Evaluation of adding Lidocaine to Morphine in patient controlled analgesia on pain intensity after unilateral knee prosthesis surgery by spinal anesthesia

We measure pain reduction after unilateral knee arthroplasty after adding lidocaine to morphine in a patient controlled analgesia pump.

Clinical trial with a control group, with parallel groups, three blinded, randomized, phase 2-3 on 58 patients.

This study was conducted in Aria and Farabi hospitals in Mashhad. A pain pump was placed for the patients for post-operative analgesia. The pain level of the surgical site was compared with the Visual Analogue Scale method at specific time intervals. In this study, drugs were used with the same packaging and blinding was done for patients, project personnel and researchers.

Inclusion criteria: Patients with American Society of Anesthesiologists (ASA) class 1 and 2 between 45 and 75 years old, with a Body Mass Index(BMI) in the range of 20-25 should undergo spinal anesthesia for the surgery؛ Exclusion criteria: Patients with a history of epilepsy, known kidney disease, heart block, or drug addiction, Patients with a medical history that indicates hypersensitivity to lidocaine and opioids, Patients with coagulation disorders, Patients with skin infection at the injection site, a history Moderate to severe nausea and vomiting in the past 24 hours

Group A: The content of the patient controlled analgesia pump attached to the patient included 20 mg of morphine, 8 mg of Ondansetron ampoule (4 cc), 1g of Apotel (6.7 cc) and the rest of normal saline to reach a total volume of 100 cc Group B: The content of the patient controlled analgesia pump includes 10 mg of morphine, 50 cc of lidocaine 2%, 8 mg of ampoule of Ondansetron (4 cc), 1g of Apotel (6.7 cc) and the rest of normal saline to a total volume of 100 cc.

Postoperative pain; mean arterial pressure; heart rate; nausea and vomiting; systolic pressure; diastolic pressure

A simple randomization method is used. We assign an A and B code to each anesthetic intervention. With the lottery method, patients will be placed in one of two codes. In this way, 29 codes A and 29 codes B are written on the paper and each paper is placed inside a special non-transparent sealed envelope and the envelopes are randomly placed on top of each other. Upon the entry of each qualified patient, an envelope is returned by the anesthesiologist to that patient and according to the code written on the paper inside, the anesthetic method is applied.

In this study, patients are placed in two separate groups, A and B, which have the same drug composition except for one type of drug, and drugs with the same shape and packaging are injected to the patients through a patient controlled analgesia pump. The patient does not know whether he is in the control group or the intervention group. The personnel cooperating in the plan do not know the content of the pain pump. The researcher also has no knowledge of which group each patient is in and only analyzes the information.

There is no further information.