In Reply:
We read with interest the comments of Ferraro and colleagues regarding our paper evaluating a double lumen endotracheal tube (DLET) for percutaneous tracheostomy.1 The title of our paper introduces for the first time the DLET and its potential use during percutaneous tracheostomy. We specified in the abstract and text that this article was an in vitro evaluation of the DLET. The title of a scientific paper should describe the subject matter of an article, including appropriate key words for indexing, to attract potential readers' attention, especially in electronic databases. Ferraro and colleagues question the fact that our conclusion did not reflect the study's data. In our article, we concluded that use of the DLET during percutaneous tracheostomy did not impose an excessive increase in airway resistance, which is consistent with the data obtained during evaluation with continuous flow and mechanical ventilation. Furthermore, in the last sentence of our conclusion, we used the verb “may” to suggest the possibility of additional safety when using the DLET during percutaneous tracheostomy.
Ferraro and colleagues claimed that our paper over-reported in vitro data implying effects on clinical practice, but they considered it appropriate to comment on possible in vivo problems during DLET positioning. They raised concerns regarding potential difficulties passing even a small tube exchanger through the DLET. In our article, we hypothesized that, in clinical practice, the positioning of the DLET may be safely performed with an appropriate tube exchanger.1 However, we clearly reported that the cross-sectional diameter and area of the DLET were similar to those of a conventional endotracheal tube (ETT) even if the lower lumen had an elliptical shape. Furthermore, in our recent in vivo paper2 on the feasibility of DLET during percutaneous tracheostomy, we used a common tube exchanger to place the DLET without any difficulties or anatomical damage. Additionally, patients can be intubated with the DLET in a conventional manner or using a fiberoptic bronchoscope.
Ferraro and colleagues suggest an alternative clinical procedure for ventilation during percutaneous tracheostomy, already tested in vivo.3 They reported on the use of a small (5-mm internal diameter) uncuffed tube, claiming that it offered a better bronchoscopic vision without any interference with ventilation and percutaneous tracheostomy procedures.3 This method seems to guarantee oxygenation rather than ventilation during percutaneous tracheostomy because it resulted in an increased PaCO2. The improvement in ventilation using the DLET during percutaneous tracheostomy has now been reported in patients.2 Although the method proposed by Ferraro et al3 is feasible, it increases the PaCO2 and reduces the arterial pH similar to other conventional ETTs. In our recent in vivo study,2 using the DLET during percutaneous tracheostomy was not associated with any variation in gas exchange, acid/base balance, or airway pressure. Furthermore, the DLET may introduce additional advantages over conventional ETTs during percutaneous tracheostomy: it may reduce/eliminate the risk of accidental extubation and aspiration with its distal cuff, preserve the fiberoptic bronchoscope, and protect the posterior tracheal wall.
Footnotes
Support was provided solely by institutional and/or departmental sources. Dr Kacmarek discloses relationships with Covidien, Venner Medical, and Maquet. The other authors have disclosed no conflicts of interest.
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