Acute Pain, Postoperative Pain
Conditions
Keywords
Postoperative pain, Acute pain, NSAIDs, Tramadol, Ketorolac, Diclofenac, Pilot, RTC
Brief summary
This pilot randomised controlled trial compared the analgesic equivalence of three intravenous premedication regimens - tramadol 150 mg, ketorolac 60 mg, and diclofenac 150 mg - in adult patients undergoing elective minimally invasive surgery under balanced general anaesthesia. The primary outcome was postoperative pain intensity measured using the Numerical Rating Scale (NRS 0-10) at recovery room arrival and at 30, 60, and 90 minutes thereafter.
Detailed description
Acute postoperative pain remains inadequately managed in a substantial proportion of surgical patients, with particular challenges in resource-limited settings where access to potent opioids is restricted. Cross-class equianalgesic data comparing NSAIDs with weak opioids are scarce. This single-centre, double-blind, parallel-group pilot RCT was conducted at Hospital Regional "General Ignacio Zaragoza," ISSSTE, Mexico City. Thirty adult patients (ASA I-II, age 18-55 years, BMI 18.5-34.99 kg/m²) scheduled for elective laparoscopic surgery were randomised equally to receive tramadol 150 mg IV, ketorolac 60 mg IV, or diclofenac 150 mg IV, administered 45 minutes before skin incision. All patients received standardised balanced general anaesthesia. Pain was assessed using the NRS and Verbal Rating Scale (VRS) at five time points. Rescue analgesia (morphine 3 mg IV) was available on request. The trial was initially registered with the ISSSTE institutional research registry (RPI #403-2024).
Interventions
DRUGTramadol
Tramadol 150 mg IV, single dose, administered in 100 mL 0.9% saline 45 minutes before skin incision.
DRUGKetorolac
Ketorolac 60 mg IV, single dose, administered in 100 mL 0.9% saline 45 minutes before skin incision.
DRUGDiclofenac
Diclofenac 150 mg IV, single dose, administered in 100 mL 0.9% saline 45 minutes before skin incision.
Sponsors
ISSSTE Hospital Regional "Gral. Ignacio Zaragoza"
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)
Masking description
Study drugs were prepared in identical 100 mL 0.9% saline bags by personnel not otherwise involved in the study and delivered unlabelled to the responsible anaesthesiologist, ensuring blinding of both the investigator and the patient.
Intervention model description
Three-arm parallel-group pilot RCT. Participants were randomised equally (n=10 per group) to receive tramadol 150 mg IV, ketorolac 60 mg IV, or diclofenac 150 mg IV as premedication 45 minutes before skin incision.
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
* Age 18-55 years * ASA physical status I or II * Body mass index 18.5-34.99 kg/m² * Scheduled for elective minimally invasive surgery under balanced general anaesthesia * Pre-surgical pain NRS = 0 and VRS = "absence" at baseline assessment
Exclusion criteria
* Pregnancy * Known hypersensitivity to any study drug (tramadol, ketorolac, or diclofenac) * Pre-existing acute pain with NRS ≥ 4 or VRS ≥ "moderate" before surgery * Chronic pain with current analgesic use * Withdrawal of consent before premedication administration * Surgical duration exceeding 180 minutes * Conversion from laparoscopic to open surgical approach * Hypersensitivity reaction during study drug administration * Haemodynamic shock of any aetiology during the perioperative period * Requirement for postoperative mechanical ventilation due to anaesthetic-surgical complications
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative pain intensity | At recovery room arrival (Time_0), and at 30 (Time_1), 60 (Time_2), and 90 (Time_3) minutes after recovery room arrival. | Pain intensity assessed using the Numerical Rating Scale (NRS, 0-10; 0 = no pain, 10 = worst imaginable pain). Between-group comparisons performed at each time point using Kruskal-Wallis tests with Dunn post-hoc correction. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Categorical pain intensity by Verbal Rating Scale (VRS) | At recovery room arrival (Time_0), and at 30 (Time_1), 60 (Time_2), and 90 (Time_3) minutes after recovery room arrival. | Pain category assessed using a four-point Verbal Rating Scale (0 = absence, 1 = low, 2 = moderate, 3 = severe). Between-group differences assessed using Pearson's chi-squared test with Cramér's V as effect size. |
| Rescue morphine consumption | At 30 (Time_1), 60 (Time_2), and 90 (Time_3) minutes after recovery room arrival. | Number of rescue analgesic doses and total morphine consumed (mg IV) per group. Rescue analgesia (morphine 3 mg IV) was administered on patient request or clinical indication. |
| Incidence of hypersensitivity reactions | Throughout the 90-minute observation period | Hypersensitivity reactions of any grade classified according to Müller criteria (Grade I-IV). Managed per institutional protocol (hydrocortisone 100 mg IV; adrenaline 0.5 mg IM for anaphylaxis). |
Countries
Mexico
Outcome results
None listed