Prophylactic atropine administration attenuates the negative haemodynamic effects of induction of anaesthesia with propofol and high-dose remifentanil : a randomised controlled trial

BACKGROUND: Induction of anaesthesia with propofol and remifentanil often induces unwanted bradycardia and hypotension, raising concerns regarding tissue oxygenation. The electrophysiological cardiac effects of remifentanil can be reversed by atropine. OBJECTIVE: To investigate if prophylactic administration of atropine can attenuate the negative haemodynamic effects of propofol and a high dose of remifentanil during induction of anaesthesia. DESIGN: A double-blind, randomised controlled trial. SETTING: Single-centre, University Medical Center Groningen, The Netherlands. PATIENTS: Sixty euvolaemic patients scheduled for surgery under general anaesthesia. INTERVENTIONS: Anaesthesia was induced and maintained with a target-controlled infusion of propofol with a target effect-site concentration (C-e) of 2.5 mu g ml(-1), remifentanil (target-controlled infusion), (C-e 8 ng ml(-1)) and cis-atracurium. Methylatropine (500 mu g) or 0.9% saline was administered at immediately before induction of anaesthesia. MAIN OUTCOME MEASURES: The changes (Delta) in mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), rate pressure product, cerebral tissue oxygenation and peripheral tissue oxygenation between induction of anaesthesia (T-0) and 10 min later (T-10). RESULTS: Atropine significantly attenuated the changes in the outcome measures between T0 and T10. Median (inter-quartile range) changes were MAP, Delta = -24 (-40 to -21) vs. Delta = -37 mmHg (-41 to -31) (P = 0.02); HR, Delta = 0 +/- 13 vs. -19 +/- 11 bpm (P<0.01); CI, Delta = -0.4 +/- 0.7 vs. -0.9 +/- 0.6l min(-1) m(-2) (P<0.01) and rate pressure product, Delta = -3241 (-5015 to -613) vs. Delta = -5712 mm Hg min(-1) (-6715 to -3917) (P