Journal of Clinical Monitoring and Computing

, Volume 32, Issue 4, pp 687–691 | Cite as

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

  • Keisuke YoshidaEmail author
  • Tsuyoshi Isosu
  • Yoshie Noji
  • Makiko Hasegawa
  • Yuzo Iseki
  • Rieko Oishi
  • Tsuyoshi Imaizumi
  • Norie Sanbe
  • Shinju Obara
  • Masahiro Murakawa
Original Research


The oxygen reserve index (ORi™) is a new parameter for monitoring oxygen reserve noninvasively. The aim of this study was to examine the usefulness of ORi for rapid sequence induction (RSI). Twenty adult patients who were scheduled for surgical procedures under general anesthesia were enrolled. After attaching a sensor capable of measuring ORi, oxygen (6 L/min) and fentanyl (2 μg/kg) were administered. After 3 min, propofol 2 mg/kg and rocuronium 1 mg/kg were administered without ventilation. Regardless of changes in ORi, tracheal intubation was performed either 2 min after administration of propofol or when percutaneous oxygen saturation (SpO2) reached 98%. Ventilation was then provided with oxygen at 6 L/min, and trends in ORi and SpO2 during RSI were observed. Data from 16 of the 20 patients were analyzed. Before oxygen administration, the median SpO2 was 98% [interquartile range (IQR) 97–98] and ORi was 0.00 in all patients. At 3 min after starting oxygen administration, the median SpO2 was 100% (IQR 100–100) and the median ORi was 0.50 (IQR 0.42–0.57). There was an SpO2 decline of 1% or more from the peak value after propofol administration in 13 patients, and 32.5 s (IQR 18.8–51.3) before the SpO2 decrease, ORi began to decline in 10 of the 13 (77%) patients. The ORi trends enable us to predict oxygenation reduction approximately 30 s before SpO2 starts to decline. By monitoring ORi, the incidence related to hypoxemia during RSI could be reduced.


Oxygen reserve index (ORi) Rapid sequence induction (RSI) Revision L CO-oximetry 


Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This study was approved by the Ethics Committee of Fukushima Medical University (No. 2622) and has been performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Informed consent

Written informed consent was obtained from all individual participants included in the study


  1. 1.
    Smith CE. Rapid-sequence intubation in adults: indications and concerns. Clin Pulm Med. 2001;8:147–65.CrossRefGoogle Scholar
  2. 2.
    El-Orbany M, Connoly LA. Rapid sequence induction and intubation: current controversy. Anesth Analg. 2010;110:1318–25.CrossRefGoogle Scholar
  3. 3.
    Jesse ME, Eva AC, Victoria EF, Nathaniel DM, Warren SS. Modified rapid sequence induction and intubation: a survey of United States current practice. Anesth Analg. 2012;115:95–101.CrossRefGoogle Scholar
  4. 4.
    Endale GG, Desta M, Derso A, Ehtemariam A. The incidence of oxygen desaturation during rapid sequence induction and intubation. World J Emerg Med. 2014;5:279–85.CrossRefGoogle Scholar
  5. 5.
    Aoyagi T. Pulse oximetry: its invention, theory, and future. J Anesth. 2013;17:259–66.CrossRefGoogle Scholar
  6. 6.
    Pedersen T, Nicholson A, Hovhannisyan K, Moller AM, Smith AF, Lewis SR. Pulse oximetry for perioperative monitoring. Cochrane Database Syst Rev. 2014. doi: 10.1002/14651858.CD002013.CrossRefPubMedPubMedCentralGoogle Scholar
  7. 7.
    Scheeren TWL, Belda FJ, Perel A. The oxygen reserve index (ORI): a new tool to monitor oxygen therapy. J Clin Monit Comput. 2017. doi: 10.1007/s10877-017-0049-4.CrossRefPubMedPubMedCentralGoogle Scholar
  8. 8.
    Simpao AF, Gálvez JA. When seconds count, buy more time. The oxygen reserve index and its promising role in patient monitoring and safety. Anesthesiology 2016;124:750–1.CrossRefGoogle Scholar
  9. 9.
    Szmuk P, Steiner JW, Olomu PN, Ploski RP, Sessler DI, Ezri T. Oxygen reserve index: a novel noninvasive measure of oxygen reserve: a pilot study. Anesthesiology 2016;124:779–84.CrossRefGoogle Scholar
  10. 10.
    Hans KN, James EC, Peter DB. Rapid tracheal intubation with rocuronium. Anesthesiology 1999;91:131–6.CrossRefGoogle Scholar
  11. 11.
    Applegate RL 2nd, Dorotta IL, Wells B, Juma D, Applegate PM. The relationship between oxygen reserve index and arterial partial pressure of oxygen during surgery. Anesth Analg. 2016;123:626–33.CrossRefGoogle Scholar
  12. 12.
    Baraka AS, Taha SK, Aouad MT, El-Khatib MF, Kawkabani NI. Preoxygenation: comparison of maximal breathing and tidal volume breathing techniques. Anesthesiology 1999;91:612–6.CrossRefGoogle Scholar
  13. 13.
    Nimmagadda U, Chiravuri SD, Salem MR, Joseph NJ, Wafai Y, Crystal GJ, El-Orbany MI. Preoxygenation with tidal volume and deep breathing techniques: the impact of duration of breathing and fresh gas flow. Anesth Analg. 2001;92:1337–41.CrossRefGoogle Scholar
  14. 14.
    Severinghaus JW. Simple, accurate equations for human blood O2 dissociation computations. J Appl Psysiol Respir Environ Exerc Physiol. 1979;46:599–602.Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  1. 1.Department of AnesthesiologyFukushima Medical University School of MedicineFukushima CityJapan

Personalised recommendations