A unique gas measurement technology has enabled South Devon Healthcare’s Pharmacy Manufacturing Unit (PMU) at Torbay Hospital to conduct highly effective and detailed analysis of anaesthetic gases in a variety of hospital locations.
The primary function of the PMU’s quality control department is to check active ingredient levels and sterility in manufactured pharmaceutical products. However, a Gasmet DX4030 FTIR analyser was purchased to provide an anaesthetic gas monitoring service.
Torbay PMU manufactures around 200 products, including terminally sterilised injectable and topical solutions. The unit has been in operation for over 30 years and a new custom-built facility is currently under construction near Paignton. This will expand the PMU's production capability significantly, increasing staff levels to over 100, and bringing manufacture, quality control and warehousing together under one roof. The NHS is a major customer for the PMU but products are also provided to commercial companies and to an expanding group of customers overseas.
The quality control department operates a fully equipped chemical and microbiological laboratory, so its staff possess a high level of analytical expertise. It was logical therefore to involve QC staff in a review of the procedures for assessing levels of anaesthetic gases at Torbay Hospital, and these discussions led to the acquisition of a portable Gasmet FTIR analyser.
Jamie Hoyle, a PMU Quality Control Specialist, is responsible for operating the analyser. He says: 'In the past, the hospital employed contractors to check levels of anaesthetic gases, but this only provided a limited amount of information; staff were fitted with sorbent tubes, so the results merely provided an average concentration for one day, for each of the target compounds.
'The use of sorbent tubes is unable to provide a complete picture of gas levels because the method relies on the collection of air samples over a complete day and provides no detail on staff exposure in specific locations.
“In contrast, the portable FTIR analyser can be configured to provide continuous readings for up to 25 compounds, so that we can either view live readings or leave the analyser to take measurements in a specific location. This means that we are able to fully evaluate every room, identifying hotspots and locating any processes that result in higher concentrations, even if these levels are transitory.'
Ambient levels of anaesthetic gases such as nitrous oxide, sevoflurane, halothane, desflurane, and isoflurane are now routinely monitored in Torbay Hospital’s theatres, maternity areas and day surgeries. However, the analyser will also be employed at the Hospital Sterilisation and Decontamination Unit (HSDU) in Barnstaple.
Torbay Hospital's portable FTIR is a Gasmet DX4030, manufactured in Finland and supplied in the UK by Gasmet's distributor Quantitech. Initial training was provided by Quantitech's Dr Andrew Hobson, who also provided a set of calibrations so that the analyser could provide live readings for the specific anaesthetics that are employed in the hospital.
The Gasmet DX4030 is unique because it provides the high levels of analytical performance (that are traditionally available from laboratory instruments) in a portable unit that can be deployed almost anywhere. Employing FTIR (Fourier Transform InfraRed Spectroscopy) analysis the instrument produces almost instantaneous readings for multiple compounds across a wide measurement range that extends to sub-ppm levels. No sample preparation is needed; the sample gas is simply drawn into the analyser module via a sample probe. Uniquely, the whole system is battery operated, mounted in a back-pack and has an operating time of several hours.
Data collection and display is facilitated by an easy-to-use PDA (Personal Digital Assistant) user interface. The analyser module and the PDA communicate via wireless Bluetooth protocol and measurements for each compound are displayed at the touch of a button on the PDA.
One of the advantages of FTIR is that the instrument stores a full spectrum of analysis – not just for the compounds of interest. This means that users are able to exploit the Gasmet FTIR reference library that contains calibrations for thousands of different compounds. Explaining the advantages of this, Jamie Hoyle says: “It is possible to retrospectively analyse sample spectra using the instrument’s Calcmet™ software - this means that we have the ability to look at stored spectra to identify and measure almost any compound.”
In addition to the measurement of anaesthetic gases, the flexibility of the DX4030 has meant that it has also been employed in other applications for the measurement of different gases. For example, when a new coating was applied to the floor of a delivery bay, staff complained of solvent smells, so the PMU’s Quality Control department was called in to conduct a survey in order to check the safety of working conditions. No gases were found to be above workplace exposure limits so it was quickly possible to reassure staff that they were not at risk.
In common with the sorbent tube method, the use of a portable FTIR analyser provides confirmation that air quality is safe and that levels are within occupational exposure limits. However, the main advantage of the Gasmet FTIR is that it provides a great deal more information, which enables the identification of peak concentrations and the proactive management of anaesthetic gases. In addition, it also provides an in-house resource that can be deployed for the analysis of almost any gas.