Total Intravenous Anesthesia and Spontaneous Ventilation for Foreign Body Removal in Children

To the Editor In a recent study, Chen et al.1 compared the risk factors for hypoxia when using 4 different anesthetic techniques for removal of foreign bodies in children younger than 5 years old. The fact that the authors found that patients breathing spontaneously and receiving total IV anesthesia (TIVA) had more movement, breath holding, and a lower success rate with foreign body removal is not surprising and is, in our opinion, attributable to the too small doses of propofol and remifentanil administered. Subjects received a bolus of propofol (3\N5 mg/kg) and remifentanil (1 μg/kg) followed by infusions of propofol (100\N150 μg/kg/min) and remifentanil (0.1 μg/kg/min). Simulations (TIVATrainer®) of the doses described would have produced near steady-state (15 minutes) effect-site concentration of propofol of 2.9 μg/mL based on the Paedfusor model2 and remifentanil of 0.55 μg/mL based on the Rigby-Jones model.3 These concentrations would be considered low even in adults. Moreover, most children will tolerate larger does of remifentanil (and propofol) while maintaining spontaneous respiration.4 Our institutional practice is to use TIVA with remifentanil and propofol for most of our patients undergoing airway endoscopy. In a prospective study, we found the mean remifentanil dose to be 0.21 (SD 0.31) μg/kg/min and propofol infusion rate to be 368 (SD 103) μg/kg/min.5 The wide interindividual variability dictates that drugs are titrated to clinical effect within a wide dose range. The greater incidence of laryngospasm in the TIVA group might also reflect the too small dose of the drugs. Reflex laryngeal responses occur less frequently and of shorter duration with propofol anesthesia compared with sevoflurane,6 and propofol is often used for treatment of mild laryngospasm. We conclude that the increased complication rate seen in the group using TIVA and spontaneous ventilation may have been due to the low doses used and not a result of the technique selected. Stephan Malherbe, MBBCh, FFA(SA), MMed, FRCP J. Mark Ansermino, MBBCh, MSc(Inf), FFA(SA), FRCPC Department of Pediatric Anesthesia British Columbia Children's Hospital Vancouver, British Columbia, Canada [email protected]

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.