Correspondence  |   February 2008
Propofol Infusion and Lactic Acidosis
Author Affiliations & Notes
  • Lluís Gallart, M.D., Ph.D.
  • *Hospital Universitari del Mar, Institut Municipal d’Investigacions Mèdiques, Universitat Autònoma de Barcelona, Barcelona, Spain.
Article Information
Correspondence   |   February 2008
Propofol Infusion and Lactic Acidosis
Anesthesiology 2 2008, Vol.108, 331. doi:
Anesthesiology 2 2008, Vol.108, 331. doi:
To the Editor:—
We read with interest the retrospective study from Cravens et al.  1 about propofol infusion syndrome. The authors reported a high incidence of slight metabolic acidosis during prolonged propofol infusion in patients who received a total dose of approximately 20 mg/kg.
The main cause of propofol infusion syndrome would be cumulative high-dose propofol, whereas low doses would be safe.2–5 However, there is a lack of studies looking for acidosis related to propofol infusion, and prospective studies are needed to confirm the relation between high-dose propofol and acidosis and to guarantee the safety of low-dose propofol routinely used for sedation or anesthesia. Regarding the latter, our group recently performed a prospective randomized trial in 42 patients scheduled to undergo thoracotomy to evaluate the effects of almitrine and inhaled nitric oxide on oxygenation.6 Arterial blood gases and lactic acid were determined in all patients: the former because arterial oxygen tension was the main variable, and the latter to discard lactic acidosis that could be an eventual complication of almitrine administration.7,8 All of the patients in the study received intravenous anesthesia with propofol and remifentanil.6 The research protocol and the administration of propofol were strictly standardized. In all of the patients, anesthesia was induced with 1 mg · kg−1· h−1propofol and maintained with 3 mg · kg−1· h−1propofol, so that all of the patients received an average dose of 6 mg/kg propofol.
Arterial pH and lactic acid concentrations did not significantly change during the study, remaining within the normal range in all patients (7.35–7.45 and 0.5–1.6 mm, respectively).6 
These results suggest that our patients were not at risk of propofol infusion syndrome after receiving approximately a third of the dose administered by Cravens et al.  1 
In conclusion, we did not observe lactic acidosis in patients receiving low-dose propofol. These results can be useful to support the safety of short-duration, low-dose propofol, strengthening the hypothesis that acidosis after propofol infusion would be related to cumulative high doses of the drug.
*Hospital Universitari del Mar, Institut Municipal d’Investigacions Mèdiques, Universitat Autònoma de Barcelona, Barcelona, Spain.
Cravens GT, Packer DL, Johnson ME: Incidence of propofol infusion syndrome during noninvasive radiofrequency ablation for atrial flutter or fibrillation. Anesthesiology 2007; 106:1134–8Cravens, GT Packer, DL Johnson, ME
Wysowski DK, Pollock ML: Reports of death with use of propofol (Diprivan) for nonprocedural (long-term) sedation and literature review. Anesthesiology 2006; 105:1047–51Wysowski, DK Pollock, ML
Kam PC, Cardone D: Propofol infusion syndrome. Anaesthesia 2007; 62:690–701Kam, PC Cardone, D
Ahlen K, Buckley CJ, Goodale DB, Pulsford AH: The “propofol infusion syndrome”: The facts, their interpretation and implications for patient care. Eur J Anaesthesiol 2006; 23:990–8Ahlen, K Buckley, CJ Goodale, DB Pulsford, AH
Crozier TA: The “propofol infusion syndrome”: myth or menace? Eur J Anaesthesiol 2006; 23:987–9Crozier, TA
Silva-Costa-Gomes T, Gallart L, Valles J, Trillo L, Minguella J, Puig MM: Low- versus  high-dose almitrine combined with nitric oxide to prevent hypoxia during open-chest one-lung ventilation. Br J Anaesth 2005; 95:410–6Silva-Costa-Gomes, T Gallart, L Valles, J Trillo, L Minguella, J Puig, MM
B’chir A, Mebazaa A, Losser MR, Romieu M, Payen D: Intravenous almitrine bismesylate reversibly induces lactic acidosis and hepatic dysfunction in patients with acute lung injury. Anesthesiology 1998; 89:823–30B’chir, A Mebazaa, A Losser, MR Romieu, M Payen, D
Gallart L, Lu Q, Puybasset L, Umamaheswara Rao GS, Coriat P, Rouby JJ: Intravenous almitrine combined with inhaled nitric oxide for acute respiratory distress syndrome. The NO Almitrine Study Group. Am J Respir Crit Care Med 1998; 158:1770–7Gallart, L Lu, Q Puybasset, L Umamaheswara Rao, GS Coriat, P Rouby, JJ