Marvin G Chang, Takashi Sakano, Benjamin S Levin, David Convissar, Edward A Bittner
{"title":"Reduced Effective Oxygen Delivery and Ventilation with a Surgical Facemask Placed under Compared to over an Oxygen Mask: A Comparative Study.","authors":"Marvin G Chang, Takashi Sakano, Benjamin S Levin, David Convissar, Edward A Bittner","doi":"10.1155/2022/4798993","DOIUrl":null,"url":null,"abstract":"<p><strong>Objectives: </strong>Consensus guidelines for perioperative anesthesia management during the COVID-19 pandemic recommend that patients wear a facemask in addition to their oxygen mask or nasal cannulae following tracheal extubation, where this is practical. The effects on effective oxygen delivery and ventilation of a surgical facemask under compared to over an oxygen (O<sub>2</sub>) mask are unclear.</p><p><strong>Design: </strong>Single-center, comparative pilot study. <i>Setting</i>. Endoscopy procedure room at a major academic hospital.</p><p><strong>Subjects: </strong>Five healthy anesthesiologists. <i>Interventions</i>. Using a carbon dioxide (CO<sub>2</sub>) sampling line positioned at the lips, the fraction of inspired O<sub>2</sub> (FiO<sub>2</sub>), fraction of expiratory O<sub>2</sub> (FeO<sub>2</sub>), expiratory end-tidal CO<sub>2</sub> (EtCO<sub>2</sub>), and respiratory rate (RR) were measured under the following conditions: (1) a surgical facemask only, (2) a surgical facemask under an O<sub>2</sub> mask, (3) an O<sub>2</sub> mask only, and (4) a surgical facemask over an O<sub>2</sub> mask. <i>Measurements and Main Results</i>. The sampled fractional expired oxygen (FeO<sub>2</sub>) at the lips was significantly lower when the surgical facemask was under compared to when over the O<sub>2</sub> mask (27.9± 1.68 vs. 49.9 ± 6.27, <i>p</i> = 0.001), while there was no significant difference in inspired oxygen (FiO<sub>2</sub>). The sampled expiratory EtCO<sub>2</sub> was significantly higher when the surgical facemask was under the O<sub>2</sub> mask compared to when over the O<sub>2</sub> mask (28.3 ± 8.5 vs. 23.5 ± 7.6, <i>p</i> = 0.026). The RR was not significantly different when the surgical facemask was under compared to over the O<sub>2</sub> mask.</p><p><strong>Conclusions: </strong>Effective oxygen delivery and ventilation was reduced (lower FeO<sub>2</sub> and increased EtCO<sub>2</sub>) when a surgical facemask was placed under compared to over an O<sub>2</sub> mask.</p>","PeriodicalId":7834,"journal":{"name":"Anesthesiology Research and Practice","volume":" ","pages":"4798993"},"PeriodicalIF":1.6000,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8777390/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Anesthesiology Research and Practice","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1155/2022/4798993","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2022/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"ANESTHESIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives: Consensus guidelines for perioperative anesthesia management during the COVID-19 pandemic recommend that patients wear a facemask in addition to their oxygen mask or nasal cannulae following tracheal extubation, where this is practical. The effects on effective oxygen delivery and ventilation of a surgical facemask under compared to over an oxygen (O2) mask are unclear.
Design: Single-center, comparative pilot study. Setting. Endoscopy procedure room at a major academic hospital.
Subjects: Five healthy anesthesiologists. Interventions. Using a carbon dioxide (CO2) sampling line positioned at the lips, the fraction of inspired O2 (FiO2), fraction of expiratory O2 (FeO2), expiratory end-tidal CO2 (EtCO2), and respiratory rate (RR) were measured under the following conditions: (1) a surgical facemask only, (2) a surgical facemask under an O2 mask, (3) an O2 mask only, and (4) a surgical facemask over an O2 mask. Measurements and Main Results. The sampled fractional expired oxygen (FeO2) at the lips was significantly lower when the surgical facemask was under compared to when over the O2 mask (27.9± 1.68 vs. 49.9 ± 6.27, p = 0.001), while there was no significant difference in inspired oxygen (FiO2). The sampled expiratory EtCO2 was significantly higher when the surgical facemask was under the O2 mask compared to when over the O2 mask (28.3 ± 8.5 vs. 23.5 ± 7.6, p = 0.026). The RR was not significantly different when the surgical facemask was under compared to over the O2 mask.
Conclusions: Effective oxygen delivery and ventilation was reduced (lower FeO2 and increased EtCO2) when a surgical facemask was placed under compared to over an O2 mask.