The effect of single dose prophylactic intravenous Aminophylline on prevention of postoperative shivering following lower limb orthopedic surgeries under spinal anaesthesia.

The effect of single dose prophylactic intravenous Aminophylline on prevention of postoperative shivering following lower limb orthopedic surgeries under spinal anesthesia

Two arm parallel group randomized trial with 30 patients in each group, randomized with block randomization method

This study will be performed in labor ward , Madani hospital, Karj on all participants lower limb orthopedic surgeries under spinal anesthesia who are eligible for the study. Patients who have consciously signed a consent form to participate in the project will be randomly assigned to two groups. The randomization list will be prepared by the statistician. Treatments will be placed in sealed envelopes and will be kept by the out-of-study nurse. After identification of the eligibility of the patient, the procedure will be explained to her and informed consent will be obtained ,completing the final information is the responsibility of the person who is unaware of the type of treatment. The statistician will also be blind.

exclusion criteria: Contraindications to spinal anesthesia, Surgery duration more than 90 minutes, Bleeding more than 0.5 liters, Sensitivity to aminophylline, Taking drugs that interfere with aminophylline, Tachycardia greater than 110 beats per minute or history of arrhythmia prior to injection, Inclusion criteria: Patients with PS ASA grade 1, BMI 19 to 26 ,Having a full fast , Candidate for lower limb orthopedic surgery under spinal anesthesia

Intervention group: Patients receive intravenously 1.5 mg / kg aminophylline in 100 cc of normal saline . Control group: Patients receive intravenously normal saline

Shivering, body temperature, vital signs

Our sample size is 60 people, with 30 people in each group. Block randomization method was designed by epidemiologist using STATA version 13 software. The number of blocks considered is 6.

The random allocation list will solely available to the epidemiologist. 60 cards containing sequences of treatments will be written and be placed inside sealed envelopes. A10-digit random code, as the patient’s identification number, will be provided for each packet. When the physician announces the eligibility of a patient, the nurse will provide the physician with the envelope. None of the patients should be aware of the type and process of treatment. Also, the person evaluating the outcomes is a third person who is unaware of the random allocation process and type of treatment. Data analysis will be carried out by a statistician who is aware of all the processes performed