Oxygen Reserve Index™ (ORi™)

Oxygen Reserve Index™ (ORi™)

Clinical Evidence

Assessing the incidence of hyperoxia and the effectiveness of Oxygen Reserve Index-guided FiO2 titration in hyperoxia prevention

Sarıtaş PU, Sarıtaş A, Poyraz MÇ, Aydın G.  Perioper Med (Lond). 2024 Oct 7;13(1):99. doi: 10.1186/s13741-024-00456-x. 

Oxygen reserve index vs. peripheral oxygen saturation for the prediction of hypoxemia in morbidly obese patients: a prospective observational study

Saraçoğlu KT, Arslan G, Saraçoğlu A, Sezen Ö, Ratajczyk P, Gaszynski T. BMC Anesthesiol. 2024 Oct 11;24(1):367. doi: 10.1186/s12871-024-02755-8.

Oxygen titration with Oxygen Reserve Index in minimally invasive repair of pectus excavatum, a randomized controlled trial

Mirzayev A, Cakmak G, Abdullayev R, Lacin T, Aykac Z, Saracoglu A. North Clin Istanb. 2024 Sep 11;11(5):382-390. doi: 10.14744/nci.2023.45556. 

Evaluation of oxygen administration in cesarean section under spinal anesthesia via lung ultrasound and the oxygen reserve index

Canıtez MA, Ayoğlu H, Okyay RD, Bollucuoğlu K, Baytar Ç, Çeviker G, Küçükosman G, İncegül BG, Pişkin Ö. BMC Anesthesiol. 2024 Aug 8;24:277. doi: 10.1186/s12871-024-02669-5.

Role of oxygen reserve index monitoring in patients undergoing robot-assisted radical prostatectomy: a retrospective study

Ryu JH, Jeon YT, Sim KM, Lee S, Oh AY, Koo CH. World J Urol. 2024 Apr 13;42(1):232. doi: 10.1007/s00345-024-04938-x.

High, Low, and Minimal Flow Anaesthesia Management: Effects on Oxygen Reserve Index and Arterial Partial Oxygen Pressure.

Dastan R, Kefeli Celik H, Doganay Z. J Coll Physicians Surg Pak. 2023 Nov;33(11):1223-1228. doi: 10.29271/jcpsp.2023.11.1223. 

Association between Oxygen Reserve index and arterial partial pressure of oxygen during one-lung ventilation: a retrospective cohort study

Bang YJ, Seong Y, Jeong H. J Anesth. 2023 Oct 3. doi: 10.1007/s00540-023-03259-4.

Evaluation of the relationship between the stop-bang score with oxygen reserve index and difficult airway: a prospective observational study

Alp ID, Köksal BG, Bollucuoğlu K, Küçükosman G, Pişkin Ö, Baytar Ç, Okyay RD, Ayoğlu H. Brazilian Journal of Anesthesiology (English Edition). 2023 Jul 28.

Is there value in measuring oxygen reserve index during rapid sequence induction for cesarean delivery

Lee S, You AH, Choi JH. Is there value in measuring oxygen reserve index during rapid sequence induction for cesarean delivery? J Obstet Gynaecol Res. 2023 Jan 4. doi: 10.1111/jog.15547.

Investigation of preoxygenation methods in cesarean surgeries with the oxygen reserve index

Kocakulak D, Küçükosman G, Köksal BG, Baytar Ç, Okyay RD, Bollucuoğlu K, Öztürk T, Pişkin Ö, Ayoğlu H. Saudi Med J. 2022 Dec;43(12):1317-1323. doi: 10.15537/smj.2022.43.12.20220548.

Oxygen reserve index guided fraction of inspired oxygen titration to reduce hyperoxemia during laparoscopic gastrectomy: A randomized controlled trial

Ahn JH, Shim JG, Park J, Lee SH, Ryu KH, Cho EA. Medicine (Baltimore). 2022 Nov 18;101(46):e31592. doi: 10.1097/MD.0000000000031592.

Heart rate variability and oxygen reserve index during cardiorespiratory events in patients undergoing ophthalmic arterial chemotherapy: a prospective observational study

Cho YJ, Jung DE, Oh Y, Nam K, Lee HC, Jeon Y, Cho YD, Kim TK. J Clin Monit Comput. 2022 Apr;36(2):557-567. doi: 10.1007/s10877-021-00687-z. Epub 2021 Mar 18. 

Evaluation of Oxygenation in Low- and High-Flow Anesthesia Applications by Oxygen Reserve Index: A Randomized Prospective Study

Oztoprak H, Kucukosman G, Aydin BG, Okyay RD, Piskin O, Ayoglu H. Med Bull Haseki. 2022;60:104-112. doi: 10.4274/haseki.galenos.2022.7753.

Oxygen reserve index for non-invasive early hypoxemia detection during endotracheal intubation in intensive care: the prospective observational NESOI study

Hille H, Le Thuaut A, Canet E, et al.

The use of oxygen reserve index in one-lung ventilation and its impact on peripheral oxygen saturation, perfusion index and, pleth variability index

Sagiroglu G, Baysal A, Karamustafaoglu YA. BMC Anesthesiol. 2021;21(1):319. doi:10.1186/s12871-021-01539-8

ORi™: a new indicator of oxygenation

Ishida Y, Okada T, Kobayashi T, Uchino H. [published online ahead of print, 2021 Apr 26]. J Anesth. 2021;1-7. doi:10.1007/s00540-021-02938-4

Oxygen Reserve Index Guided Oxygen Titration in One Lung Ventilation With Low Fresh Gas Flow

Saraçoğlu A, Yamansavci Şirzai E, Yildizeli B, Yüksel M, Aykaç ZZ. Turk J Med Sci. 2021;10.3906/sag-2009-149. doi:10.3906/sag-2009-149.

Oxygen Reserve Index: Utility as an Early Warning for Desaturation in High-Risk Surgical Patients

Neal W Fleming, Amrik Singh, Leonard Lee, Richard L Applegate 2nd Anesth Analg. 2020 Aug 12.

Study of early warning for desaturation provided by Oxygen Reserve Index in obese patients

Tsymbal E, Ayala S, Singh A, Applegate RL 2nd, Fleming NW. [published online ahead of print, 2020 May 18]. J Clin Monit Comput. 2020;10. doi:10.1007/s10877-020-00531-w

Oxygen Reserve Index Predicts Hypoxemia During One-Lung Ventilation: An Observational Diagnostic Study.

Alday E, Nieves JM, Planas A. J Cardiothorac VascAnesth. 2020 Feb;34(2):417-422.

Oxygen reserve index (ORi™) contributes to prediction of hypoxemia and patient safety during tracheal stent insertion using rigid bronchoscopy: a case report.

Niwa Y, Shiba J, Fujita H, Oka R, Takeuchi M. J Clin Monit Comput. 2018 Dec 5.

Effects of indigo carmine intravenous injection on oxygen reserve index (ORi™) measurement.

Isosu T, Yoshida K, Oishi R, Imaizumi T, Iseki Y, Sanbe N, Ikegami Y, Obara S, Kurosawa S, Murakawa M. J Clin Monit Comput. 2018 Aug;32(4):693-697.

Oxygen Reserve Index: Validation of a New Variable.

Vos JJ, Willems CH, van Amsterdam K, van den Berg JP, Spanjersberg R, Struys MMRF, Scheeren TWL. Anesth Analg. 2018 Aug 22.

Usefulness of oxygen reserve index (ORi™), a new parameter of oxygenation reserve potential, for rapid sequence induction of general anesthesia.

Yoshida K, Isosu T, Noji Y, Hasegawa M, Iseki Y, Oishi R, Imaizumi T, Sanbe N, Obara S, Murakawa M. J Clin Monit Comput. 2017 Sep 27.

The oxygen reserve index (ORi): a new tool to monitor oxygen therapy

Scheeren TWL, FJ Belda, A Perel. J Clin Monit Comput, 2017. DOI 10.1007/s10877-017-0049-4.

Oxygen Reserve Index: An early warning for desaturation in critically ill patients.

Lee L, Singh A, Applegate R, and Fleming N. Proceedings from the 2017 IARS Annual Meeting, Washington, DC. Abstract #A1406.

The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery.

Applegate RL 2nd, Dorotta IL, Wells B, Juma D, Applegate PM. Anesth Analg. 2016 Mar 22. [Epub ahead of print] PubMed PMID: 27007078.

Oxygen Reserve Index (ORi): validation of a new variable

Scheeren T.W.L., Spanjersberg R., Struys M.M.R.F. Proceedings from the 2016 EuroAnaesthesia Congress, London, UK. Abstract 01AP04-9.

Oxygen Reserve Index A Novel Noninvasive Measure of Oxygen Reserve—A Pilot Study.

Szmuk P, Steiner JW, Olomu, PN, Ploski, RP, Sessler, DI, Ezri, T. Anesthesiology 2016; 124:00-00. doi:10.1097/ALN.0000000000001009

Oxygen Reserve Index - a New, Noninvasive Method of Oxygen Reserve Measurement

Szmuk P, Steiner J., Olomu P., Dela Cruz J., Sessler D. American Society of Anesthesiologists 2014; BOC12.

Assessing the incidence of hyperoxia and the effectiveness of Oxygen Reserve Index-guided FiO2 titration in hyperoxia prevention

Sarıtaş PU, Sarıtaş A, Poyraz MÇ, Aydın G.  Perioper Med (Lond). 2024 Oct 7;13(1):99. doi: 10.1186/s13741-024-00456-x. 

Oxygen reserve index vs. peripheral oxygen saturation for the prediction of hypoxemia in morbidly obese patients: a prospective observational study

Saraçoğlu KT, Arslan G, Saraçoğlu A, Sezen Ö, Ratajczyk P, Gaszynski T. BMC Anesthesiol. 2024 Oct 11;24(1):367. doi: 10.1186/s12871-024-02755-8.

Oxygen titration with Oxygen Reserve Index in minimally invasive repair of pectus excavatum, a randomized controlled trial

Mirzayev A, Cakmak G, Abdullayev R, Lacin T, Aykac Z, Saracoglu A. North Clin Istanb. 2024 Sep 11;11(5):382-390. doi: 10.14744/nci.2023.45556. 

Oxygen reserve index versus conventional peripheral oxygen saturation for prevention of hypoxaemia: A randomised controlled trial

Kim EH, Park JB, Kang P, Ji SH, Jang YE, Lee JH, Kim HS, Kim JT. Eur J Anaesthesiol. 2024 Sep 1;41(9):687-694. doi: 10.1097/EJA.0000000000002018.

Evaluation of oxygen administration in cesarean section under spinal anesthesia via lung ultrasound and the oxygen reserve index

Canıtez MA, Ayoğlu H, Okyay RD, Bollucuoğlu K, Baytar Ç, Çeviker G, Küçükosman G, İncegül BG, Pişkin Ö. BMC Anesthesiol. 2024 Aug 8;24:277. doi: 10.1186/s12871-024-02669-5.

Role of oxygen reserve index monitoring in patients undergoing robot-assisted radical prostatectomy: a retrospective study

Ryu JH, Jeon YT, Sim KM, Lee S, Oh AY, Koo CH. World J Urol. 2024 Apr 13;42(1):232. doi: 10.1007/s00345-024-04938-x.

Comparison of oxygen reserve index according to the remimazolam or dexmedetomidine for intraoperative sedation under regional anesthesia-A single-blind randomized controlled trial.

Lee S, Kim M, Kang HY, Choi JH, Kim MK, You AH. Front Med (Lausanne). 2023 Nov 15;10:1288243. doi: 10.3389/fmed.2023.1288243.

Adequate Oxygenation State Maintained during Electroconvulsive Therapy in Nonobese Patients Using the Oxygen Reserve Index: A Pilot Study

Kadoi Y, Ohta J, Sasaki Y, Saito S. Case Reports in Anesthesiology. 2023 Nov 6;2023.

Investigation of the association between oxygen reserve index and arterial partial oxygen pressure in anesthetized dogs

Watanabe T, Kanno N, Suzuki S, Yogo T, Harada Y, Hara Y. Veterinary Anaesthesia and Analgesia. 2023 Sep 22.

Apnea Management During WATCHMAN Device Deployment with Apneic Oxygenation: A Case Report of Three Cases

Maeda M, Yoshikawa Y, Oura S, Takahashi K, Ohno S, Hirata N, Yamakage M. Annals of Cardiac Anaesthesia. 2023 Oct 1;26(4):458-60.

Rapid sequence induction of anesthesia: works in progress and steps forward with focus to oxygenation and monitoring techniques

Del Santo T, DI Filippo A, Romagnoli S. Minerva Anestesiol. 2023 Oct 18. doi: 10.23736/S0375-9393.23.17569-9.

Apnea Management During WATCHMAN Device Deployment with Apneic Oxygenation: A Case Report of Three Cases

Maeda M, Yoshikawa Y, Oura S, Takahashi K, Ohno S, Hirata N, Yamakage M. Annals of Cardiac Anaesthesia. 2023 Oct 1;26(4):458-60.

Association between Oxygen Reserve index and arterial partial pressure of oxygen during one-lung ventilation: a retrospective cohort study

Bang YJ, Seong Y, Jeong H. J Anesth. 2023 Oct 3. doi: 10.1007/s00540-023-03259-4.

Investigation of the association between oxygen reserve index and arterial partial oxygen pressure in anesthetized dogs

Watanabe T, Kanno N, Suzuki S, Yogo T, Harada Y, Hara Y. Veterinary Anaesthesia and Analgesia. 2023 Sep 22.

Evaluation of the relationship between the stop-bang score with oxygen reserve index and difficult airway: a prospective observational study

Alp ID, Köksal BG, Bollucuoğlu K, Küçükosman G, Pişkin Ö, Baytar Ç, Okyay RD, Ayoğlu H. Brazilian Journal of Anesthesiology (English Edition). 2023 Jul 28.

Oxygen Reserve Index and Arterial Partial Pressure of Oxygen: Relationship in Open Heart Surgery

Fadel ME, Shangab MO, Walley HE, Al Taher H, Lobo FA. J Clin Monit Comput. 2023 Apr 7. doi: 10.1007/s10877-023-01001-9.

Is there value in measuring oxygen reserve index during rapid sequence induction for cesarean delivery

Lee S, You AH, Choi JH. Is there value in measuring oxygen reserve index during rapid sequence induction for cesarean delivery? J Obstet Gynaecol Res. 2023 Jan 4. doi: 10.1111/jog.15547.

Perioperative monitoring of the oxygen reserve: where do we stand?

Massari, D., de Keijzer, I.N. & Vos, J.J. 2023. J Clin Monit Comput. https://doi.org/10.1007/s10877-023-01085-3.

Investigation of preoxygenation methods in cesarean surgeries with the oxygen reserve index

Kocakulak D, Küçükosman G, Köksal BG, Baytar Ç, Okyay RD, Bollucuoğlu K, Öztürk T, Pişkin Ö, Ayoğlu H. Saudi Med J. 2022 Dec;43(12):1317-1323. doi: 10.15537/smj.2022.43.12.20220548.

Oxygen reserve index guided fraction of inspired oxygen titration to reduce hyperoxemia during laparoscopic gastrectomy: A randomized controlled trial

Ahn JH, Shim JG, Park J, Lee SH, Ryu KH, Cho EA. Medicine (Baltimore). 2022 Nov 18;101(46):e31592. doi: 10.1097/MD.0000000000031592.

Heart rate variability and oxygen reserve index during cardiorespiratory events in patients undergoing ophthalmic arterial chemotherapy: a prospective observational study

Cho YJ, Jung DE, Oh Y, Nam K, Lee HC, Jeon Y, Cho YD, Kim TK. J Clin Monit Comput. 2022 Apr;36(2):557-567. doi: 10.1007/s10877-021-00687-z. Epub 2021 Mar 18. 

Evaluation of Oxygenation in Low- and High-Flow Anesthesia Applications by Oxygen Reserve Index: A Randomized Prospective Study

Oztoprak H, Kucukosman G, Aydin BG, Okyay RD, Piskin O, Ayoglu H. Med Bull Haseki. 2022;60:104-112. doi: 10.4274/haseki.galenos.2022.7753.

The use of oxygen reserve index in one-lung ventilation and its impact on peripheral oxygen saturation, perfusion index and, pleth variability index

Sagiroglu G, Baysal A, Karamustafaoglu YA. BMC Anesthesiol. 2021;21(1):319. doi:10.1186/s12871-021-01539-8

ORi™: a new indicator of oxygenation

Ishida Y, Okada T, Kobayashi T, Uchino H. [published online ahead of print, 2021 Apr 26]. J Anesth. 2021;1-7. doi:10.1007/s00540-021-02938-4

Oxygen Reserve Index Guided Oxygen Titration in One Lung Ventilation With Low Fresh Gas Flow

Saraçoğlu A, Yamansavci Şirzai E, Yildizeli B, Yüksel M, Aykaç ZZ. Turk J Med Sci. 2021;10.3906/sag-2009-149. doi:10.3906/sag-2009-149.

Oxygen Reserve Index Predicts Hypoxemia During One-Lung Ventilation: An Observational Diagnostic Study.

Alday E, Nieves JM, Planas A. J Cardiothorac VascAnesth. 2020 Feb;34(2):417-422.

Study of early warning for desaturation provided by Oxygen Reserve Index in obese patients

Tsymbal E, Ayala S, Singh A, Applegate RL 2nd, Fleming NW. [published online ahead of print, 2020 May 18]. J Clin Monit Comput. 2020;10. doi:10.1007/s10877-020-00531-w

Oxygen Reserve Index: Utility as an Early Warning for Desaturation in High-Risk Surgical Patients

Neal W Fleming, Amrik Singh, Leonard Lee, Richard L Applegate 2nd Anesth Analg. 2020 Aug 12.

ORI monitoring allows a reduction of time with hyperoxia in critically ill patients: the randomized control ORI study.

Lasocki S, Brochant A, Leger M, Gaillard T, Lemarié P, Gergaud S, Dupré P. Intensive Care Med. 2019 Aug 13. doi:10.1007/s00134-019-05732-9.

Adjustment of oxygen reserve index (ORi™) to avoid excessive hyperoxia during general anesthesia.

Yoshida K, Isosu T, Noji Y, Ebana H, Honda J, Sanbe N, Obara S, Murakawa M.
JCMC. 2019. https://doi.org/10.1007/s10877-019-00341-9.

Oxygen reserve index (ORi™) contributes to prediction of hypoxemia and patient safety during tracheal stent insertion using rigid bronchoscopy: a case report.

Niwa Y, Shiba J, Fujita H, Oka R, Takeuchi M. J Clin Monit Comput. 2018 Dec 5.

Evaluating Preoxygenation Using Oxygen Reserve Index (ORI™) in Healthy Adult Volunteers

Nanako Tanaka, M.S.N., Kiyoyuki Miyasaka, M.D., Katsuyuki Miyasaka, M.D.,Ph.D.
Proceedings from the Annual American Society of Anesthesiologists Meeting, San Francisco, October 2018.

Effects of indigo carmine intravenous injection on oxygen reserve index (ORi™) measurement.

Isosu T, Yoshida K, Oishi R, Imaizumi T, Iseki Y, Sanbe N, Ikegami Y, Obara S, Kurosawa S, Murakawa M. J Clin Monit Comput. 2018 Aug;32(4):693-697.

Oxygen Reserve Index: Validation of a New Variable.

Vos JJ, Willems CH, van Amsterdam K, van den Berg JP, Spanjersberg R, Struys MMRF, Scheeren TWL. Anesth Analg. 2018 Aug 22.

Monitoring the Oxygen Reserve Index can contribute to the early detection of deterioration in blood oxygenation during one-lung ventilation.

Koishi W, Kumagai M, Ogawa S, Hongo S, Suzuki K. Minverva Anestesiol. 2018 May 14.

ORi pour moins d’hyperoxie en reanimation

Brochant A, Dupre P, Gaillard T, Lemarie P, Gergaud S, and Lasocki S.. Proceedings from SFAR 2018, Paris, France. Abstract #R244.

Usefulness of oxygen reserve index (ORi™), a new parameter of oxygenation reserve potential, for rapid sequence induction of general anesthesia.

Yoshida K, Isosu T, Noji Y, Hasegawa M, Iseki Y, Oishi R, Imaizumi T, Sanbe N, Obara S, Murakawa M. J Clin Monit Comput. 2017 Sep 27.

The oxygen reserve index (ORi): a new tool to monitor oxygen therapy

Scheeren TWL, FJ Belda, A Perel. J Clin Monit Comput, 2017. DOI 10.1007/s10877-017-0049-4.

Oxygen Reserve Index: An early warning for desaturation in critically ill patients.

Lee L, Singh A, Applegate R, and Fleming N. Proceedings from the 2017 IARS Annual Meeting, Washington, DC. Abstract #A1406.

The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery.

Applegate RL 2nd, Dorotta IL, Wells B, Juma D, Applegate PM. Anesth Analg. 2016 Mar 22. [Epub ahead of print] PubMed PMID: 27007078.

Oxygen Reserve Index (ORi): validation of a new variable

Scheeren T.W.L., Spanjersberg R., Struys M.M.R.F. Proceedings from the 2016 EuroAnaesthesia Congress, London, UK. Abstract 01AP04-9.

Oxygen Reserve Index A Novel Noninvasive Measure of Oxygen Reserve—A Pilot Study.

Szmuk P, Steiner JW, Olomu, PN, Ploski, RP, Sessler, DI, Ezri, T. Anesthesiology 2016; 124:00-00. doi:10.1097/ALN.0000000000001009

Oxygen Reserve Index - a New, Noninvasive Method of Oxygen Reserve Measurement

Szmuk P, Steiner J., Olomu P., Dela Cruz J., Sessler D. American Society of Anesthesiologists 2014; BOC12.

Oxygen reserve index for non-invasive early hypoxemia detection during endotracheal intubation in intensive care: the prospective observational NESOI study

Hille H, Le Thuaut A, Canet E, et al.

Clinical Evidence Key:

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This section is intended to provide access to clinical studies conducted using Masimo noninvasive technologies, parameters, and products. We cannot guarantee that all published clinical studies, abstracts and research are listed here. To view individual clinical studies please click on the appropriate tab.

Some uses of the manufacturer’s devices described in the information may not have been approved or cleared by the FDA. See manufacturer labeling for the indications in the product’s cleared indications for use statement.

Clinical evidence is provided to illustrate the performance and accuracy of Masimo technologies. Federal law restricts Masimo devices for medical uses to sale by or on the order of a physician.

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