Incidence of Anesthetic Awareness may be Higher in Low Flow Anesthesia

There is a growing interest in applying techniques of low flow anesthesia in different groups of surgical patients. Numerous studies confirm the benefits of low flow anesthesia in comparison to anesthesia with high flow, whereby its limitation and disadvantages have been addressed. The main advantages of low-flow anesthesia techniques involve three areas: pulmonary-anesthesia with low fresh gas flow improves the dynamics of inhaled anesthesia gas, increases mucociliary clearance, maintains body temperature and reduces water loss; economic-reduction of anesthesia gas consumption that results in significant savings of more than 75% and ecological reduction of atmospheric pollution. In addition, the use of these techniques promotes greater understanding of breathing systems and pharmacokinetics of inhalation anesthesia [1,2]. Limitations and disadvantages of this type of anesthesia are: need of modern anesthetic equipment and obligatory gas monitoring, inability to quickly alter inspired concentrations, accumulation of undesirable gases in the respiratory circle, uncertainty about inspired concentrations and faster absorbent exhaustion [3]. Small amounts of inhaled anesthetics in low flow anesthesia (concentrations of the volatile anesthetics may be too low and may cause consciousness during anesthesia) might result in higher incidence of awareness and patients experiencing awareness and recall [4,5].