Steve Morris Anesthetic Gas Reclamation, LLC Nashville, Tennessee Dynamic Gas Scavenging System (DGSS®) – The Next Generation of Scavenger Interface Steve Morris Anesthetic Gas Reclamation, LLC Nashville, Tennessee

What’s wrong with active scavenging? Simple, effective, and low maintenance BUT Inefficient, costly, and energy-intensive

“Active” interface valve State of the art for 40 years…

An alternative approach to active scavenging – the “Dräger box” No popoff – open design

Typical hospital central evacuation pump 50 ft3min-1 (1500 lpm) continuous flow 24 hours a day…

PROBLEM Continuous flow of 50 l/min for each OR requires a large vacuum producer Capital cost Ongoing energy requirement Maintenance/replacement Risk of overload/fire with older installations http://www.beaconmedaes.com/PDFs/library/WAGD.pdf

SOLUTION Rework scavenging system to be efficient! Reduce room air entrainment to zero Reduce equipment and energy costs Potentially reduce vacuum pump size by 40-60%

Dynamic Gas Scavenging System - DGSS® New scavenging interface for anesthesia machines – first innovation in 30 years Conserves vacuum from hospital system Enables collection of undiluted waste anesthetic gas Replaces current scavenging interface

Prototype DGSS® First tested in Vanderbilt University OR suite in 2007

DGSS history Developed to facilitate WAG recovery Converts high-flow WAGD to low-flow FDA 510(k) done – December 2006 Now in full production

Current DGSS WAG inlets and evac output configurable in location and fitting type

Installation requirements 12VDC power (500 mA) via external adapter Specific machine mount 19 or 30mm WAG exhaust (single or dual) Although approved as external device, the DGSS technology will, in future, be incorporated into existing machine design…

DGSS is the first step… Low-flow WAGD enables anesthetic reclamation through condensation (cold-trap) technology Recapture efficiencies are ~99% in pilot testing

Waste Anesthetic Flows and Concentrations before and after DGSS installation (GE Aestiva) FGF (Sevo 2%) Scavenger flow (L/min) Scavenger conc (%) DGSS flow (L/min) DGSS conc (%) 2 lpm Vent on 36 0.1 8.0 0.5 Vent off 2.0 1.9 5 lpm 0.3 10.8 0.9 5.0 Anesthesia and Analgesia, in press 2011

Conclusions Waste anesthetic gas flows may be dramatically reduced with a modified interface valve Scavenging ventilator drive gas reduces the efficiency of the system This modified interface is a necessary first step toward efficient recovery of volatile anesthetics with cryogenic condensation