Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05085119 |
| Other study ID # |
RBHP 2019 GODET 3 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 9, 2021 |
| Est. completion date |
August 10, 2022 |
Study information
| Verified date |
February 2023 |
| Source |
University Hospital, Clermont-Ferrand |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The ORI™ or Oxygen Reserve Index (Masimo, Irvine, CA, USA) is a non-invasive monitoring
system for measuring oxygen reserve. It is a digital sensor (almost identical to the SpO2
sensor) which allows an analysis of the absorption of arterial, venous and capillary
components. The measured index, unitless, ranges from 0.00 to 1.00 for moderate hyperoxia
levels: from 100 to 200 mmHg. It can alert the clinician to a drop in oxygen stores via the
drop in SvO2 before a drop in SpO2 is observed. We propose to carry out a study to elucidate
correlation between ORI™ and PaO2.
Description:
Pulse oximetry or SpO2 is the standard and mandatory monitoring of oxygenation during
mechanical ventilation of intensive care and operating theatre patients. Its use is based on
the difference in infrared and red light absorptions of oxyhaemoglobin and reduced
haemoglobin. The calculation of the absorption percentage takes into account the pulsatility
of the signal, reflecting the arterial component, while eliminating the continuous signal,
reflecting the venous component. It is then considered that SpO2 is a reflection of SaO2, or
arterial oxygen saturation. Oxygen exists in two forms in the arterial circulation: dissolved
(PaO2) or bound to haemoglobin (SaO2).
Because of the sigmoidal shape of the oxyhaemoglobin dissociation curve, SpO2 is a late
marker of arterial hypoxaemia. Indeed, SpO2 only starts to decrease after a marked drop in
PaO2.
Hypoxaemia is a frequent situation, both in the operating theatre during the period of
securing the airway, intra-operatively, or post-operatively, after extubation, on episodes of
alveolar hypoventilation, such as atelectasis. In intensive care units, it can occur in
injured lungs with various aetiologies (infectious, inflammatory, cardiac, etc). It is an
independent predictive factor of mortality.
Exposure of patients to high hyperoxia (FiO2>0.7), over a long period of time, can lead to
pulmonary endothelial damage (due to the formation of reactive oxygen species, ROS),
denitrogenation atelectasis, and possibly a systemic inflammatory cascade. It is currently
suggested that hyperoxia may also have a haemodynamic impact, with a fall in cardiac output
and peripheral vasoconstriction, particularly in healthy volunteers and patients with cardiac
decompensation. However, hyperoxia is a frequent situation during the perioperative period as
it provides safety and a potential oxygen reserve in case of adverse events: hemodynamic
degradation, cardiac arrest, extubation...
The ORI™ or Oxygen Reserve Index (Masimo, Irvine, CA, USA) is a non-invasive monitoring
system for measuring oxygen reserve. It is a digital sensor (almost identical to the SpO2
sensor) which allows an analysis of the absorption of arterial, venous and capillary
components. The measured index, unitless, ranges from 0.00 to 1.00 for moderate hyperoxia
levels: from 100 to 200 mmHg. It can alert the clinician to a drop in oxygen stores via the
drop in SvO2 before a drop in SpO2 is observed.
There is little literature on ORI™. A previous study showed a poor correlation between ORI™
(ranging from 0.24 to 0.55) and PaO2, which ranged from 100 to 150 mmHg, respectively. The
company, Masimo, has recently made a change in its algorithm, allowing it to re-calibrate its
sensor. However, no new correlation research has been conducted. We therefore propose to
carry out a new test phase.
