Introduction: Hyperbaric oxygen (HBO₂) therapy is generally safe and well tolerated. However, known side effects do exist. Elevation in the blood pressure of patients undergoing HBO₂ therapy is a less defined potential side effect. We sought to better quantify effects of HBO₂ on blood pressure (BP) in patients undergoing HBO₂.

Methods: A retrospective chart review was performed on quality assurance data captured on all patients undergoing HBO₂ between March 2012 and October 2015 at a large tertiary referral university hospital hyperbaric center.

Results: We identified 155 patients who received 3,147 hyperbaric oxygen treatments. For all treatments there was an overall increase in the median systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) following treatment (Table 2). No statistically significant difference was found when comparing patients with and without hypertension. Calcium channel blockers (CCB) and beta-blockers (BB) were found to have an agonizing effect while ACE inhibitors (ACEI) were found to have a protective effect (Table 4). The change in SBP was less with each additional treatment in patients undergoing more than one treatment.

Discussion: The current study demonstrates that absolute rises in blood pressure do occur as a result of HBO2 therapy. However, the extent of this effect is not large. BB and CCB had agonizing effects while ACEI had a protective effect. Finally, there was a protective effect with more treatments.