Continuous FTIR Gas Analyzer Monitors Hospital Anesthetics: Case Study B y A ntti H eikkilä Thirty-two different sampling points are located in locations where anaesthetic gases are present. odern hospitals are equipped with scavenging and ventilation systems that help to minimize the exposure of staff to anesthetic gases that may be present due to leaks from the anesthetic breathing circuit (including the mask), or from the escape of gases during connection or unhooking of the system, or from patient exhaled anesthetics. The Mater Dei Hospital in Malta has installed a continuous sampling and monitoring system from Gasmet of Finland that monitors a range of anesthetic gas levels in 32 locations including operating theaters and recovery rooms. The analyzer (Gasmet™ FCX) employs FTIR gas analysis technology to deliver fast accurate data for a range of chemical compounds simultaneously. This data is used to raise alarms when levels exceed pre-set thresholds and to help the hospital staff lower exposure to anesthetic gases by changing working practices. Built in 2007, the Mater Dei Hospital is the only general acute teaching hospital in Malta, providing acute healthcare services in addition to facilities for training doctors, nurses, pharmacists, dentists and other healthcare professionals. The hospital employs over 3800 staff members and approximately 130 surgical operations are conducted every day. Anesthetic gases cannot be detected by their odor until concentrations are very high, so workplace levels of anesthetic gases are measured by a Gasmet FCX instrument which is a wall-mounted multiparameter gas analyzer with a built-in computer in a dust and moisture protected cabinet. Designed specifically for process gas monitoring and workplace air quality measurements, the FCX series of analyzers provide long-term, unattended, continuous monitoring with data logging and alarm capability. The sampling system is comprised of 32 tubes ranging from 1 meter to 100 meters in length, and the sampling/ flushing times have been optimized according to the length of each tube. Each sampling point is mounted approximately 2m above floor level; for example, in the theatres they are mounted on the same pendant that supports the anesthetic machine. Measurement time is approximately 10 seconds per sample and the total cycle time is 18 minutes.

Current data, including a multipoint summary, is displayed on the unit’s PC screen via Calcmet™ software, which enables hospital staff to view any concentrations that exceed target levels. In addition, the hospital has implemented Envidas software to make the data available on a password protected website to provide accessibility for hospital staff from any location. The system is set to display readings for nitrous oxide, desflurane, sevoflurane and isoflurane, and threshold values have been set at 2 ppm for N2O and 0.5 ppm for the others. Initially, the alarm output from the analyzer was connected...