Ultrasound-guided Superficial Cervical Plexus Block for Pain Management After Orthognathic Surgery.

Postoperative pain management is very important in patients underwent orthognathic surgery. Effective pain control provides early mobilization, shorter hospital stay and it increases the satisfaction of the patients. Opioid agents may provide effective pain management, however opioid agents have undesirable adverse effects such as respiratory depression, sedation, constipation, nausea and vomiting etc. Ultrasound (US) -guided regional anesthesia techniques may be preferred for pain management in patients underwent orthognathic surgery. Regional anesthesia techniques may provide effective postoperative pain management as a part of multimodal analgesia regimens. US-guided bilateral superficial cervical plexus block (SCPB) have been performed for several head and neck surgeries and it provides effective pain control. The cervical plexus presents between the longus capitis and middle scalene muscles, under the prevertebral fascia. It is formed by the C2-4 cervical spinal nerves. There are the end points of these nerves in the interfascial area under the SCM. Thus, the superfascial branches of the cervical plexus may be blocked by injecting local anesthetic under the SCM. Cervical plexus may be blocked with deep or superficial technique. The deep CPB is defined as a paravertebral block. The deep branches may be targeted by this method. However it has some major disadvantages such as intravascular injection, epidural or subarachnoid injection, and phrenic nerve palsy, due to the deepness of the injection. Otherwise; SCPB is a superficial method and it has lower complication rate compared to the deep CPB. In an anatomical study, it has been reported that with SCPB there was spread of dye into the deep cervical fascia. The authors emphasized that this mechanism may explain the efficacy of the SCPB. Thus, with the SCPB both the superficial branches and the deep nerve roots may be blocked. Therefore, SCPB may provide effective pain management following orthognathic surgery. In the literature, there are no randomized clinical studies about pain management with US-guided SCPB after orthognathic surgery, yet.

The aim of this study is to evaluate the efficacy of the US-guided SCPB for postoperative analgesia management after orthognathic surgery. The primary aim is to evaluate postoperative opioid consumption and the secondary aim is to evaluate postoperative pain scores (VAS), adverse effects related with opioids (allergic reaction, nausea, vomiting) compared to no intervention control group.