INTRODUCTION

Level-of-consciousness monitoring allows anesthesia clinicians to measure the effects of anesthesia and sedation on the brain, allowing them to deliver anesthesia with more precision. With the variety of anesthetic techniques, agents, and approaches utilized during anesthesia for cosmetic surgery, a consciousness monitor is one of the important tools that aid in the goal of improving patient care and achieving excellent outcomes.

EVOLUTION OF PATIENT MONITORING

Patient assessment and intraoperative monitoring during anesthesia has undergone gradual change and refinement. Observations of clinical signs such as pupil response, patterns of respiration, quality of the pulse, and movement were first augmented by direct measurement of physiologic endpoints including blood pressure, heart rate, and respiratory rate and volume. With the development of pulse oximetry and capnography, precise assessments of ventilatory management could be made. The use of end-tidal agent analysis and peripheral nerve stimulation provided anesthesia clinicians the ability to measure pharmacologic agent concentration and effect, respectively. Although not used during cosmetic surgery, cardiac function can be evaluated using technologies that range from pulmonary artery catheters and transesophageal echocardiography to new methods of continuous blood pressure and cardiac output monitoring.

Despite the remarkable improvements in assessment of the cardiovascular and pulmonary function during anesthesia, direct determination of the effect of the anesthetic and sedative agents on the central nervous system has remained limited. Careful clinical investigations demonstrated that hemodynamic responses do not necessarily provide an accurate representation of the central nervous system responsiveness to anesthetic agents.