Impact of Preoxygenation Time on End-tidal Oxygen Concentration and on Hypoxic Events Occurring After Intubation in the Intensive Care Unit.

Not Applicable

Withdrawn

Brief Summary: Preoxygenation is recommended before performing tracheal intubation. In intensive care units (ICU) patients, there is no specific recommendation regarding the duration of preoxygenation, which usually is applied for 3 to 5 minutes. Monitoring the effectiveness of preoxygenation with end-tidal oxygen concentration (EtO2) is strongly recommended in the operating room but it is never used in ICUs. The first aim of this pilot study is to assess the effect of the preoxygenation duration on EtO2, and secondarily, as an exploratory objective, to determine whether targeting a given value of EtO2 during preoxygenation might insure a safer intubation than when targeting pulse oximetry (SpO2).

Detailed Description: This is a multicenter randomized controlled pilot study. 110 patients who require intubation in the ICU will be randomly assigned, with a 1:1 ratio, to 3 or 5 minutes of preoxygenation duration. EtO2 will be continuously measured but hidden to the clinician. The primary outcome measure will be the obtention of an optimal preoxygenation defined by an EtO2 \>90%. Secondary outcomes include the occurrence of hypoxia and complications during the procedure.

A pulse oximetry (SpO2) greater than or equal to 96% (SpO2 ≥ 96%) at the end of preoxygenation will be the target in each group. If at the end of the preoxygenation, SpO2 is still lower than 96%, clinician will be allowed to extend the duration of preoxygenation (up to 5 minutes in the 3 minutes period of preoxygenation group and up to 8 minutes in the 5 minutes period of preoxygenation group).

End-tidal oxygen concentration (EtO2) will be measured during preoxygenation and will be hidden to the clinician in order to not influence the duration of preoxygenation.

Recruitment & Eligibility

Inclusion Criteria

Patients older than 18 years
Requiring intubation in ICU
Free express oral and informed consent of the patient or a proxy in case of impossibility for the patient to consent; emergency inclusion possible when legal representatives and patient's family are not present

Exclusion Criteria

Intubation for cardiac arrest
End-tidal oxygen concentration monitoring not available
Preoxygenation with high-flow nasal oxygenation
Previous participation to the study
Patient known, at time of inclusion, as being under guardianship, tutorship or curator
Pregnancy or breastfeeding
Lack of social security number

Arm && Interventions

Group	Intervention	Description
3 minutes period of preoxygenation	Preoxygenation	3 minutes of preoxygenation : participants in this group will receive 3 minutes of preoxygenation before intubation
5 minutes period of preoxygenation	Preoxygenation (longer)	5 minutes of preoxygenation: participants in this group will receive 5 minutes of preoxygenation before intubation

Primary Outcome Measures

Name	Time	Method
Percentage of patients who reach an EtO2 of 90%	3 minutes	To compare the percentage of patients who reach an EtO2 of 90% or higher (optimal preoxygenation) at the end of the preoxygenation period between patients randomized in the 3-min and those randomized in the 5-min preoxygenation duration group.

Secondary Outcome Measures

Name	Time	Method
Incidence of severe hypoxemia	End of preoxygenation	Severe hypoxemia will be defined by SpO2\<80% for more than 5 seconds during the intubation procedure from the end of preoxygenation to 5 minutes after invasive mechanical ventilation
Incidence of severe complications	30 minutes after intubation	Severs complications occuring within 30 minutes following the intubation procedure will be evaluate and compare between the two groups
Partial Pressure of Oxygen (PaO2)	0 minute	Measurement of PaO2
Partial Pressure of Oxygen	at the 4th minute on average (3rd or 5th minute depending on the randomisation group)	Measurement of PaO2 at the end of the preoxygenation
Expired oxygen fraction (FeO2)	Through preoxygenantion, i.e., an average of 4 minutes (a minimum of 3 and a maximum of 8 minutes)	FeO2 during preoxygenation will be recorded every minutes
Lowest Pulsed saturation with Oxygen (SpO2)	30 minutes after the end of preoxygenation	The lowest SPO2 obtained within 30 minutes after the end of preoxygenation will be compared between the 2 groups
Incidence of hypoxemia	5 minutes after intubation	Hypoxemia will be defined by SpO2\<90% during the intubation procedure

Locations (3): CH de DAX
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Dax, France
CHR d'Orléans
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Orléans, France
CHRU de TOURS
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Tours, France