A new adjunctive system to obtain higher PaO₂ with nasal cannula or catheter: double trunk mask

Introduction

In our experience, very often, even with a non-rebreathing mask (NRM), high oxygen delivery to patient with the existent materials is insufficient. However, many of these patients need high oxygen therapy for a limited period of time. In this study we report our experience with a new device that serves to increase the concentration of oxygen delivered by a classical nasal cannula or catheter. It is not an oxygen mask.

Aim

To demonstrate how a simple adjunctive system to classical nasal cannula or catheter improves considerably the oxygenation of patients at constant O₂ flow rate.

Design

Prospective, observational study.

Method

The double trunk mask (DTM) is a modified tusk mask described by Hnatiuk. It is composed by a normal aerosol mask with 22 mm of diameter lateral holes, 38 cm of long flexible tubing are inserted to each side of the mask. The DTM is just applied to the face of the patients who already receive O₂ through a nasal cannula or catheter. Forty-five consecutive patients, admitted in the ER or ICU, and needing oxygen delivery, are included in our study. The data collected are: PaO₂, PaCO₂, breathing rate with a mean flow rate of 3.58 l/min, at t0, t30 min prior to DTM and then 30 min after DTM application.

Results

Table 1 Results

Conclusions

In patients who remain insufficiently oxygenated although receiving O₂ with classical nasal cannula or catheter, the DTM is a new, simple and efficient system to obtain high PaO₂ at the same O₂ flow rate and without significant change in PaCO₂.