Effect of body position on gas exchange after bronchoalveolar lavage.

Objective: To assess the possible influence of body position on oxygen saturation after bronchoscopy (BC) with bronchoalveolar lavage (BAL).

Design: Prospective, open, randomized study.

Setting: The respiratory unit of a first level, community hospital.

Patients: Forty-one consecutive patients in which BC with BAL, using at least 150 mL of BAL fluid, was performed.

Method: We randomly assigned 21 patients to lie in lateral decubitus (LD) with the lung where BAL was performed uppermost after BC, and 20 to lie in supine position (SP). Oxygen saturation (SO2) was measured for all patients from 10 min before to 30 min after the end of the BC. Saturation parameters were compared for both groups.

Results: Mean SO2 was significantly lower after than before the BC, both for LD and SP groups (LD: 91.4+/-3% vs. 94.9+/-2%, respectively; P=0.0001) (SP: 91.6+/-3 vs. 95.8+/-3%, respectively; P=0.0003). We did not find significant differences between LD and SP groups, after BC, regarding mean SO2 (91.4+/-3% vs. 91.6+/-3%), minimum SO2 (86.2+/-4.5% vs. 86.6+/-5.4%, respectively) or percentages of registry time at saturations below 90% (26.3+/-35.9% vs. 27.6+/-38.2%, respectively) (P:NS for all values).

Conclusion: BC with BAL caused significant oxygen desaturation in our patients. We have not been able to demonstrate a significant influence of body position on SO2 after BAL.