Preemptive Paracetamol for Postoperative Pain

Study Overview
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Brief Summary
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The purpose of this study is to test whether a dose of paracetamol given before surgical incision is more effective at reducing postoperative pain and analgesic consumption in cervical spine surgery versus a dose given at the end of surgery.

Official Title
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Preemptive Paracetamol for Postoperative Pain: a Randomised, Double-blind, Two Way Crossover Trial

Conditions
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Pain, Surgical Wound

Intervention / Treatment
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* Drug: Intravenous paracetamol
* Drug: Intravenous saline 0.9%


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18-80 years old Patients listed for non-malignant cervical spinal surgery General anaesthesia Capacity to give informed consent Ability to use PCA device and pain score scale ASA I, II and III >50kg in weight Exclusion Criteria: Allergy or sensitivity to paracetamol, proparacetamol or morphine Liver disease Renal disease (creatinine clearance <30ml/min) Bleeding disorder Chronic alcoholism Chronic malnutrition Dehydration G6PD deficiency Hypernatraemia (Na >150) Hypokalaemia (K <3.5) and hyperchloraemia Pregnancy or breast-feeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Preemptive paracetamol<br>1000mg intravenous paracetamol given ≥15 minutes before surgical incision and intravenous saline 15 minutes before the end of surgery | Drug: Intravenous paracetamol<br>* 1000mg intravenous solution for infusion<br>Drug: Intravenous saline 0.9%<br>* 0.9% sodium chloride in order to ensure double-blinding<br>|
| Active Comparator: Postincision paracetamol<br>Intravenous saline ≥15 minutes before surgical incision and 1000mg intravenous paracetamol given 15 minutes before the end of surgery | Drug: Intravenous paracetamol<br>* 1000mg intravenous solution for infusion<br>Drug: Intravenous saline 0.9%<br>* 0.9% sodium chloride in order to ensure double-blinding<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Morphine consumption | Measured from PCA machine | 24 hours postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to first analgesic request | In minutes | 24 hours | 
| Nausea and vomiting | Incidence of nausea or vomiting 24 hours postoperatively | 24 hours | 
| Pruritus | Incidence of pruritus 24 hours postoperatively | 24 hours | 
| Sedation | Incidence of sedation 24 hours postoperatively | 24 hours | 
| Urinary retention | Incidence of urinary retention 24 hours postoperatively | 24 hours | 
| Allergic reaction | Incidence of allergic reaction (defined as diagnosed by clinician 24 hours postoperatively) | 24 hours | 
| Pain score | Numeric rating scale (NRS) | 1 hour | 
| Pain score | Numeric rating scale (NRS) | 2 hours | 
| Pain score | Numeric rating scale (NRS) | 6 hours | 
| Pain score | Numeric rating scale (NRS) | 12 hours | 
| Pain score | Numeric rating scale (NRS) | 24 hours |