Department of Emergency Medicine, Lincoln Medical Center, Bronx, NY.
Department of Emergency Medicine, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia.
Ann Emerg Med. 2019 Sep;74(3):410-415. doi: 10.1016/j.annemergmed.2019.01.038. Epub 2019 Mar 14.
Preoxygenation is important to prevent oxygen desaturation during emergency airway management. The purpose of this study is to describe the use of end tidal oxygen (eto) during rapid sequence intubation in the emergency department.
This study was carried out in 2 academic centers in Sydney, Australia, and New York City. We included patients undergoing rapid sequence intubation in the emergency department. A standard gas analyzer was used to measure eto. Preoxygenation methods included nonrebreather mask and bag-valve-mask ventilation. We measured eto before preoxygenation and at administration of rapid sequence intubation medications. We also characterized peri-intubation SpO, identifying instances of SpO less than 90%.
We included 100 patients during a 6-month period. Median eto level before and after preoxygenation was 53% (interquartile range [IQR] 43% to 65%) and 78% (IQR 64% to 86%), respectively. One fourth of patients achieved an eto level greater than 85%. Median eto level achieved varied with preoxygenation method, ranging from 80% (IQR 60% to 87%) for the nonrebreather mask group to 77% (IQR 65% to 86%) for the bag-valve-mask group. The method with the highest median eto level was nonrebreather mask at flush rate (86%; IQR 80% to 90%) and the lowest median eto level was nonrebreather mask at 15 L/min (57%; IQR 53% to 60%). Eighteen patients (18%) experienced oxygen desaturation (SpO <90%); of these, 14 (78%) did not reach an eto level greater than 85% at induction.
ETO varied with different preoxygenation techniques employed in the emergency department. Most patients undergoing rapid sequence intubation did not achieve maximal preoxygenation. Measuring ETO in the emergency department may be a valuable adjunct for optimizing preoxygenation during emergency airway management.
预充氧对于防止紧急气道管理期间的氧饱和度降低很重要。本研究的目的是描述在急诊科进行快速序贯插管时使用呼气末氧（ETO）的情况。
本研究在澳大利亚悉尼和纽约市的 2 个学术中心进行，纳入在急诊科行快速序贯插管的患者。使用标准气体分析仪测量 ETO。预充氧方法包括无重复呼吸面罩和球囊-面罩通气。我们在预充氧前和快速序贯插管药物给药时测量 ETO。我们还对插管期间的 SpO2 进行了特征描述，确定了 SpO2 低于 90%的情况。
在 6 个月的时间里，我们纳入了 100 名患者。预充氧前后 ETO 水平的中位数分别为 53%（四分位距[IQR] 43%65%）和 78%（IQR 64%86%）。四分之一的患者 ETO 水平大于 85%。不同预充氧方法的 ETO 水平中位数不同，范围从无重复呼吸面罩组的 80%（IQR 60%87%）到球囊-面罩通气组的 77%（IQR 65%86%）。ETO 水平最高的方法是冲洗速率下的无重复呼吸面罩（86%；IQR 80%90%），最低的是 15 L/min 下的无重复呼吸面罩（57%；IQR 53%60%）。18 名患者（18%）出现氧饱和度降低（SpO2<90%）；其中 14 名（78%）在诱导时 ETO 水平未超过 85%。
ETO 随急诊科使用的不同预充氧技术而变化。大多数行快速序贯插管的患者并未达到最大预充氧。在急诊科测量 ETO 可能是优化紧急气道管理期间预充氧的有价值的辅助手段。
