Muscle relaxation does not influence venous oxygen saturation during cardiopulmonary bypass.
OBJECTIVE
To examine whether the omission of neuromuscular blocking drugs during cardiopulmonary bypass (CPB) is associated with increased anesthetic requirements, higher frequency of intraoperative movements, and lower venous oxygen saturation (SvO(2)).


METHODS
Prospective, randomized study.


METHODS
Large community hospital.


METHODS
30 ASA physical status III and IV patients scheduled for cardiac surgery.


METHODS
Patients were randomized to one of two groups: group 1 (n = 15) received a 3xED(95) bolus dose of cisatracurium at induction and thereafter no more neuromuscular blocking drug; group 2 (n = 15) received a continuous infusion of cisatracurium during the entire procedure.


METHODS
Both groups received a standardized anesthetic with bispectral index-guided propofol target-controlled infusion and a remifentanil infusion steered by hemodynamic changes. Venous oxygen saturation was continuously determined during CPB.


RESULTS
Propofol consumption was 5.4 +/- 1.7 and 4.4 +/- 1.0 mg/(kg/h) in groups 1 and 2, respectively (P = 0.07). Remifentanil consumption was 0.15 +/- 0.05 and 0.17 +/- 0.05 mug/(kg/min) in groups 1 and 2, respectively (P = 0.19). In groups 1 and 2, no patient recalled any intraoperative phenomena; none moved or had diaphragmatic contractions. During CPB, SvO(2) was 81.3 +/- 3.2% (76%-85%) in group 1 and 80.6 +/- 3.1% (73%-85%) in group 2 (P = 0.53).


CONCLUSIONS
Omitting the continuous administration of neuromuscular blocking drugs during CPB did not increase anesthetic requirements. No intraoperative movements occurred, nor was there decreased SvO(2).
Cammu
Guy
G
Department of Anesthesia and Critical Care Medicine, O.L.V. Clinic, 9300 Aalst, Belgium. guy.cammu@olvz-aalst.be
Cardinael
Sara
S
Lahousse
Sabine
S
Eecke
Gudrun Ver
GV
Coddens
José
J
Foubert
Luc
L
Gooris
Theo
T
Deloof
Thierry
T
D000368:Aged; D000762:Anesthesia Recovery Period; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D001279:Atracurium / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D002315:Cardiopulmonary Bypass / Q000379:methods*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous / Q000379:methods; D007275:Injections, Intravenous / Q000379:methods; D007902:Length of Stay; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009466:Neuromuscular Blocking Agents / Q000008:administration & dosage / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood*; D010880:Piperidines / Q000008:administration & dosage; D015742:Propofol / Q000008:administration & dosage; D011446:Prospective Studies; D000077208:Remifentanil; D014680:Veins
D018686:Anesthetics, Intravenous; D009466:Neuromuscular Blocking Agents; D010880:Piperidines; D001279:Atracurium; D000077208:Remifentanil; C101584:cisatracurium; D010100:Oxygen; D015742:Propofol