Background: Massive arterial air embolism is a rare but devastating complic
ation of cardiac operations. Several treatment modalities have been propose
d, but hyperbaric oxygen is the specific therapy. Methods: The Israel Naval
Medical Institute is the only referral hyperbaric center in this country f
or acute care patients. We reviewed our experience in the hyperbaric oxygen
treatment of massive arterial air embolism during cardiac operations. Resu
lts: Seventeen patients were treated between 1985 and 1998, Eight patients
(47.1%) experienced a complete neurologic recovery; 6 patients (35.3%) rema
ined unconscious at discharge, and 3 patients (17.6%) died. Mean (+/- SD) d
elay from the end of the operation to hyperbaric therapy was 9.6 +/- 7.4 ho
urs (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 (1
6-20 hours) for patients who died (1-way analysis of variance; P = .002). T
he source of variance among the groups mainly resulted from the short delay
for patients who experienced complete recovery compared with the other 2 g
roups (Tukey test). All 5 patients cr ho were treated within 3 hours from t
he operation and 50% (2 of 4 patients) of those patients treated 3 to 5 hou
rs 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 asso
ciation between outcome and treatment delay was found to be statistically s
ignificant (tau = 0.65 with exact 2-sided P value = .0007). Conclusion: Hyp
erbaric oxygen therapy should be administered as soon as possible after mas
sive arterial air embolism during cardiac operations.