SPI-directed Analgesia for Vitreoretinal Surgeries

Influence of Surgical Pleth Index-guided Analgesia Using Different Techniques on the Perioperative Outcomes in Patients Undergoing Vitreoretinal Surgery Under General Anaesthesia: Randomised, Controlled Trial

The aim of this randomized trial is to assess the efficacy of SPI-directed analgesia for vitreoretinal surgeries (VRS), presence of PONV and oculocardiac reflex (OCR) and compare Numerical Rating Scale (NRS) with Surgical Pleth Index (SPI) for monitoring pain perception postoperatively.

Patients received general anaesthesia alone or combined with either preemptive analgesia using topical solution of 0,5% proxymetacaine or peribulbar block (0,5% bupivacaine with 2% lidokaine) or preemptive intravenous infusion of 1,0 g of metamizol or preemptive intravenous infusion of acetaminophen in a doseof 10-15mg/kg of body weight.

Monitoring depth of anaesthesia using spectral entropy (SE) and quality of neuromuscular block are routine in modern anaesthesia, whereas monitoring of analgesia still requires further studies. Recently, the Surgical Pleth Index (SPI) was added as a surrogate variable showing the nociception-antinociception balance into abovementioned parametres constituting a novel approach in monitoring patients intraoperatively, known as adequacy of anaesthesia (AoA) or tailor-made anaesthesia.

Inclusion Criteria:

• written consent to participate in the study
• written consent to undergo general anaesthesia alone or combined with different techniques of pre-emptive analgesia and vitreoretinal surgery

Exclusion Criteria

• history of allergy to local anaesthetics or metamizole
• necessity of administration of vasoactive drugs influencing SPI monitoring
• pregnancy