高压氧下氧分压、呼出气氧浓度及生命体征的变化

Changes of partial pressure of oxygen,oxygen concentration of expired gas and basic vital signs in hyperbaric oxygen

目的观察高压氧(HBO)下健康志愿者的经皮氧分压、呼出气中氧浓度及心率、呼吸、血压的变化。方法选取9名健康志愿者行高压氧治疗,共19次。升压20 min受试者吸入舱内空气。压力升至0.1 MPa后,受试者戴面罩吸入纯氧,25 min后停止吸氧,减压出舱。加压前、开始稳压、吸氧过程中及出舱时,用密封储气袋收集受试者呼出的气体,同时记录受试者经皮氧分压、心率、呼吸频率和血压等的变化。出舱后迅速测定储气袋中氧浓度。结果常压下受试者呼出气中氧浓度、经皮氧分压分别为17.9%和66 mmH g,压力升至0.1 MPa时分别为19.1%和132 mmH g,吸氧后两者迅速增高,2 min时氧浓度达到91%左右,之后氧浓度上升缓慢,4 min时达到最大值94%。4 min时经皮氧分压达到817 mmH g,之后上升速度减慢,吸氧结束时达到922 mmH g。与加压前相比,吸氧结束时受试者心率减慢(P<0.05),血压和呼吸频率无显著变化。结论高压氧治疗的初始阶段受试者经皮氧分压、呼出气中氧浓度迅速升高,4 min时氧浓度达到最大,经皮氧分压持续缓慢增高。高压氧可减慢心率,但对呼吸频率、血压没有明显影响。

Objective To assess the changes of partial pressure of oxygen,concentration of oxygen in exhaled gas,heart rate,respiratory rate and blood pressure in healthy volunteers exposed to hyperbaric oxygen（ HBO）. Methods Nine healthy volunteers were exposed to HBO.They breathed air in chamber for 20 min during ascending,inhaled in oxygen during the next 25 min through oral- nasal mask,then depressed to atmosphere. We collected gas from the volunteers and measured the concentration of oxygen,and recorded Pt O2 simultaneously. Heart rate,respiratory rate and blood pressure were measured before and after hyperbaric oxygen therapy. Results The concentration of oxygen and Pt O2 were 17.9%,66 mm Hg under atmosphere,and increased to 19. 1%,132 mm Hg after pressurization. They arose apparently when oxygen was inhaled. The concentration of oxygen reached to 91% in 2 min,and approached to the maximum in 4min. Pt O2 reached to 817 mm Hg in 4 min and 922 mm Hg at the end of therapeutic process. Comparing to beginning,heart rate of the volunteers decreased apparently after oxygenation（ P 0. 05）,respiratory rate and blood pressure did not change. Conclusion Pt O2 and the concentration of oxygen from volunteers rose severely during the process of oxygenation,and oxygen concentration reached to the maximum in 4 min and Pt O2 increased slowly after that. HBO reduced heart rate,and had no effect on respiratory rate and blood pressure.