Double-lumen tubes and auto-PEEP during one-lung ventilation.

Area of Science:

• Anesthesiology
• Respiratory Physiology
• Thoracic Surgery

Background:

• Double-lumen tubes (DLTs) are essential for one-lung ventilation (OLV) in thoracic anesthesia.
• The narrow lumen of DLTs may increase resistance and contribute to auto-positive end-expiratory pressure (auto-PEEP).

Purpose of the Study:

• To investigate the impact of adult-sized DLTs on dynamic auto-PEEP during OLV.
• To quantify the DLT's contribution to auto-PEEP in patients undergoing thoracic surgery.

Main Methods:

• Prospective clinical study involving 72 patients undergoing thoracic surgery.
• Dynamic auto-PEEP was measured with various right- and left-sided DLTs.
• Air trapping was induced by altering the inspiration-to-expiration ratio to determine pressure gradients and auto-PEEP.

Main Results:

• The pressure gradient across the DLT (ΔPDLT) was 2.3 cm H2O.
• The mean total auto-PEEP was 2.9 cm H2O, with DLTs accounting for 27-31% of this value.
• DLT size and side did not significantly influence auto-PEEP levels.

Conclusions:

• DLTs contribute a small, clinically insignificant amount to overall auto-PEEP during OLV.
• The choice of DLT size or side does not meaningfully alter the risk of developing auto-PEEP.