Arend O, Harris A, Martin B J, Holin M, Wolf S
Augenklinik der Med. Fak, RWTH Aachen, Germany.
Acta Ophthalmol (Copenh). 1994 Jun;72(3):332-6. doi: 10.1111/j.1755-3768.1994.tb02768.x.
Hyperoxic-hypercapnic gas mixture ('carbogen': 6% CO2-94% O2) is widely used clinically. Its influence on retinal perfusion remains unclear, since past work suggests that high O2 may reduce and high CO2 may increase retinal blood flow. To examine the changes in retinal blood velocity during 'hyperoxic-hypercapnic' gax mixture breathing, we quantified retinal blood velocity indices. Twenty-eight healthy subjects were studied using scanning laser video fluorescein angiograms at baseline and after gas inhalation. Retinal arteriovenous passage time and mean arterial dye velocity were measured by means of a digital image processing system. Arterial diameter measurements showed no change (4%) during carbogen breathing. Increased arterial Pco2 and Po2 resulted in small but statistically significant increases in systolic and diastolic blood pressure and heart rate (each c. 8%, p < 0.05), and a dramatic increase in mean dye velocity (27%, p < 0.01), with parallel reduction in arteriovenous passage time (40%, p < 0.01). The substantial acceleration of retinal dye velocity and transit under combined hyperoxia and hypercapnia strongly suggests that this clinically standard gas mixture may indeed improve oxygenation without reducing retinal perfusion.
高氧-高碳酸气体混合物（“卡波金”：6%二氧化碳-94%氧气）在临床上被广泛使用。其对视网膜灌注的影响仍不明确，因为过去的研究表明高氧可能会减少而高二氧化碳可能会增加视网膜血流量。为了研究在“高氧-高碳酸”气体混合物呼吸过程中视网膜血流速度的变化，我们对视网膜血流速度指标进行了量化。使用扫描激光视频荧光血管造影术对28名健康受试者在基线时和吸入气体后进行了研究。通过数字图像处理系统测量视网膜动静脉通过时间和平均动脉染料速度。在吸入卡波金期间，动脉直径测量显示没有变化（4%）。动脉血二氧化碳分压和氧分压升高导致收缩压、舒张压和心率小幅但具有统计学意义的升高（各约8%，p<0.05），平均染料速度显著增加（27%，p<0.01），同时动静脉通过时间平行缩短（40%，p<0.01）。在高氧和高碳酸联合作用下视网膜染料速度和通过时间的大幅加快强烈表明，这种临床标准气体混合物确实可以在不减少视网膜灌注的情况下改善氧合。
