Continuous extrapleural infusion of ropivacaine 0.2% after cardiovascular surgery via the lateral thoracotomy approach.
OBJECTIVE
The pharmacokinetics of ropivacaine 0.2% were evaluated during a 48-hour continuous extrapleural infusion with 2 different infusion rates in patients undergoing cardiovascular surgery. The hypotheses that no toxic plasma concentrations of ropivacaine would be reached and that proportionality exists among plasma concentrations and dosage used were tested.


METHODS
A prospective, randomized, nonblinded study.


METHODS
The investigation was performed as a single-center study in the Division of Cardiovascular Anesthesia, University Hospital of Zurich, in Switzerland.


METHODS
Seventeen consenting adults scheduled for elective cardiovascular surgery, with or without extracorporeal bypass, via the lateral thoracotomy approach were enrolled.


METHODS
For postoperative pain relief, patients were randomly assigned to receive continuous extrapleural infusion of ropivacaine 0.2% at a rate of either 6 or 9 mL/h over 48 hours.


RESULTS
Plasma concentrations of ropivacaine reached toxic levels (>2.2 mg/L) in 25% of cases. No proportionality of plasma concentrations of ropivacaine existed when the 2 dosing regimens were compared.


CONCLUSIONS
Plasma concentrations of ropivacaine, administered at the given dose and rates during continuous extrapleural infusion, are unpredictable and may reach toxic levels in patients undergoing major cardiothoracic surgery.
Maurer
Konrad
K
Division of Cardiovascular Anesthesia, University Hospital of Zurich, Zurich, Switzerland.
Blumenthal
Stephan
S
Rentsch
Katharina M
KM
Schmid
Edith R
ER
D000368:Aged; D000577:Amides / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood*; D013504:Cardiovascular Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007260:Infusion Pumps / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D035422:Pleural Cavity / Q000187:drug effects / Q000378:metabolism; D011446:Prospective Studies; D000077212:Ropivacaine; D013908:Thoracotomy / Q000009:adverse effects / Q000379:methods*
D000577:Amides; D000077212:Ropivacaine