SPI-directed Analgesia for Vitreoretinal Surgeries

Medical University of Silesia176 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

SINGLE

Enrollment

176

Conditions

Vitreoretinal Surgeries Postoperative Nausea and Vomiting

Interventions

MetamizolDRUG

in group A patients will receive pre-emptive analgesia using intravenous infusion of metamizol in a single dose of 1-1,25 gram

AcetaminophenDRUG

in group P patients will receive pre-emptive analgesia using intravenous infusion of acetaminophen in a single dose of 10-15 mg per kg of body weight

0,5 % bupivacaine with of 2% lidocaineDRUG

in group PBB patients in group BF will receive regional peribulbar block using a solution of 0,5% bupivacaine (2,5 ml) with 2% lidocaine (2,5 ml)

ProxymetacaineDRUG

in group T patients will receive topical analgesia using a solution of 0,5% Alcaine

Eligibility

Sex: ALLMin age: 18 YearsMax age: 90 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

pain perception intraoperatively

The investigators will compare the efficacy of analgesia intraoperatively according to technique of analgesia used preoperatively. The investigators will administer a rescue dose of fentanyl intravenously in a dose of 1 mcg per kg of body weight in the case when SPI value increases over 15 points in SPI scale every 5 minutes until SPI value decreases back to baseline value. Additionally, the investigators will analyse rescue fentanyl consumption in abovementioned groups

Time frame: intraoperatively

oculocardiac reflex rate

The investigators will compare the rate of presence of OCR intraoperatively in studied groups

Time frame: intraoperatively

Secondary Outcomes

pain perception postoperatively

The investigators will compare the efficacy of analgesia postoperatively according to technique of analgesia used preoperatively: either local peribulbar block or topical analgesia or intravenous infusion of either metamizol or acetaminophen. The investigators use NRS and compare it with SPI values.

Time frame: up to one hour after discharge to postoperative unit.

PONV

The investigators will compare the presence of PONV after emergence from GA in studied groups. The investigators will observe patients postoperatively and record any incidence of nausea or vomiting and in the abovementioned case the investigators will administer a standard dose of antiemetic drug.

Time frame: up to one hour