Methods: This prospective, randomized, double-blinded study was performed between 1 February 2008 and 1 December 2008. A total of 20 ASA III-IV patients (12 males, 8 females; mean age 59.35; range 18 to 69 years) who underwent coronary artery bypass graft surgery, were included in either the Levobupivacaine group (Group LB, n=11) or Placebo group (Group P, n=9). Group LB patients received 0.25% levobupivacaine (1.35 mg/kg) locally infiltrated in both sides of the sternum in addition to routine procedures. The placebo group received no additional local anesthesia. Postoperative verbal rating skala (VRS) scores, morphine consumption and pulmonary functions were evaluated in all patients.

Results: Less complaints and lower VRS scores were observed in group LB compared to group P at different hours following extubation (p<0.05). Significantly lower 24-hour morphine consumption was found in group LB compared with group P (p<0.001). Significant decreases were recorded in pulmonary functions after surgery in both groups, however decreasing amounts of pulmonary function were not different between the two groups (p>0.05).

Conclusion: Parasternal block and local infiltration using levobupivacaine was effective for decreasing postoperative pain, however levobupivacaine was inefficient for prevention of pulmonary function deterioration following surgery. Further studies with more patients are needed to elucidate this topic.