Comparison of different size left-sided double-lumen.

To the Editor,

We appreciate the review and the comments regarding our article, “Comparison of different size left-sided double-lumen tubes for thoracic surgery.” Although we agree, one size cannot fit all, a 35F DLT can be safely used for most adult patients. Amar et al. also showed that the use of a 35F DLT in adults was associated with a similar and not worse incidence of the most common clinical outcomes in comparison to conventional sizing recommendations.[1234]

It has been recommended by some investigators to keep the bronchial cuff inflation pressures less than 25 cm H2O to avoid compromise of mucosal blood flow.[5] It has been demonstrated that cuff pressure does not necessarily correlate to pressure exerted on the bronchial wall.[5] We did not specifically record the pressure or the amount of air inflated in the bronchial cuff between the two groups; however, it was never more than 5 mL of air. Inflation of the bronchial cuff was only done under direct visualization with the fiberoptic scope and only enough air to create a visible seal around the left main bronchus. In our study, we had no issues maintaining the end tidal carbon dioxide (ETCO2) below 45 mmHg and no events of sustained high peak airway pressures or issues with ventilation.

A recent study published by Kar et al.[6] showed that a smaller DLT than recommended for lung isolation did not lead to any clinically appreciable problems in lung isolation, surgeon complaint, or complications associated with spillage. Time to lung collapse was not part of our study; however, we agree that a larger DLT may lead to quicker lung collapse when isolating. Although this may be statistically significant, it is unlikely to be clinically significant. Bussieres et al. showed that surgeons could not reliably determine which device was being used based on the time and quality of lung collapse when comparing double-lumen tubes and bronchial blockers.[7]

In conclusion, although there were limitations to our smaller study, we do agree that a 35F DLT cannot be used for all patients, but can safely be used in most adult patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.