Symptoms and General Pathology

All Conditions

Facies

Hypoxia

Signs and Symptoms, Respiratory

David Ferreira, MD, PhD

High Flow Nasal Oxygen Therapy (HFNO) is a new oxygenation tool that is becoming increasingly widespread in perioperative anaesthesia. The benefits of this oxygenation tool are based on different physiological principles. These include the reduction of dead space by "flushing" the nasopharyngeal cavities, positive airway pressure and the warming and humidification of inspired air. In addition, the high flow rates used ensure that the patient's inspiratory demand is covered, allowing for the delivery of oxygen-enriched and controlled air. It is simple to use, with the only parameters to be set being gas flow and FiO2. The use of HFNO appears to allow a prolongation of apnoea time without desaturation in apneic ventilation.

Mainly studied in ENT surgery because of the interest that this oxygenation strategy presents with the absence of recourse to oro-tracheal intubation (OTI), several authors will use it in the framework of micro-laryngoscopy surgery in suspension. However, its use as an oxygenation strategy during panendoscopy has been little explored. Panendoscopy is a common procedure that requires deep and short anesthesia. The main challenge is the sharing of the airway between the anesthesia team and the surgical team. Learning to use this new method or the impact of operator experience has never been explored.

Currently, there are several strategies to ensure oxygenation during this specific type of ENT management:

* Mechanical ventilation with oro-tracheal intubation (OTI)
* Face mask ventilation (FMV)
* Jet ventilation
* HFNO Each of these methods has advantages and disadvantages, which explains why there are no clear recommendations to date on the preferred anesthesia and oxygenation technique. Regardless of the method chosen, the risks remain significant for the patient, particularly the risk of hypoxemia during a desaturation episode.

For several years, the strategy of oxygenation during panendoscopy and the number of practitioners performing this procedure has evolved in our centre.

* 2017, with the arrival of the HFNO in the operating room.
* 2020, during the SARS-CoV2 pandemic, changes in the organisation of the anaesthesiology department had to take place and the number of practitioners performing this procedure increased significantly.

The main objective of this study was to evaluate the impact of the evolution periods of the oxygenation strategies and the experience of the operators on the incidence of patients with at least one intra-procedural hypoxemia (SpO2 \< 90% for more than one minute).

All patients who had a panendoscopy from 01 January 2015 to 31 December 2020 were analysed. The anaesthetists in our centre are divided into different practice specialties, so a small number of them regularly perform anaesthesia in ENT surgery. We divided the anaesthetists who performed panendoscopies during the study period into two categories in order to compare the incidence of severe hypoxaemia (SpO2 \< 90%) among them :

* Experienced anaesthetists (practitioner who has performed at least 30 panendoscopies per year for two consecutive years)
* Non-experienced anaesthetists (practitioner who has performed at least one panendoscopy per year and does not meet the criteria for expertise)

Impact of the Experience of Anaesthetists in Changing Ventilation Strategies During Panendoscopy on the Incidence of Intraoperative Hypoxaemia

Proportion of patients with oxygen desaturation (SpO2 \< 90%) for more than 1 minute.

Proportion of patients within each of the ventilation modalities used in panendoscopies Proportion of patients requiring repeat face mask ventilation (at least one reventilation outside the initial denitrogenation)

Proportion of patients intubated during panendoscopy

Time (minutes) from induction of anaesthesia to discharge from the operating room

Complications are : Extreme bradycardia \< 30 beats per minute, hemodynamic instability defined by MAP \< 40 mmHg, hypercapnia (more than 80 mmHg)

Centre Hospitalier Universitaire de Besancon

Principal Investigator

Central Nervous System Depressants

All Drugs and Chemicals

Anesthetics

During the period from January 1, 2015, to December 31, 2016, all panendoscopies performed with FMV, whether urgent or scheduled and regardless of indication, were included. Panendoscopies performed with any other oxygenation method were excluded.

During the period from January 1, 2018, to December 31, 2019, all panendoscopies performed with HFNO, urgent or scheduled and regardless of indication, were included. Panendoscopies performed with any other oxygenation method were excluded.

Panendoscopy is a common procedure that requires deep and short anesthesia. The main challenge is the sharing of the airway between the anesthesia team and the surgical team. There are several methods to ensure oxygenation during this type of procedure: oro-tracheal intubation, jet ventilation, spontaneous ventilation anesthesia, apneic ventilation with intermittent face mask ventilation. There is no consensus regarding the best airway management technique for this procedure. Regardless of the method chosen to ensure oxygenation during this procedure, the risk of hypoxemia during desaturation episodes is significant.

However, the use of HFNO seems to show a prolongation of apnea time without desaturations (\< 90% SpO2) and seems to allow the performance of panendocoscopies.

In the Besançon University Hospital, since 2017, all panendoscopies are performed with HFNO. Before 2017, panendoscopies were performed under face mask ventilation. The main of the study hypothesis is that HFNO brought a gain in terms of safety, especially on the desaturation rate compared to face mask ventilation.

The investigators will carry out a quasi-experimental study comparing two periods. The first period concerns the years 2015-2016. It aims to study patients who had panendoscopies performed under FMV. The second period covers the years 2018-2019. It aims to study patients who had panendoscopies performed under HFNO.

The year 2017 is considered as the washout period necessary to avoid the learning effect of the HFNO introduced during that year.

Currently, there are several strategies to ensure oxygenation during this specific type of ENT management:

* Mechanical ventilation with oro-tracheal intubation (OTI)
* face mask ventilation (FMV)
* Jet ventilation
* HFNO Each of these methods has advantages and disadvantages, which explains why there are no clear recommendations to date on the preferred anesthesia and oxygenation technique. Regardless of the method chosen, the risks remain significant for the patient, particularly the risk of hypoxemia during a desaturation episode.

In 2017, HFNO was introduced for panendoscopies in the Besançon University Hospital. Before 2017, panendoscopies were mainly perfomed with intermittent face mask ventilation.

The objective of the study is to compare the FMV group (patients receiving panendoscopy and ventilated with FMV during 2015-2016) with the HFNO group (patients receiving panendoscopy and oxygenated with HFNO during 2018-2019) with respect to perprocedural hypoxemia (SpO2\<90% for more than 1 minute).

Secondary objectives are to compare complications, use of oro-tracheal intubation, and procedure duration between the two oxygenation methods.

Comparison of HFNO and FMV on Desaturations During Panendoscopy Under General Anesthesia

Comparison of High-flow Nasal Oxygen Therapy and Face Mask Ventilation on Desaturations During Panendoscopy Under General Anesthesia

Proportion of patients requiring repeat face mask ventilation (at least one reventilation outside the initial denitrogenation)

Time (minutes) from induction of anaesthesia to discharge from the operating theatre

Complications are : mild bradycardia (between 45 and 30 beats per minute), hypotension defined by MAP (between 65 and 40mmHg), hypercapnia (betaween 60 and 80 mmHg)

Complications are : Tracheotomy, extreme bradycardia \< 30 beats per minute, hemodynamic instability defined by MAP \< 40mmHg, hypercapnia (more than 80 mmHg)

Study title	NCT ID	Conditions	Eligibility	Organization
Impact of the Experience of Anaesthetists in Changing Ventilation Strategies During Panendoscopy on the Incidence of Intraoperative Hypoxaemia	NCT05601570	ENT Tumor	18 Years -	Centre Hospitalier Universitaire de Besancon
Impact of the Experience of Anaesthetists in Changing Ventilation Strategies During Panendoscopy on the Incidence of Intraoperative Hypoxaemia	NCT05601570	ENT Tumor	18 Years -	Centre Hospitalier Universitaire de Besancon
Comparison of HFNO and FMV on Desaturations During Panendoscopy Under General Anesthesia	NCT05593718	ENT Tumor	18 Years -	Centre Hospitalier Universitaire de Besancon

Spots Global Cancer Trial Database for face mask ventilation