Comparison of the effect of different doses of paracetamol with ketamine in reducing pain in limb trauma patients in the prehospital environment

Determining the effect of paracetamol in comparison with ketamine on reducing pain in limb trauma patients in pre-hospital environment

Clinical trial with four groups of parallel, double-blind, randomized, phase 3 on 1200 patients. Due to the fact that it is not possible to blind the technicians in a station for the type of intervention, randomization will be done for the station.

This study is a double-blind clinical trial that will be performed in the pre-hospital emergency system of Tehran.

Inclusion criteria: Patients aged 18 to 70 years with limb trauma, Patients with acute limb trauma, weight between 50 to 115 kg, systolic blood pressure over than 90 mm Hg and visual Analogue scale over than 3. Exclusion criteria: History of drug abuse, known allergy to ketamine and acetaminophen, alcohol abuse and overdose, history of liver problems, history of seizures, GCS less than 14, multiple trauma patient, instability of vital signs, pregnant, lactating, blood pressure above 110/180

3 emergency stations IM ketamine injection 3 emergency stations IV ketamine injection 3 emergency stations acetaminophen with dose of 1 gram 3 emergency stations acetaminophen with dose of 2 gram

Pulse rate; Number of breaths; Systolic and diastolic blood pressure; Oxygen saturation; GCS; Visual Analogue scale; Age; Gender; Type of injury; Duration of the intervention until delivery to the hospital

Due to the fact that individual randomization is not possible for patients as well as blinding technicians in an emergency stations for the type of intervention, randomization will be done in a cluster unit and for the emergency stations. In this method, 12 emergency stations are selected from the emergency stations of Tehran Emergency Center and randomization study will be performed for 4 arms by block randomization method and using Stata v14 software. In such a way that after preparing a list of 12 emergency stations and assigning codes 1 to 4 for each of the study arms, 3 emergency stations randomization for IM ketamine injection, 3 emergency stations IV ketamine injection, 3 emergency stations acetaminophen with dose of 1 gram and 3 emergency stations for acetaminophen with dose of 2 grams. In each of the station will inject the same drug given for all patients that specialized with the conditions of admission to the study. All site technicians will be kept unaware of the type of intervention that is taking place at other stations. Sampling in the station will continue until reaching 300 people in each group (specified sample size).

Due to the fact that it is not possible to blind the technicians in a database for the type of intervention, cluster randomization will be done for the database and so blinding will also be done at the emergency stations level. So that the technicians of each emergency stations participating in the study will be kept unaware of the type of intervention of the other emergency stations and they will not be informed which other emergency stations participate in this study and what kind of intervention and medication they use.