Clinical trial NCT06578468: End-Tidal Oxygen for Intubation in the Emergency Department
Official title: Preoxygenation Using End-Tidal Oxygen for Rapid Sequence Intubation in the Emergency Department (The PREOXED Trial) - a Multicentre Stepped Wedge Cluster Randomised Control Trial
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Critical Illness
Hypoxia
Respiratory Failure
Keywords: Emergency Intubation
Lead sponsor: Sydney Local Health District
Sponsor class: OTHER_GOV
First posted: 2024-08-29
Enrollment: 1400
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Stepped-wedge randomised control trial
Primary purpose: DIAGNOSTIC

Brief summary: Rapid Sequence Intubation (RSI) is a high-risk procedure in the emergency department (ED). Patients are routinely preoxygenated (given supplemental oxygen) prior to RSI to prevent hypoxia during intubation. For many years anaesthetists have used end-tidal oxygen (ETO2) levels to guide the effectiveness of preoxygenation prior to intubation. The ETO2 gives an objective measurement of preoxygenation efficacy. This is currently not available in most EDs.

This trial evaluates the use of ETO2 on the rate of hypoxia during intubation for patients in the ED.

Detailed description: BACKGROUND AND INTRODUCTION

Rapid Sequence Intubation (RSI) is a common procedure in Emergency Departments (ED). However, it is a high-risk procedure and is associated with significant complications including hypoxia, failed intubation, hypotension, trauma and aspiration. (1-3) Specifically, hypoxia during intubation can lead to poor outcomes such as dysrhythmias, haemodynamic compromise, hypoxic brain injury and death and therefore oxygen desaturation is of primary concern during any intubation procedure. (4, 5) In order to prevent desaturation events during intubation, a number of steps are taken by clinicians. These include optimal patient positioning, adequate preoxygenation, assessment of airway anatomy and development of a detailed airway plan as well as the use of apnoeic oxygenation.(6)

Effective preoxygenation is vital to ensure that the patient does not develop hypoxia during the period between induction (administration of sedative and paralytic agents) and restoration of ventilation by successful endotracheal intubation or rescue breathing. Various methods of preoxygenation have been developed to wash the nitrogen out of the lungs (denitrogenation) which allows the functional residual capacity (FRC) to act as an oxygen reservoir during intubation, which prolongs safe apnoea time, therefore, preventing desaturation whilst an endotracheal tube (ETT) is placed.

Adequate preoxygenation is especially important for those patients at highest risk of hypoxia during the RSI. This patient group includes those with underlying lung pathology e.g. pneumonia, patients with increased metabolic demand e.g. sepsis, patients with an oxygen requirement prior to RSI, or patients with underlying conditions that predisposes to hypoxia e.g. obesity.

For many years anaesthetists have used end-tidal oxygen (ETO2) levels to guide the effectiveness of preoxygenation. ETO2 measures the exhaled oxygen concentration and is a marker of the oxygen concentration in the alveoli. Prior to induction, anaesthetists most commonly preoxygenate with a face-mask seal via either a circle circuit, Mapleson circuit, or bag valve mask. ETO2 provides an objective measurement of preoxygenation efficacy. The Difficult Airway Society guidelines suggest aiming for an ETO2 of ≥87% prior to commencing RSI.(7) ETO2 levels are not routinely measured in Emergency Departments.

Currently, it is not possible to measure the effectiveness of preoxygenation in the ED. Pulse-wave oximetry reflects peripheral oxygen saturation and not the pulmonary oxygen concentration. Therefore, to attempt to optimize preoxygenation the emergency clinician currently can only use time as a surrogate. The typically recommended duration of preoxygenation is \> 3 minutes.

Recently, the investigators conducted two multi-site studies (Ethics identifier: 2019/ETH06644) that investigated the use of ETO2 in the ED.(8, 9) The first study was conducted with clinicians blinded to the ETO2 result (8). The investigators demonstrated that preoxygenation was uniformly poor with only 26% of patients achieving the required target ETO2 of ≥85%. The investigators then completed a second study where clinicians had access to ETO2 values and found that the proportion of patients reaching levels ≥85% was improved to 67% of patients. (9) The prevalence of hypoxemia (SpO2 \<90%) in the group blinded to ETO2 was 18% (n=18, 95% CI: 11% to 27%) and was 8% in the group where ETO2 was available (n = 8, 95% CI: 4% to 15%). These studies indicate that the use of ETO2 may substantially improve preoxygenation in the ED and therefore reduce the risk of hypoxia.

These studies, however, were focused on preoxygenation practices and not patient-oriented outcomes (hypoxia) and were limited in design and resources. Consequently, it is still unclear whether the use of ETO2 in the ED leads to improved clinical outcomes.

RATIONALE FOR PERFORMING THE STUDY

The aim of this study is to determine the effectiveness of ETO2 monitoring in preventing desaturation for patients with a high risk of hypoxia undergoing RSI in ED.

HYPOTHESIS

The investigators hypothesise that the use of ETO2 monitoring leads to reduced rates of oxygen desaturation during the peri-intubation period compared to when it is not used.

Eligibility criteria: Inclusion Criteria:

1. The patient is located in the ED resuscitation bay of the participating centre.
2. The planned procedure is orotracheal intubation using a laryngoscope and RSI technique with preoxygenation for patients who are spontaneously breathing.
3. The patient is deemed to be at a high risk of hypoxia during RSI as per the treating ED clinician, as defined by:

   * Any patient requiring any form of oxygen therapy before preoxygenation.
   * Any patient with respiratory pathology based on clinical or radiological findings. Including, but not limited to:

     * Pneumonia, pulmonary oedema, acute respiratory distress syndrome (ARDS), aspiration, pulmonary contusion from trauma, infective exacerbations of known lung disease (e.g. asthma, pulmonary fibrosis, emphysema) or pulmonary embolism (PE)
   * Any patient with high oxygen consumption. Including, but not limited to:

     * Sepsis, Diabetic ketoacidosis, alcohol or drug withdrawal, seizures, thyrotoxicosis
   * Any underlying patient condition that may predispose to hypoxemia. Including, but not limited to:

     * Obesity, pregnancy, underlying lung disease (e.g. asthma, pulmonary fibrosis, emphysema), severe injury- hypovolaemia/haemorrhage.
   * or any other patient that the treating clinician has a high concern for hypoxemia during RSI.

Exclusion Criteria:

1. Patient is known to be less than 18 years old.
2. The patient has a supraglottic device in-situ e.g iGel or LMA.
3. The patient is known to be pregnant.
4. The patient is known to be a prisoner.
5. The patient was intubated in the prehospital environment.
6. Immediate need for tracheal intubation precludes preoxygenation i.e. the patient is in cardiac arrest.

Primary outcomes:
measure: Incidence of hypoxia
timeFrame: The time when laryngoscope first enters the mouth to 2 minutes after the endotracheal tube [ETT] is confirmed on waveform capnography
Secondary outcomes:
measure: Lowest oxygen saturations
timeFrame: The time when laryngoscope first enters the mouth to 2 minutes after the endotracheal tube [ETT] is confirmed on waveform capnography
Other outcomes:
measure: Time from preoxygenation to endotracheal intubation
timeFrame: Preoxygenation start time to endotracheal intubation confirmation
measure: Incidence of severe oxygen desaturation (SpO2 <80%)
timeFrame: Induction of sedative medications and 2 minutes post ETT confirmation
measure: Incidence of very severe oxygen desaturation (SpO2 <70%)
timeFrame: Induction of sedative medications and 2 minutes post ETT confirmation
measure: Incidence of the number of patients with pre-oxygenation method changes to achieve higher ETO2 in intervention arm
timeFrame: During preoxygenation
measure: Incidence of the number of patients with pre-oxygenation technique changes to achieve higher ETO2 in intervention arm
timeFrame: During preoxygenation
measure: Number of re-oxygenation events
timeFrame: During preoxygenation
measure: Cardiovascular complications during RSI
timeFrame: Induction of sedative medications and 2 minutes post ETT confirmation
measure: Other complications during RSI
timeFrame: Induction of sedative medications and 2 minutes post ETT confirmation
Locations:
city: Minneapolis
country: United States
facility: Hennepin Medical Center
state: Minnesota
city: Albuquerque
country: United States
facility: University of New Mexico Medical Center
state: New Mexico
city: Bronx
country: United States
facility: Lincoln Medical Center
state: New York
city: Sydney
country: Australia
facility: Westmead Hospital
state: New South Wales
city: Sydney
country: Australia
facility: Royal Prince Alfred Hospital
state: New South Wales
city: Sydney
country: Australia
facility: Liverpool Hospital
state: New South Wales
city: Sydney
country: Australia
facility: Northern Beaches Hospital
state: New South Wales
city: Sydney
country: Australia
facility: Royal North Shore Hospital
state: New South Wales
city: Melbourne
country: Australia
facility: The Alfred Hospital
state: Victoria
Study officials:
affiliation: Sydney Local Health District
name: Matthew Oliver, MBBS
role: STUDY_CHAIR
affiliation: Lincoln Medical Center
name: Nick Caputo, Md
role: STUDY_CHAIR
References:
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citation: Oliver M, Caputo ND, West JR, Hackett R, Sakles JC. Emergency physician use of end-tidal oxygen monitoring for rapidsequence intubation. J Am Coll Emerg Physicians Open. 2020 Sep 28;1(5):706-713. doi: 10.1002/emp2.12260. eCollection 2020 Oct.
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