Background and Goal of Study:
Subcutaneous implantable venous access devices through the subclavian vein are routinely implanted under local anaesthesia. However, patients complain of pain during the injection of local anaesthesia. This randomized, double-blind study evaluated the effectiveness of sodium bicarbonate-buffered lidocaine on  reducing pain during subcutaneous implantable venous access devices. Patients satisfactions were evaluated immediately after the procedure.
Materials and Methods:
A prospective double-blind study was conducted over a period of 14 months (February 2015 to March 2016). Patients were randomized to receive either buffered (PH= 7.33) or plane lidocaine (PH= 3.50).  All insertions were made by the same operator using a standard technique. All patients underwent real-time ultrasound-guided cannulation of the subclavian vein. Pain and satisfaction were evaluated on a VAS score (0-100 mm).
Results:
A total of 120 patients were enrolled in this study. There was no difference detected between the two treatment groups pre-procedure and during needle insertion. Patients reported significantly lower pain scores with the buffered versus non-buffered lidocaine 15.70 ± 7.58 mm vs.46.90 ± 12.27 mm (p<0.001).  The time of anesthesia onset was shorter with buffered lidocaine 3.25±1.33 minute vs.5.46±1.28 (p=0.01). Overall patient satisfaction is high for implantation of venous access devices under local anaesthesia. There was no difference between the two groups regarding satisfaction.
Conclusion(s):
During vein cannulation under local anesthesia, pain is mainly due to acidity of the lidocaine solution. In our study, we showed that buffering lidocaine with sodium bicarbonate significantly reduces pain during intra parenchymal injections.

06 / The effect of buffered lidocaine in local anaesthesia during subcutaneous implantable venous access devices insertion: a prospective, randomized, double-blind study