Quantitative evaluation for the effects of hyperbaric oxygen Intervention on carotid artery elasticity

Abstract

Ohjectlve To evaluate quantitatively the effect of hyperbaric oxygen (HBO) on carotid artery elasticity with bilateral carotid artery parameters by echo tracking (ET).Methods Forty-one patients who received HBO therapy were assigned to the HBO group ( group 1 ),20 healthy subjects assigned to the hyperbaric air group ( group 2) and still another 20 healthy subjects were assigned to the high-flow oxygen therapy group ( group 3).The patients of group 1 breathed pure oxygen at 0.20 MPa for a duration of 60 min,and the subjects of group 3 breathed pure oxygen at normal pressure also for a duration of 60 rmin.For the first 2 groups,bilateral carotid artery elasticity was measured with ET,at a time right before entrance into the chamber and right after exit from the chamber; and for group 3,measurement was made with ET,at a time right before oxygen breathing and right after oxygen breathing.The measured data included vascular pressure-strain elasticity modulus (Ep),data of artery stiffness (β) and artery compliance (AC).Results For the HBO group,when patients came out of the chamber,Ep and β levels were significantly decreased,while AC data were significantly increased,with statistical significance,when compared with that of pre-HBO therapy[preintervention of HBO: Ep ( 129.04 ± 52.47 ) kPa,β: (9.75 ± 3.83),AC: ( 0,86 ± 0.34 ) mm2/kPa; postintervention of HBO: Ep: ( 112.38 ± 50.94 ) kPa,β: ( 8.29 ± 3.66 ),AC: (0.99 ± 0.45 ) mm2/kPa ]( P ＜0.0l ).For the hyperbaric air group,when subjects came out of the chamber,Ep and β levels were decreased,while AC data were increased,all with statistical significance,when compared with that before entrance into the chamber (P ＜ 0.0 l or P ＜ 0.05 ).For the high-flow oxygen therapy group,no differences could be detected in Ep,β and AC data measured both before and after oxygen breathing,without statistical significance ( P ＞0.05).For those in group 1 and group 2,with an age of less than 40,Ep,β and AC data all improved,when they came out of the chamber (P ＜0.01 or P ＜0,05 ),with HBO group having more significant improvement than the hyperbaric air group.And statistical significance could be noted,when a comparison was madebetween the two ( P ＜ 0.01 or P ＜ 0.05 ).Conclusions HBO intervention could improve carotid artery elasticity. Key words: Hyperbaric oxygen; Carotid arteries; Echo tracking