[Low-level nitrous oxide: risk assessment and risk management]

Protossido d’azoto a basso tenore: risk assessment e risk management

The administration of mixes with a low content of nitrous oxide (generally of 50% N,0 in O,) is commonly used for pain management, inducing a light level of sedation, in endoscopy interventions, dentistry, particularly in the paediatric field, during childbirth sessions, etc... Potential negative health effects associated with acute and hypothesized chronic workplace exposure not only limits it use in the operating room but causes several critical issues when used in environments that are not dedicated to operating activities and consequently, do not come with sufficient air changes and appropriate anaesthetic gas scavenging systems. The aim was to assess occupational exposure of staff during mixes, with a low content of nitrous oxide, administration in patients undergoing digestive endoscopy procedure during use of a double face mask with a demand valve and a portable gas evacuation and dedicated system compared with a conventional single face mask without scavenging system. NO concentrations, representing exposure values, were monitored within proximity to staff with a spectrophotometric acoustic multipoint system. The samples of 45 endoscopic procedures, taken at the breathing area zone of the staff, to more heights and in more sampling points of endoscopy environments analyzed, have detected a mean of 450$347 (standard deviation) ppm of nitrous oxide without scavenging system and a mean of 28$55ppm with double mask with a demand valve and portable gas evacuation system, significantly different values to the U Mann-Whitney test, with statistical significance p-value <0.001. In conclusion, the absence of specific regulatory limits for diagnostic and or therapeutic procedures that use nitrous oxide in non-operating room environments, as well as the absence of rules or guidelines that indicate what systems of administration of anaesthetic gases should be used in those same environments, often not equipped with evacuation systems, require a prompt discussion of the scientific community of new rules on the use of mixtures with a low concentration of nitrous oxide.