Oxygen Therapy in Ischemic Stroke

To the Editor:Previous studies of therapeutic oxygen in stroke have had conflicting results, and the latest study by Rusyniak et al 1 seems to suggest that hyperbaric oxygen therapy (HBO) is harmful in ischemic stroke.The authors have already discussed how several inadequacies in trial design might explain their negative results.We wish to draw attention to additional features in their study that might offer important insights into the design of future studies of oxygen in stroke.The authors evaluated the safety, feasibility, and efficacy of using HBO in a sham-controlled pilot study of 33 patients with acute (Ͻ24 hours) ischemic stroke.The HBO group (17 patients) received 100% oxygen at 2.5 atm absolute (ATA), and the sham group (16 patients) received 100% oxygen at 1.14 ATA, both for 60 minutes.Outcomes were measures at 24 hours and 90 days