title: Use of lidocaine in endotracheal intubation. Blood and urine concentrations in patients and deceased after unsuccessful resuscitation.
abstract: In toxicological analysis of postmortem samples the local anesthetic lidocaine is often identified. In most cases, lidocaine levels result from its use as aid in endotracheal intubation. The range of the drug's concentration in blood and urine was studied under controlled conditions from a cohort of cardiac surgery patients (n=35). Plasma concentrations 1 h after exposure to lidocaine in the range of the recommended 81 mg coating the endotracheal tube were less than 0.2 mg/l, its metabolite monoethylglycinxylidide (MEGX) less than 0.05 mg/l (median ratio 0.18, range 0.03-1.23). Also the concentrations of lidocaine and MEGX in urine samples were low (less than 1.2 and 0.1 mg/l, respectively) with MEGX/lidocaine ratios of 0.11 (median, range up to 1.2). These data were compared with results obtained by analyzing postmortem blood and urine samples of 18 deceased with a documented cardiopulmonary resuscitation attempt prior to death. Blood concentrations were in the same range (lidocaine median 0.07, range 0.02-1.07 mg/l; MEGX median 0.01, range <0.001-0.044 mg/l); besides low lidocaine concentrations in urine. MEGX was detected only in 2 out of 9 urine samples. The results of the present study confirm that lidocaine is absorbed in the trachea from the endotracheal tube coated with lidocaine containing gel. Postmortem quantitative results can be explained on the basis of the data obtained in the controlled study.
authors.affiliation: Institute of Legal Medicine, Department of Forensic Toxicology, Kennedyallee 104, 60596 Frankfurt/Main, Germany. Electronic address: wunder@med.uni-frankfurt.de.
authors.forename: Cora
authors.initials: C
authors.lastname: Wunder
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, General Hospital Linz, Krankenhausstraße 9, 4021 Linz, Austria.
authors.forename: Jens
authors.initials: J
authors.lastname: Meier
authors.affiliation: Department of Anesthesia, Intensive Care Medicine and Pain Therapy, Theodor Stern Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Reyher
authors.affiliation: Institute of Legal Medicine, Department of Forensic Toxicology, Kennedyallee 104, 60596 Frankfurt/Main, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Könitz
authors.affiliation: Institute of Legal Medicine, Department of Forensic Toxicology, Kennedyallee 104, 60596 Frankfurt/Main, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Paulke
authors.affiliation: Department of Anesthesia, Intensive Care Medicine and Pain Therapy, Theodor Stern Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Zacharowski
authors.affiliation: Institute of Legal Medicine, Department of Forensic Toxicology, Kennedyallee 104, 60596 Frankfurt/Main, Germany.
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Toennes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000097:blood* / Q000627:therapeutic use / Q000652:urine*; D016887:Cardiopulmonary Resuscitation; D013504:Cardiovascular Surgical Procedures; D015331:Cohort Studies; D053593:Forensic Toxicology; D005782:Gels; D006801:Humans; D007442:Intubation, Intratracheal; D008012:Lidocaine / Q000031:analogs & derivatives / Q000097:blood* / Q000627:therapeutic use / Q000652:urine*; D008875:Middle Aged
chemical_list: D000779:Anesthetics, Local; D005782:Gels; D008012:Lidocaine; C001173:monoethylglycinexylidide
keywords: Cardiac surgery; Forensic toxicology; Lidocaine; Local anesthetics; Postmortem toxicological analysis; Resuscitation