Hyperbaric Oxygen Preconditioning Reduces Postoperative Brain Edema and Improves Neurological Outcomes After Surgical Brain Injury

The present study was designed to examine if hyperbaric oxygen preconditioning (HBO-PC) is neuroprotective in a mouse model of surgical brain injury (SBI). C57BL mice were administered 100% oxygen for 1 h at 2.5 ATA for 5 consecutive days and subjected to SBI on the following day. The HBO-PC+SBI animals were compared to sham and normoxia+SBI groups for brain water content in different brain regions at 24 and 72 h after surgery. Blood-brain barrier (BBB) permeability was evaluated using Evan's blue dye extravasation al. 24 h. Neurological assessment of the animals was done by a blinded observer at 24 and 72 h. The results showed that brain water content was significantly increased in the right (ipsilateral) frontal lobe surrounding the site of resection. This was attenuated by HBO-PC at 24 and 72 h. However, HBO-PC did not have any effect on the increased BBB permeability observed after SBI. Significant neurological deficits were observed after SBI. HBO-PC improved neurological deficits at 72 h on the 21-point sensorimotor scale and at 24 and 72 h on the wire hang and beam balance scoring. In conclusion, HBO-PC attenuates post-operative brain edema and improves neurological outcomes following SBI.