Histologic Evaluation of Normobaric Oxygen Therapy Safety in an Animal Model

Background: Oxygen therapy, as a therapeutic modality, can be used for long periods of times. However, it may be accompanied by potential complications and side effects. Objectives: To evaluate the side effects of normobaric oxygen therapy in rabbits. Materials and Methods: In a double-blind experiment, 28 white New Zealand rabbits were randomized into an oxygen treatment group (n = 14) and a control group (n = 14). The oxygen treatment group received 100% oxygen at a flow rate of 5 L/min for 1 h daily, for 1 month. The animals were euthanized at the end of the study, and following autopsy a histological evaluation was carried out to detect levels of oxygen toxicity in their; lungs, liver, brain, heart, kidney, eyes and spleen. Results: Histological evaluation revealed no evidence of toxicity in the examined tissues, compared with the control group. Conclusions: Oxygen therapy at a flow rate of 5 L/min for 1 h daily for 1 month had no systemic toxicity and it appears to be safe in rabbits.