title: Population pharmacokinetics of lidocaine administered during and after cardiac surgery.
abstract: OBJECTIVE
  The objective of this study was to determine the pharmacokinetics of lidocaine in a 48-hour infusion in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).
  
  
  METHODS
  A retrospective substudy of a clinical trial assessing the efficacy of intravenous lidocaine for postoperative cognitive decline.
  
  
  METHODS
  A university hospital.
  
  
  METHODS
  Ninety-nine patients undergoing cardiac surgery with CPB.
  
  
  METHODS
  After the induction of anesthesia, lidocaine was administered as a bolus of 1 mg/kg and followed by a continuous infusion at 4 mg/min for the 1st hour, 2 mg/min for the 2nd hour, and 1 mg/min for the next 46 hours.
  
  
  RESULTS
  Blood samples were taken at baseline, the end of CPB, and 24 and 48 hours after CPB for the measurement of the plasma concentration of lidocaine. Lidocaine levels increased significantly over time despite a constant rate of infusion (p < 0.05). The pharmacokinetics of lidocaine was best described by a 2-compartment model, and body weight was found to be a significant factor for the volume of the central compartment and clearance. The final pharmacokinetic parameters were V(1)(L) = 0.0619*weight, V(2)(L) = 187, CL(1) (L/min) = 0.00419*weight, and CL(2) (L/min) = 8.92.
  
  
  CONCLUSIONS
  A 2-compartment pharmacokinetic model best describes the plasma concentrations of a 48-hour lidocaine infusion in patients undergoing cardiac surgery with CPB. The inclusion of body weight as a covariate on clearance and central compartment improves the model. Lidocaine infusions should be dosed by body weight and decreased after 24 hours to avoid potential toxicity in long-term infusions.
authors: Department of Anesthesiology, Mackay Memorial Hospital, Taipei, Taiwan. hsumd@ms1.mmh.org.tw
authors: Yung-Wei
authors: YW
authors: Hsu
authors: Jacques
authors: J
authors: Somma
authors: Mark F
authors: MF
authors: Newman
authors: Joseph P
authors: JP
authors: Mathew
references: Ann N Y Acad Sci. 1971 Jul 6;179:383-98
references: 5285383
references: Clin Pharmacokinet. 1978 May-Jun;3(3):177-201
references: 350470
references: Stroke. 2009 Mar;40(3):880-7
references: 19164788
references: Clin Pharmacol Ther. 1984 May;35(5):617-26
references: 6713773
references: Clin Pharmacokinet. 1984 Jul-Aug;9(4):354-63
references: 6467768
references: Eur J Pain. 1997;1(2):141-8
references: 15102415
references: Br J Anaesth. 1983 Dec;55(12):1173-7
references: 6652007
references: Clin Pharmacol Ther. 1975 Jun;17(6):669-76
references: 1139858
references: Clin Pharmacol Ther. 1983 Jul;34(1):14-22
references: 6861434
references: J Clin Pharmacol. 1981 Apr;21(4):181-94
references: 7240439
references: J Thorac Cardiovasc Surg. 1988 Oct;96(4):634-41
references: 3172810
references: Ther Drug Monit. 2001 Apr;23(2):81-92
references: 11294522
references: Ann Intern Med. 1973 Apr;78(4):499-508
references: 4694036
references: Anesthesiology. 2001 Apr;94(4):566-73
references: 11379674
references: J Pharmacokinet Biopharm. 1987 Apr;15(2):101-15
references: 3612496
references: Ann Intern Med. 1977 Dec;87(6):700-6
references: 931206
references: J Pharm Sci. 1984 Jan;73(1):136-8
references: 6694073
references: Anesth Prog. 1998 Winter;45(1):38-41
references: 9790008
references: Anesthesiology. 1996 May;84(5):1043-50
references: 8623997