Optiflow (high flow humified nasal oxygen) is used in several settings frequently (ICU, during elective general anaesthesia- commonly here on the TOE list, in certain ENT patients, and more commonly now in obese or obstetric patients for preoxygenation). To the investigators knowledge no one has quantified the common complications associated with it (based on a literature search in November 2017 using PubMed and Google; using the search terms "high flow nasal oxygen" combined with "complications", "side effects", "nasal dryness" and "epistaxis"). The investigators were unable to find any existing research that examined the days following HFNO use and specifically looked for minor side effects) The investigators have had anecdotal feedback from patients that they tend to experience respiratory symptoms post HFNO.

THe investigators would like to determine how often this occurs and how long it lasts for which would be pertinent to consent, and informing patients prior to the procedure, and also serve to improve the literature on this up and coming technique.

The study aims to evaluate what is the frequency and severity of respiratory tract symptoms following the use of high flow nasal humidified oxygen? Participants will be from 2 sub groups:

1. Patients already undergoing TOE (as this is the most common and consistent group who have optiflow- about 4-5 patients per week)
2. Volunteers (staff) who would agree to experience the optiflow whilst awake for the same period as those undergoing TOE

The study will involve a 7 day follow up survey to see if they had experienced complications (runny nose, nasal discomfort, sore throat, epistaxis), what their severity was and how long they lasted for.

Inclusion criteria:

1. Volunteers (staff) - from the anaesthetics department and willing to be exposed to HFNO
2. Patients listed for all those undergoing elective TOE requiring sedation and use of HFNO
3. present at Torbay Hospital
4. Greater than 18 years of age. No upper age limit
5. Able to give informed consent

Exclusion Criteria:

1. patient refusal
2. lack of capacity
3. poor understanding of English
4. respiratory tract symptoms
5. blocked nostrils
6. current or recurrent epistaxis
7. nasal steroid treatment
8. Ages <18 years
9. Unable to give informed consent