Dynamic%20Gas%20Scavenging%20System%20(DGSS

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Dynamic Gas Scavenging System (DGSS) The Next
Generation of Scavenger Interface

• Steve Morris
• Anesthetic Gas Reclamation, LLC
• Nashville, Tennessee

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Whats wrong with active scavenging?

• Simple, effective, and low maintenance
• BUT
• Inefficient, costly, and energy-intensive

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Active interface valve State of the art for
40 years
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An alternative approach to active scavenging
the Dräger box No popoff open design
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Typical hospital central evacuation pump 50
ft3min-1 (1500 lpm) continuous flow 24 hours a
day
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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

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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

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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

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

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DGSS history

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

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

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DGSS is the first step

• Low-flow WAGD enables anesthetic reclamation
  through condensation (cold-trap) technology
• Recapture efficiencies are 99 in pilot testing

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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 36 0.1 2.0 1.9

5 lpm
Vent on 36 0.3 10.8 0.9
Vent off 36 0.3 5.0 1.9
Anesthesia and Analgesia, in press 2011
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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