Bathe Janina, Malik Sadia, Pinnschmidt Hans O, Zitzmann Amelie, Behem Christoph R, Trepte Constantin C, Reuter Daniel A
Center of Anaesthesiology and Intensive Care Medicine, Hamburg-Eppendorf University Medical Center, Martinistr. 52, 20246, Hamburg, Germany.
Institute for Biostatistics, Hamburg-Eppendorf University Medical Center, Hamburg, Germany.
J Clin Monit Comput. 2022 Dec;36(6):1767-1774. doi: 10.1007/s10877-022-00825-1. Epub 2022 Feb 15.
Preoxygenation is a crucial manoeuvre for patients' safety, particularly for morbidly obese patients due to their reduced pulmonary reserve and increased risk for difficult airway situations. The oxygen reserve index (ORI™) was recently introduced as a new parameter of multiple wavelength pulse oximetry and has been advocated to allow assessment of hyperoxia [quantified by the resulting arterial oxygen partial pressure (PaO)]. This study investigates if ORI can be used to evaluate the impact of two different preoxygenation manoeuvres on the grade of hyperoxia. Two preoxygenation manoeuvres were sequentially evaluated in 41 morbidly obese patients: First, breathing 100% oxygen for 5 min via standard face mask. Second, after achieving a second baseline, 5 min of non-invasive ventilation (NIV) with 100% oxygen. The effect of preoxygenation on ORI compared to PaO was evaluated and whether differences in the two preoxygenation manoeuvres can be monitored by ORI. Overall correlation of PaO and ORI was significant (Spearman-Rho coefficient of correlation 0.818, p < 0.001). However, ORI could not differentiate between the two preoxygenation manoeuvres although the PaO values for NIV preoxygenation were significantly higher compared to standard preoxygenation (median 505 mmHg (M1) vs. 550 mmHg (M3); p < 0.0001). In contrast, ORI values did not differ significantly (median 0.39 (M1) vs. 0.38 (M3); p = 0.758). Absolute values of ORI cannot be used to assess effectiveness of a preoxygenation procedure in bariatric patients, mainly because its range of discrimination is considerably lower than the high ranges of PaO attained by adequate preoxygenation. Trial registration German Clinical Trials Register: DRKS00025023 (retrospectively registered on April 16th, 2021).
预给氧是保障患者安全的关键操作，对于病态肥胖患者而言尤为重要，因为他们的肺储备功能降低，气道困难情况的风险增加。氧储备指数（ORI™）最近作为多波长脉搏血氧饱和度测定的一个新参数被引入，并被提倡用于评估高氧血症[通过所得动脉血氧分压（PaO）进行量化]。本研究调查ORI是否可用于评估两种不同预给氧操作对高氧血症程度的影响。对41例病态肥胖患者依次评估了两种预给氧操作：首先，通过标准面罩呼吸100%氧气5分钟。其次，在达到第二个基线后，进行5分钟的100%氧气无创通气（NIV）。评估了预给氧对ORI与PaO的影响，以及ORI是否能监测两种预给氧操作之间的差异。PaO与ORI的总体相关性显著（Spearman-Rho相关系数为0.818，p < 0.001）。然而，尽管NIV预给氧的PaO值与标准预给氧相比显著更高（中位数505 mmHg（M1）对550 mmHg（M3）；p < 0.0001），但ORI无法区分这两种预给氧操作。相比之下，ORI值无显著差异（中位数0.39（M1）对0.38（M3）；p = 0.758）。ORI的绝对值不能用于评估肥胖患者预给氧程序的有效性，主要是因为其区分范围远低于适当预给氧所达到的高PaO范围。试验注册 德国临床试验注册中心：DRKS00025023（于2021年4月16日追溯注册）。
