Temperature Dependent Changes in I-gel Masks

Johann Wolfgang Goethe University Hospital

Status: Completed

Conditions: Airway Management

Treatments: Device: Comparison of physcial parameters

Study type: Observational

Funder types: Other

Identifiers

NCT03976726

05/19

Details and patient eligibility

About

The i-gel® mask is a second generation, single use supraglottic airway device which does not have an inflatable cuff. The cuff consists of a thermoplastic elastomer and its mechanism of sealing still remains unclear. Various theories such as temperature-dependent changes in hardness and volume expansion as well as fluid absorption have been discussed.

Full description

The i-gel® mask (Intersurgical, Workingham, UK), is a second generation, single use supraglottic airway device. In contrast to other devices its' cuff consists of a thermoplastic elastomer (styrene-ethylene-butadine-styrene) instead of an inflatable cuff.

Previous studies have shown, that over time the sealing improved compared to the moment of insertion. The sealing process may be based on various mechanisms. It is assumed, that the warming from room to body temperature leads to an improved adaptation to the patient-specific anatomy due to a softening of the elastomer. By definition, an elastomer is softened by the effect of temperature and become harder when reaching the glass transition temperature.

In this context, Dingley et al. described a change in the degree of hardness as a function of temperature. Prewarmed i-gel® masks (42°C, 30min.) seem to have smaller leak volumes compared to masks stored at room temperature postinsertion in paralyzed patients, but was not reproducible in non-paralyzed patients. Looking at the sealing pressure Chauhan et al. reported that i-gel® masks required a lower pressure compared to masks with an inflatable cuff.

At this point it is not yet clear, whether the thermoplastic cuff material only expands due to an increase in temperature. Liquid absorption and a consecutive expansion is also theoretically conceivable.

Therefore, the aim of the present study is to examine the i-gel® mask within the scope of a benchtop study for temperature-dependent volume expansion and liquid absorption.

Enrollment: 15 patients

Sex: All

Volunteers: No Healthy Volunteers

Inclusion criteria

• Elective surgery

Exclusion criteria

• Contraindications for the use of i-gel masks.
• Emergency operation
• non fasted patient

Trial design

15 participants in 3 patient groups

i-gel size #3

Description:

Results of benchtop investigations are compared to in patient-used masks. Increasement of weight, volume expansion and decrease of density are measured.

Treatment:

Device: Comparison of physcial parameters

i-gel size #4

Description:

Results of benchtop investigations are compared to in patient-used masks. Increasement of weight, volume expansion and decrease of density are measured.

Treatment:

Device: Comparison of physcial parameters

i-gel size #5

Description:

Results of benchtop investigations are compared to in patient-used masks. Increasement of weight, volume expansion and decrease of density are measured.

Treatment:

Device: Comparison of physcial parameters