DAS Small Research Grants

Guys and St Thomas' NHS Foundation Trust, London

Title
New videolaryngoscopy scoring system development

Amount
£1,804

Scientific Abstract

Background
Videolaryngoscopes are now widely used in clinical practice and they have shown to be particularly helpful when faced with a difficult airway. Traditionally, during intubation the Cormack-Lehane (CL) classification has been used to describe the laryngeal inlet view.

Aims
We developed a new VL scoring system which we believe will give sufficient information for reproducible results across operators and devices. Our scoring system involves nine-panel square grid over a VL video-screen with each square representing a specific quadrant. The purpose is to record in which quadrant the laryngeal inlet appears at the time of intubation.

Methodology
This will be a manikin based, proof of concept study. We aim to recruit both trainees and consultants with varying degrees of experience in the use of VLs. We will compare how the grid system scores against the CL classification in terms of accuracy and reliability.

Expected outcomes
We hypothesise that our new scoring system will be reproducible and easy to use.

Implications
The results of this manikin study will determine whether there is value in evaluating this scoring system in patients, and if so, will lead to clinical studies and potentially a revolution in the description of VL intubation.

St John's Hospital, Scotland

Title
The use of a second generation LMA as a rescue device in patients with previous head and neck radiotherapy

Amount
£2,000

Scientific Abstract
Patients with previous radiotherapy for head and neck cancer may present for surgery during treatment or later. Following assessment these patients may be suitable for standard airway management as per the DAS guidelines.

If Plan A (intubation) fails, then a second generation LMA (i-Gel) should be inserted (Plan B). Our clinical experience is that an i-Gel can sometimes be difficult to insert in this subgroup of patients and may therefore not be a reliable rescue device for them. No studies have specifically looked at the i-Gel's performance in this patient group.

We will assess insertion success of the i-Gel LMA in patients with previous head and neck radiotherapy presenting for elective surgery under general anaesthesia, where they are planned for an IV induction and intubation. Prior to intubation we will insert an i-Gel (up to two insertion attempts, and two different sizes used as per DAS guidance) and assess success. We need to recruit 62 patients to achieve an adequately powered study.

If we find the i-Gel is successful as a rescue device this will further strengthen the DAS recommendations. If it does not perform well this may necessitate further research to modify the guidelines for this patient population.

University College London Hospitals

Title
Clinical Trial of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) Oxygen in Women having Planned Caesarean Delivery

Amount
£2,035

Scientific Abstract

Background
Recent obstetric airway management guidelines discuss the importance of pre-oxygenation prior to general anaesthesia to maximise the apnoea time before desaturation occurs. They recommend aiming for an end tidal oxygen fraction of greater than 90%.

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) is a novel method of pre-oxygenation that delivers warm, humidified oxygen at high flow rates and significantly prolongs the apnoea time of normal adults. By comparison, pregnant women have increased oxygen consumption, a shortened apnoea time and a higher incidence of difficult airway so THRIVE pre-oxygenation may be of benefit.

Aims
Determine Effective Number (EN90) of vital capacity breaths required to pre-oxygenate 90% of pregnant women to an end tidal oxygen fraction of 90% and investigate the effect of mouth open or closed.

Methodology
Parturients will be recruited prior to elective Caesarean section, randomised to start with mouth open or closed and be assigned a number of vital capacity breaths. Following the assigned administration of THRIVE, it will be exchanged for a face mask attached to an anaesthetic circuit to collect end-tidal gas monitoring.

We propose using an up-down sequential allocation methodology to determine the EN90 and imbed a case-control trial to compare mouth open versus mouth closed.

Princess of Wales Hospital, Cardiff

Title
Developing a framework for the assessment of Single Use Video Laryngoscopes

Amount
£2,000

Scientific Abstract
Currently there is no standard for video laryngoscopes, although there is a standard, BS EN ISO 7376:2009 [, which covers direct laryngoscopes. This standard includes requirements for strength, rigidity and illumination which could also be considered important for video laryngoscopes.

This project will be a laboratory-based exploratory study. We intend to measure the strength and rigidity of a number of disposable/single use Size 3 blades from different manufacturers and the illumination provided.