Baum J, Sachs G, vd Driesch C, Stanke H G
Abteilung für Anästhesie und Intensivmedizin, Krankenhaus St. Elisabeth-Stift, Damme, Germany.
Anesth Analg. 1995 Jul;81(1):144-6. doi: 10.1097/00000539-199507000-00029.
Several cases of unexpected high carboxyhemoglobin (COHb) levels in patients undergoing general anesthesia were observed. To avoid carbon monoxide (CO) intoxication, the use of high fresh gas flows and frequent changes of the absorbent were recommended. However, due to economic and ecologic considerations, low-flow anesthetic techniques have advantages. Thus, the subject urgently needed to be reexamined. In 1001 patients undergoing enflurane or isoflurane anesthesia, blood samples were taken 30 min after fresh gas flow reduction to 0.5 L/min and analyzed for COHb. The absorbent canisters, containing soda lime, were used for several days. The statistical mean and SD of COHb was 1.17% +/- 0.97% in the range of 0%-7.6%. There was no statistical difference between the COHb values when broken down by the duration of use of the absorbent canisters. In no case were dangerously high COHb levels observed. As recently revealed, only dry absorbents produce CO if exposed to volatile anesthetics containing a CHF2-moiety. Thus, all measures must be avoided that dry out the absorbent. Low-flow anesthesia preserves the moisture content of the absorbent and, thus, seems to be a factor protecting from CO generation.
观察到几例全身麻醉患者出现意外的高碳氧血红蛋白（COHb）水平。为避免一氧化碳（CO）中毒，建议使用高新鲜气流并频繁更换吸收剂。然而，出于经济和生态考虑，低流量麻醉技术具有优势。因此，这个问题迫切需要重新审视。在1001例接受恩氟烷或异氟烷麻醉的患者中，在新鲜气流降至0.5L/min后30分钟采集血样并分析COHb。装有苏打石灰的吸收剂罐使用了几天。COHb的统计平均值和标准差在0%-7.6%范围内为1.17%±0.97%。按吸收剂罐使用时间细分时，COHb值之间无统计学差异。在任何情况下都未观察到危险的高COHb水平。正如最近所揭示的，只有干燥的吸收剂在接触含有CHF2部分的挥发性麻醉剂时才会产生CO。因此，必须避免所有使吸收剂变干的措施。低流量麻醉可保持吸收剂的水分含量，因此似乎是防止产生CO的一个因素。
