SPI-directed Analgesia for Vitreoretinal Surgeries

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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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

Conditions
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Vitreoretinal Surgeries, Postoperative Nausea and Vomiting, Postoperative Pain

Intervention / Treatment
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* Drug: Metamizol
* Drug: Acetaminophen
* Drug: 0,5 % bupivacaine with of 2% lidocaine
* Drug: Proxymetacaine


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: metamizol<br>analgesic drug | Drug: Metamizol<br>* in group A patients will receive pre-emptive analgesia using intravenous infusion of metamizol in a single dose of 1-1,25 gram<br>Drug: 0,5 % bupivacaine with of 2% lidocaine<br>* 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)<br>* Other names: Lidocaine;|
| Experimental: acetaminophen<br>analgesic drug | Drug: Metamizol<br>* in group A patients will receive pre-emptive analgesia using intravenous infusion of metamizol in a single dose of 1-1,25 gram<br>Drug: 0,5 % bupivacaine with of 2% lidocaine<br>* 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)<br>* Other names: Lidocaine;Drug: Proxymetacaine<br>* in group T patients will receive topical analgesia using a solution of 0,5% Alcaine<br>* Other names: Alcaine;|
| Experimental: 0,5 % bupivacaine with of 2% lidocaine<br>a volume of 5 ml of analgesic solution for regional peribulbar block | Drug: Acetaminophen<br>* 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<br>* Other names: paracetamol;Drug: 0,5 % bupivacaine with of 2% lidocaine<br>* 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)<br>* Other names: Lidocaine;Drug: Proxymetacaine<br>* in group T patients will receive topical analgesia using a solution of 0,5% Alcaine<br>* Other names: Alcaine;|
| Experimental: Proxymetacaine<br>topical analgesia | Drug: Acetaminophen<br>* 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<br>* Other names: paracetamol;Drug: Proxymetacaine<br>* in group T patients will receive topical analgesia using a solution of 0,5% Alcaine<br>* Other names: Alcaine;|
| Placebo Comparator: control group<br>patients will receive no pre-emptive analgesia. standard doses of fentanyl will be used intraoperatively. | Drug: Metamizol<br>* in group A patients will receive pre-emptive analgesia using intravenous infusion of metamizol in a single dose of 1-1,25 gram<br>Drug: Acetaminophen<br>* 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<br>* Other names: paracetamol;Drug: 0,5 % bupivacaine with of 2% lidocaine<br>* 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)<br>* Other names: Lidocaine;Drug: Proxymetacaine<br>* in group T patients will receive topical analgesia using a solution of 0,5% Alcaine<br>* Other names: Alcaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | intraoperatively | 
| oculocardiac reflex rate | The investigators will compare the rate of presence of OCR intraoperatively in studied groups | intraoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | 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. | up to one hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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paracetamol, metamizol, Surgical Pleth Index (SPI), General Anaesthesia (GA),, Numerical Rating Scale (NRS), Adequacy of Anaesthesia (AoA), Peribulbar Block (PBB), Topical Analgesia (TA), Oculocardiac reflex (OCR), Postoperative nausea nad vomiting (PONV)