Jones J G, Bembridge J L, Sapsford D J, Turney J H
Cambridge University Department of Anaesthesia, Addenbrooke's Hospital, UK.
Nephrol Dial Transplant. 1992;7(2):110-6. doi: 10.1093/oxfordjournals.ndt.a092078.
A new technique for recording and analysing continuous measurements of oxygen saturation (SpO2) by pulse oximeter during haemodialysis was used to compare changes in SpO2 in eight patients during two 4 h periods of dialysis using a cuprophane membrane, once using an acetate dialysate, and once using bicarbonate. The computer-derived patterns of SpO2 show whether hypoxaemia was caused mainly by extrapulmonary abnormalities (ventilatory control) or intrapulmonary abnormalities (V/Q distribution). The patterns of oxygen saturation were analysed for (i) stability, (ii) the lower median 20th centile of SpO2, and (iii) time below a SpO2 of 90%. Not all patients had reduced oxygenation during acetate dialysis. Three of eight patients had a stable pattern with acetate dialysis and six of eight were stable with bicarbonate. Five of eight patients had a lower SpO2 with acetate but one patient had a lower SpO2 with bicarbonate. Four patients had prolonged, clinically significant periods of oxygen desaturation with SpO2 less than 90%; two of these had particularly prolonged periods during acetate (62 min and 12 min), but one patient showed a longer period during bicarbonate than acetate dialysis (7 min). In two patients the SpO2 declined to less than 84%. The patterns of SpO2 suggested that the decrease in oxygen saturation was due more to extrapulmonary abnormalities causing an instability in ventilatory control rather than to venous admixture. It is recommended that pulse oximetry is used to identify patients at risk of hypoxaemia, to monitor these patients during haemodialysis, and to administer oxygen to those whose SpO2 falls below 90%, particularly if they have anaemia or cardiovascular disease.
一种用于记录和分析血液透析期间通过脉搏血氧仪连续测量氧饱和度（SpO2）的新技术，被用于比较8名患者在使用铜氨膜进行两次4小时透析期间SpO2的变化，一次使用醋酸盐透析液，一次使用碳酸氢盐透析液。计算机得出的SpO2模式显示低氧血症主要是由肺外异常（通气控制）还是肺内异常（V/Q分布）引起的。分析了氧饱和度模式的以下方面：（i）稳定性；（ii）SpO2的第20百分位数下限中位数；（iii）SpO2低于90%的时间。并非所有患者在醋酸盐透析期间氧合都会降低。8名患者中有3名在醋酸盐透析时模式稳定，8名中有6名在使用碳酸氢盐时稳定。8名患者中有5名在使用醋酸盐时SpO2较低，但有1名患者在使用碳酸氢盐时SpO2较低。4名患者出现了临床上显著的长时间氧饱和度降低，SpO2低于90%；其中2名在醋酸盐透析期间有特别长的时间（62分钟和12分钟），但有1名患者在碳酸氢盐透析期间出现的时间比醋酸盐透析更长（7分钟）。2名患者的SpO2降至低于84%。SpO2模式表明，氧饱和度的降低更多是由于肺外异常导致通气控制不稳定，而非静脉血掺杂。建议使用脉搏血氧测定法来识别有低氧血症风险的患者，在血液透析期间监测这些患者，并对SpO2低于90%的患者给予吸氧，特别是如果他们有贫血或心血管疾病。
