CASE REPORT Propofol Infusion Syndrome Associated with Short-Term Large-Dose Infusion During Surgical Anesthesia in an Adult Antonios Liolios, MD, Jean-Michel Gue ´rit, MD, PhD, Jean-Louis Scholtes, MD, PhD, Christian Raftopoulos, MD, PhD, and Philippe Hantson, MD, PhD Department of Intensive Care, Laboratory of Neurophysiology, Department of Anesthesiology, Department of Neurosurgery, Cliniques Saint-Luc, Universite ´ catholique de Louvain, Brussels, Belgium In this case report we describe a case of propofol infu- sion syndrome in an adult after a short-term infusion of large-dose propofol during a neurosurgical procedure. Large-dose propofol (9 mg · kg -1 ·h -1 ) was given for only 3 h during surgery and was followed by a small- dose infusion (2.3 mg · kg -1 ·h -1 ) for 20 h postopera- tively. The patient had also received large doses of methylprednisolone. He developed a marked lactic acidosis with mild biological signs of renal impairment and rhabdomyolysis but no cardiocirculatory failure. There were no other evident causes of lactic acidosis as documented by laboratory data. We believe this is the first report of reversible lactic acidosis associated with a short duration of large-dose propofol anesthesia. (Anesth Analg 2005;100:1804 –6) P ropofol infusion syndrome (PRIS) is reported with an increasing frequency in adults (1,2). As the pathophysiology remains poorly under- stood, accurate documentation of new cases is essen- tial (3). This report describes a case of reversible lactic acidosis in an adult after short-term propofol infusion of doses larger than 5 mg · kg -1 ·h -1 . Consecutive determinations of blood lactate and electrolytes al- lowed a better interpretation of propofol-associated metabolic acidosis. Case Report A 42-yr-old man (77 kg weight) without a medical history underwent elective surgery for a brainstem cavernous angi- oma. Preoperative routine laboratory investigation was nor- mal. Anesthesia and surgery were uneventful. Anesthesia was achieved by the administration of sevoflurane. Propofol was added as required to achieve adequate anesthesia as dictated by intraoperative neuromonitoring (somatosensory evoked potentials). Propofol was initially infused at a rate of 400 mg/h (5.2 mg · kg -1 ·h -1 ). A first arterial blood gas analysis, including lactate levels obtained 1 h later, was normal. After 90 min, propofol infusion was increased to 700 mg/h (9 mg · kg -1 ·h -1 ) for a period of 3 h to achieve adequate anesthesia and was then tapered down to 180 mg/h (2.3 mg · kg -1 ·h -1 ) at the end of surgery. Surgery lasted for 7.5 h. IV fluid therapy during the procedure included 1 L 0.9% NaCl and 2 L hydroxyethyl starch, 6%. Arterial blood gas values at the end of the rapid propofol infusion rate were normal but there was an increasing lac- tate level (3.4 mmol/L) (Table 1). No hypothermia was observed during the procedure and the minimal rectal tem- perature during the procedure was 36.4°C. Two episodes of moderate hypertension were noted (systolic blood pressure, 160 mm Hg) and were treated by small doses of urapidil and clonidine. The patient was also given methylprednisolone (30 mg/kg initially and 5.4 mg · kg -1 ·h -1 for 23 h thereaf- ter) at the end of surgery because there was suspicion of spinal cord injury during surgery as judged by the evoked potentials, which revealed worsening of somatosensory con- duction. He was then transferred to the intensive care unit (ICU) for postoperative management. Admission and follow-up blood gas analysis and other laboratory data ap- pear in Table 1. Lactic acidosis progressed without evidence of hemodynamic instability, tissue hypoxia or severe inflam- mation (C-reactive protein 0.9 mg/L). Nine hours after start- ing propofol infusion, lactate levels reached a plateau of approximately 6.0 mmol/L with an isolated spike of 10.8 mmol/L at 13 h after the beginning of the infusion (normal lactate levels, 1.3 mmol/L). Serum chloride re- mained near baseline values and the anion gap progres- sively increased in parallel with the increasing serum lactate values. Laboratory results 10 h after the end of the procedure revealed creatinine kinase 3384 IU/L (MM isoenzyme) (nor- mal, 400 IU/L; admission value, 389 IU/L; peaked at 3480 IU/L 44 h after the procedure, decreased to 1303 IU/L 48 h after propofol was stopped), serum creatinine 1.6 mg/dL (normal, 1.4 mg/dL; admission value, 1.30 mg/dL), and normal blood glucose. Serum potassium concentration re- mained within normal range. Urinary output was adequate Accepted for publication November 23, 2004. Address correspondence and reprint requests to Philippe Hant- son, MD, PhD, Department of Intensive Care, Cliniques Universi- taires St-Luc, Avenue Hippocrate, 10, 1200 Brussels, Belgium. Ad- dress e-mail to hantson@rean.ucl.ac.be DOI: 10.1213/01.ANE.0000153017.93666.BF ©2005 by the International Anesthesia Research Society 1804 Anesth Analg 2005;100:1804–6 0003-2999/05