Clinical evaluation of Engström's electrically controlled ELSA for low flow closed circuit anesthesia
Igarashi, M.; Nakae, Y.; Ichimiya, N.; Watanabe, H.; Iwasaki, H.; Namiki, A.
Masui. Japanese Journal of Anesthesiology 42(2): 249-254
1993
ISSN/ISBN: 0021-4892 PMID: 8437358 Document Number: 421062
Many anesthesiologists are now interested in low flow, closed circuit anesthesia from an economical and environmental point of view. In order to evaluate clinically a newly developed electronically controlled anesthesia machine Engstrom's ELSA, we compared low flow, closed circuit anesthesia on 38 ASA I-II patients using ELSA, with high flow anesthesia on 12 ASA I-II patients using a conventional anesthesia machine. The results were as follows: 1. We could perform safe and economical low flow, closed circuit anesthesia using ELSA's injection vaporizer and accurate monitoring devices for O-2, N-2O, CO-2 and concentrations of various volatile anesthetic agents. 2. Under low flow anesthesia, isoflurane consumption was 5.3 +- 1.1 ml cntdot h-1 cntdot Vol%-1 (mean +- SE) with ELSA, which is about one fourth of the high flow anesthesia consumption (22.6 +- 2.1 ml cntdot h-1 cntdot Vol%-1 (mean +- SE)). 3. Low flow closed circuit anesthesia could maintain significantly higher temperature and humidity compared with high flow anesthesia. 4. Under low flow anesthesia of more than 7 hrs, color of soda lime becomes blue, but this does not affect FI-O-2 nor Pa-CO-2, and the method is clinically safe for patients.