A Practical Approach to Adult One-Lung Ventilation
Highlights
- with a patient in the lateral position and laterally flexed, there can be partial obstruction of the distal trachea. Therefore, ventilating the dependent lung via the tracheal lumen may be difficult, requiring higher pressures. There is also a risk of air trapping in that lung. (View Highlight)
- Adult DLTs commonly come in sizes 35, 37, 39, and 41 Fr. (View Highlight)
- The French scale is the external diameter of the tracheal segment (in mm) multiplied by three (View Highlight)
- A properly sized DLT is one that passes easily through the glottis and advances without resistance within the trachea, with the bronchial component passing into the intended bronchus without difficulty (View Highlight)
- A traditional approach would be to use 37 and 39 Fr DLTs for average sized female and male patients respectively (View Highlight)
- The depth of insertion of the DLT correlates to the height of an average sized patient and is given by the formula 12 + (patient height)/10 cm, measured at the teeth (View Highlight)
- Immediately after the initiation of OLV, there is a fall in arterial oxygenation and saturation which gradually picks up as hypoxic pulmonary vasoconstriction (HPV) increases. HPV is characteristically biphasic, with an early response beginning within the first few seconds to reach a maximum in about 15 min, followed by a second phase that begins about 30–40 min later to peak at 2 h (View Highlight)
- While there is no accepted figure for the safest lower limit of oxygen saturation during OLV, a value ≥90% is recommended. (View Highlight)
- Increase FiO2 to 1.0. This can be employed in all patients except those who have received bleomycin for malignancy. (View Highlight)
- Perform recruitment manoeuvre to the ventilated lung. This may, however, cause transient hypotension and transient worsening of hypoxemia if more blood is diverted to the non-ventilated lung. (View Highlight)