Effects of Ketamine in Post-operative Pain and Recovery Outcomes in Bilateral Third Molar Surgery Under General Anaesthesia

Low dose sub-anaesthetic dose of ketamine has been shown to reduce postoperative pain and analgesic consumption. However, due to the heterogeneous results, the standard dosing regimen has not been available. Recently, its effect in postoperative outcomes and the development of post-operative surgical pain has also been suggested.

Ketamine has been shown to reduce post-operative early inflammation especially serum IL-6. Therefore, study in its effects in post- operative pain and outcomes due to inflammation is suggested. Only few clinical studies assessed post-operative pain are related to inflammation.

Pain after third molar surgery is a good model of postoperative acute inflammatory pain.

A previous study showed that there was no benefit to administer ketamine before or after oral surgery for pain relief. However, other studies demonstrated that ketamine used as sedative or local ketamine in third molar surgery could reduce postoperative dental pain, swelling and trismus.

Postsurgical facial oedema is difficult to quantify accurately as it is three dimensional. Over the years, various measurement techniques have been tried to measure oedema objectively. These include direct linear measurement using tape or flexible rulers across fixed soft tissue landmarks, standardized stereophotographic measurements, computerized tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and three - dimensional (3D) laser scanning. Recently, three dimensional image reconstructions using a reversed engineering technique has been developed and is used in the manufacturing industry. This technology could be applied in a clinical setting for monitoring soft tissue changes.

In this study, the investigators will aim to study the use of sub-anaesthetic dose of ketamine in post-operative dental pain and recovery outcomes.

The investigators hypothesise that post-operative pain after Bilateral Third Molar under General Anaesthesia is less in patients receiving sub-anaesthetic does of ketamine before incision. The magnitude of this effect will be compared with a positive control group (dexamethasone) as well as a placebo group (normal saline). Further, the investigators aim to demonstrate whether ketamine can reduce post-operative facial oedema and other post-operative outcomes.