Mid-IR spectrometer monitors waste anesthetic gas to protect healthcare workers

Situation / Background

Waste anesthetic gases pose a significant health hazard in hospital settings and must be monitored and controlled to protect healthcare workers. Both the time-weighted average and the peak values must be monitored and can differ by several orders of magnitude.

Two current measurement methods are badges worn by healthcare workers, which are analyzed after exposure, and gas analyzers, which must be preconfigured for the anesthetic gases in question. Neither method can correctly identify and measure impulse events; thus, healthcare workers may be exposed to peak levels of waste anesthetic gases without their knowledge.

Typical waste anesthetic gases measurement methods are not sensitive enough to simultaneously measure low levels of these gases nor fast enough to measure transient leakage levels that are above permissible values. DRS Daylight Solutions has developed ChemDetect™, a line of mid-infrared spectrometer solutions that can address the need for improvement in waste anesthetic gas monitoring.

Solution (products + services that were implemented)

During open-heart surgery on a sheep, simultaneous readings of waste anesthetic gases were taken with a common gas analyzer and ChemDetect™, a DRS Daylight Solutions mid-IR spectrometer using tunable External Cavity Quantum Cascade Laser™ technology and solid state detectors.

Readings were taken in various areas of the operating room, including near the operating table and near the gas handling equipment. To further the testing, in an empty operating room, other waste anesthetic gases were released and measured by both instruments. The following four anesthetic gases were measured with both instruments simultaneously: Isoflurane, Desflurane, Halothane, and Sevoflurane.

The ChemDetect™ spectrometer identified each gas and displayed the concentration without any preempting by the user. The traditional gas analyzer required the user to first put it into a measurement mode, which also presumed that the user knew which gas was being measured. This extra step, which relies on customer interaction, introduces a possible failure point in the use of a gas analyzer.

Results

The ChemDetect™ spectrometer was more responsive and more sensitive to the waste anesthetic gases and thus was better able than the typical gas analyzer to protect healthcare workers, who may be chronically or acutely exposed to these gases. Isoflurane, Desflurane, Halothane, and Sevoflurane levels were tested with a 1.22 meter gas cell with a 10s update rate.

Sensitivity to the waste anesthetic gases tested was significantly higher on the DRS Daylight Solutions mid-IR spectrometer by a factor of 3 than the typical gas analyzer used. ChemDetect™ also registered the correct full value in spike tests and responded as much as 6 minutes faster than the typical gas analyzer.