title: Glycine and ammonia plasma concentrations during sedation with remifentanil in critically ill patients.
abstract: OBJECTIVE
  To investigate glycine and ammonia plasma concentrations during a 72-h remifentanil infusion and the relationship between glycine concentration and remifentanil infusion rate.
  
  
  METHODS
  A prospective open-label observational clinical trial in a trauma and a neurosurgical intensive care unit in a university teaching hospital.
  
  
  METHODS
  Nine consecutive patients requiring sedation and ventilatory support for at least 72 h. One was excluded due to acute cardiac failure.
  
  
  METHODS
  Patients were sedated with remifentanil and propofol. Glycine and ammonia plasma concentrations were measured every 12 h during an intravenous remifentanil infusion performed over 72 h, and 24 h after the end of the infusion. Cumulative remifentanil dose and rate of infusion were recorded for each patient. Clinical and biological signs of glycine toxicity were evaluated.
  
  
  RESULTS
  Glycine and ammonia plasma concentrations did not exceed the toxic threshold at any time. Plasma glycine concentration measured at the end of remifentanil infusion was significantly correlated with the mean weighted rate of remifentanil infusion and with the cumulative remifentanil dose. A correlation between plasma glycine concentration and creatinine clearance at the end of remifentanil infusion was also documented.
  
  
  CONCLUSIONS
  Plasma glycine concentration was correlated with the remifentanil cumulative dose and the infusion rate and did not reach the toxic threshold. As glycine concentration was also correlated with creatinine clearance and because remifentanil was the only source of exogenous glycine, additional data are necessary to ascertain the safety of remifentanil infusion in ICU patients.
authors.affiliation: Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Bonnet
authors.affiliation: Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.|Department of Anesthesia and Intensive Care, Toulouse University Hospital, Paul Sabatier University, Toulouse, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Minville
authors.affiliation: Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Asehnoune
authors.affiliation: Laboratory of Biochemistry, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Bridoux
authors.affiliation: Laboratory of Biochemistry, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
authors.forename: Joséphine
authors.initials: J
authors.lastname: Poggi-Bach
authors.affiliation: Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Duranteau
authors.affiliation: Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France. dan.benhamou@bct.aphp.fr.
authors.forename: Dan
authors.initials: D
authors.lastname: Benhamou
mesh_terms: D000328:Adult; D000641:Ammonia / Q000097:blood*; D003404:Creatinine / Q000097:blood; D016638:Critical Illness; D005260:Female; D005998:Glycine / Q000097:blood*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000008:administration & dosage / Q000494:pharmacology*; D015742:Propofol / Q000494:pharmacology; D011446:Prospective Studies; D000077208:Remifentanil
chemical_list: D006993:Hypnotics and Sedatives; D010880:Piperidines; D000641:Ammonia; D003404:Creatinine; D000077208:Remifentanil; D005998:Glycine; D015742:Propofol