Venous Cannulation Pain to Guide Choice of Anesthetic Method

The Use of Venous Cannulation Pain for Evaluation of Pain Sensitivity in an Attempt to Guide Pain Therapy During and Following Anesthesia

The investigators have recently shown that pain associated with peripheral venous cannulation can be used to predict the risk of postoperative pain, where patients grading their pain associated with venous cannulation (VCP) above 2.0 VAS units had 3.4 times higher risk of moderate or severe postoperative pain after laparoscopic cholecystectomy and 1.7 times higher risk in a mixed group of patients and surgeries.

The aim of this study is to investigate whether pain sensitivity measurements using VCP can be used to choose anesthesia treatment protocol with the aim to lower acute postoperative pain in those with high risk. In patients with low risk we aim to lower the amount of opioids given.

The investigators will perform a randomized controlled trial randomizing patients to different treatment protocols depending on their pain associated with venous cannulation. There will be two set of instructions for perioperative treatment, one for those grading pain associated with venous cannulation <2.0 (low-pain) and another for those grading VCP ≥2.0 (high-pain).

The low-pain group will be randomized to standard treatment or opioid-free anesthesia. The high-pain group will be randomized to standard treatment or extra in form of additives like esketamine and clonidine.

In the low-pain group the investigators aim for non-inferiority with the gain being avoiding opioids. In the high-pain group the investigators aim for lower post-operative pain.

Inclusion Criteria:

• Adults with an American Society of Anesthesiologists (ASA) physical status I or II, undergoing elective laparoscopic surgery at Hallands´ hospital.

Exclusion Criteria:

• Inability to understand information regarding the study. Refusal to give consent. Severe cardiovascular disease. AV-block II. Requirement of additional procedures during surgery, like conversion of laparoscopic to open surgery, incomplete registration of study measurements.