Prospective randomised comparison of Marsh and Schnider pharmacokinetic models for propofol during induction of anaesthesia in elective cardiac surgery

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Viterbo, JF (Author) Other; Andre P Lourenco (Author) FMUP; Leite-Moreira AF (Author) FMUP; Pinho, P (Author) Other; Barros, F (Author) Other

Journal

Title: European Journal of Anaesthesiology

Vol. 29

Pages: 477-483

ISSN: 0265-0215

Publisher: Wolters Kluwer Health

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 15 Citations

Other information

Authenticus ID: P-002-56Q

DOI: 10.1097/eja.0b013e3283542421

Abstract (EN): Context Haemodynamic stability during induction is a cornerstone of cardiac anaesthesia. The evaluation of pharmacokinetic models for propofol during induction is lacking. Objective To compare haemodynamics during cardiac anaesthesia induction with two pharmacokinetic models. Design Randomised controlled trial. Setting Department of Cardiothoracic Surgery, Sao Joao Hospital; July to December 2010. Patients Ninety consecutive elective adult cardiac surgical patients. Intervention Random assignment to effect-site targetcontrolled infusion by Marsh (n = 45) or Schnider (n = 45) pharmacokinetic models with an equilibration constant of 1.2 min(-1) adapted to Marsh's model. Invasive blood pressure measurements, propofol dose, and bispectral index (BIS) were recorded. After an initial target concentration of 1.5 mu g ml(-1), concentrations were upward-titrated in 0.5 mu g ml(-1) increments until the BIS was < 50. Results No differences were observed between Marsh and Schnider models in required propofol dose (0.99 +/- 0.26 vs. 0.93 +/- 0.31 mg kg(-1), P = 0.322), decrease in mean blood pressure (25 +/- 13 vs. 22 +/- 14%, P = 0.192) or the need for vasopressors (20 vs. 24%, P = 0.800), but the use of the Marsh model resulted in a lower predicted effect-site concentration (2.3 +/- 0.4 vs. 2.7 +/- 0.6 mu g ml(-1), P = 0.006) and shorter time to induction (296 +/- 59 vs. 338 +/- 87 s, P = 0.024). There was a greater decrease in mean blood pressure in older patients (> 60 years; 29 +/- 10 vs. 22 +/- 11%, P = 0.004) irrespective of model, butobese (BMI >= 30 kg m(-2)) and nonobese patients did not differ. Main outcome measures Decrease in mean blood pressure. Conclusion In effect-site targeting with a 1.2 min(-1) equilibration constant, Marsh's model is comparable to Schnider's during induction of anaesthesia.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7