## 3 Results  
A total of 126 patients were enrolled in this study. In the Parastermal group, the median age was 67 \(\pm\) 10 years, while in the Control group was 70 \(\pm\) 10; both groups had a higher prevalence of males, and the mean body mass index (BMI) was 26.5 kg/m\({}^{2}\)\(\pm\) 2.1 in the Parastermal group and 27.8 kg/m\({}^{2}\)\(\pm\) 1.1 in the Control group.  
Aortocorony bypass in extracorporeal circulation (CEC) was the most performed intervention overall (57% in Parastermal group and 65% in Control group), followed by valvular surgery (30% and 25%, respectively); less frequent were off-pump aortocorony bypasses, combined bypasses plus valvular surgery and thoracic aorta aneurysm. Surgical average duration was 230.7 \(\pm\) 53.5 min in the Parastermal group, and 213 \(\pm\) 40.8 min in the Control group (Table 1).  
Intraoperative fentanyl consumption emerged to be significantly higher in the Control group with a mean of 864.3 mcg compared to 406.3 mcg in the Parastermal group (\(p\)-value < 0.001). Intraoperative remifentanil administration was not statistically significative between the two groups.  
Median (IQR) postoperative pain at awakening, expressed as maximum NRS scale value (range 0-10), was 2 (0-4.5) in the Parasternal and 3 (0-6) in the Control group (\(p\) = 0.07); in the next 6 h it was 0 (0-3) in the Parasternal and 2 (0-4) in the Control group,  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Parastermal (63)** & **Control (63)** & \(p\)**-Value** \\ \hline Age (years) & 67 \(\pm\) 10 & 69.6 \(\pm\) 10 & 0.17 \\ Sex (M/F) & 33/30 & 35/28 & 0.8 \\ BMI (kg/m\({}^{2}\)) & 26.7 \(\pm\) 4 & 26.5 \(\pm\) 3.3 & 0.9 \\ Chronic opiates medication & 2 (3\%) & 3 (5\%) & \(>\)0.9 \\ Diabetes Mellitus & 13 (21\%) & 12(19\%) & \(>\)0.9 \\ Pre-existing pulmonary disorders & 11 (17\%) & 10 (16\%) & 0.88 \\ Type of surgery & & & \\ CABG & 36 (57\%) & 41 (65\%) & \\ CABG off pump & 3 (5\%) & 4 (6\%) & \\ Valvular surgery & 19 (30\%) & 16 (25\%) & 0.6 \\ CABG + valvular surgery & 4 (6\%) & 1 (2\%) & \\ Thoracic aorta aneurysm & 1 (2\%) & 1 (2\%) & \\ Surgery duration (min) & 230.7 \(\pm\) 53.5 & 213 \(\pm\) 40.8 & 0.08 \\ \hline \hline \end{tabular} Values are expressed in mean \(\pm\) standard deviation or in number of patients (%); CABG = coronary artery bypass surgery.  
\end{table}
Table 1: Patients’ characteristics.  
while it was 0 in both groups during the following hours. However, pain was always under 4 at 48 h after extubation (mild pain) in both groups.  
Postoperative opiates were requested by 30% of patients in the Parastermal group and by 29% of patients in the Control group. Furthermore, both groups showed no difference in the median (IQR) consumption of postoperative morphine during the first 24 h (0 (0-2) mg). Furthermore, the median (IQR) time to first opioid administration was similar (30 (10-45) mg for parastermal group vs. 30 (11-60) mg for control group) (Table 2).  
Mean extubation time from admission in ICU was 191 \(\pm\) 48 min in the Parasternal group and 305 \(\pm\) 62 min in the Control group (Table 1).  
Respiratory performance was evaluated by the TriFlo Inspiratory Exerciser and was expressed in the number of balls moved up during inspiration one hour after extubation. The median number of balls moved up was 2 (1-2) in the Parasternal group versus 1 (1-2) in the Control group.  
Side effects, such as nausea, vomiting and delirium, were present in a small percentage of patients (2-3%) in both groups. Data regarding respiratory performance and side effects are reassumed in Table 3.