Anatomic evaluation of postural bronchial drainage of the lung with special reference to patients with tracheal intubation: which combination of postures provides the best simplification?

Abstract

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 B(1), B(2), B(1 + 2), B(3), and B(6) 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 degrees ) at the subsegmental bronchial origin was sometimes evident, and this made postural drainage difficult. Drainage of B(3) and B(6) was often difficult because they formed angles of < 45 degrees from the horizontal in certain postures (supine for B(3) and prone for B(6)). Further, we found a 45 degrees rotative prone position effective for draining B(1)a and B(6). CONCLUSION: Our anatomic findings predicted increased effectiveness in a sequence of postures: supine, 45 degrees rotative prone with left side up, 45 degrees 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 degrees right-side-up supine and 45 degrees rotative prone with head raised 45 degrees positions seemed helpful if added to the basic sequence.