center operating room, which was ventilated with 25 air exchanges per hour. The study was carried out in 2 parts. Each subject was supine, and oxygen was applied by a standard nondivided nasal cannula. The subjects were draped as routinely done for ophthalmic procedures. Oxygen concentrations were measured by using an Ohmeda Rascal II gas analyzer beneath the drapes and at the hypothetical surgical site with oxygen flow rates of 0, 1, 2, 3, and 4 L/min, allowing 5 minutes to elapse after a change in flow rate was made. Following a 10-minute break, the subjects were redraped, and the procedure was repeated using a scavenger system consisting of a suctioning system connected to wall suction at 170 to 190 mm Hg. Although the mean +/- SD oxygen saturation never fell below 95% (97.75% +/- 1.54%), mean +/- SD oxygen concentrations beneath the drapes were lower than normal room air concentrations (19.08% +/- 0.51%) when no oxygen was delivered to the patient. With supplemental oxygen and no scavenger system, oxygen concentrations beneath the drapes were consistently elevated (as high as 45% with 4 L/min) compared with normal ambient concentrations (21%) or with concentrations obtained at the surgical site (as high as 23.4%). With the scavenger system in place, mean +/- SD oxygen concentrations reached 34.08% +/- 5.52% beneath the drapes. Statistical analyses revealed that significantly higher oxygen concentrations occurred beneath the drapes with each incremental change in oxygen flow rate, and regardless of the oxygen flow rate used, oxygen concentrations beneath the drapes were significantly reduced with the use of the scavenger system.
（1）描述在模拟接受补充氧气的小型外科手术患者的健康受试者手术单下的氧气浓度方面的微环境，以及（2）评估在手术单下使用清除系统的效果。在一个每小时进行25次空气交换通风的门诊手术中心手术室，对12名健康志愿者受试者的便利样本进行了研究。该研究分两部分进行。每个受试者仰卧，通过标准的未分开的鼻导管给予氧气。受试者按照眼科手术的常规方式进行铺单。在氧气流速为0、1、2、3和4升/分钟的情况下，使用Ohmeda Rascal II气体分析仪在手术单下和假设的手术部位测量氧气浓度，在流速改变后等待5分钟。休息10分钟后，重新为受试者铺单，并使用由连接到170至190毫米汞柱壁式吸引器的抽吸系统组成的清除系统重复该过程。尽管平均±标准差血氧饱和度从未低于95%（97.75%±1.54%），但在不给患者输送氧气时，手术单下的平均±标准差氧气浓度低于正常室内空气浓度（19.08%±0.51%）。与正常环境浓度（21%）或在手术部位获得的浓度（高达23.4%）相比，在补充氧气且没有清除系统的情况下，手术单下的氧气浓度持续升高（4升/分钟时高达45%）。使用清除系统时，手术单下的平均±标准差氧气浓度达到34.08%±5.52%。统计分析表明，随着氧气流速的每一次增加，手术单下的氧气浓度显著升高，并且无论使用何种氧气流速，使用清除系统时手术单下的氧气浓度均显著降低。
