The development of patient-controlled sedation pump for minor surgical procedures

Abstract

Patient-controlled sedation systems, in which the patient has control of sedative administration, have been shown to be effective and safe for patients undergoing minor procedures. Safety depends on the adequacy of the step-wise increase in dose of the sedative, the lockout time and patient’s ability to adjust the effective activation of the handset. While there is no patient-controlled sedation (PCS) system available domestically, we have developed a new purpose-built PCS pump, and determined its degree of precision using a microweight measuring scale. The PCS system was designed to be applied to most intravenous sedatives and work through a newly developed operating software algorithm that titrates the doses and lockout times. Our system titrates the doses through software modification, and for experimental purposes, the number of steps for handset activation by the patient was set to four, and the lockout time was set to 30 s. The degree of precision of the PCS system was tested using an electronic weighing scale. The comparison of the amount infused via the PCS system with weight on the scale showed nearly same patterns at the four infusion stages, and the difference was minimal (3% on average at each infusion step). We designed and manufactured a pilot button-type PCS pump capable of use by the patient for optimal sedation, and confirmed the precise working mechanism of the pump, thereby reducing the margin of error for infusion accuracy to 3% or less on average.