Skip to main content
  • Poster presentation
  • Open access
  • Published:

Positive changes in the continuous desaturation index during mechanical ventilation are associated with mortality due to acute respiratory failure


We have previously shown that the desaturation index (DI) and the continuous desaturation index (CDI) displayed on the desaturation index monitoring system (DIMS) have a high sensitivity and specificity to identify lung dysfunction [1, 2]. However, dynamic changes during mechanical ventilation (MV) that may reflect the patient's response for MV treatment have not yet been tested.


Fifty-eight patients with and without ALI/ARDS were followed during the first 24 hours of MV with the DIMS. The system computes the CDI from the positive end-expiratory pressure (PEEP), the inspired fraction of oxygen (FiO2) and arterial saturation by pulse oximetry (SpO2) [1, 2]. The CDI is a percentage that is displayed graphically and numerically. Patients were divided into three groups according to the initial (first hour) CDI. Group (G) I (n = 16), CDI above 90%. GII (n = 22), CDI between 70 and 90%. GIII (n = 20), CDI below 70%. Then, changes in the CDI were calculated every hour (CDIh1 minus CDIh2, CDIh2 minus CDIh3, and so forth), three types of changes were expected: no change (even), negative changes (improvement of lung function) and positive changes (worsening of lung function). The mean of CDI changes was calculated at 6, 12, 18 and 24 hours after the initial recording. All patients were followed and mortality associated with acute respiratory failure (ARF) was recorded.


Changes (mean ± standard deviation) at 6 hours for GI: -1.82 ± 4.2, GII: -2.27 ± 9.2 and GIII: 2.52 ± 5.2 (P = 0.061). At 12 hours: GI: -2.2 ± 4.9, GII: -2.2 ± 9.1 and GIII: 6.07 ± 13.7 (P = 0.014). At 18 hours: GI: -1.36 ± 5.2, GII: -4.24 ± 11 and GIII: 5.47 ± 19.2 (P = 0.068). At 24 hours: GI: -2.09 ± 4.7, GII: -4.24 ± 12.8 and GIII: 8.53 ± 27.8 (P = 0.058). The mortality rate was 17.9% for GI, 33.3% for GII and 73.3% for GIII (P = 0.01). The association between positive changes and mortality was 30.8% for GI, and 100% for GII and GIII (P = 0.01).


We conclude that positive changes in the CDI during the MV are associated with mortality due to ARF. The CDI may help to improve the MV settings according to the patient's response to the FiO2 and PEEP treatment.


  1. Vazquez de Anda GF, et al.: Intensive Care Med. 2004,30(Suppl 1):A0230.

    Google Scholar 

  2. Vazquez de Anda GF, et al.: Crit Care. 2005,9(Suppl 1):P89. 10.1186/cc3152

    Article  PubMed Central  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article

Vazquez de Anda, G., Larraza, S., Talavera, J. et al. Positive changes in the continuous desaturation index during mechanical ventilation are associated with mortality due to acute respiratory failure. Crit Care 15 (Suppl 1), P197 (2011).

Download citation

  • Published:

  • DOI: