Glycine and ammonia plasma concentrations during sedation with remifentanil in critically ill patients.
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.
Bonnet
Marie-Pierre
MP
Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
Minville
Vincent
V
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.
Asehnoune
Karim
K
Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
Bridoux
Delphine
D
Laboratory of Biochemistry, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
Poggi-Bach
Joséphine
J
Laboratory of Biochemistry, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
Duranteau
Jacques
J
Département d'Anesthésie-Réanimation, Bicêtre University Hospital, AP-HP, 78 rue du Général Leclerc, 94275, Le Kremlin Bicêtre Cedex, France.
Benhamou
Dan
D
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.
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
D006993:Hypnotics and Sedatives; D010880:Piperidines; D000641:Ammonia; D003404:Creatinine; D000077208:Remifentanil; D005998:Glycine; D015742:Propofol