Hyperbaric oxygen therapy for massive arterial air embolism during cardiac operations

Background: Massive arterial air embolism is a rare but devastating complication of cardiac operations. Several treatment modalities have been proposed, but hyperbaric oxygen is the specific therapy. Methods: The Israel Naval Medical Institute is the only referral hyperbaric center in this country for acute care patients. We reviewed our experience in the hyperbaric oxygen treatment of massive arterial air embolism during cardiac operations. Results: Seventeen patients were treated between 1985 and 1998. Eight patients (47.1%) experienced a complete neurologic recovery; 6 patients (35.3%) remained unconscious at discharge, and 3 patients (17.6%) died. Mean (± SD) delay from the end of the operation to hyperbaric therapy was 9.6 ± 7.4 hours (range, 1-20 hours). This delay was 4.0 ± 3.4 hours (1-12 hours) for patients who had a full neurologic recovery, 12.8 ± 7.1 hours (5-20 hours) for patients with severe neurologic disability, and 18.0 ± 2.0 hours (16-20 hours) for patients who died (1-way analysis of variance; P = .002). The source of variance among the groups mainly resulted from the short delay for patients who experienced complete recovery compared with the other 2 groups (Tukey test). All 5 patients who were treated within 3 hours from the operation and 50% (2 of 4 patients) of those patients treated 3 to 5 hours from operation experienced a full neurologic recovery. With a delay of 9 to 20 hours, only 1 of 8 patients had a full neurologic recovery. The association between outcome and treatment delay was found to be statistically significant (τ = 0.65 with exact 2-sided P value = .0007). Conclusion: Hyperbaric oxygen therapy should be administered as soon as possible after massive arterial air embolism during cardiac operations.