Background: Although several sequences of specific postures, each corresponding to a particular lung segment, have been recommended for therapeutic bronchial drainage, these are based on little or no anatomic evidence. Moreover, because these sequences are too complex, especially for intubated patients, they require simplification.
Materials and methods: The courses of the segmental bronchi B1, B2, B1 + 2, B3, and B6 and their subsegmental bronchi are extremely variable. This can result in a small branching angle at the subsegmental bronchial origin. Using 106 lungs, we measured the branching angles of the subsegmental bronchi and examined their running directions in each posture of the sequences recommended for bronchial drainage.
Results: A small branching angle (< 120°) at the subsegmental bronchial origin was sometimes evident, and this made postural drainage difficult. Drainage of B3 and B6 was often difficult because they formed angles of < 45° from the horizontal in certain postures (supine for B3 and prone for B6). Further, we found a 45° rotative prone position effective for draining B1a and B6.
Conclusion: Our anatomic findings predicted increased effectiveness in a sequence of postures: supine, 45° rotative prone with left side up, 45° rotative prone with right side up, and return to supine for simple, safe, and effective bronchial drainage, especially for patients with tracheal intubation. The 10° right-side-up supine and 45° rotative prone with head raised 45° positions seemed helpful if added to the basic sequence.