title: Falsely low values of oxygen saturation measured by pulse oximetry in a boy treated with Chinese herb tea.
abstract: An 8-year-old boy suffering from progressive glioblastoma was scheduled for neurosurgery. Prior to induction of anaesthesia pulse oximetry measured 64 % saturation of oxygen (SpO2). Arterial blood gas analysis revealed normal oxygen saturation and normal oxygen partial pressure. After having ruled out technical problems of pulse oximetry the neurosurgical procedure was halted. Meticulous examination of the child's history and medication did not explain a possible interaction of drugs with pulse oximetry. A Chinese herb tea had been given to the child, but was then stopped on the day of admission. The surgical procedure took place the next day without any complications. During the subsequent inpatient stay, repeated blood gas analyses showed normal oxygenation, but pulse oximetry measured initially SpO2values of 64 %, gradually increasing over 7 days up to 91 % by the time of discharge from hospital. Blood samples were taken and analysed. Absorption spectroscopy from the patient's blood showed an uncommon absorption maximum at 684 nm besides the normal maxima. The normalisation of SpO2values after stopping Chinese herb tea administration leads to the conclusion that one of its ingredients caused the distorted pulse oximetry measurement.
authors.affiliation: Department of Anaesthesiology, Klinikum der Universität München, Marchioninistraße 15, 81377, Munich, Germany. agnes_meidert@web.de.
authors.forename: Agnes S
authors.initials: AS
authors.lastname: Meidert
authors.affiliation: Laser-Forschungslabor, LIFE Center, Klinikum der Universität München, Feodor-Lynen-Str. 19, 81377, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lang
authors.affiliation: Laser-Forschungslabor, LIFE Center, Klinikum der Universität München, Feodor-Lynen-Str. 19, 81377, Munich, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Hennig
authors.affiliation: Department of Anaesthesiology, Klinikum der Universität München, Marchioninistraße 15, 81377, Munich, Germany.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bernasconi
authors.affiliation: Department of Neurosurgery, Klinikum der Universität München, Marchioninistraße 15, 81377, Munich, Germany.
authors.forename: Aurelia
authors.initials: A
authors.lastname: Peraud
authors.affiliation: Department of Anaesthesiology, Klinikum der Universität München, Marchioninistraße 15, 81377, Munich, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Briegel
authors.affiliation: Department of Anaesthesiology, Klinikum der Universität München, Marchioninistraße 15, 81377, Munich, Germany.
authors.forename: Tanija K
authors.initials: TK
authors.lastname: Hüttl
mesh_terms: D000758:Anesthesia; D001784:Blood Gas Analysis; D002648:Child; D004365:Drugs, Chinese Herbal / Q000009:adverse effects*; D006801:Humans; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D028321:Plant Preparations / Q000009:adverse effects*; D015203:Reproducibility of Results; D000069459:Teas, Herbal
chemical_list: D004365:Drugs, Chinese Herbal; D028321:Plant Preparations; D000069459:Teas, Herbal; D010100:Oxygen
keywords: Absorption spectroscopy; Blood gas analysis; Chinese herb tea; Diagnostic error; Low oxygen saturation; Pulse oximetry