{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T23:25:07Z","timestamp":1782861907396,"version":"3.54.5"},"reference-count":29,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2022,5,31]],"date-time":"2022-05-31T00:00:00Z","timestamp":1653955200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metabolites"],"abstract":"<jats:p>Regional anaesthesia is well established as a standard method in clinical practice. Currently, the local anaesthetics of amino-amide types such as prilocaine are frequently used. Despite routine use, complications due to overdose or accidental intravenous injection can arise. A non-invasive method that can indicate such complications early would be desirable. Breath gas analysis offers great potential for the non-invasive monitoring of drugs and their volatile metabolites. The physicochemical properties of o-toluidine, the main metabolite of prilocaine, allow its detection in breath gas. Within this study, we investigated whether o-toluidine can be monitored in exhaled breath during regional anaesthesia in an animal model, if correlations between o-toluidine and prilocaine blood levels exist and if accidental intravenous injections are detectable by o-toluidine breath monitoring. Continuous o-toluidine monitoring was possible during regional anaesthesia of the cervical plexus and during simulated accidental intravenous injection of prilocaine. The time course of exhaled o-toluidine concentrations considerably differed depending on the injection site. Intravenous injection led to an immediate increase in exhaled o-toluidine concentrations within 2 min, earlier peak and higher maximum concentrations, followed by a faster decay compared to regional anaesthesia. The strength of correlation of blood and breath parameters depended on the injection site. In conclusion, real time monitoring of o-toluidine in breath gas is possible by means of PTR-ToF-MS. Since simulated accidental intravenous injection led to an immediate increase in exhaled o-toluidine concentrations within 2 min and higher maximum concentrations, monitoring exhaled o-toluidine may potentially be applied for the non-invasive real-time detection of accidental intravenous injection of prilocaine.<\/jats:p>","DOI":"10.3390\/metabo12060502","type":"journal-article","created":{"date-parts":[[2022,6,1]],"date-time":"2022-06-01T03:33:18Z","timestamp":1654054398000},"page":"502","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Non-Invasive O-Toluidine Monitoring during Regional Anaesthesia with Prilocaine and Detection of Accidental Intravenous Injection in an Animal Model"],"prefix":"10.3390","volume":"12","author":[{"given":"Beate","family":"Brock","sequence":"first","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0055-6098","authenticated-orcid":false,"given":"Patricia","family":"Fuchs","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Svend","family":"Kamysek","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"},{"name":"Ambulance and Rescue Service, Rostock District Administration, Mecklenburg-Vorpommern, 18209 Bad Doberan, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Udo","family":"Walther","sequence":"additional","affiliation":[{"name":"Institute of Pharmacology and Toxicology, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Selina","family":"Traxler","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2869-3588","authenticated-orcid":false,"given":"Giovanni","family":"Pugliese","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"},{"name":"Max Planck Institute for Chemistry, 55128 Mainz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1619-0315","authenticated-orcid":false,"given":"Wolfram","family":"Miekisch","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jochen K.","family":"Schubert","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6138-6515","authenticated-orcid":false,"given":"Phillip","family":"Trefz","sequence":"additional","affiliation":[{"name":"Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, 18057 Rostock, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,31]]},"reference":[{"key":"ref_1","first-page":"182","article-title":"Toxicity of local anaesthetics-Have recommended maximal doses any relevance?","volume":"48","author":"Zink","year":"2007","journal-title":"Anasthesiol. 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