Low-flow and minimal-flow anaesthesia using the laryngeal mask airway

Abstract

This study was designed to investigate whether the advantages of low- and minimal-flow anaesthesia can be combined with the laryngeal mask airway (LMA). Seventy female patients undergoing routine gynaecological surgery were investigated. After induction of anaesthesia and after positioning a laryngeal mask airway nos 3 and 4, patients were ventilated for 20 min with a fresh gas flow of 6L min⁻¹. Thereafter, the flow was reduced to 1L min⁻¹ in 50 patients and to 0.5L min⁻¹ in 20 patients. Once in the proper position,the LMA allowed flow reduction in all patients, indicating that no gas leakage occurred. It is concluded,that the application of low-flow and even minimal-flow anaesthesia is an alternative to high-flow anaesthesia. It can result in high annual savings and minimization of pollution. However, its use should be restricted to those anaesthesiologists who are experienced with the laryngeal mask airway and minimal-flow anaesthesia.