title: Propylene glycol-induced lactic acidosis in a patient receiving continuous infusion pentobarbital.
abstract: OBJECTIVE
  To report a case of probable propylene glycol (PG) toxicity in a patient receiving continuous infusion of pentobarbital for refractory status epilepticus.
  
  
  METHODS
  A 59-year-old woman with a declining mental status was admitted to the intensive care unit for management of status epilepticus. After failing to achieve the therapeutic endpoint of electroencephalogram burst suppression with a continuous infusion of propofol, the sedative regimen was changed to continuous infusion of pentobarbital. The patient received a loading dose of 450 mg (5 mg/kg), and the maintenance infusion was titrated to a dose of 10 mg/kg/h to achieve burst suppression. Twelve hours after the pentobarbital infusion was started, the patient developed an anion gap metabolic acidosis, elevated serum lactate level, hyperosmolality, and increased osmolal gap. The pentobarbital infusion was discontinued, and the patient's acidosis and hyperosmolality resolved.
  
  
  CONCLUSIONS
  Pentobarbital contains 40% v/v of PG, which was thought to be a potential source of the patient's metabolic derangements. Reports of toxicity with drugs containing PG, particularly intravenous lorazepam, have been well described in the literature. What we describe, however, is one of few reports involving intravenous pentobarbital. The Naranjo probability scale supports a probable drug-related adverse event in our patient.
  
  
  CONCLUSIONS
  PG toxicity is a potential complication associated with intravenous pentobarbital. Practitioners should be aware of the PG content of pentobarbital and should be familiar with the signs and symptoms associated with PG toxicity.
authors.affiliation: Critical Care, Department of Pharmacy, University of Massachusetts Memorial Medical Center, Worcester, MA 01655, USA. melissa.miller@umassmemorial.org
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Miller
authors.forename: Allison
authors.initials: A
authors.lastname: Forni
authors.forename: Dinesh
authors.initials: D
authors.lastname: Yogaratnam
mesh_terms: D000140:Acidosis, Lactic / Q000139:chemically induced* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D007262:Infusions, Intravenous; D008875:Middle Aged; D010424:Pentobarbital / Q000008:administration & dosage; D014677:Pharmaceutical Vehicles / Q000008:administration & dosage / Q000009:adverse effects*; D019946:Propylene Glycol / Q000008:administration & dosage / Q000009:adverse effects*; D013226:Status Epilepticus / Q000188:drug therapy
chemical_list: D006993:Hypnotics and Sedatives; D014677:Pharmaceutical Vehicles; D019946:Propylene Glycol; D010424:Pentobarbital